Acute Ataxia
While the common etiologies of acute ataxia are benign, some diagnoses require emergent intervention. Acute ataxia is usually the result of cerebellar dysfunction, but may also be due to conditions affecting vestibular function, motor output, and/or sensory input. The most common causes (Table 15.1) are intoxications (alcohol, benzodiazepines, anticonvulsant medications) and parainfectious viral infections. However, serious concerns include a mass lesion (posterior fossa, brainstem, spinal cord), hydrocephalus, head trauma, meningitis, encephalitis, post-ictal state, and a metabolic or vascular etiology.
Clinical Presentation
Ataxia is the impaired coordination of movements, usually manifested as unsteady, wide-based gait or truncal instability (titubation). More subtle signs of ataxia include dysmetria (undershoot/overshoot), intention tremor, dysdiadochokinesia (impaired rapid alternating movements), dysrhythmic “scanning” speech, and nystagmus. In general, acute ataxia evolves over <72 hours.
Parainfectious Acute Cerebellar Ataxia
Acute cerebellar ataxia most often occurs days to weeks after a viral infection (before or after an exanthem), such as varicella or Epstein–Barr virus (EBV), but it can also follow an immunization. Typically, a preschool-aged child presents with a short history (hours to days) of incoordination, unsteady gait, tremor, speech abnormalities, titubation, and/or nystagmus). The mental status and the remainder of the neurologic examination are normal. The well appearance of the child helps distinguish this entity from encephalitis and meningitis. The CSF may be normal, or there may be a mild pleocytosis or protein elevation.
Acute Cerebellitis
Acute cerebellitis is a potentially worrisome process, which can occur during or after a systemic infection, such as with EBV, varicella, rotavirus, Mycoplasma, or HHV-6. In contrast to a pure cerebellar syndrome, there are more global neurologic features, including headache, vomiting, and altered mental status. The clinical presentation is related to cerebellar edema and brainstem compression, with potential fourth ventricular outflow obstruction and resultant hydrocephalus. Neuroimaging abnormalities are confined to the cerebellum.
Acute Disseminated Encephalomyelitis
Acute disseminated encephalomyelitis (ADEM) is an immune-mediated, inflammatory demyelinating disease of the CNS that often presents with ataxia two days to four weeks after a viral infection or vaccination. In contrast to acute cerebellar ataxia, by definition patients with ADEM have encephalopathy. This may present as lethargy or behavioral changes, often associated with multifocal neurologic findings on examination. The brain MRI reveals diffuse, patchy T2 signal abnormalities, usually involving the white matter more than gray matter.
Toxic Ingestion
Toxic ingestions are the second most frequent cause of acute ataxia, affecting both toddlers (accidental) and adolescents (intentional). The most common agents implicated are anticonvulsants (e.g., benzodiazepines, phenytoin, carbamazepine), ethanol, marijuana, tricyclic antidepressants, and dextromethorphan. Associated symptoms may include decreased consciousness, vomiting, or seizures.
Meningitis
Ataxia, with or without fever, may be the first sign of bacterial or viral meningitis (pp. 422–425). Other meningeal signs, such as nuchal rigidity and Kernig’s and Brudzinski’s signs, may also be present.
Encephalitis
A viral infection affecting the brainstem can present with ataxia and cranial nerve abnormalities (pp. 383–386). There is minimal effect on the level of consciousness unless higher cortical structures are also involved. Common agents are varicella, enterovirus, echovirus, adenovirus, and coxsackievirus. CSF findings are consistent with viral meningitis (pleocytosis without significant protein elevation or hypoglycorrhachia).
Posterior Fossa Tumor
A posterior fossa tumor usually presents with an insidious onset of headaches and vomiting, with slowly progressive ataxia. Acute ataxia can occur as the result of obstructive hydrocephalus, hemorrhage into the lesion, or edema.
Stroke
Sickle cell disease, congenital heart disease, and hypercoagulable states can cause vertebrobasilar disease or hemorrhagic strokes, presenting with ataxia (pp. 493–498). Trauma may be associated with vertebral artery dissection and stroke.
Paraneoplastic Syndrome
Oposoclonus–myoclonus syndrome is a paraneoplastic process, most often associated with neuroblastoma. It presents with ataxia, opsoclonus (chaotic “dancing eye movements”), and irritability.
Transverse Myelitis
Transverse myelitis is a presumed parainfectious inflammation at a specific level of the spinal cord. It may initially present with ataxia, back or neck pain, and paresthesias, followed by the rapid development of weakness at and below the level of the lesion.
Guillain-Barré Syndrome
In the Miller-Fisher variant of Guillain-Barré syndrome, ataxia is accompanied by ophthalmoplegia (usually diplopia). This may be followed by areflexia, an ascending weakness, and autonomic symptoms (flushing, pulse and blood pressure changes, gastrointestinal symptoms). Classically, the CSF demonstrates cytoalbuminologic dissociation (elevated protein without pleocytosis).
Migraine Syndrome
Basilar migraines and hemiplegic migraines can present with ataxia, dizziness, and diplopia. In addition, patients with migraine may have benign paroxysmal vertigo, which can be difficult to differentiate from ataxia.
Diagnosis
Determine the time of onset, progression of the symptoms (chronic ataxia usually results from tumors, metabolic disorders, or hereditary ataxias), associated symptoms, and whether there was any antecedent trauma, viral illness, rash, or toxin exposure. Inquire about the possibility of recreational drug use, ingestion (including ethanol), or overuse of prescription (anticonvulsants, sedatives, TCAs) and over-the-counter medications (dextromethorphan, topical diphenhydramine applied over a large surface area).
Pertinent general physical examination findings include fever, meningeal signs, viral exanthem (varicella, measles), and an ethanol or marijuana odor.
A careful neurologic examination is necessary to confirm the presence of ataxia (truncal, appendicular, and/or gait), and to identify associated findings (encephalopathy, headache, opthalmoplegia, opsoclonus). Abnormal mental status suggests a toxic ingestion, ADEM, meningitis, encephalitis, or stroke.
A posterior fossa mass can be associated with intracranial hypertension, bulging anterior fontanelle, papilledema with absence of spontaneous venous pulsations, cranial nerve palsies (head tilt, lateral gaze palsy, facial weakness), or long-tract findings (hemiparesis, spasticity, extensor plantar responses).
Consider Guillain-Barré syndrome if the patient is hyporeflexic or areflexic. Check for a sensory level, suggestive of a spinal cord lesion (transverse myelitis, tumor).
Acute Cerebellar Ataxia
In acute cerebellar ataxia, mental status is preserved, there are no meningeal signs, the sensory examination is normal, and there is no focal weakness. For most of the disorders listed in Table 15.1, the associated lethargy helps to distinguish these entities from acute cerebellar ataxia.
Vertigo
It can be difficult to distinguish an unsteady stance or gait secondary to vertigo (acute labyrinthitis, migrainous vertigo, benign positional vertigo) from ataxia. This is particularly true in children who are unable to articulate a sense of motion or spinning. Nausea, vomiting, and nystagmus usually accompany vertigo, which can be provoked or worsened by changes in head position.
ED Management
If the child is lethargic, immediately assess the airway, breathing, and cardiovascular functions, give oxygen if necessary, and obtain intravascular access. If there is papilledema, focal neurologic findings, bradycardia, or hypertension, begin treatment for increased intracranial pressure (pp. 527–529) and arrange for an emergent noncontrast head CT scan to rule-out a posterior fossa lesion. If meningitis is suspected, obtain a blood culture and give meningitic doses of IV antibiotics (pp. 422–425) before obtaining the head CT.
If the head CT reveals no evidence of increased intracranial pressure or mass effect, perform a lumbar puncture, including a measurement of the opening pressure (with the patient’s legs extended). To evaluate for a toxic ingestion, check serum osmolality (increased with ethanol), and blood level of the suspected drug (e.g., ethanol, phenobarbital, phenytoin, or carbamazepine). If there is encephalopathy, arrange for a brain MRI, to evaluate for ADEM and cerebellitis.
An evaluation for an inborn error of metabolism is necessary only if the patient has a past history of recurrent episodic ataxia, mental status changes, or a family history of metabolic disorders. Obtain liver function tests, serum amino acids, urine organic acids, lactate, pyruvate, and ammonia. These tests are most valuable if they are obtained before IV fluids and dextrose are given.
Indications for Admission
Bibliography
Acute Hemiparesis and Stroke
Acute hemiparesis in children can be difficult to recognize due to subtle motor signs, sometimes confounded by encephalopathy or pain. Thus, there can be a delay in the recognition of a potentially emergent medical situation. The most common etiologies of acute hemiparesis are ischemic or hemorrhagic stroke, prolonged focal seizures or post-ictal period (Todd’s paralysis), acute disseminated encephalomyelitis, meningitis, encephalitis, brain abscess, mass lesions, and hemiplegic migraine. While serious bacterial infections such as sepsis, endocarditis, and meningitis have well-established associations with arterial ischemic stroke in children, minor infections (such as a viral URI) in the week prior to presentation are more common. Other etiologies of acute hemiparesis include blood dyscrasias, vasculopathies, vascular malformations, and trauma (Table 15.2).
Note: hemiplegic migraine and acute infantile hemiplegia are diagnoses of exclusion
Clinical Presentation
The clinical presentation of acute ischemic stroke varies by age, and size and location of the injury. An infant may have an asymmetric startle response or absent grasp reflex on the affected side. Toddlers can demonstrate subtle hemiparesis as a refusal to reach with the weaker side, or an asymmetric gait. A larger stroke typically presents with decreased level of consciousness, hypertension, apnea, seizures, or hypotonia. Older children may present like adults, with visual field deficits, gaze deviation, aphasia, dysphagia, or other neurological deficits accompanying the hemiparesis. Alteration of consciousness and seizures can occur with a large ischemic or hemorrhagic stroke, meningitis, and encephalitis. Initially, there will be flaccid weakness of the involved arm or leg, which may evolve over days to weeks to a decorticate posture (shoulder adduction, flexion of the elbow, wrist, and fingers; pronation of the hand; extension of the knee; and eversion and plantar flexion of the foot). Subacute to chronic hemiparesis is associated with hyperreflexia, spasticity, and extensor plantar reflexes (corticospinal tract signs).
Arterial Ischemic Stroke (AIS)
AIS is defined as an acute focal neurological deficit lasting >24 hours, associated with neuroradiological evidence of cerebral infarction (diffusion changes on MRI). The most common risk factors are congenital heart disease, preceding infection, red blood cell disorders such as sickle cell disease, and genetic or acquired coagulopathies. Non-inflammatory arteriopathies include arterial dissection, Moyamoya syndrome, and transient cerebral vasculopathy. Infectious conditions include bacterial meningitis, encephalitis, brain abscess, sepsis, and viral infections such as varicella, influenza, HIV, and parvovirus B19.
Intracranial Hemorrhage
An intracranial hemorrhage typically has a sudden onset and rapid evolution. Headache, vomiting, and obtundation are common, and there may be other signs of increased intracranial pressure, such as hypertension, bradycardia, and papilledema (pp. 527–529). Seizures may also occur early in the course.
Hemiplegic Migraine
Hemiplegic migraine is a rare form of migraine. It can be sporadic or familial, with onset often in childhood. It is a stroke mimic, and may be associated with impaired consciousness, inability to speak, and typical migraine features like headache, nausea, and photophobia.
Acute Alternating Hemiplegia of Childhood
Acute alternating hemiplegia of childhood is a rare disorder presenting with episodic sudden weakness and altered mental status. The motor deficit persists for minutes to days and is often followed by seizures and slowed mentation. The typical patient is under three years of age and previously well. Repeated episodes can affect one or both sides of the body, but the child is well in between and neuroimaging studies are all normal.
Diagnosis
Although the etiology may not be definitively determined in the ED, inquire about the onset of the weakness, progression of symptoms, and occurrence of seizures, fever, trauma, infections (URI, sinusitis, mastoiditis), or change in mental status. Determine past medical history (sickle cell disease, congenital heart disease, coagulopathies, lupus, neurofibromatosis, epilepsy, prior hemiparetic episode). Consider non-accidental trauma, particularly in an infant or toddler.
On physical examination, check for hypertension and a bulging fontanelle, which may indicate increased intracranial pressure, and nuchal rigidity suggesting an infectious process (meningitis, encephalitis). Examine the skin for neurofibromas and café-au-lait spots, check for cyanosis, and look for signs of head or neck trauma. Auscultate the head and neck for a bruit and the chest for a cardiac murmur.
Perform a thorough neurologic exam, with special attention to mental status, strength, and reflexes. A unilateral, nonexpanding, hemispheric lesion does not necessarily cause a change in mental status. If the patient is lethargic, consider a brainstem stroke, bihemispheric stroke, hemorrhage, infection, metabolic derangement, or post-ictal state.
ED Management
Management takes priority over etiologic diagnosis. Perform a quick survey to assess the adequacy of the airway, breathing, and cardiovascular function, and obtain a complete set of vital signs. Check the extraocular movements (EOMs), pupil size and reactivity, and the fundi for papilledema, and assess the level of consciousness. See pp. 527–529 for the management of increased intracranial pressure, but allow for permissive hypertension (avoid iatrogenic hypotension, which can worsen the cerebral hypoperfusion in children with acute stroke). Secure an IV and obtain blood for a CBC, platelet count, PT and PTT, sickle cell testing (if patient’s status is unknown), focused drug/toxin testing, inflammatory markers (ESR and/or CRP), Dextrostix, comprehensive metabolic panel, VBG or ABG, and a blood culture if the patient is febrile or has meningeal signs.
Immediately consult a pediatric neurologist and/or neurosurgeon, and arrange for a noncontrast CT scan to rule-out hemorrhage or an emergent brain MRI to evaluate for ischemic stroke. If there is no evidence of mass effect (tumor, acute infarct, hematoma) or increased intracranial pressure, perform a lumbar puncture (including opening pressure) and obtain specimens for cell count, protein and glucose, Gram stain, and culture. Save an additional tube of CSF in the event that testing for varicella zoster virus, herpes simplex virus, or enterovirus is indicated (elevated CSF WBC or protein).
For patients with AIS, thrombolytic therapy is warranted if symptom onset is within three hours for treatment with IV tPA and within 3–6 hours for intra-arterial tPA. However, most children present too late (>24 hours) for these therapies to be beneficial. If arterial thrombosis is discovered in a large vessel, consult with neurointerventional radiology to determine if emergent clot retrieval is indicated.
If the patient has fever and altered mental status, empirically treat with broad-spectrum antibiotics and acyclovir until cultures and herpes PCR are negative. The management of sickle cell disease (pp. 370–375), encephalitis (pp. 383–386), meningitis (pp. 422–425), and headache (pp. 515–521) is discussed elsewhere.
Indications for Admission
Bibliography
Acute Weakness
Although acute weakness is uncommon in childhood, it usually indicates a significant neurologic disorder. The possibility of rapid progression to respiratory failure makes the onset of acute weakness a true neurologic emergency until the cause and course are established.
Clinical Presentation and Diagnosis
The history is vital to defining the underlying process. Determine the time of onset, progression, pattern of weakness (unilateral, bilateral, hemi-, di-, para-, or quadriparetic; flaccid versus spastic), fluctuation of weakness with time, shortness of breath (respiratory muscle involvement), difficulty swallowing or choking, and associated systemic features. Always inquire about associated sensory changes, muscle or extremity pain, and bladder or bowel incontinence. It is also important to differentiate weakness from ataxia, which can be challenging in young children. A history of fever or viral prodrome suggests an infectious or parainfectious process.
Guillain-Barré Syndrome (GBS)
GBS, or acute demyelinating polyneuropathy, is the most common cause of acute flaccid paralysis in otherwise healthy children. It is usually a post-vaccination or post-infectious phenomenon; about two-thirds of patients have a history of an antecedent respiratory tract or gastrointestinal (Campylobacter most frequent) infection. GBS is characterized by premonitory sensory changes or pain, ascending motor weakness, and depressed or absent deep tendon reflexes, with intact bowel and bladder sphincter function. There may be associated cranial nerve involvement (bilateral facial weakness is most common). The weakness is often asymmetric at the onset, but becomes symmetrical as the disease progresses. About 10% of patients have serious respiratory, cardiac, and/or autonomic dysfunction, which may progress rapidly and be unrelated to the degree of motor weakness.
Examination of the CSF early in the course may show a mild pleocytosis, but later the classic finding is cytoalbuminologic dissociation: marked elevation of protein without pleocytosis.
Miller-Fisher Syndrome (MFS)
Patients with this GBS variant have external ophthalmoplegia, ataxia, and muscle weakness with areflexia. These children may also have other cranial nerves palsies. Most of these patients have cross-reacting antibodies to GQ1b ganglioside.
Myasthenia Gravis
Myasthenia gravis (MG) is a rare autoimmune disorder that causes weakness by impeding postsynaptic neuromuscular transmission, typically related to blocking the acetylcholine receptor. Weakness develops subacutely (over weeks to months), and commonly presents as ptosis, diplopia, or blurry vision due to extraocular muscle weakness, with or without generalized muscle weakness. Patients with bulbar weakness may present with difficulty in chewing and swallowing, drooling, nasal voice, or poor cough. Fluctuation of the weakness and fatigability are hallmarks of MG, as the symptoms are least prominent on awakening, and become more obvious through the day. Rarely, there may be a severe acute presentation with life-threatening weakness of the respiratory musculature (myasthenic crisis). Patients typically have normal mental status, pupillary reflexes, deep tendon reflexes, sensation, and coordination. Ptosis becomes evident with sustained upward eye gaze (at least 30 seconds). The diagnosis is confirmed by a therapeutic challenge with edrophonium.
Acute Flaccid Myelitis
Although poliomyelitis is very rare in the United States, it may occur in a patient with a history of incomplete or inadequate immunization. Clusters of cases of polio-like myelitis have emerged in the summer/fall months recently. The leading identified viral cause is enterovirus D68, and possibly other enteroviruses (echovirus, Coxsackievirus). It typically presents with a history of a mild febrile illness, with headache, sore throat, vomiting, and fatigue, followed by a few days of recovery. Then the patient has recurrent fever accompanied by weakness, lethargy, and irritability, which may be associated with meningeal signs. There is selective destruction of motor neurons (anterior horn cells), characterized by motor weakness, as well as severe back, neck, and muscle pain. The disease tends to preferentially affect proximal muscles and the legs, but bulbar involvement may also occur, causing dysphagia, dysarthria, and difficulty managing secretions. Reflexes are decreased or absent, but the sensory examination is normal. The CSF shows a pleocytosis with protein elevation.
Transverse Myelitis
Transverse myelitis is an inflammatory, demyelinating process that develops over hours to days in patients without evidence of a compressive lesion. Transverse myelitis can occur alone (known as clinically isolated syndrome) or as part of other demyelinating diseases, including neuromyelitis optica, acute disseminated encephalomyelitis, or multiple sclerosis. Patients usually present with acute paraparesis, paresthesia (bilateral segmental sensory loss below the level of inflammation), sphincter dysfunction, absent deep tendon reflexes, and extensor plantar responses.
Spinal Cord Pathology
Spinal cord lesions can produce acute weakness with either paraplegia or quadriplegia. Trauma is the most likely cause. Patients with Down syndrome or rheumatoid arthritis are particularly susceptible to C1 to C2 subluxation, which can result in quadriparesis. The presence of fever and vertebral tenderness strongly suggests a spinal epidural abscess, which is a neurosurgical emergency. Weakness can also be caused by paraspinal or spinal cord tumor with acute cord compression, spinal cord infarction (most common in the thoracic levels), or hemorrhage secondary to arteriovenous malformation.
Infantile Botulism
Botulism (pp. 379–380) causes a fairly rapid progression of cranial nerve dysfunction (diplopia, ptosis, pupillary dilation, dysarthria, dysphagia) and weakness. With infantile botulism there is a history of constipation, followed by a subacute progression of bulbar and extremity weakness, presenting as a symmetric ascending paralysis, inability to suck and swallow, and ptosis, which may progress to generalized flaccidity and respiratory compromise.
Tick Paralysis
A toxin released by dog and wood ticks prevents the release of acetylcholine at nerve endings, causing a rapidly progressive (12–48 hours), ascending, generalized paralysis. Deep tendon reflexes are depressed or absent and there may also be mild facial muscle weakness, dysarthria, dysphagia, ptosis, double vision, and respiratory compromise.
Tick paralysis must be considered in the differential diagnosis of any child presenting with acute ataxia, which is quickly followed by acute ascending paralysis, especially during the late spring and summer seasons. In contrast to Guillain-Barré syndrome, there is no elevation of the CSF protein. A high index of suspicion is imperative as any delay of diagnosis and treatment may result in life-threatening respiratory failure.
Metabolic Causes
Metabolic causes (hypokalemia, hypo- and hypercalcemia, hypo- and hyperthyroidism) typically have associated systemic manifestations. Episodic paralysis, particularly during rest after exercise, suggests periodic paralysis, especially if there is a positive family history.
Other Causes
Acute or subacute weakness with a rash, fever, and myalgias suggests an inflammatory process such as dermatomyositis, polymyositis, or systemic lupus erythematosus. Certain toxins, especially the anticholinesterase-inhibiting insecticides (organophosphates, carbamates), cause acute weakness.
ED Management
Ask about change in voice (nasal voice), dysphagia, shortness of breath, bladder fullness, constipation, or incontinence of urine or stool. Perform a careful neurologic examination to define the extent, pattern, fluctuation, and fatigability of the weakness, and document any associated sensory findings (particularly a sensory level). Neck flexion/extension weakness may be a sign of impending respiratory compromise, as C3–C5 also innervate the diaphragm. Check the rectal tone and percuss or obtain an ultrasound of the bladder for fullness secondary to urinary retention. Examine the skin for a rash or a tick (often found hidden in hairy areas) and palpate muscles for pain. Evaluate for signs of respiratory distress, like paradoxical breathing. Ask the patient to count aloud as high as they can, after maximal inspiration, in one breath – each number equals about 100 mL in vital capacity. To assess the respiratory status, obtain an ABG, pulse oximetry, negative inspiratory force (<20 cm H2O indicates respiratory weakness), and forced vital capacity (<20–25 mL/kg is worrisome).
Obtain a CBC, electrolytes, glucose, and urinalysis. If the patient is febrile, also check a blood culture and ESR. A lumbar puncture is indicated, particularly if Guillain-Barré syndrome is suspected, but it can be delayed until after consulting a pediatric neurologist. Obtain an MRI of the spine, with contrast, if the patient has signs and symptoms suggestive of spinal cord pathology. Potentially life-threatening spinal cord lesions are located in the upper cervical cord, which can affect the nerves innervating the pharyngeal muscles and diaphragm, and upper thoracic lesions above T6, which can result in autonomic dysreflexia and lead to hypertension, bradycardia, diaphoresis, and urinary retention.
Admit a patient with Guillain-Barré syndrome, myasthenic crisis, acute transverse myelitis, or acute flaccid myelitis to the intensive care unit, as respiratory compromise can occur acutely. Consult a neurologist, who may recommend plasmapheresis, high-dose IV gamma globulin (2 g/kg divided over 2–5 days), or IV methylprednisolone (30 mg/kg/day, 1 g/day maximum). However, during a myasthenic crisis, IV steroids can cause initial worsening of weakness, even though high-dose prednisone is used as a maintenance treatment.
To diagnose myasthenia gravis at bedside, perform a Tensilon (edrophonium chloride) test in consultation with a pediatric neurologist. Another diagnostic maneuver is to apply a cold pack to the eyelids. If the patient has myasthenia, the ptosis may improve.
The management of the trauma victim is detailed on pp. 749–758, but if there is any history of trauma, stabilize the patient in a neutral position. Obtain the appropriate spine films (cervical, areas of tenderness), and consult neurosurgery.
If a spinal epidural abscess or spinal cord compression is suspected, obtain an urgent neurosurgery and neurology consultation.
See pp. 379–380 for the treatment of botulism.
For tick paralysis, remove the tick, including the mouth parts; if these are left behind, toxin may continue to release into the host. Symptoms resolve quickly with treatment, estimated around 1.5 days.
Arrange for psychological counseling if the weakness is determined to be psychogenic.
Indications for Admission
Acute weakness of any etiology, including suspected psychogenic weakness if unable to ambulate.
Bibliography
Anti-NMDA Receptor Encephalitis
The understanding of pediatric acute neuropsychiatric syndromes has expanded since the discovery of the N-methyl-D-aspartate (NMDA) receptor antibody and other antibody-mediated autoimmune encephalopathies. Although the differential diagnoses of acute neuropsychiatric disorders is broad, most of these diseases are reversible with proper treatment. Therefore, it is extremely important to expeditiously diagnose these disorders.
Clinical Presentation
Anti-NMDA receptor encephalitis presents with the rapid onset (less than three months) of the following major groups of symptoms:
abnormal (psychiatric) behavior or cognitive dysfunction;
speech dysfunction (pressured speech, verbal reduction, mutism);
seizures, either focal or generalized;
movement disorder, dyskinesias, or rigidity/abnormal postures;
decreased level of consciousness;
autonomic dysfunction or central hypoventilation.
Teenagers usually present with abnormal behavior (psychosis, delusions, hallucinations, agitations, aggression, catatonia) followed by sleep problems and movement disorders. Compared to the teenagers, young children more frequently present with seizures and abnormal movements.
Diagnosis
Consider anti-NMDA receptor encephalitis if the patient presents with the rapid onset (under three months) of a combination of abnormal (psychiatric) behavior or cognitive dysfunction, speech dysfunction, seizures, movement disorder, altered level of consciousness, and autonomic dysfunction. The definite diagnosis requires IgG anti-GluN1 antibodies and reasonable exclusion of other disorders such as meningitis and encephalitis.
ED Management
If an acute neuropsychiatric syndrome is suspected, consult a neurologist who will direct the evaluation. In general, an MRI with and without gadolinium is indicated, although it can sometimes be normal. Urgently obtain a head CT if the patient has focal weakness, cranial nerve palsy or ataxia. If the CT is normal, perform a lumbar puncture for cell count and differential, protein, glucose, bacterial culture, HSV PCR, autoimmune encephalopathy panel (which includes testing for NMDA receptor antibodies), oligoclonal bands, and IgG index, and save at least 2–3 mL of CSF to send for further investigations, based on MRI findings.
Once the studies are obtained, start antibiotics (meningitic doses) and acyclovir if there are white cells in the CSF.
Indications for Admission
Bibliography
Breath-Holding Spells
Breath-holding spells are common (about 5% incidence) paroxysmal nonepileptic events of infancy, which typically begin at 6–18 months and disappear by six years in 90% of cases. Spell frequency can range from several per day, to once per year, but the majority have 1–6 spells per week. In 30% of cases, there is a positive family history of breath-holding. Although the physiologic basis of breath-holding is unclear, the episodes are not associated with an increased risk of epilepsy.
Clinical Presentation
The term breath-holding is a misnomer, as these episodes are involuntary and occur during expiration. Breath-holding spells are brief, lasting about 30 seconds. They are classified based on color change – cyanotic or pallid. A child generally has only one type of spell.
Cyanotic Spell
A cyanotic spell is often preceded by vigorous crying, which may be due to anger, frustration, fear, or pain. The child becomes silent and holds their breath in expiration, followed by a rapid onset of cyanosis and loss of consciousness, sometimes accompanied by limpness, rigid limbs, or opisthotonos.
Pallid Spell
A pallid spell is triggered by sudden fright, pain, or minor head trauma. The child may gasp or cry briefly, stops breathing, loses consciousness, and becomes pale and limp. Clonic jerks may be noted at the end of a more severe episode. Pallid breath-holding spells are due to an exaggerated vagal response, leading to cerebral hypoperfusion.
Diagnosis
The diagnosis is made from the history, as the patient usually appears well and back to baseline upon arrival in the ED. Breath-holding spells are often confused with seizures, but convulsions generally do not have an external precipitating factor, such as sustained crying or minor injury. Also, spells may be confused with syncopal episodes. Fainting is very unusual in young children, however, and is not usually associated with rigidity or opisthotonos.
ED Management
If the history of the event is typical and a thorough neurologic examination is normal, reassure the family about the benign, self-resolving nature of the episodes (no risk of epilepsy). Children with breath-holding spells have normal developmental and intellectual outcomes. Advise the parents to place the child in the lateral recumbent position during a spell. As iron-deficiency anemia has been associated with breath-holding spells, check CBC and ferritin level, and treat with iron as indicated. Spells resolve in 50% of patients on iron therapy. As these convulsive spells are nonepileptic, anticonvulsants are not indicated.
If the history is unusual or unclear, obtain a CBC, fingerstick glucose, basic chemistry panel, calcium, and perform an ECG with rhythm strip to rule-out a prolonged QT syndrome (see Syncope, pp. 79–82, and Cyanosis, pp. 70–71). If a seizure cannot be ruled out from the history, or there is a long post-ictal period, ask about a family history of epilepsy, inquire about developmental delay, examine for focal neurologic signs or neurocutaneous stigmata (café-au-lait macules or ash leaf spots), advise the family to take a video of further episodes, schedule a routine EEG, and refer to neurology.
Follow-up
Suspicion for seizures, such as spells associated with a prolonged post-ictal period: pediatric neurology follow-up in 2–4 weeks
Indications for Admission
Bibliography
Coma
Terms describing mental status are often misused, with variable meanings to different medical providers. The neurologic definitions of these terms, in order of decreasing level of arousal, follow.
Lethargy
Lethargy is severe drowsiness, with difficulty maintaining an aroused state. The patient can be aroused by moderate stimuli and answers questions when addressed, but will drift to sleep without continual stimulation.
Obtundation
The obtunded patient can slowly respond to verbal or tactile stimuli and follow simple commands, but is never alert between sleep states.
Stupor
The stuporous patient responds only to vigorous/painful and repeated stimuli. When undisturbed, the patient lapses back into an unresponsive state.
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