Correlation between Mirror Movements and Recovery of Motor Power in Stroke Patients

Park, Ki Jong; Choi, Nack Cheon; Kim, Nam Gon; Yun, Hae Jeong; Hong, Joon Gy; Kwon, Oh Young; Lim, Byeong Hoon

Abstract

BACKGROUND: Mirror movement is common in young children, and it could be seen in normal adults. Several mechanisms including motor pathway reorganization involved in motor recovery after stroke. Motor pathway reorganization has been reported to be a mechanism in several studies of patients with mirror movement. However, the correlation of motor recovery and mirror movement has been debated. We studied the degree of mirror movement in stroke patients compared with a controlled group to look into their relationship.
METHODS
Our controls were 50 adults without neurologic symptoms and signs. The hemiparetic group was comprised 94 patients who had incurred unilateral brain lesion: 36 patients were acute stroke patients, 58 patients were chronic stroke patients. Mirror movements were assessed by three different tasks: abduction of thumb, sequential finger tapping, and grasping. We analyzed mirror movements in controls and patients, and tried to find a correlation between the degree of mirror movement and the recovery of motor power in chronic stroke patients.
RESULTS
In controls, male exhibited more frequent mirror movement than female at specific tasks, and there was no difference between tasks of right or left hand. In stroke patients, there was more mirror movement in the nonparetic hand than in the paretic one during the movement of contralateral hand. In acute stroke, the frequency of mirror movement had no variability according to the degree of motor power. The recovery of motor power at a late stage was not correlated with the degree of mirror movement. Consclusions: Motor pathway reorganization seems to be insignificant for motor recovery because the degree of mirror movement was not correlated with the recovery of motor power in this study.