1. VASCULAR - HEMORRHAGE IN THE GLOBUS PALLIDUS
A Sample Case: A right-handed 65 yr old man had suffered a stroke. Reduced pain and temperature sense as well as spasticity, weakness, and a positive Babinski were still present on his left side but all symptoms were gradually lessening by 2 yrs after the stroke. However, he gradually developed slow, involuntary movements of his hands and feet which were marked by severe hyperflexion and hyperextension which often left his hands fixed in bizarre poses for several seconds. His wife reported that the abnormal movements were not present when he was asleep.
His general physical exam was unremarkable including the CV system. The neurologic exam showed him to be alert and well oriented with respect to time and place. Cranial nerves were normal. The limbs were somewhat weaker on the left side with slightly brisker deep tendon reflexes. New findings included abnormal posturing and writhing movements at the joints of the hands and feet on the left. When seated and asked to hold the arms outstretched the left arm wandered about while the left leg did the same. The writhing interfered with voluntary movements and automatic movements such as his gait. There was no dysmetria or intention tremor on either side.
The left-sided hemiparesis of both limbs, and other symptoms of the upper motor neuron syndrome, is due to injury of corticospinal fibers on the right. It is probably not due to a cortical lesion since memory and mental status were always normal. Development of athetoid involuntary movements on the left after a period of time following the stroke suggests injury to the right globus pallidus and/or its efferent pathways, which may become evident upon resolution of the injury, i.e., swelling and edema, to the corticospinal fibers. Since the globus pallidus influences the ipsilateral thalamus and motor cortex the symptoms appear on the opposite side due to the crossing of pyramidal tract, though which the influence of the basal ganglia is expressed.
Sudden onset, suggests a cerebrovascular event rather than a space taking tumor or degenerative process. Weakness and athetoid movements also are suggestive of a small localized lesion in the vicinity of the globus pallidus and internal capsule. The vessels which supply the globus pallidus and the adjacent posterior limb of the internal capsule are the lateral striate branches of the middle cerebral artery.