A reticulo-frontal disconnection syndrome.

Persistent executive deficit, usually seen following prefrontal damage, is reported in a patient recovering from head trauma. Repeated neuroradidological examinations failed to reveal a lesion within the frontal lobes, but a circumscribed lesion in the ventral mesencephalic tegmentum was found. It is proposed that the observed syndrome was caused by damage to mesencephalic reticular nuclei and their projections into prefrontal cortex. The concept of a "reticulo-frontal disconnection syndrome" is introduced and its possible role in head trauma and schizophrenia discussed.