The examination reveals loss of radial pulses, and sometimes a carotid bruit is present. Diagnosis is based on characteristic angiographic findings in the aorta and its major branches. Cerebral hypoperfusion secondary to stenosis of the carotid and vertebral arteries and complications of hypertension cause the neurological complications. The signs and symptoms include visual loss, vertigo, syncope, seizures, hemiplegia, and headaches. Treatment consists of corticosteroids and immunosuppressive agents such as methotrexate and cyclophosphamide. Management of hypertension is critical, and antiplatelet agents are useful in preventing thrombosis. Parkinsonism has been reported in ten patients, and changes in basal ganglia on brain imaging are inconsistent (Khubchandani et al. Ophthalmoplegia, diplopia, sudden blindness, or ptosis can occur, and findings of papilledema, optic neuritis, retinal hemorrhage, and vasculitis ("cotton wool spots") have been described. The most common clinical manifestations of neuropsychiatric lupus are depression, memory problems, emotional lability, trouble with concentration, and psychosis. Other antibody systems such as antiribosomal P antibodies, antineuronal antibodies, or lymphocytotoxic antibodies also may be associated with an increased risk for neurological involvement. The pathogenesis of neuropsychiatric lupus is likely to be multifactorial, including autoantibody production, microangiopathy, intrathecal production of proinflammatory cytokines, and premature atherosclerosis. Cyclophosphamide is used in the management of severe neuropsychiatric lupus unresponsive to other modalities. Unfortunately no published neuropsychiatric lupus treatment trials in children exist. It remains unclear whether children require earlier or more aggressive treatment programs to prevent long-term neurological sequelae. Clinical manifestations include sinus problems, pulmonary disease (cough and hemoptysis), and glomerulonephritis. Nervous system involvement occurs less frequently in children than in adults, but manifestations may include neuropathy (mononeuritis multiplex, polyneuropathy), myopathy, seizures, stroke, hemorrhage, dural venous thrombosis, pachymeningitis, cerebritis, and myelopathy. Involvement of the optic nerve, seventh and eighth cranial nerves, chiasm, and pituitary gland can occur. A definitive diagnosis requires tissue diagnosis by biopsy of lung, skin, or kidney. Maintenance therapy includes methotrexate, azathioprine, leflunomide, trimethoprim-sulfamethoxazole, etanercept, and rituximab. BehçetDisease Definitive diagnosis of Behçet disease requires recurrent oral ulcerations (aphthous or herpetiform) plus two of the following: recurrent genital ulcerations, ocular lesions (uveitis or retinal vasculitis), skin lesions (erythema nodosum, pseudofolliculitis, papulopustular lesions, acneiform nodules), and a positive pathergy test (skin reaction to a needle prick). Several review studies have documented Behçet disease in childhood and adolescence. According to Saip and colleagues (2005), headache is the most common neurological symptom. Other neurological complications include encephalomyelitis, seizures, brainstem and basal ganglia involvement, aseptic meningitis, pseudotumor cerebri, and dural sinus thrombosis. Vasculitis of both the arterial and venous systems, associated with thrombosis and arterial aneurysms, can occur. Treatment includes corticosteroids, sulfasalazine, colchicine, and immunomodulating agents such as methotrexate, cyclosporine, azathioprine, interferon-, and infliximab. The latter is rare in children and consists of a monophasic form of the disease with good response to steroids. Angiography is diagnostic, showing small and mediumsized vessel beading, or alternating segmental narrowing and ectasia. Early diagnosis and treatment with corticosteroids, and in certain cases with cyclophosphamide, will reduce the high morbidity previously reported and the frequency of recurrences. Neurological complications do not occur unless hypoxic periods are prolonged and severe. The incidence of associated bradycardia increases with the duration of the apnea and correlates with the severity of hypoxia. Apnea can be idiopathic (idiopathic apnea of prematurity) or can be caused by intraventricular hemorrhage, seizures, obstruction, atelectasis, pneumonia, sepsis, meningitis, phrenic nerve paralysis, gastroesophageal reflux, hypovolemia, and heart failure. It also can cause long-term deleterious effects on neuronal and intellectual functioning, with behavioral changes, restlessness, aggressive behavior, memory problems, and poor test performance. Some of the neurobehavioral deficits are not totally reversed with treatment of the apnea. The typical symptoms of dry eyes (xerophthalmia) and dry mouth (xerostomia) are secondary to infiltration of the salivary and lacrimal glands with lymphocytes and plasma cells. The neurological problems in Sjögren syndrome include aseptic meningitis, infarction, optic neuritis, myelopathy, seizures, encephalopathy, behavioral changes, and motor and sensory neuropathy. The main laboratory features are nonspecific anemia, leukopenia, and hypergammaglobulinemia. Lymphocytic infiltration of the salivary glands of the lower lip is characteristic of Sjögren syndrome and confirms the diagnosis. The movements, which began in the third month, were exacerbated by respiratory failure and were attenuated during sleep. One patient had histopathological evidence of neuronal loss and astrocytosis in the basal ganglia and thalamus. The use of indwelling intravenous catheters can result in venous thrombosis and cerebral thromboembolism. Other contributing factors for thrombotic complications include associated diabetes, chronic inflammation, acquired thrombophilia due to hepatic insufficiency, and cholestasis. Children are more likely to develop seizures and space-occupying lesions and less likely to develop cranial nerve palsies (Baumann et al. Sarcoid granulomas are more commonly located in the cerebral hemispheres than in the posterior fossa. They probably result from extension of the inflammatory process through the Virchow­Robin spaces. White-matter sarcoid lesions seen on T2-weighted images can resemble the tumefactive demyelinating lesions seen in multiple sclerosis. Histologically, the diagnostic feature of sarcoidosis is the presence of noncaseating granuloma. It also occurs in association with neurofibromatosis type I, von Hippel-Lindau syndrome, and Guillain­Barré syndrome. Neurological complications develop in more than 40% of patients with malignant hypertension: stroke, encephalopathy, fever, opisthotonos, muscle twitching, myoclonus, and cranial neuropathies. It is mostly seen with hemolytic-uremic syndrome, acute glomerulonephritis, and medication use. Initial clinical features are headache, projectile emesis, fatigue, and meningismus, followed by rapid onset of encephalopathy and generalized seizures. Whereas retinal arteriolar spasm is a more characteristic sign, papilledema is seen in only one-third of cases. Prompt management and safe reduction of blood pressure are very important in the management of hypertensive encephalopathy. Antiepileptic medications are used to treat persistent seizures, but chronic therapy usually is not required. It can also be associated with visual loss, hallucinations, lethargy, and transitory motor deficits. It is postulated that dysfunction in cerebral autoregulation causes perivascular edema that compresses surrounding microvessels, leading to proliferative endarteritis. This process increases the vulnerability to Sarcoidosis Sarcoidosis is an idiopathic, chronic, multisystem, granulomatous disease, uncommon in children. The clinical presentation varies between younger (before 4 years of age) and older children (8 to 15 years) and is different from that in the adult population (Yanardag et al. Children younger than 4 years of age present mainly with a maculopapular rash, uveitis, and arthritis. In the age group 8 to 15 year olds, signs and symptoms include fever, cough, lymphadenopathy, malaise, ocular lesions, and abnormalities on the chest radiograph. In 1985, Edward Blau described families with autosomal dominant granulomatous disease similar to early-onset sarcoidosis. Recent data have suggested that Blau syndrome and early-onset sarcoidosis may represent the same disease. This may be due to poor placental transfer of vitamin K, marginal vitamin K content in breast milk, or maternal use of medications that interfere with vitamin K stores or function. The neurological complications are caused by subarachnoid or intraparenchymal hemorrhage. Administration of vitamin K intramuscularly at birth prevents hemorrhagic disease of the newborn. Vasospasm, endothelial dysfunction, and an inflammatory state could be the explanation in the absence of hypertension. In three out of 11 patients in one series, epilepsy developed despite clinical and radiographic evidence of recovery, requiring chronic antiepileptic drug therapy (Morris et al. It can also lead to increased cerebrovascular resistance and diminished cerebral blood flow. Neurological complications include stroke, developmental delay, tremor, spastic diplegia, hemiparesis, monoparesis, mental retardation, and learning deficits. Treatment consists of partial exchange transfusion, adequate hydration, and correction of associated metabolic disorders. The most common underlying lesion is an intracranial arterial stenosis or obstruction, often seen in the proximal middle cerebral and anterior cerebral arteries. Sickled erythrocytes cause chronic injury to the vessel endothelium, resulting in a narrow lumen. Spontaneous acute epidural and subgaleal hematomas are rare complications of sickle cell crises (Dahdaleh et al. The most common neurological signs are hemiparesis, speech abnormalities, focal seizures, gait dysfunction, headaches, and neurocognitive deficits. In the Cooperative Study of Sickle Cell Disease, seizures were an independent risk factor for silent infarction. All patients with seizures had decreased cerebral perfusion ipsilateral to an electroencephalographic abnormality, suggesting that a complex mechanism of large- and small-vessel disease and hypoperfusion plays a role in the pathogenesis of seizures. The survivors typically have choreoathetoid cerebral palsy, highfrequency deafness, and mental retardation. Fortunately, the classic clinical picture of kernicterus is rare with improved nursery care and early treatment of jaundice. Moyamoya disease is a relatively uncommon neurovascular complication of sickle cell disease and is a risk factor for stroke and transient ischemic episodes despite prophylactic blood transfusion. Partial exchange transfusion is standard therapy in the setting of occlusive crisis and ischemic injury. Indications for anticoagulation are dissection and sinus venous thrombosis, especially with coexistent prothrombotic abnormalities and recurrent stroke. Emerging prophylactic regimens include citrulline, arginine, aspirin, and overnight oxygen supplementation (Kirkham et al. Hemophilia Studies show that 42% of patients with hemophilia B and 34% of patients with hemophilia A suffer neurological complications. These include intracranial hemorrhage, peripheral nerve lesions due to intramuscular hemorrhage after minor injuries, and spontaneous hematoma formation in the groin or other closed anatomical spaces. Other affected nerves are the lumbosacral plexus, median nerve, radial nerve, and lateral cutaneous nerve. Hemophilic "pseudotumor" in the spinal canal and cranium has been described, as well as spinal epidural and subdural hematomas presenting as back pain and torticollis (Cuvelier et al. Klinge and associates (1999) reported the incidence of intracranial hemorrhage in 42. Trauma, the most important factor, occurred in 57% of cases either during birth (30%) or later (27%). Nelson and colleagues (2000) evaluated the incidence and sequelae of 2- to 5-mm focal white-matter hyperintensities on T2-weighted images in hemophiliac patients and reported no correlation with neurological factors; the investigators concluded that the findings were incidental. The diagnosis requires at least two major criteria (thrombocytopenia, Coombs-negative microangiopathic hemolytic anemia, neurological dysfunction) and two minor criteria (fever, renal dysfunction, circulating thrombi). Thrombosis of small arterioles, venules, and capillaries leads to cerebral microinfarctions. Neurological Complications of Systemic Disease: Children 845 Neurological symptoms consist of lethargy, headache, confusion, and visual and speech disturbances. Hemolytic-UremicSyndrome Hemolytic-uremic syndrome frequently follows an episode of gastroenteritis caused by an enteropathogenic strain of Escherichia coli (O157:H7). However, it also follows Shigella, Salmonella, Campylobacter, and viral infections. The syndrome is more common in children younger than 4 years of age and is the most frequent cause of acute renal failure in young children. Neurological complications predict a severe outcome and may include encephalopathy, seizures, stroke, behavioral changes, and blindness. The most common causes of liver failure in children are fulminant viral or autoimmune hepatitis, drug ingestion (acetaminophen, salicylates, valproic acid), Reye syndrome, mitochondrial diseases, galactosemia, tyrosinemia, and Wilson disease. Understanding of the pathogenesis, which probably is multifactorial, is incomplete. In 10% of patients with hepatic encephalopathy, however, serum ammonia levels are normal. Clinically evident encephalopathy in children with chronic liver disease appears to be less common than in adults. It is possible, however, that encephalopathy is underdiagnosed in children because of its more subtle manifestations.

Additional information:

• Dydrogesterone
• Azathioprine

Vasculitic neuropathy-electrodiagnostic findings and association with malignancies. These disorders can occur with and without a cancer association and while they affect individuals of all ages some syndromes preferentially affect young adults and children (Armangue et al. In these disorders T-cell mechanisms appear to play a predominant role in mediating the neuronal dysfunction that is often irreversible (Burton et al. In contrast, in the autoimmune encephalitis with antibodies to neuronal cell surface/synaptic antigens (further referred to in this chapter as autoimmune encephalitis), the associated antibodies appear to mediate the neuronal dysfunction by direct interaction with the target antigens (Hughes et al. These effects are reversible and although the process of recovery can be prolonged, patients with these syndromes often have full or substantial recovery after immunotherapy. Patients with autoimmune encephalitis develop complex neuropsychiatric symptoms including memory loss, changes in behavior or cognition, psychosis, seizures and movement disorders. At presentation one or a few of these symptoms may predominate and can mislead the diagnosis until additional symptoms develop over days or weeks. Patients may initially be diagnosed with idiopathic encephalitis, likely viral but with negative viral studies. Autoimmune encephalitis should be included in the differential diagnosis of any patient, especially if young, with a rapidly progressive encephalopathy of unclear origin. Any immunological type of autoimmune encephalitis can have a relapsing course and therefore the diagnosis of these disorders should be considered in patients with a past history of encephalitis or relapsing encephalopathy. The immunological trigger of autoimmune encephalitis is varied and in many cases yet to be established. In some patients the presence of a systemic tumor that expresses the target neuronal/synaptic proteins appears to be important. The viral-like prodrome reported by many patients may play a role and this premise is supported by recent studies showing the development of autoimmune encephalitis after herpes simplex encephalitis (Armangue et al. There are some patients in whom autoimmune encephalitis overlaps with demyelinating disorders; whether there is a relationship between the two syndromes is not yet clear. It is most common in young women and children, who represent about 80% of patients, but can also affect men and older individuals. The syndrome is highly characteristic and usually occurs as a multi-stage process. Patients develop acute psychiatric symptoms, seizures, memory deficits, decreased level of consciousness, and dyskinesias (orofacial, limb, and trunk) (Dalmau et al. Autonomic instability is common and in about half of the patients results in central hypoventilation often requiring weeks of mechanical ventilation. Responses to Immunotherapies 1197 82 Almost80%ofcaseshavefullor substantialrecoveries. Children are often brought to medical attention due to mood and behavioral change at times with new onset seizures, movement disorders, insomnia, or reduction of speech. Partial syndromes with predominant psychiatric symptoms or abnormal movements, and less severe phenotypes can occur, although almost all patients eventually develop several elements of the syndrome (Kayser et al. Atypical symptoms such as cerebellar ataxia or hemiparesis can occur and are more common in children than in adults. Approximately 45% of female patients over 18 years have unior bilateral ovarian teratomas compared to less than 9% of girls under 14 years of age. The majority of patients who receive immunotherapy have full or substantial recoveries, including cases where treatment was delayed by several months. For patients with cancer the neurological outcome appears dependent on successful treatment of the tumor. Seizures have been reported in just under half of cases and about 70% have an underlying tumor in the lung, breast, or thymus. When the disorder is cancer-related the onset of the encephalitis usually precedes the cancer diagnosis. The median age of patients in one study was 62 years, with older patients more likely to have cancer than those that were younger. The presenting features are almost always those of typical limbic encephalitis with memory loss, confusion, and prominent seizures (Hoftberger et al. The majority of patients respond to immunotherapy; however, about half have relapses. Those with relapses usually respond to treatment but these responses are often partial, resulting in cumulative memory or behavioral deficits. It is unclear whether chronic immunosuppression has a role in preventing or reducing the risk of the relapses. Five of the six had status epilepticus and one of these patients also had epilepsia partialis continua. Four of the patients required pharmacologically induced coma due to the refractoriness of the seizures. The age of the patients ranged from 3 to 63 years with a median age of 22, and five were men. In all six patients the onset of the seizures was preceded by or associated with a change in behavior or cognition. None of the patients had an associated cancer although one had a history of Hodgkin lymphoma. Half of the patients had a good response to immunotherapy despite the severity of the illness and the seizures. One 4-year-old child had substantial recovery without immunotherapy but still required anti-epileptics to control seizures 2. Many had other autoimmunities that could explain the broader spectrum of symptoms in this group. Some patients develop brief tonic or myoclonic-like seizures (also called faciobrachial dystonic seizures) that precede the memory and cognitive deficits (Irani et al. The rapidly progressive memory disturbance along with myoclonic-like movements can lead to the suspicion of rapid onset dementia such as Creutzfeldt­Jakob disease. The disorder is usually not cancer associated and less than 10% of patients have an underlying neoplasm, usually a thymoma. About 80% of patients have substantial responses to immunotherapy although many of them are left with mild deficits that prevent them from returning to work. More than half of the patients complain of neuropathic pain while some develop severe insomnia with abnormal motor activation (Irani et al. The patients developed agitation, paranoia, hallucinations, myoclonus, tremor, and/or seizures. The severe diarrhea resulted in substantial weight loss in two patients, resulting in extensive evaluations for a primary gastrointestinal disorder. None of the patients had cancer, and the course was protracted with relapses often occurring in the setting of reduced immunotherapy. These cases are mostly not related to cancer and patients often have good responses to immunotherapy. OtherDisorders the co-occurrence of limbic encephalitis and Hodgkin lymphoma is known as Ophelia syndrome. Only a few cases have been reported since the initial description in 1982 and four have been identified with antibodies to the metabotropic glutamate receptor 5 (mGluR5). Antibodies against mGluR1 have been identified in a few patients with idiopathic or paraneoplastic cerebellar ataxia associated with Hodgkin lymphoma (Lancaster et al. Antibodies to the dopamine-2 receptor have been described in the serum of some patients with basal ganglia encephalitis, Sydenham chorea, and Tourette syndrome (Dale et al. Studies of additional cases will clarify the relationship of the autoimmune responses and the syndromes. In six patients the disorder was progressive over years while two other patients had a rapidly progressive course that resulted in death 2 and 6 months after symptom onset. Only one patient improved with immunotherapy; this patient had a sudden death, likely due to autonomic dysfunction. The autopsy of two patients showed neuronal loss and gliosis associated with an atypical tauopathy mainly involving the tegmentum of the brainstem and the hypothalamus. There was no glial pathology, tau-positive grains, or globular glial inclusions that would allow classification of these cases within any of the currently known tauopathies. Based in data that demonstrate a pathogenic role of the antibodies, treatments are focused on antibody depletion and immunosuppression. In tumor-associated cases, a first step in management should be its identification and treatment. While it is not known if this applies to other disorders it strongly supports early tumor treatment when appropriate (Titulaer et al. Almost all of these patients had good outcomes at 24 months of follow-up (Titulaer et al. Patients who did not respond to the first-line therapies and then received second-line immunotherapy with rituximab and/or cyclophosphamide had better outcomes than those who continued with first-line immunotherapy or who received no further immunotherapy. This suggests that prompt initiation of second-line immunosuppression when there is no clear response to first-line treatment should be strongly considered. Some of these patients had additional clinical features such as alterations of behavior and sleep, seizures, trismus, or neurogenic pruritus (Mas et al. Cerebellar ataxia and glutamic acid decarboxylase antibodies: Immunological profile and long-term impact of immunotherapy. Pediatric anti-N-methyl-D-aspartate receptor encephalitis-clinical analysis and novel findings in a series of 20 patients. Encephalitis and antibodies to dipeptidyl-peptidase-like protein-6, a subunit of Kv4. Antibodies to surface dopamine-2 receptor in autoimmune movement and psychiatric disorders. Causes of encephalitis and differences in their clinical presentations in England: a multicentre, population-based prospective study. N-Methyl-D-aspartate receptor antibodies in post-herpes simplex virus encephalitis neurological relapse. Progressive encephalomyelitis, rigidity, and myoclonus: a novel glycine receptor antibody. Frequency and characteristics of isolated psychiatric episodes in antiN-methyl-d-aspartate receptor encephalitis. Aggressive course in encephalitis with opsoclonus, ataxia, chorea, and seizures: the first pediatric case of gamma-aminobutyric acid type B receptor autoimmunity. Herpes simplex encephalitis relapse with chorea is associated with autoantibodies to N-methyl-D-aspartate receptor or dopamine-2 receptor. Evidence of T-cell mediated neuronal injury in stiff-person syndrome with antiamphiphysin antibodies. Paraneoplastic cerebellar ataxia due to autoantibodies against a glutamate receptor. Cerebrospinal fluid T cell responses against glutamic acid decarboxylase 65 in patients with stiff person syndrome. Hypoxic-ischemic brain injury-albeit less well defined and less clearly understood than anoxic-ischemic injury-can occur in patients with respiratory arrest or severe hypoxemia. Success of intervention under these conditions may be predicated on early correction of hypoxemia and hypovolemia. The time interval until correction may be less important than the initial severity of the abnormality. Although the pathophysiology of brain injury caused by cardiac arrest is reasonably well understood, less is known about neuroprotection. For over a decade, there has been enthusiasm that induced hypothermia could not only improve survival rates but also improve neurological outcomes (Broccard, 2006), but this has recently been questioned (Nielsen et al. This article critically evaluates the current knowledge of anoxicischemic brain injury after cardiac and respiratory arrest. Studies have reported tools for predicting outcomes, and guidelines for prediction of poor outcome have been developed by the American Academy of Neurology (Wijdicks et al. The accuracy of these predictors after the use of therapeutic hypothermia is a subject of ongoing investigations. Is the damage to the brain permanent and present at ictus, or are there processes at work that could potentially be influenced and modulated First, with cardiac arrest, whether due to asystole or ventricular fibrillation, there is no measurable flow to the brain. In addition, the shockable rhythms (ventricular tachycardia and ventricular fibrillation) have a better outcome than "nonshockable" rhythms such as asystole and bradyarrhythmias, reflected by restoration of adequate cerebral blood flow when ejection fraction of the ventricle improves (Callans, 2004). This time interval is poorly defined, but we know that the neuronal oxygen stores are depleted within 20 seconds of cardiac arrest, and cerebral necrosis occurs as a result of ischemia. There is some uncertainty about whether hypoxemia alone could produce necrosis and, although it can cause damage (preferentially in the striatum), necrosis is rarely seen even in patients with arterial Po2 values less than 20 mm Hg. Necrosis of the cortex involves layers three, four, and five and is pathologically known as laminar necrosis. The vulnerability of these areas may be explained by the presence of receptors for excitatory neurotransmitters or the high metabolic demands of these neurons. The cell death cascade that involves several modulatory and degradation signals has been documented in global cerebral ischemia, but whether manipulation of these processes is effective remains unclear (Ogawa et al. A caspase inhibitor did not affect neurological outcome after 6 minutes of cardiopulmonary arrest in rats (Teschendorf et al. Glutamate efflux due to ischemic injury increases intracellular calcium concentration, which results in neuronal injury. The excess release of calcium leads to other processes that include activation of catabolic enzymes and endonucleases. This concept is based on the premise that after resumption of circulation, there are major microcirculatory reperfusion deficits. Also, the use of hypertonic hyperoncotic solutions improved these perfusion deficits.

Everlasting Pea (Lathyrus). Prasugrel.

• Any medical use.
• How does Lathyrus work?
• Are there safety concerns?
• What is Lathyrus?
• Dosing considerations for Lathyrus.

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Patients often attribute symptoms of an idiopathic disorder to chemical exposure when no other cause can be found. Such patients have often been exposed to several chemical agents or are known to abuse alcohol or other drugs, thereby further confounding the issue. Single case reports that an agent is neurotoxic are unreliable, especially when the neurological symptoms are frequent in the general population. Epidemiological studies may be helpful in establishing a neurotoxic basis for symptoms. However, many of the published studies are inadequate because of methodological problems such as the selection of appropriate control subjects. Recognition of a neurotoxic basis for neurobehavioral disorders, for example, requires matching of exposed subjects and unexposed controls for many factors including age; gender; race; premorbid cognitive ability; educational, social, and cultural background; and alcohol, recreational drug, and medication use. Laboratory test results are often unhelpful in confirming that the neurological syndrome is caused by a specific agent, either because the putative neurotoxin cannot be measured in body tissues or because the interval since exposure makes such measurements meaningless. The part of the central, peripheral, or autonomic nervous system and the neuromuscular apparatus damaged by exposure to neurotoxins depends on the responsible agent. Then it must be determined whether any of these chemicals are known to be neurotoxic and whether symptoms are compatible with the known toxicity of the suspected compound. Many neurotoxins can produce clinical disorders that resemble well-known metabolic, nutritional, or degenerative neurological disorders, and it is therefore important to consider these and any other relevant disease processes in the differential diagnosis. Neurotoxins cause diffuse rather than focal or lateralized neurological dysfunction. In recognizing new neurotoxic disorders, a clustering of cases is often important, but this may not be evident until patients are referred for specialist evaluation. Depending on the neurotoxin, and on the duration and level of exposure, it most commonly takes the form of an acute or chronic encephalopathy or a peripheral neuropathy. Although progression may occur for several weeks after exposure has been discontinued ("coasting"), it is eventually arrested, and improvement may then follow, depending on the severity of the original disorder. Prolonged or progressive deterioration long after exposure has been discontinued, or the development of neurological symptoms months to years after exposure, suggests that a neurotoxic disorder is not responsible. With discontinuation of exposure, the neuropathy "coasts," arrests, and may then slowly reverse, but residual neurological deficits are common. These consist particularly of spasticity and cerebellar ataxia; the peripheral neuropathy usually remits because regeneration occurs in the peripheral nervous system. Electrodiagnostic studies provide evidence of an axonal sensorimotor polyneuropathy. Workers exposed to acrylamide may be monitored electrophysiologically by recording sensory nerve action potentials, which are attenuated early in the course of the disorder, or by measuring the vibration threshold. Histopathological studies show accumulation of neurofilaments in axons, especially distally, and distal degeneration of peripheral and central axons. The affected central pathways include the ascending sensory fibers in the posterior columns, the spinocerebellar tracts, and the descending corticospinal pathways. Involvement of postganglionic sympathetic efferent nerve fibers accounts for the sudomotor dysfunction. Measurement of hemoglobin­acrylamide adducts may be useful in predicting the development of peripheral neuropathy. They also are used as grouting agents for mines and tunnels, a solution of the monomer being pumped into the ground where polymerization is allowed to occur. The monomer is neurotoxic, and exposure may occur during its manufacture or in the polymerization process. Acrylamide can be formed by cooking various carbohydrate-rich foods at high temperatures, but consumption is unlikely to be sufficient for neurotoxicity. The acrylamide is distributed widely throughout the body and is excreted primarily through the kidneys. The mechanism responsible for its neurotoxicity is unknown, but it has been related to an inhibitory effect on presynaptic function (LoPachin and Gavin, 2012) by damage to the nerve terminal involving membrane fusion mechanisms and tubulovescicular alterations (Pennisi et al. Clinical manifestations of acrylamide toxicity depend on the severity of exposure. Acute high-dose exposure results in confusion, hallucinations, reduced attention span, drowsiness, and other encephalopathic changes. A peripheral neuropathy of variable severity may occur after acute high-dose or prolonged low-level exposure. The neuropathy is a lengthdependent axonopathy involving both sensory and motor fibers. Hyperhidrosis and dermatitis may develop before the neuropathy is evident clinically in those with repeated skin exposure. Ataxia from cerebellar dysfunction also occurs and relates to degeneration of afferent and efferent cerebellar fibers and Purkinje cells. Neurological examination reveals distal sensorimotor deficits and early loss of all tendon reflexes rather than simply the Achilles reflex, which is usually affected first in most length-dependent neuropathies. Gait and limb ataxia are usually greater than can be accounted for AllylChloride Allyl chloride is used for manufacturing epoxy resins, certain insecticides, and polyacrylonitrile. Intra-axonal accumulation of neurofilaments occurs multifocally before axonal degeneration in animals exposed to this compound. CarbonDisulfide Carbon disulfide is used as a solvent or soil fumigant, in perfume production, in certain varnishes and insecticides, in the cold vulcanization of rubber, and in manufacturing viscose rayon and cellophane films. Toxicity occurs primarily from inhalation or ingestion but also may occur transdermally. The pathogenetic mechanism is uncertain but may involve an essential metal-chelating effect of carbon disulfide metabolites, direct inhibition of certain enzymes, or the release of free radicals following cleavage of the carbon-sulfur bond. Acute inhalation of concentrations exceeding 300 to 400 ppm leads to an encephalopathy, with symptoms that vary from mild behavioral disturbances to drowsiness and, ultimately, to respiratory failure. Behavioral disturbances may include explosive behavior, mood swings, mania or depression, confusion, and other psychiatric disturbances. Long-term exposure to concentrations between 40 and 50 ppm may produce similar disturbances. Minor affective or cognitive disturbances may be revealed only by neuropsychological testing. Long-term exposure to carbon disulfide may lead also to extrapyramidal (parkinsonian) or pyramidal deficits, impaired vision, absent pupillary and corneal reflexes, optic neuropathy, and a characteristic retinopathy. Neuroimaging may reveal cortical-especially frontal-atrophy, as well as lesions in the globus pallidus and putamen. Such findings have been held to support the presence of a microangiopathy (Chuang et al. A clinical or subclinical polyneuropathy develops after exposure to levels of 100 to 150 ppm for several months or to lesser levels for longer periods and is characterized histologically by focal axonal swellings and neurofilamentary accumulations. Recovery from the peripheral neuropathy generally follows the discontinuation of exposure, but some central deficits may persist. HexacarbonSolvents the hexacarbon solvents n-hexane and methyl n-butyl ketone are both metabolized to 2,5-hexanedione, which targets proteins required for the maintenance of neuronal integrity (Spencer et al. Workers involved in the manufacturing of footwear, laminating processes, and cabinetry, especially in confined, unventilated spaces, may be exposed to excessive concentrations of these substances. Methyl n-butyl ketone is used in the manufacture of vinyl and acrylic coatings and adhesives and in the printing industry. Exposure to either of these chemicals by inhalation or skin contact leads to a progressive distal sensorimotor axonal polyneuropathy; partial conduction block may also occur. Optic neuropathy or maculopathy and facial numbness also have followed n-hexane exposure. The neuropathy is related to a disturbance of axonal transport, and histopathological studies reveal giant multifocal axonal swelling and accumulation of axonal neurofilaments, with distal degeneration in peripheral and central axons. Myelin retraction and focal demyelination are found at the giant axonal swellings. Acute inhalation exposure may produce feelings of euphoria associated with hallucinations, headache, unsteadiness, and mild narcosis. This has led to the inhalation of certain glues for recreational purposes, which causes pleasurable feelings of euphoria in the short term but may lead to a progressive, predominantly motor neuropathy and symptoms of dysautonomia after high-dose exposure and a more insidious sensorimotor polyneuropathy following chronic use. The conduction slowing relates to demyelinating changes and is unusual in other toxic neuropathies. A reduction in the size of sensory nerve action potentials may occur in the absence of clinical or other electrophysiological evidence of nerve involvement. Despite cessation of exposure, progression of the neurological deficit may continue for several weeks or rarely months (coasting) before the downhill course is arrested and recovery begins. Severe involvement is followed by incomplete recovery of the peripheral neuropathy. When the polyneuropathy does resolve, previously masked signs of central dysfunction, such as spasticity, may become evident. Other modes of exposure include poorly ventilated home heating systems, stoves, and suicide attempts. Carbon monoxide binds to hemoglobin with high affinity to form carboxyhemoglobin; it also limits the dissociation of oxyhemoglobin and binds to various enzymes. Acute toxicity leads to headache, disturbances of consciousness, and a variety of other behavioral changes. Motor abnormalities include the development of pyramidal and extrapyramidal deficits. Treatment involves prevention of further exposure to carbon monoxide and administration of pure or hyperbaric oxygen, although the evidence is conflicting regarding the utility of hyperbaric oxygen in this setting (Buckley et al. Neurological deterioration may occur several weeks after partial or apparently full recovery from the acute effects of carbon monoxide exposure, with recurrence of motor and behavioral abnormalities. The degree of recovery from this delayed deterioration is variable; full or near-full recovery occurs in some instances, but other patients lapse into a persistent vegetative state or severe parkinsonism. Pathological examination shows hypoxic and ischemic damage in the cerebral cortex as well as in the hippocampus, cerebellar cortex, and basal ganglia. The delayed deterioration has been related to a diffuse subcortical leukoencephalopathy, but its pathogenesis is uncertain. EthyleneOxide Ethylene oxide is used to sterilize heat-sensitive medical equipment and as an alkylating agent in industrial chemical synthesis. Operators of sterilization equipment should wear protective ventilatory apparatus to prevent occupational exposure. Acute exposure to high levels produces headache, nausea, and a severe, reversible encephalopathy. Long-term exposure to ethylene oxide or ethylene chlorohydrin-as can occur, for example, in operating-room nurses and sterilizer workers- may lead to a peripheral sensorimotor axonopathy and mild cognitive changes. Neuropathy may be produced in rats by exposure to ethylene oxide, and the residual ethylene oxide in sterilized dialysis tubing may contribute to the polyneuropathy occurring in patients undergoing chronic hemodialysis. MethylBromide Methyl bromide has been used as a refrigerant, insecticide, fumigant, and fire extinguisher, but its use has been banned in many countries because of its ozone-depleting properties. Its high volatility may lead to work-area concentrations sufficient to cause neurotoxicity from inhalation. Following acute high-level exposure, an interval of several hours or more may elapse before the onset of symptoms. Because methyl bromide is odorless and colorless, subjects may not even be aware that exposure has occurred, so chloropicrin, a conjunctival and mucosal irritant, is commonly added to methyl bromide to warn of inhalation exposure. Acute exposure to lower concentrations may result in conspicuous mental changes including confusion, psychosis or affective disturbances, headache, nausea, dysarthria, tremulousness, myoclonus, ataxia, visual disturbances, and seizures. Long-term low-level exposure may lead to a polyneuropathy in the absence of systemic symptoms. Distal paresthesias are followed by sensory and motor deficits, loss of tendon reflexes, and an ataxic gait. Visual disturbances, optic atrophy, and upper motor neuron deficits may occur also. The basis of the neurotoxicity is uncertain but methyl phosphates formed in cells may contribute to its neuronspecific toxicity via cholinesterase inhibition (Bulathsinghala and Shaw, 2014). Tremor, convulsions, and coma may follow acute high-level exposure, but the effects of chronic low-level exposure are uncertain. Chlordecone, which belongs to this group, may produce a neurological disorder characterized by "nervousness," tremor, clumsiness of the hands, gait ataxia, and opsoclonus. Organophosphates Organophosphates are used mainly as pesticides and herbicides but are also used as petroleum additives, lubricants, antioxidants, flame retardants, and plastic modifiers. Most cases of organophosphate toxicity result from exposure in an agricultural setting, not only among those mixing or spraying the pesticide or herbicide but also among workers returning prematurely to sprayed fields. Absorption may occur through the skin, by inhalation, or through the gastrointestinal tract. Organophosphates inhibit acetylcholinesterase by phosphorylation, with resultant acute cholinergic symptoms, with both central and neuromuscular manifestations. Symptoms include nausea, salivation, lacrimation, headache, weakness, and bronchospasm in mild instances and bradycardia, tremor, chest pain, diarrhea, pulmonary edema, cyanosis, convulsions, and even coma in more severe cases. Pralidoxime accelerates reactivation of the inhibited acetylcholinesterase, and atropine is effective in counteracting muscarinic effects, although it has no effect on the nicotinic effects, such as neuromuscular cholinergic blockade with weakness or respiratory depression. Functional recovery may take approximately 1 week, although acetylcholinesterase levels take longer to reach normal levels. Measurement of paraoxonase status may be worthwhile as a biomarker of susceptibility to acute orga- nophosphate toxicity; this liver and serum enzyme hydrolyzes a number of organophosphate compounds and may have a role in modulating their toxicity (Costa et al. Carbamate insecticides also inhibit cholinesterases but have a shorter duration of action than organophosphate compounds. The symptoms of toxicity are similar to those described for organophosphates but are generally milder. Certain organophosphates cause a delayed polyneuropathy that occurs approximately 2 to 3 weeks after acute exposure even in the absence of cholinergic toxicity.

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There is a mouse model showing that cisternal injection of these antibodies causes cerebellar dysfunction (Martin-Garcia et al. The latter includes medication to increase the release of acetylcholine and immunomodulation. The use of 3,4-diaminopyridine results in moderate to marked neurological improvement in 80% of patients (McEvoy et al. Long-term immunosuppression with prednisone or azathioprine should be considered if symptoms continue despite the use of 3,4-diaminopyridine. Lambert­EatonMyasthenicSyndrome Clinical Findings Neurological symptoms usually develop before the tumor diagnosis and gradually progress over weeks or months. Neurological examination shows proximal weakness, occurring in the legs more than in the arms, and absent or depressed tendon reflexes, which may potentiate after a brief muscle contraction. Strength may improve after brief exercise, but continued exercise increases weakness. At slow rates of repetitive nerve stimulation (2­5 Hz), a decremental response of greater than 10% is obtained. At fast rates of repetitive nerve stimulation (20 Hz or greater) or after maximal voluntary muscle contraction, facilitation occurs and an incremental response of at least 100% is seen. MyastheniaGravis Clinical Findings Myasthenia gravis is a postsynaptic disorder of neuromuscular transmission. The main features are weakness and fatigability of skeletal muscles that improves with rest and worsens with activity. Ptosis and diplopia occur in most patients, and symptoms remain localized to the extraocular and eyelid muscles in 15% of patients. In the rest, weakness becomes generalized and can impair respiration to the extent that mechanical ventilation is necessary. Patients with thymoma often have additional antibodies against skeletal muscle proteins such as titin and others (Somnier and Engel, 2002). Therapeutics based in targeting the abnormal cytokine and chemokine profiles are emerging, with variable responses (Levine, 2005; Musuruana and Cavallasca, 2011; Narazaki et al. AcuteNecrotizingMyopathy Clinical Findings this rare disorder is characterized by the acute to subacute onset of progressive, symmetric proximal muscle weakness. The course is usually severe with rapid generalization and involvement of respiratory and pharyngeal muscles leading to death (Galani et al. Serum creatine kinase concentrations are markedly elevated and electrophysiological studies demonstrate myopathic findings. Muscle histology shows severe necrotic changes with minimal or no inflammatory infiltrates. The differential diagnosis of an acute necrotizing myopathy in patients with cancer includes chemotherapy and cytokine-induced rhabdomyolysis (Anderlini et al. Dermatomyositis Clinical Findings Dermatomyositis and polymyositis are immune-mediated inflammatory diseases of muscle. An association exists between cancer and dermatomyositis in adults, but an association with malignancy is less clear for polymyositis, with cohort studies reporting conflicting results (Antiochos et al. The symptoms of paraneoplastic dermatomyositis are the same as those in patients without cancer. Cutaneous changes include purplish discoloration of the eyelids (heliotrope rash) with edema and erythematous lesions over the knuckles. The presence of necrotic skin ulcerations and pruritus is suggested to indicate an underlying cancer (Mahe et al. Neck flexors, pharyngeal and respiratory muscles are commonly involved and may lead to aspiration and hypoventilation. Serum creatine kinase concentrations are often elevated, although normal levels are occasionally found, even in patients with profound muscle weakness. Tumor Association Acute necrotizing myopathy has been reported in association with solid tumors including carcinoma of the lung, bladder, breast, and gastrointestinal tract (Levin et al. ParaneoplasticVisualSyndromes Clinical Findings Paraneoplastic involvement of the visual system may affect the retina, and less frequently, the uvea and optic nerves (Ko et al. Because paraneoplastic visual syndromes are rare, the more important considerations are metastatic infiltration of the optic nerves, toxic effects of chemotherapy or radiation therapy, and severe anemia. The symptoms of paraneoplastic retinopathy are photosensitivity, progressive loss of visual acuity and color perception, central or ring scotomas, and night blindness. Funduscopic examination is frequently normal, or may show nonspecific optic disc pallor and arteriolar narrowing. Patients typically present with the acute onset of night blindness and shimmering, flickering, or pulsating photopsias. Tumor Association the tumors most commonly associated with dermatomyositis are breast, lung, ovarian, and gastric malignancies. Less frequently associated are cancer of the pancreas, thymoma, germ-cell tumors, melanoma, nasopharyngeal cancer, and lymphoma. Immune Responses Abnormalities of both humoral- and cellular-mediated immunity are found in patients with dermatomyositis, although the target antigen is not known. Patients with anti-synthetase antibodies have dermatomyositis or polymyositis associated with interstitial lung disease. Treatment In some patients, muscle and dermatological symptoms improve coincidently with treatment of the tumor. Anti-enolase antibodies predominantly associate with central cone abnormalities, and may also occur without cancer association (Adamus et al. Autoantibodies against retinal proteins in paraneoplastic and autoimmune retinopathy. Limbic encephalitis and small cell lung cancer-clinical and immunological features. Acute rhabdomyolysis after concurrent administration of interleukin-2, interferon-alfa, and chemotherapy for metastatic melanoma. Carcinoma associated paraneoplastic peripheral neuropathies in patients with and without anti-onconeural antibodies. Effects of intravenous immunoglobulin on muscle weakness and calciumchannel autoantibodies in the Lambert-Eaton myasthenic syndrome. Clinical outcome in adult onset idiopathic or paraneoplastic opsoclonus-myoclonus. Cell-mediated auto-immunity in paraneoplastic neurologic syndromes with anti-Hu antibodies. Intravenous immunoglobulins in the therapy of paraneoplastic neurological disorders. Melanoma-associated paraneoplastic retinopathy: case report and review of the literature. A clinical pattern-based etiological diagnostic strategy for sensory neuronopathies: a French collaborative study. Cancer risks of dermatomyositis and polymyositis: a nationwide cohort study in Taiwan. A controlled trial of high-dose intravenous immune globulin infusions as treatment for dermatomyositis. Ma1, a novel neuronal and testis specific protein, is recognized by the serum of patients with paraneoplastic neurologic disorders. Identification of delta/notch-like epidermal growth factor-related receptor as the Tr antigen in paraneoplastic cerebellar degeneration. P/Q type calciumchannel antibodies in paraneoplastic cerebellar degeneration with lung cancer. Paraneoplastic limbic encephalitis: neurological symptoms, immunological findings, and tumor association in 50 patients. Anti-Ma and anti-Ta associated paraneoplastic neurological syndromes: 22 newly diagnosed patients and review of previous cases. Association of antineural autoantibodies in a patient with paraneoplastic cerebellar syndrome and small cell lung carcinoma. Incidence of serum anti-P/O-type and anti-N-type calcium channel autoantibodies in the Lambert-Eaton myasthenic syndrome. Anti-Hu antibody neuropathy: a clinical, electrophysiological, and pathological study. Autonomic dysfunction in the Lambert-Eaton myasthenic syndrome: serologic and clinical correlates. Paraneoplastic jaw dystonia and laryngospasm with antineuronal nuclear autoantibody type 2 (anti-Ri). Sleep disturbance and rage attacks in opsoclonus-myoclonus syndrome: response to trazodone. Long-term neurologic outcome in children with opsoclonus-myoclonus associated with neuroblastoma: a report from the Pediatric Oncology Group. Antibody repertoire in paraneoplastic cerebellar degeneration and small cell lung cancer. Analysis of antibodies to neuronal surface antigens in adult opsoclonus-myoclonus. Anti-amphiphysin I antibodies in patients with paraneoplastic neurological disorders associated with small cell lung carcinoma. An uncontrolled trial of rituximab for antibody associated paraneoplastic neurological syndromes. Clinical outcome of patients with anti-Hu-associated encephalomyelitis after treatment of the tumor. Favourable prognosis in Lambert-Eaton myasthenic syndrome and small-cell lung carcinoma. A helpful clinical sign predictive of cancer in adult dermatomyositis: cutaneous necrosis. Intrathecal injection of P/Q type voltage-gated calcium channel antibodies from paraneoplastic cerebellar degeneration cause ataxia in mice. Small-cell lung cancer, paraneoplastic cerebellar degeneration and the Lambert-Eaton myasthenic syndrome. Orchiectomy for suspected microscopic tumor in patients with antiMa2-associated encephalitis. Autoantibodies in idiopathic inflammatory myopathy: an update on clinical and pathophysiological significance. Utility of anti-Hu antibodies in the diagnosis of paraneoplastic sensory neuropathy. Paraneoplastic cerebellar degeneration associated with antineuronal antibodies: analysis of 50 patients. Survival and outcome in 73 anti-Hu positive patients with paraneoplastic encephalomyelitis/sensory neuronopathy. Differences in clinical features between the Lambert-Eaton myasthenic syndrome with and without cancer: an analysis of 227 published cases. Despite our understanding of the pathophysiology of anoxic-ischemic injury based on careful animal experiments, the clinical reality is discouraging. Clinical trials using barbiturates or calcium channel antagonists have been unsuccessful (Maramattom and Wijdicks, 2005). Improvement of outcome might come from very early intervention and administration of neuroprotective agents at the onset of resuscitation, rather than when a patient enters the hospital. However, the current literature provides no criteria on which a good outcome can be reliably predicted. Most studies have specifically concentrated on the examination of the patient, assuming a poor outcome. Clinical neurological examination follows a standard procedure, with examination of the brainstem reflexes, motor response to pain, specific attention to myoclonus, and spontaneous or elicited eye movement abnormalities. Because the brainstem is far more resilient to anoxic-ischemic injury than the cortex, brainstem reflexes, including the pupillary reflex to light, are often normal. Absent pupil responses can be caused by a high dose of intravenous atropine used during resuscitation, although a pupil response can often still be found when examined under the magnifying glass. Fixed, dilated pupils presenting 6 hours after resuscitation are a sign of poor prognosis, but this is rarely present in isolation and is usually an indication that the brainstem has also been involved in the anoxic-ischemic injury. Corneal reflexes have been absent in about a third of patients, but they often reappear soon. Sustained upward gaze is often indicative of a significant global bihemispheric injury that may include the thalamus. A proposed mechanism explaining this phenomenon is a complete disinhibition of the vestibulo-ocular reflexes from the cerebellar flocculus (Nakada et al. While forced upgaze is usually associated with poor outcomes, it is still compatible with survival in about 12%­15% of cases (Fugate et al. In some patients, downward gaze can be elicited using rapid head shaking or attempting to elicit a vestibular ocular response (Johkura et al. Other eye abnormalities, including ping-pong gaze or periodic lateral gaze deviations, have not been specifically examined for their prognostic value (Diesing and Wijdicks, 2004). Continuous blinking is often a common finding in comatose patients, although its anatomical substrate is unknown. An important clinical sign is myoclonus status epilepticus, defined as continuous and vigorous jerking movements involving facial muscles, limbs, and abdominal muscles (Thomke et al. These jerks can often be elicited or aggravated by touch or hand clap and may also involve the diaphragm, which complicates ventilation. Myoclonus status epilepticus is an agonal phenomenon indicating a very poor prognosis. This sustained, diffuse, vigorous myoclonus should not be confused with occasional myoclonic jerks.