To understand that cerebellar dysfunction may either induce or correct

stereotypy.

While stereotypy due to cerebellar hemorrhage has been

reported (Lee,2014), elimination of stereotypy as a result of cerebellar

hemorrhage has not heretofore been described.

A 67 year old right handed male, nine months prior to

presentation, fell sustaining left cerebellar hemispheric hemorrhage, requiring a

decompressive craniotomy. Since then he suffered from gain instability,

clumsiness of his left hand, change in cadence of speech, and dysarthria. He had

difficulty with fine motor movements of his left hand (eg: tying knots) which

gradually resolved along with the gait instability. Prior to the cerebellar

hemorrhage, he had frequent epochs of each hand rubbing the outer portion of

the ipsilateral thigh in a habitual fashion. These adventitious movements began in

childhood and would occur when he was distracted or concentrating on other

activities. After the cerebellar hemorrhage, the stereotypic movements of the left

hand, the side ipsilateral to the hemorrhage, totally resolved; the stereotypical

movements of the right hand persisted unabated.

Abnormalities in neurological examination: Cranial Nerve (CN) VII: left

central weakness. Motor examination: Tone: 1 plus cogwheel rigidity right upper

extremity. Drift testing: left abductor digiti minimi sign. Gait: unstable, wide

based. Tandem gait: unstable. Cerebellar examination: bilateral finger to nose

dysmetria, left more than right. Dysdiadochokinesia in the left upper extremity.

Holmes rebound phenomenon: positive on the left. Reflexes: 1 plus left triceps.

Quadriceps femoris bilaterally pendular, left more than right. Bilateral absent

ankle jerks. Bilateral Hoffman reflexes.

If the stereotypy was of basal ganglia or frontal lobe origin, the

elimination of facilitatory cerebellar input may act to paradoxically eliminate such

adventitious movements. In those who present with stereotypy, evaluation of

cerebellar pathways is warranted.