[Clinical manifestation of small thalamic hemorrhage]

CT scan is useful for the simultaneous evaluation of the relation between the thalamic lesions and the clinical manifestations. According to CT findings, twenty-three patients with thalamic hemorrhage measuring less than 2 cm in size could be classified into 4 groups: 1) anterior group--hematoma located in the anterior nuclear group, 2) medial group--hematoma located in the medial nuclear group, 3) lateral group--hematoma located in the lateral nuclear group close to the internal capsule, 4) posterior group--hematoma located in the pulvinar. The clinical manifestations of both the anterior and medial groups were characterized by the disturbance of consciousness followed by the mental impairment; the lateral group, by the hemiparesis or hemiplegia with the sensory disturbance, and the posterior group, especially with left thalamic lesions, by the speech disturbance. The motor palsy in cases of thalamic hemorrhage differed from that of putaminal hemorrhage: the patients with thalamic hemorrhage could move their fingers despite being unable to move their shoulders and elbows, or the motor weakness was more severe in their lower extremities than in their upper ones. As the sensory disturbance, the sensory impairment (hypesthesia) was frequently associated with the numbness (dysesthesia). The prognosis of motor palsy, ocular manifestations, and speech disturbance was good, whereas that of sensory and mental disturbance was not always good.