Pediatric emergency medicine trisk 0409 0409

ADEM is an immune-mediated demyelinating condition, generally
monophasic, which often occurs postinfectiously, predominantly in school-age
children. It is usually associated with focal neurologic deficits, often including
ataxia and various degrees of encephalopathy, but also cranial nerve
abnormalities, pyramidal signs, and speech impairment. Maximal severity is
usually observed within 2 to 5 days from onset of symptoms. MRI usually shows
reversible, ill-defined white matter lesions with frequent involvement of brain
(including cortical and subcortical structures such as thalami and basal ganglia)
and spinal cord. CSF often shows lymphocytic pleocytosis and increased protein.
Acute cerebellitis is defined as an acute cerebellar syndrome usually in the
context of a nonspecific recent infection, accompanied by altered mental status
and cerebellar edema on brain imaging.
TABLE 15.1
COMMON CAUSES OF ACUTE ATAXIA
Acute cerebellar ataxia
Drug ingestion
Guillain–Barré syndrome a
a Indicates

weakness or vertigo that may mimic ataxia.

Toxic ingestions (Table 15.3 ) are a common problem in the pediatric
population, and should always be considered among other medical etiologies. A
detailed history including available drugs in the child’s home, or the home of any
caregivers, can be critical in making this diagnosis. Benzodiazepines cause
lethargy, altered mental status, and ataxia. Antiepileptic drugs (AEDs),
particularly phenytoin and carbamazepine, are also causes of ataxia in the
pediatric population. Ingestions of these medications can often present with
nystagmus with ataxia. Dextromethorphan, a primary ingredient in many overthe-counter cough suppressants, is also an important drug to consider in an ataxic
patient. At lower doses, this can cause euphoria, which leads to its abuse,
particularly among adolescents; however, in higher doses it can cause ataxia.

Ethanol is a common substance of abuse among adolescents, but must also be
considered in younger children as ethanol is prevalent in many homes in the form
of beverages, cough syrups, and mouthwash and can lead to ataxia from
cerebellar dysfunction. Marijuana and synthetic cannabinoids are other common
substances of abuse that can lead to ataxia along with their myriad of symptoms,
and should be considered in a patient presenting with associated tachycardia or