ABSTRACT
Case Presentation ................................................................................................... 133 Differential Diagnosis ............................................................................................ 134 Diagnostic Approach ............................................................................................. 136 Treatment Strategy ................................................................................................. 137 Long-Term Outcome .............................................................................................. 138 Pathophysiology/Neurobiology .............................................................................. 138 Clinical Pearls ........................................................................................................ 139 Suggested Reading ................................................................................................. 139
The patient is an 11-year-old ambidextrous female with symptomatic intractable epilepsy who was referred for evaluation and treatment. At three years of age, she developed a fever, became confused, and within 2-3 hours began having persistent right hemibody myoclonic/clonic activity. She was admitted to an intensive care unit, and multiple antiepileptic drugs were required to fully control her seizures. Cerebrospinal uid studies were positive for herpes simplex virus (HSV). Her initial EEG showed bilateral, independent, temporal, periodic epileptiform discharges (see Figure 17.1), and her initial neuroimaging studies revealed bilateral temporal edema. Though she was aggressively treated with acyclovir, the encephalitis caused signicant impairment in (primarily short-term) memory, receptive and expressive language function (less than 15 words spoken intelligibly), and intractable epilepsy. However, she remembers individuals’ names and several events prior to her neurological insult. Her present seizure semiology consists of predominantly generalized myoclonic and tonic events, with a frequency of 10-25 seizures per week. Prior medications include topiramate, phenobarbital, valproic acid (which caused hyperalbuminemia), oxcarbazepine, and phenytoin. A vagus nerve stimulator (VNS) was placed at the age of 9 years, but this was also unsuccessful in controlling her seizures. Her present antiepileptic medications include lamotrigine, felbamate, and zonisamide. A recent videoEEG study revealed interictal generalized and independent left and right
Viral encephalitis is one of the most common causes of symptomatic status epilepticus. HSV, affecting about 1 or 2 cases per 500,000 per year, is the most common cause of encephalitis in the United States. HSV acquired congenitally or in the
temporal epileptiform discharges (see Figure 17.2A). Two of ten seizures witnessed during monitoring were focal in onset, and these rapidly secondarily generalized. She also had generalized myoclonic/tonic events (see Figure 17.2B) that resembled exor spasms (with elevation and exion of both upper and lower extremities), and generalized myoclonic-astatic events during which she would fall forward. A brain MRI study revealed left temporal lobe encephalomalacia, as well as periventricular and subcortical white-matter signal hyperintensities; there was also widening of the sylvian ssure, and deepening and widening of sulci extending into the posterior portion of the left temporal lobe (see Figure 17.3). Neuropsychological testing revealed a functional level comparable to a 2-to 3-year-old child, and signicant short-term memory decits. After reviewing the results, a complete corpus callosotomy was recommended. At the 6-month follow-up visit, her mother described ve brief (<1 minute) seizures, three of which involved right hemibody and two with left arm and face involvement. She has not had any generalized events nor has she fallen or injured herself since surgery.
