This is a nearly 3 -year-old boy who was completely well until 6 months ago when he experienced two brief (<2 minute) generalized convulsions 1 month apart, both associated with fever Although these were diagnosed as simple febrile seizures, he was referred to a pediatric neurologist who ordered a routine 1 5T brain magnetic resonance imaging (MRI) scan . This study was interpreted as normal . However, the outpatient electroencephalogram (EEG) study revealed generalized background slowing and generalized atypical spike-wave discharges occurring at a frequency of 2 .0-2 .5Hz (See Figure 25. 1). A follow-up 24-hour video-EEG study captured multiple generalized myoclonic and tonic seizures, both associated with generalized spike-wave discharges, followed by voltage suppression No focal or lateralizing features were noted This patient was placed on valproic acid monotherapy. Despite serum levels (in the 100-120 range), he continued to have frequent seizures and then developed "drop" seizures that became progressively more frequent Further medication trials with topiramate, zonisamide, levetiracetam, and clonazepam were unsuccessful, and he was ultimately placed on the ketogenic diet His generalized myoclonic seizures improved substantially, but he was still experiencing several drop seizures per day Notably, his speech and attention became slowly impaired, and he developed difficulty walking, with mild ataxia A high-resolution (3T) brain MRI was interpreted as normal, and a comprehensive metabolic/genetic workup
FIGuRE 25.1 Generalized 2-2 . 5 Hz slow spike-wave complexes (solid arrow) and spikes lateralized to the left and right hemispheres (dashed and open arrow, respectively) .
(including genetic testing for severe myoclonic epilepsy of infancy) failed to reveal an etiology As his neurological condition steadily worsened, he underwent an anterior two-thirds corpus callosotomy as a palliative procedure, to which he responded favorably Although he experienced a transient left foot drop after surgery, his speech returned slowly (but not fully), and within a month he was able to put three words together again He was weaned off the ketogenic diet, and remained on a regimen of zonisamide and levetiracetam . His gait and ataxia improved, and he was having only 1-2 "drop" seizures per day, but none of the myoclonic or tonic seizures
Was this article helpful?