Violent recurrent ballism associated with infections in two children with static encephalopathy

A variety of cerebral insults can result in static encephalopathy with developmental delays and relatively fixed motor and cognitive deficits. We describe two boys with static encephalopathy who experienced recurrent episodes of generalized, violent ballism seemingly provoked by relatively minor infectious illnesses or surgical procedures. These episodes first began at ages 14 and 9 years, respectively. The baseline clinical states included relatively mild choreoathetosis plus cognitive impairment, as well as spasticity and/or ataxia. These episodes of ballism developed over hours, remained for weeks, and ultimately returned to baseline. Neuroleptics, anticonvulsants, and benzodiazepines were only partially beneficial; responses corresponded to the degree of sedation. Potential for self-injury or rhabdomyolysis/myoglobinuria led to the use of general anesthetics or neuromuscular blocking agents during selected episodes. Blood, urine, and cerebrospinal fluid studies, magnetic resonance imaging head scans, and electroencephalography revealed no diagnostic clues as to the precise causative factor precipitating these episodes.