Prediction of Early Motor Recovery in Patients with Thalamic Hemorrhage by Using Somatosensory Evoked Magnetic Fields

Abstract

The purpose of this study was to investigate the relationship between acute somatosensory evoked magnetic fields (SEFs) and early motor recovery in patients with thalamic hemorrhage. Nine patients with thalamic hemorrhage were participated in this study. SEFs. evoked by the electrical stimulation to right and left lower lip, thumb, median nerve, ulnar nerve and posterior tibial nerve, were measured within 72 hours after the onset of thalamic hemorrhage (acute stage). As neurological examinations, the motor paresis of the affected upper extremity (UE), fingers and lower extremity (LE) based on Ueda's 12 grades evaluating method and sensory functions, i.e. two-point discrimination sense, touch sense and joint position sense of affected side, were assessed both at acute stage and one month after the onset of thalamic hemorrhage (subacute stage). Majority of patients who had shown acute median, ulnar and posterior tibial nerve SEFs findings in the affected hemisphere demonstrated good motor recovery of the affected UE, fingers and LE at subacute stage. In contrast, majority of patients who had not shown the acute SEFs findings in the affected hemisphere demonstrated poor motor recovery of all the parts at subacute stage. The similar relationship between the acute SEFs and the motor recovery was also found between the acute SEFs and the sensory function recovery at subacute stage. These results suggest that acute median, ulnar and posterior tibial nerve SEFs findings from the affected hemisphere might indicate not only sensory functions but also the function of corticospinal tract and contribute to the prediction of motor recovery approximately one month after the onset of thalamic hemorrhage.