Anterior Cerebral Artery Strokes with Isolated Supplementary Motor Area Involvement Presenting with Fluctuating Deficits

Abstract

Background

Strokes involving the anterior cerebral artery (ACA) are known for lower limb predominant weakness and features like motor neglect and alien hand syndrome. While fluctuating neurological deficits are common in middle cerebral artery strokes, they are less reported in ACA territory strokes. This case series presents three patients with waxing and waning weakness in ACA infarcts involving the supplementary motor area (SMA).

Methods

Three patients with isolated medial parasagittal infarcts involving SMA were included in the study between 2019 and 2024. Clinical assessments, including blood pressure monitoring, imaging (computerised tomography and magnetic resonance imaging), risk factor evaluation and cardiac workup, were done. The fluctuating symptoms were recorded, and no major post-stroke complications were observed.

Results

All patients exhibited fluctuating neurological deficits, defined as changes in the National Institutes of Health Stroke Scale score ≥2, with episodes of improvement and worsening before eventual recovery. The infarcts localised to the SMA, suggesting a unique mechanism being involved, similar to the SMA syndrome. This pattern has been termed ‘pendular stroke’, reflecting the oscillating nature of the deficits.

Conclusions

The fluctuating course observed in these ACA strokes may represent a form of SMA syndrome. Recognising this pattern as ‘pendular stroke’ can guide clinicians to make informed management decisions and avoid unnecessary interventions for transient worsening of symptoms.