Localization and Network Connectivity of Lesions Causing Limb Ataxia in Patients With Stroke
Oliver Liesmäki1, Jaakko Kungshamn1, Olli Likitalo1
1From the Turku Brain and Mind Center (O. Liesmäki, J.K., O. Likitalo, E.G.E., A.B.-G., J.A., I.S., E.M.M., P.Y., J.J.), Clinical Neurosciences, University of Turku; Neurocenter (O. Liesmäki, J.K., O. Likitalo, J.A., E.M.M., S.R., P.Y., J.J.), Turku University Hospital, Finland; Center for Brain Circuit Therapeutics (M.U.F.), Brigham & Women's Hospital, Boston, MA; and Department of Neurology (M.U.F.), University Hospital Wuerzburg, Germany.
Neurology
|August 29, 2024
Summary
Stroke-induced limb ataxia can stem from diverse brain lesion locations. These diverse lesions converge on a shared network, primarily involving the cerebellum and its peduncles, explaining the manifestation of ataxia.
Area of Science:
- Neuroscience
- Neurology
- Stroke Research
Background:
- Ataxia is typically linked to cerebellar dysfunction.
- However, ataxia can occur without apparent cerebellar damage, as seen in anterior circulation stroke.
- The underlying mechanisms of ataxia in such cases remain unclear.
Purpose of the Study:
- To investigate if stroke lesions causing limb ataxia share a common brain network.
- To identify the specific network involved in stroke-related limb ataxia.
Main Methods:
- A prospective cohort study of adult stroke patients with new-onset ataxia.
- Clinical assessments for limb ataxia at baseline and 4-month follow-up.
- Voxel-based lesion-symptom and lesion network mapping, comparing lesion locations and functional connectivity in patients with and without ataxia.
- Validation in an independent stroke patient cohort.
Main Results:
- Limb ataxia lesions were found in diverse locations, with 54% outside the cerebellum and cerebellar peduncles.
- No specific lesion location was directly associated with ataxia.
- However, lesions causing ataxia consistently connected to a common network centered on the intermediate zone of the cerebellum and cerebellar peduncles.
- This network association was confirmed in an independent cohort.
Conclusions:
- Stroke-related limb ataxia arises from lesions in various brain regions.
- These heterogeneous lesions converge on a specific, common brain network.
- This network localization explains the occurrence of ataxia even with non-cerebellar stroke damage.
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