ACUTE ATAXIA IN 3 YR OLD

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• 3 yr old child had hand foot mouth disease 1 wk ago , now presents with unstediness of gait. she can sit,but cannot hold spoon. there was no vomiting or fussiness. no h/o ingestion of medications. no h/o eardicharge/ uri

• What is the probable dx?
• What are the life threatening causes?
• What are the common causes?
• What all points in history are to be noted?
• What do you specifically look in physical examination?

• Acute ataxia is an uncommon presenting complaint in children. Although causes of acute ataxia include life-threatening conditions such as mass lesions and central nervous system (CNS) infection, the majority of children have a benign, self-limited process. Historical features, specific physical findings, and selected ancillary studies can identify most causes of ataxia, particularly those that are serious and require stabilization and intervention

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• Acute cerebellar ataxia — Acute cerebellar ataxia is the most common cause of childhood ataxia, accounting for about 30 to 50 percent of all cases. It is a self-limited syndrome that is frequently postinfectious and typically seen in children between two and five years of age. The diagnosis of acute cerebellar ataxia can only be made after exclusion of other more serious illnesses such as toxic ingestions, central nervous system infection, structural intracranial lesions, metabolic derangement, or neurodegenerative disorders

Life-threatening conditions

•  Life-threatening causes of acute ataxia in children are fortunately uncommon. For those conditions that create a mass effect, signs and symptoms of increased intracranial pressure (such as vomiting, headache, or papilledema) are typically evident. Etiologies include tumors, hemorrhage, stroke, and infection

History 

•  Most children with ataxia present with refusal to walk or with a wide-based, “drunken” gait. Specific features of the history that may help to identify the underlying cause of the ataxia include the following:
• Onset of symptoms – A rapid onset is typically indicative of a traumatic, infectious, post-infectious, or toxic etiology. Guillain-Barré syndrome (GBS) and metabolic syndromes usually present with a slower, more progressive onset of symptoms, usually over a few days. A slower and relatively insidious course is characteristic of brainstem and cerebellar tumors, although medulloblastomas may grow rapidly, and acute decompensation may occur secondary to obstructive hydrocephalus or hemorrhage into the lesion.
• Associated symptoms – Important associated symptoms include:•Otalgia, vertigo, and vomiting in association with acute ataxia suggest acute labyrinthitis. An older child with inner ear disease may complain of dizziness. Most children also have nystagmus.
• Recurrent night-time or early-morning headaches with or without vomiting are symptoms of increased intracranial pressure that may develop with a brain tumor. The absence of these symptoms, however, does not exclude the diagnosis. Personality and behavioral changes may also signal the presence of increased intracranial pressure with hydrocephalus.
• Abnormal mental status is a worrisome symptom that can develop in many conditions that cause acute ataxia, including mass lesions, central nervous system (CNS) infection, toxic exposure, trauma, stroke, and inborn errors of metabolism.
• Access to medications (prescription medications, anticonvulsants, over-the-counter drugs, drugs of abuse, and ethanol), and other toxic substances should be determined.
• A history of antecedent head trauma is consistent with an intracranial injury, whereas neck trauma suggests a stroke as the result of a vascular injury to the vertebral or basilar artery.
• Patients with a recent infection or vaccination may have a post-infectious demyelinating process such as acute cerebellar ataxia, GBS, or acute post-infectious demyelinating encephalomyelitis (ADEM).
• Previous similar episodes of acute ataxia suggest an episodic disorder such as a migraine syndrome, seizure, or inborn error of metabolism.
• Children with family members with ataxia may have migraine syndromes, hereditary ataxias, or inborn errors of metabolism.

Physical examination 

•  A systematic, yet flexible, approach to the physical examination is necessary to localize the source of the child’s symptoms. For young children who may be anxious or uncomfortable, careful observation of the patient’s movements and social interactions with the caregiver may provide more information than some parts of the formal examination.

General examination 

•  Abnormal vital signs must be recognized immediately. As an example, bradycardia, abnormal respiratory pattern, and hypertension may occur with increased intracranial pressure. The presence of fever is consistent with an infectious process. Other pertinent features of the general examination include the following:
• Bulging of the anterior fontanel may indicate increased intracranial pressure with a life-threatening cause of ataxia.
• An ipsilateral head tilt may be associated with posterior fossa tumors.
• For the child who tolerates a funduscopic examination, papilledema indicates increased intracranial pressure as may occur in posterior fossa tumors that obstruct spinal fluid flow leading to hydrocephalus.
• Nystagmus can develop with vestibular, cerebellar, or brainstem disorders. Opsoclonus may be associated with an occult neuroblastoma.
• Otitis media and hearing loss in association with vomiting and intense vertigo indicate acute labyrinthitis.
• Meningismus with fever and a toxic appearance is concerning for a CNS infection.
• A healing rash or viral exanthem may be a clue to the infectious antecedent in acute post-infectious cerebellar ataxia. Tick paralysis may be the cause of ataxia when an attached tick is noted.

Neurologic examination 

•  The neurologic examination includes specific examination techniques as well as observations made while taking the history and throughout the general physical examination. The approach to the neurologic examination of a child is discussed in detail separately.

Findings that are associated with various causes of acute ataxia include the following:

• Mental status – Abnormal mental status suggests ingestion, ADEM, meningitis, encephalitis, or stroke. Lethargy may be present in many inborn errors of metabolism. By comparison, children with post-infectious acute cerebellar ataxia are normally alert and interactive.
• Cranial nerves – Abnormalities of cranial nerve function suggest posterior fossa lesions, brainstem encephalitis, or the Miller Fisher syndrome.
• Motor examination – Children with the acute onset of weakness may stagger as an attempt to compensate. This gait abnormality may be mistaken for true ataxia and has been called “paretic” ataxia. Paretic ataxia is proportional to the degree of weakness. It may be due to Guillain-Barré syndrome (GBS), botulism, myasthenia gravis, transverse myelitis, or tick paralysis [10]. Deep tendon reflexes are absent in patients with GBS, botulism, and tick paralysis.
• Sensory examination – Impairment of proprioceptive input may result in sensory ataxia, as may occur with GBS.
• Cerebellar examination – A cerebellar lesion is the likely cause of ataxia for a patient with an abnormal cerebellar examination. However, patients with significant cerebellar dysfunction may have no specific findings. Cerebellar signs include abnormalities in gait, speech, and coordination of voluntary movement. Gait is typically wide-based, unsteady, lurching, or staggering. Speech abnormalities include fluctuations in clarity, rhythm, tone, and volume. Patients may have difficulty maintaining truncal position (titubation). Coordination of voluntary movement, as demonstrated with over- or under-shooting (best seen on finger-nose testing) and difficulty with rapid alternating movements (dysdiadochokinesia), is poor. Hypotonia and tremor may also occur.

Findings that localize the disorder within the cerebellum include the following:

• Vermis (midline cerebellar) lesions cause dysarthria, truncal titubation and gait abnormalities.
• Lesions of the cerebellar hemispheres result in ipsilateral limb dysmetria, hypotonia, and tremor. Children may veer in the direction of the affected cerebellar hemisphere when walking.

Laboratory

• Toxicologic screen – A urine screen for drugs of abuse or blood for specific drug levels (as suggested by the history) may be the most useful diagnostic test for children with acute ataxia if clinically suspected
• Blood glucose – A bedside test for blood glucose will quickly identify children with hypoglycemia.
• Metabolic evaluation – For children with episodic acute ataxia and other features that suggest an inborn error of metabolism (such as altered mental status or family history), the following tests may be useful: liver function tests, blood pH, CBC, quantitative amino acid determinations of blood and urine, serum lactate, pyruvate and ammonia levels, and urine organic acids.
• Cerebrospinal fluid (CSF) examination – CSF should be obtained whenever there is concern for CNS infection, such as meningitis or encephalitis. Otherwise, CSF examination is rarely indicated for the emergent evaluation of a child with acute ataxia. Moderate CSF protein elevation can occur in acute cerebellar ataxia, ADEM, and multiple sclerosis. CSF protein is also usually elevated in Guillain-Barré syndrome, but it may be normal in as many as 20 percent of children within a week of symptom onset [2]. Neuroimaging should be obtained before a lumbar puncture is performed when there is concern for increased intracranial pressure.
• Imaging — Neuroimaging should be obtained for patients with acute ataxia who have altered levels of consciousness, focal neurologic signs, cranial neuropathies, marked asymmetry of ataxia, concern for a mass lesion, or a history of trauma. Imaging may also be helpful when considering a diagnosis of exclusion, such as acute cerebellar ataxia or a conversion disorder.
• Magnetic resonance imaging (MRI) is the imaging modality of choice for patients with acute ataxia, although MRI may be difficult to obtain emergently. It is superior to computed tomography (CT) for detection of posterior fossa lesions such as tumors, strokes, and abscesses. In addition, patients with demyelinating diseases or brainstem encephalitis may have abnormalities detected with MRI.
• CT is generally more available emergently than MRI. CT can usually detect conditions that require immediate surgical intervention such as hydrocephalus, traumatic injury, and many mass lesions.
• Electrophysiologic studies — Electrophysiologic studies are rarely necessary for the evaluation of acute ataxia. In consultation with a pediatric neurologist, EEG is indicated for children who may be having seizures, as suggested by altered levels of consciousness and/or fluctuating clinical signs. EEG may also demonstrate nonspecific abnormalities that are clues to a metabolic etiology or toxic exposure. Although electrophysiologic studies are the most specific and sensitive tests for diagnosis of Guillain-Barré syndrome, they may not be helpful early in the disease

• 1.ataxia charts