The impact of initial vascular morphology on outcomes in patients with intracranial vertebral artery dissection presenting with isolated headache.

Objective: The prognosis of isolated headache intracranial vertebral artery dissection (iVAD) without subarachnoid hemorrhage (SAH) or stroke is unknown. The authors of this study aimed to evaluate isolated headache iVAD prognosis.

Methods: This is a single-center retrospective study of consecutive patients who presented with headache as their main complaint and underwent MRI between November 2016 and August 2022; those with acute isolated headache iVAD who were followed up for vascular morphological stability were eligible for study inclusion. The patients were divided into three groups based on the vascular morphology at initial diagnosis: aneurysm dilatation without stenosis (group 1), aneurysm dilatation with stenosis (group 2), and no aneurysm dilatation (group 3). Prognosis, time to radiological stability, and final vascular morphology were compared among the groups.

Results: One hundred five patients with isolated headache iVAD were included in the study. During a median follow-up of 478 (IQR 143-1094) days, none of the patients developed SAH or stroke, but 3/41 (7%) patients in group 1 underwent endovascular intervention for aneurysm enlargement. Patients in group 1 required significantly more long-term follow-up for morphological stability (p = 0.013), primarily due to aneurysm enlargement (p < 0.001), and were more likely to require surgical intervention (p = 0.043) than those in the other two groups. Residual aneurysm risk was significantly associated with initial vascular morphology in group 1 (OR 7.28, 95% CI 2.30-23.1, p < 0.001).

Conclusions: Most patients with isolated headache iVAD had a favorable prognosis. However, patients with aneurysm dilatation without stenosis required the most careful follow-up, as this group had the highest aneurysm enlargement risk from early disease onset through the chronic phase. In such cases, patients may require surgical intervention to prevent critical conditions.