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

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