Essential heredofamilial tremor, commonly known as intention tremor, is a poorly understood disease. Although it has been attributed to cerebellar lesions, its pathogenesis has not been fully elucidated, and severe cases of long standing have been considered intractable to all forms of therapy. This paper reports 3 cases which show that chemothalamectomy in the region of the lateral ventral and posteroventrolateral nuclei can abolish this type of tremor. In addition it may throw some light on the pathophysiology underlying the syndrome.
Intention tremor is similar to the tremor characteristic of cerebellar disease and also in many respects resembles that which occurs in multiple sclerosis. It appears or is augmented during voluntary movement and usually affects primarily the upper extremities. Usually the first manifestation is in the distal portion of the extremities, and tremor later involves the entire extremities and later the head. Occasionally, however, head tremor is the first symptom