Recurrent Transient Paresthesias After Revascularization for Moyamoya Disease: Hemodynamic Diagnostic Challenges in a Patient With Post-radioiodine Hypothyroidism.

Moyamoya disease (MMD) is a chronic progressive cerebrovascular arteriopathy characterized by stenosis or occlusion of the terminal internal carotid arteries (ICAs) with compensatory collateral vessel formation. Although surgical revascularization reduces ischemic risk, recurrent neurologic symptoms may persist and can create a diagnostic challenge when structural imaging remains stable. We report the case of a 31-year-old Black woman with a prolonged course of MMD complicated by prior hemorrhagic and ischemic cerebrovascular events who continued to experience recurrent transient unilateral paresthesias after bilateral direct superficial temporal artery (STA)-middle cerebral artery (MCA) bypasses and subsequent indirect burr-hole revascularization. During the current presentation, she developed worsening left facial numbness, which was consistent with her established paresthesia pattern, and a severe headache without new focal deficits beyond baseline. Computed tomography angiography demonstrated unchanged chronic right-sided steno-occlusive disease with extensive collateralization and preserved distal flow, although diffusion-weighted MRI and dedicated perfusion imaging were not obtained during this encounter; prior MRI during similar episodes had shown no new infarction. Her course was further complicated by a history of post-radioiodine hypothyroidism with previously documented periods of thyroid instability, as well as inconsistent adherence to secondary prevention therapy and specialty follow-up. This case highlights a post-revascularization diagnostic problem: distinguishing recurrent hemodynamic, migrainous, and ischemic symptoms in collateral-dependent moyamoya circulation can be difficult when large vessel imaging is stable. This distinction could not be definitively resolved in the current case because diffusion-weighted MRI and perfusion imaging were not obtained during the acute episode. It emphasizes the importance of timeline-based diagnostic reasoning, cautious interpretation of adherence history, and individualized long-term surveillance after revascularization.