Isolated hypoglossal nerve palsy from carotid dissection shows 65.6% favorable outcomes with medical management in 87 adult patientsEarly imaging helps diagnose hypoglossal nerve palsy from carotid artery dissection

BackgroundHypoglossal nerve palsy (HNP) secondary to extracranial internal carotid artery dissection (ICAD) is a rare but clinically important condition that may be overlooked, particularly in the absence of ischemic lesions on brain imaging. We aimed to systematically characterize its clinical features, diagnostic patterns, treatment strategies, and outcomes.MethodsA systematic review was conducted in accordance with PRISMA 2020 guidelines and registered in PROSPERO (CRD420251141162). PubMed, Scopus, Web of Science, and Embase were searched without language or date restrictions. Studies reporting adult patients with HNP attributable to ICAD were included. Clinical data, imaging findings, treatment modalities, and outcomes were extracted and analyzed descriptively and exploratorily.ResultsA total of 73 studies comprising 87 patients were included. The mean age was 48.5 years, and 86.2% were male. Isolated HNP was observed in 64.3% of cases, and diagnostic error occurred in 31.0%, frequently leading to delayed management. Most patients were managed medically (89.7%), and overall favorable outcomes were achieved in 65.6% of patients. Surgical or endovascular treatment was performed in a minority of cases (10.3%). The presence of pseudoaneurysm was significantly associated with increased likelihood of surgical or endovascular treatment (p = 0.007) and shorter follow-up duration (p = 0.015), although overall outcomes did not differ between groups.ConclusionExtracranial ICAD presenting as HNP is an uncommon but clinically important condition with a substantial risk of diagnostic delay. Early vascular imaging should be considered in patients with isolated or atypical hypoglossal nerve palsy, even in the absence of ischemic lesions on brain MRI. Most patients achieve favorable outcomes with medical therapy; however, selected patients—particularly those with pseudoaneurysm or persistent or progressive symptoms—may require surgical or endovascular intervention. Further large-scale studies are needed to refine patient selection and optimize management strategies.Systematic review registrationhttps://www.crd.york.ac.uk/PROSPERO/view/CRD420251141162, identifier (CRD420251141162).