Degeneration of the Inferior Cerebellar Peduncle After Middle Cerebral Artery Stroke

Abstract

Background and Purpose— Deafferentation of the cortico-ponto-cerebellar pathway has been proposed as a key mechanism of crossed cerebellar diaschisis. Although the cerebellum receives afferent stimuli from both cortico-ponto-cerebellar and spinocerebellar pathways, evidence on whether spinocerebellar deafferentation contributes to a hypofunctional cerebellum is lacking. Therefore, we aimed to determine whether changes in the spinocerebellar pathway occur after middle cerebral artery stroke. Methods— Twenty-three patients admitted to our inpatient rehabilitation facility and 23 age-matched healthy controls were retrospectively enrolled. Patients’ functional ambulation category was determined and the Medical Research Council muscle scale test of the lower limb muscles was performed at admission and discharge. The fractional anisotropy (FA) values of the corticospinal tract and the inferior cerebellar peduncle (ICP), as the final route of the dorsal spinocerebellar pathway, were compared between the groups. The FA laterality indices of the ICP and corticospinal tract were calculated as follows: (FA affected −FA unaffected )/(FA affected +FA unaffected ). Pearson correlation analysis and multivariate linear regression models were used to determine the associations between the FA laterality indices and ambulatory function. Results— The FAs of the corticospinal tract and ICP were lower in the patient group than in the control group. The FA laterality index of the corticospinal tract was not correlated with the functional ambulation category or Medical Research Council muscle scale score at admission or discharge. The FA laterality index of the ICP at the pontomedullary junction was positively correlated with the functional ambulation category and Medical Research Council muscle scale scores of all hemiplegic lower limb muscles at admission and discharge. The FA laterality index of the ICP at the pontomedullary junction was independently associated with the functional ambulation category according to the multivariate regression models. Conclusions— ICP degeneration occurs in the subacute and early chronic phase of middle cerebral artery stroke. The lower FA laterality index of the ICP was indicative of poorer ambulatory and lower limb function.

Longitudinal changes in the inferior cerebellar peduncle and lower limb motor recovery following subcortical infarction

“…Our nding of decreased FA and increased MD in the contralesional ICP seems inconsistent with the structural changes in this area in subacute supratentorial stroke patients. Kim et al [6] found a marked FA reduction and MD increase in the contralesional ICP at 27 days after stroke in the patient group compared with the control group. This discrepancy in results may be due to experimental design differences.…”

“…Based on the ndings of previous studies, our result that lower limb motor function was also associated with ICP integrity is noteworthy. Kim et al [6] considered that insu cient peripheral proprioceptive stimulation to the cerebellum from a weak lower limb may result in secondary degeneration in the contralesional spinocerebellar pathway, but they could not fully determine whether FA reduction in the contralesional ICP was affected by hemiplegic muscles, a hypofunctional cerebellum, or both due to the retrospective and cross-sectional design of their study. We found that ALFF in the contralesional anterior lobe of the cerebellum reduced sharply at week 4 but increased somewhat at week 12 after onset.…”

“…Recently, Kim et al [6] found a secondary degeneration characterized by reduced fractional anisotropy (FA) and elevated mean diffusivity (MD) in the contralesional ICP in 23 patients with subacute middle cerebral artery (MCA) stroke, a change associated with patients' ambulatory and lower limb function.…”

Persistence of Glenohumeral Subluxation is Correlated with Prolonged Existence of Crossed Cerebellar Diaschisis in a Hemiplegic Stroke Survivor: A Pilot Study

“…For two decades, various methods have been used to study the impact of CCD on stroke-related symptoms like postural asymmetry [1]. It is generally believed that CCD is caused by an interruption of either the cortico-ponto-cerebellar pathway or the dentate-rubro-thalamo-cortical pathway [11,12]. However, no study has been done to explore the close relationship between GHS and CCD.…”

Longitudinal changes in the inferior cerebellar peduncle and lower limb motor recovery following subcortical infarction

“…Recently, Kim et al [ 6 ] found a secondary degeneration characterized by reduced fractional anisotropy (FA) and elevated mean diffusivity (MD) in the contralesional ICP in 23 patients with subacute middle cerebral artery (MCA) stroke, a change associated with patients’ ambulatory and lower limb (LL) function. They believed that insufficient peripheral proprioceptive stimulation to the cerebellum due to LL weakness might result in secondary changes in the spinocerebellar pathway, but they could not fully determine whether FA reduction in the contralesional ICP was affected by hemiplegic muscles, a hypofunctional cerebellum, or both, due to the retrospective and cross-sectional design of their study.…”