The Mechanism of Ipsilateral Ataxia in Lacunar Hemiparesis: SPECT Perfusion Imaging

Abstract

Background and Purpose: Although ataxic hemiparesis is a common lacunar syndrome, the precise mechanism underlying hemiataxia is not clear. We attempted to identify ataxia-related, cerebral blood flow changes in patients presenting with ataxic hemiparesis after acute capsular infarct. Methods: We used 99mTc-ECD brain perfusion single-photon emission computed tomography to evaluate regional cerebral blood flow in 12 patients with ataxic hemiparesis caused by capsular infarct, and we compared the regional blood flow of these patients with that of 11 patients with pure motor hemiparesis caused by similar lesions. Results: The ipsilateral red nucleus blood flow was significantly decreased in the ataxic hemiparesis patients, whereas the ipsilateral red nucleus blood flow was increased in the pure motor hemiparesis patients. Crossed cerebellar diaschisis (decreased contralateral cerebellar blood flow) was seen in ataxic hemiparesis patients; similarly, it was seen in pure motor hemiparesis patients. Conclusions: Our findings suggest that ataxia in hemiparetic patients with capsular infarct can be caused by ipsilateral red nucleus dysfunction secondary to cortico-rubral pathway disruption at the internal capsule. i 2014 S. Karger AG, Basel

Possible association of crossed cerebellar diaschisis with cerebellar ataxia in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy

“…Taken together, the cerebellar dysfunction of our patient might have resulted from the disruption of both CPC and/or CTC pathways caused by the white matter lesions and lacunar lesions in the periventricular areas, basal ganglia, or pons. However, CCD was found not only in ataxic hemiparesis patients caused by lacunar infarctions but also in pure motor hemiparesis patients, 9 implying that CCD is not necessarily associated with the development of ataxia. Anyway, since cerebellar signs are likely to be masked by pyramidal signs or frontal dysfunction caused by subcortical infarction, physicians need to be alert to them.…”

Advances in differential diagnosis of cerebrovascular diseases in magnetic resonance imaging: a narrative review

“…It often shows central low-signalintensity lesions in internal capsule in T2/FLAIR image alongside multiple small hyperintensity lesions in both cerebral hemispheres (Figure 4F). It can be caused by many different factors including ischemic stroke, mutations in POLR3A characterized by high phenotypic heterogeneity including central hypomyelination in MRI (122,136).…”

Ataxic Hemiparesis

“…In addition, AH has been reported following basis pontine infarction and CCD (Sakai et al 1986), as well as with CCD due to Creutzfeldt-Jakob disease (Kastenbauer et al 2001). Recently, a study of capsular infarction showed that CCD was seen not only in AH but also in pure motor monoparesis, suggesting that it is not specifically associated with ataxia (Yamamoto et al 2015). This study showed blood flow in the ipsilateral red nucleus was decreased in AH, indicating that AH with capsular infarction can be caused by ipsilateral red nucleus dysfunction secondary to disruption of the cortico-rubral pathway at the internal capsule.…”