Mid-gestation right basal ganglia lesion: clinical observations in two children.

OBJECTIVE

To describe the neurobehavioral syndrome in two children with destruction of the right basal ganglia ostensibly from amniocentesis needle penetration at 17 weeks of gestation.

BACKGROUND

Early-life unilateral lesions of the basal ganglia are rare and the resulting syndrome not described.

METHODS

Both children had repeated clinical assessments, MRI and (18)F-fluorodeoxyglucose PET scans, and psychometric and achievement testing over 10 years.

RESULTS

Right basal ganglia destruction was similar and virtually coextensive in both children; optic nerve and oculomotor dysfunction were disparate. One had a right temporal pole porencephalic cyst with anomalous overlying cortex. The clinical syndrome included left hemiparesis with distal spasticity and without hypotrophy; extraocular movement disorders; severe episodic disinhibition, impulsiveness, hitting reflexively, and extreme emotional lability. Outbursts of screaming and cursing resembled "sham rage." Both had mild intellectual retardation with competent language but poor nonverbal and visual-spatial abilities, visual memory, and daily living and socialization skills.

CONCLUSIONS

The shared behavioral and cognitive syndrome is most reasonably attributed to the right basal ganglia lesions, which were complete and coextensive in both, whereas other lesions were partial, milder, and disparate. Early destruction of the right basal ganglia may preclude normal development of right hemisphere functions without evidence of plasticity and appears associated with intense disinhibition and impulsiveness of aggressive attack activities and with general lability and dyscontrol of emotion.