What question did this study set out to answer?

To explore the role of the pre-Supplementary Motor Area in recovery from verbal fluency deficits following cerebellar stroke.

April 5, 2026

Compensatory Augmentation in the Pre-Supplementary Motor Area Mediates Aspects of Verbal Fluency Recovery Following Cerebellar Stroke: A Multimodal SPECT and f-NIRS Pilot Study

Key Points

To explore the role of the pre-Supplementary Motor Area in recovery from verbal fluency deficits following cerebellar stroke.
Utilized multimodal SPECT imaging to evaluate brain perfusion.
Employed f-NIRS to measure oxygenated hemoglobin in the pre-SMA during verbal fluency tasks.
Stratified patients into Good and Poor recovery subgroups based on verbal fluency performance.
Tracked longitudinal changes in neural activity and cognitive recovery.
SPECT imaging showed widespread perfusion abnormalities consistent with diaschisis.
Patients had significantly impaired verbal fluency compared to controls.
The Good Recovery subgroup demonstrated significantly increased oxygenated hemoglobin in the pre-SMA.
Longitudinal data indicated reduced pre-SMA activity correlating with cognitive recovery.

Abstract

BackgroundCerebellar lesions commonly induce executive dysfunction; however, the underlying neuroplastic mechanisms remain unclear. The fronto-cerebellar diaschisis model, where focal cerebellar damage disrupts widespread frontal networks, offers a compelling hypothesis. Given the pre-supplementary motor area (pre-SMA)'s established role in executive functions, we investigated its specific contribution to post-stroke impairment and its potential function as a dynamic compensatory node during recovery.MethodsWe employed a multimodal approach: resting-state SPECT imaging assessed brain perfusion, and f-NIRS quantified pre-SMA oxygenated hemoglobin (oxy-Hb) during a phonemic verbal fluency task (VFT) in 11 patients and 12 age-matched controls. Patients were stratified into Good (N = 6) and Poor (N = 5) recovery subgroups based on VFT performance to isolate the compensatory process. Longitudinal f-NIRS data tracked neural activity changes concurrent with cognitive recovery.ResultsSPECT revealed widespread perfusion abnormalities consistent with diaschisis. Patients exhibited significantly impaired VFT performance. Crucially, the Good Recovery subgroup exhibited a significantly augmented oxy-Hb response in the pre-SMA compared to controls, supporting a specific compensatory mechanism. This pre-SMA augmentation was statistically independent of the strong confounding effect of age (F(1,15) = 5.164, P = 0.038). Consistent with a transient compensatory effort, longitudinal data demonstrated a reduction in pre-SMA activity concurrent with subsequent cognitive recovery, suggesting increased neural efficiency.ConclusionsThis study provides preliminary evidence that verbal fluency deficits post-cerebellar stroke are linked to fronto-cerebellar diaschisis. Our findings suggests that the pre-SMA serve as a pivotal compensatory node supporting functional recovery. These results provide a hypothesis-generating basis for future targeted rehabilitation strategies and neuromodulatory interventions.

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Cite This Study

Shigeru Obayashi (Fri,) studied this question.

synapsesocial.com/papers/69d1fc8ea79560c99a0a22cd https://doi.org/https://doi.org/10.1177/10538135261434250

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