initially in trauma MRI of the spine is the procedure of choice to detect compressive mass lesions, but if not immediately available, plain or CT myelography is an alternative LP should not be performed without first imaging the spine if a diagnosis of spinal cord compression is possible Treatment of children with spinal injury from trauma begins with splinting and immobilization of the spine The role of high-dose methylprednisolone is controversial and there is a lack of controlled trials in the pediatric population Based on a review of the literature, the American Academy of Neurological Surgeons and the Congress of Neurosurgical Surgeons no longer recommend the use of steroid therapy Neurosurgical consultation should be obtained as soon as possible to evaluate for possible surgical decompression (see Chapter 122 Neurosurgical Emergencies ) In cases of possible epidural abscess or tumor-related masses, IV dexamethasone therapy may be beneficial, and should be considered in consultation with Neurosurgery and Oncology IV antibiotic therapy against S aureus should be started immediately In patients with a presumed infectious cause and those with cancer of unknown origin, emergent surgical decompression is indicated to alleviate pressure and to aid in diagnosis Further treatment depends on the specific organism or exact tumor type Acute Polyneuritis (Guillain–Barré Syndrome) Acute polyneuritis, also called Guillain–Barré syndrome, is characterized by symmetric ascending paralysis Pathologically, the hallmark of this disease is primary demyelination of motor and sensory nerves, believed to be caused by autoimmune mechanisms It occurs in children in all age groups but is uncommon before years of age An antecedent respiratory or gastrointestinal infection or immunization precedes the onset of illness by to weeks in more than 75% of childhood cases Weakness, commonly with an insidious onset, is the usual presenting complaint Paresthesias or other sensory abnormalities such as pain or numbness are prominent in up to 50% of cases, particularly in older children The paresthesias and paralysis are usually symmetric and ascending, although variations may occur Early in the course of illness, distal weakness is more prominent than proximal weakness Deep tendon reflexes are depressed or absent at the time of diagnosis Affected children often have an unsteady gait Cranial nerve abnormalities occur during the illness in 30% to 40% of cases and may be the predominant finding, especially in the Miller-Fisher variant of this syndrome, which is characterized by oculomotor palsies, ataxia, and areflexia, without motor weakness of the extremities The most common cranial nerve deficit is a seventh (facial) nerve palsy, followed in decreasing frequency by impairment of cranial nerves IX, X, and XI and oculomotor abnormalities Autonomic dysfunction occurs commonly and results in blood pressure lability, postural hypotension, and cardiac abnormalities; autonomic dysfunction is a disproportionate cause of morbidity and mortality Urinary retention, if it occurs, is usually seen late in the illness As the paralysis ascends, muscles of breathing may become involved, leading to respiratory embarrassment The primary aid in diagnosis is LP, which demonstrates an elevated protein level and fewer than 10 white blood cells per cubic millimeter—the so-called albuminocytologic dissociation CSF glucose is normal The protein elevation occurs in almost all cases but may be delayed for weeks, usually peaking in the second or third week of illness Emergency electromyography (EMG) and nerve conduction velocity testing are not indicated EMG may detect the presence of nerve conduction velocity delay; however, it is usually not demonstrable until the second or third week of illness Contrast-enhanced MRI imaging has been shown to be a sensitive and useful diagnostic adjunct, and imaging will typically demonstrate enhancement of the spinal nerve roots Because of the potential for progression to life-threatening respiratory compromise, the child with Guillain–Barré syndrome should be hospitalized and observed closely Impending respiratory distress must be anticipated, and routine respiratory monitoring should be aided by specific measures of respiratory function, particularly measurement of negative inspiratory force Because autonomic dysfunction is common, blood pressure must be monitored closely and abnormalities treated vigorously Acute polyneuritis is generally self-limiting, with more than 90% of children in most series having complete or near-complete recovery In mild cases, in which children retain the ability to ambulate, only supportive care is required However, immunomodulatory therapy may be of benefit in more severely affected children Plasmapheresis and IV immunoglobulin both have been used Although wellcontrolled, blinded studies of these treatments in children are lacking, the available data suggest that both are effective in reducing the duration and severity of illness in those most severely affected Corticosteroids have not been shown to be beneficial in acute Guillain–Barré syndrome, and some evidence suggests they may actually delay recovery Myasthenia Gravis In myasthenia gravis, antibodies directed against the acetylcholine receptor protein of the postsynaptic neuromuscular junction cause intermittent failure of neuromuscular transmission Myasthenia manifests as fluctuating weakness of cranial and skeletal musculature, exacerbated by exertion The onset of symptoms may be insidious or acute Most cases affect the cranial nerves, and any cranial nerve can be involved in combination or isolation Bilateral ptosis is the most common cranial nerve deficit, followed in incidence by oculomotor impairment Generalized truncal and limb weakness is present at onset in up to half of cases and eventually develops in most children with myasthenia The diagnosis should be suspected if there is a history of worsening weakness during continual activity or if fatigability of muscle strength is demonstrable More commonly a disease seen in adults, myasthenia gravis occurs in children in three major forms: transient neonatal, infantile (congenital), and juvenile (most common) The juvenile form of myasthenia clinically mimics the adult disease The mean age of onset is years, with a female predominance of approximately 4:1 Illnesses confused with myasthenia include the muscular dystrophies, congenital myopathies, inflammatory myopathies, acute and chronic polyneuropathies, and in the infant, botulism EMG can be used to provide electrophysiologic evidence for myasthenia gravis, and the Tensilon (edrophonium) test may be used, in consultation with a neurologist, to confirm the diagnosis Although myasthenia gravis is potentially life threatening, specific management can usually be delayed until after diagnosis is made Ventilatory support may be required if there is respiratory compromise If severe weakness is present, the child should be hospitalized Treatment is begun with the use of cholinesterase inhibitors to prolong the availability of acetylcholine at the neuromuscular junction At present, the anticholinesterase of choice is pyridostigmine (Mestinon) Myasthenia has a fluctuating, unpredictable course that can be exacerbated by intercurrent illness and by certain drugs, particularly the aminoglycoside antibiotics In a known myasthenic, rapid worsening and respiratory compromise (myasthenic crises) may be difficult to differentiate from deterioration secondary to overdose of anticholinesterases (cholinergic crises) because the muscarinic side effects of the anticholinesterases, such as nausea, vomiting, cramps, and muscle fasciculations, may be absent Differentiation can be made by giving to mg of IV edrophonium after ensuring respiratory sufficiency This should result in rapid improvement in the patient with a myasthenic crisis This procedure may be falsely positive, however, and if the diagnosis is unclear, the patient should be withdrawn from all anticholinesterases and, if necessary, maintained on mechanical ventilation for 48 to 72 hours Myasthenic crises respond variably to additional anticholinesterases, and plasmapheresis or steroid therapy may be particularly useful in this situation Cholinergic crises require the immediate withdrawal of all anticholinesterases Both myasthenic and cholinergic crises mandate admission to the hospital Botulism (See Also Chapter 132 Biological and Chemical Terrorism ) Infantile botulism is a cause of acute weakness in previously well infants younger than months The illness is caused by intestinal colonization by Clostridium botulinum, which produces a neurotoxin that impairs acetylcholine release from the nerve terminal Spores of C botulinum are of ubiquitous origin, found in soil and agricultural products Honey has been found to be a particularly significant reservoir Although infant botulism occurs throughout the United States, the incidence is highest in certain areas; approximately half the cases reported have been from California, Utah, and Pennsylvania The various host factors that predispose certain infants to intestinal colonization are poorly understood The initial symptom of infantile botulism is usually constipation, followed insidiously by lethargy and feeding difficulties Physical findings at the time of presentation are hypoactive deep tendon reflexes, decreased suck and gag, poorly reactive pupils, bilateral ptosis, oculomotor palsies, and facial weakness Differential diagnosis is broad, and infants are often misdiagnosed initially The diagnosis is confirmed by identification of C botulinum toxin (usually type A or B) in the feces or isolation of the organism in stool culture, which is less sensitive EMG may supply more immediate information Affected infants require hospitalization to observe for respiratory compromise In one large series of 57 patients, 77% required endotracheal intubation because of loss of protective airway reflexes, and 68% received mechanical ventilation for some period Nasogastric or nasojejunal feedings are usually needed as well Human botulism immunoglobulin, with activity against type A and B toxins, is approved for use in infant botulism (often referred to as BabyBIG) Trials have shown decreases in disease duration and hospital length of stay in treated infants Equine botulinum antitoxin has a high rate of anaphylactic reaction in infants and is not recommended The use of cathartics or other laxatives to reduce the amount of C botulinum present in the intestine has not proven beneficial Antibiotics such as penicillin, although widely used, have not been shown to eradicate the ... all cases but may be delayed for weeks, usually peaking in the second or third week of illness Emergency electromyography (EMG) and nerve conduction velocity testing are not indicated EMG may