Neurological Side-Effects in a Series of Operations on the Basal Ganglia

Hemiballismus Complicating Stereotactic Thalamotomy

“…The incidence of this complication, however, is higher when the lesions are placed below the intercommissural line [4,16] and in the anterolateral subthalamus [2], It has been noted also that hyperki nesis occurs more frequently after bilateral thalamic surgery [12] and may involve the limbs ipsilateral to the cerebral lesion after unilateral [5] or bilateral operation [8,30]. It may also be significant that hemiballismus has never been reported to complicate surgery for dyskinesias of nonpar kinsonian origin.…”

“…Anatomical studies so far have failed to demonstrate any constant re lationship between a focal cerebral lesion and the development of hemiballismus which paradoxically can be produced and abolished by almost identical lesions [7], Reconstruction of stereotactic lesions [4] revealed little difference between lesions causing ballismus and those resulting in no side effects. The incidence of this complication, however, is higher when the lesions are placed below the intercommissural line [4,16] and in the anterolateral subthalamus [2], It has been noted also that hyperki nesis occurs more frequently after bilateral thalamic surgery [12] and may involve the limbs ipsilateral to the cerebral lesion after unilateral [5] or bilateral operation [8,30].…”

“…When a history of encephalitis was present the incidence of hemiballismus rose to 6.7°/o, compared to an incidence of 1.2°/o in patients without such history. According to Bravo et al [4], the duration of the parkinsonism and the age of the patient were important factors in determining the appearance of hemiballismus. The average age of patients with hemiballismus was 30.5 years and 48 years for the idi opathic group.…”

Surgery for Bilateral Parkinson's Disease

“…The variations of the lesions within this general area have been presented in a previous paper [3]. Change in size and site of the lesions was more common in the early part of the series, when the lesion was inflicted by means of alcohol injection and when the lesion was progressively enlarged until the desired effect had been obtained.…”

“…It was common at that time to find that, as the lesion was enlarged, it was doing so mostly in a caudal direction, due to necrosis at the bottom of the cavity where the alcohol was injected. Some of the effects of the lesions extending 5-6 millimeters below the AC-PC line have been discussed in two previous papers [2,3].…”