Age: 0.6
Sex: F
Vaccine: DTP
Symptoms: Aphasia, Ataxia, Cerebral atrophy, Childhood disintegrative disorder, Computerised tomogram head normal
Clinical narrative: Initial case retrieved via a search of the scientific literature on 28 April 2014. A seven-month old female patient, with no reported medical history, received her third dose of DPT (manufacturer and lot not reported) on an unspecified date. The patient was born full-term, weighing 6 pounds 9 ounces via spontaneous vaginal delivery without complication; APGAR scores were 10, and initial milestones were achieved as expected. Family history was significant for a brother who experienced a febrile seizure at 15 months. Nine hours after vaccination, she developed a fever of 40 degrees Celsius and experienced a generalized tonic-clonic seizure lasting three minutes. It recurred again shortly afterwards and continued for another hour before being treated in the emergency department with diazepam. Workup for systemic and central nervous system infections was negative, and CT of the brain showed no structural abnormalities. The patient returned to baseline within eight hours, and an EEG the following morning showed no abnormalities. At nine months of age, the patient developed a flu-like illness and became febrile to 39.4 degrees Celsius, subsequently suffering another generalized tonic-clonic seizure lasting approximately 10 minutes. Over the next few months she began developing subtle myoclonic jerks with prolonged one to three minute trance-like spells; at the same time, her developmental milestones began to lag, and did not begin cruising until 14 months. Over the next few years she was diagnosed with atypical absence seizures and hemiclonic seizures not controlled with multiple medications, at the rate of three to six seizures per month. By age five she suffered from mild ataxia, was unable to run or jump well, and had limited speech output. An EEG at that time showed slowing of the background with a posterior dominant rhythm of 6 Hz and frequent generalized spike-wave and polyspike-wave activity. At seven years of age she experienced an episode of status epilepticus lasting 1.5 hours, after which her seizure activity increased to almost daily, at times up to 15 episodes per day. Despite treatment with a ketogenic diet and multiple AED combinations she continued to experience seizure activity at nearly the same frequency, and frequent seizure activity was noted on EEG monitoring. By age 15, at the time the reporter examined her, she was wheelchair bound, had severe ataxia of all limbs, moderate spasticity, and hyperreflexia with no language output. Brain MRI showed diffuse atrophy and scattered white matter lesions. EEG showed continued background slowing with a posterior dominant rhythm of 7.5 Hz and frequent epileptiform interictal discharges. Treatment included levetiracetam, felbamate, and midazolam nasal spray. According to the reporter, the clinical presentation of status epilepticus during a febrile condition, and subsequent development of refractory epilepsy, was in keeping with severe myoclonic epilepsy of infancy (SMEI, or Dravet syndrome). The syndrome is also associated with genetic defects of SCN1A; testing of this patient revealed a new mutation of the SCN1A gene that was not yet well-characterized. The event remained ongoing. Documents held by sender: None.