Functional recovery and rehabilitation of postural impairment and gait ataxia in patients with acute cerebellar stroke.

Studies about recovery from cerebellar stroke are rare. The present study assessed motor deficits in the acute phase after isolated cerebellar stroke focusing on postural impairment and gait ataxia and outlines the role of lesion site on motor outcome, the course of recovery and the effect of treadmill training. 23 patients with acute and isolated cerebellar infarction participated. Deficits were quantified by ataxia scores and dynamic posturography in the acute phase and in a follow up after 2 weeks and 3 months. MRI data were obtained to correlate lesion site with motor performance. Half of the patients that gave informed consent and walked independently underwent a 2-week treadmill training with increasing velocity. In the acute phase patients showed a mild to severe ataxia with a worse performance in patients with infarction of the superior in comparison to the posterior inferior cerebellar artery. However, after 3 months differences between vascular territories were no longer significant. MRI data showed that patients with larger infarct volumes had a significantly more severe ataxia. In patients with ataxia of stance, gait and lower limbs lesions were more common in cerebellar lobules IV to VI. After 3 months a mild ataxia in lower limbs and gait, especially in gait speed persisted. Because postural impairment had fully recovered, remaining gait ataxia was likely related to incoordination of lower limbs. Treadmill training did not show significant effects. Future studies are needed to investigate whether intensive coordinative training is of benefit in patients with cerebellar stroke.

Brain changes associated with postural training in patients with cerebellar degeneration: a voxel-based morphometry study.

Recent research indicates that physiotherapy can improve motor performance of patients with cerebellar degeneration. Given the known contributions of the cerebellum to motor learning, it remains unclear whether such observable changes in performance are mediated by the cerebellum or cerebral brain areas involved in motor control and learning. The current study addressed this question by assessing the increase in gray matter volume due to sensorimotor training in cerebellar patients using voxel-based morphometry. Nineteen human subjects with pure cerebellar degeneration and matched healthy controls were trained for 2 weeks on a balance task. Postural and clinical assessments along with structural magnetic resonance imaging were performed pretraining and post-training. The main findings were as follows. First, training enhanced balance performance in cerebellar patients. Second, in contrast to controls patients revealed significantly more post-training gray matter volume in the dorsal premotor cortex. Third, training-related increase in gray matter volume was observed within the cerebellum and was more pronounced in controls than in patients. However, statistically cerebellar changes were at the trend level and thus require additional, independent confirmation. We conclude that sensorimotor training of patients with cerebellar neurodegeneration induces gray matter changes primarily within nonaffected neocortical regions of the cerebellar-cortical loop. Residual function of the cerebellum appears to be exploited suggesting either a recovery from degeneration or intact processes of cerebellar plasticity in the remaining healthy tissue.