Case report: Moyamoya disease, the culprit in an adult female presenting with left sided numbness.

Rationale: Moyamoya disease is a rare progressive cerebrovascular disease that is characterized by stenosis of the vascular branches of the internal carotid artery and the development of abnormal, fragile collateral vessels. Patients with Moyamoya disease mainly present with signs and symptoms of cerebral ischemia or cerebral hemorrhage with a typically progressive course.

Patient Concerns: Here, we present a case of an adult female presenting with left sided upper and lower limb numbness.

Diagnoses: Diagnosis is through cerebral angiographic images demonstrating the characteristic look of collateral vessels classically present in Moyamoya disease. In this case, initial angiographic imaging along with high-resolution vessel wall brain magnetic imaging were used to diagnose the patient with this disease.

Interventions: The patient was advised for surgical intervention; however, they were reluctant.

Outcomes: The patient was treated conservatively and advised for follow-up.

Lessons: This case highlights the importance of considering Moyamoya disease in the differential diagnosis of patients presenting with sudden neurological symptoms. High-resolution vessel wall MRI is a useful tool to diagnose this disease.