Cerebrovascular involvement in Erdheim-Chester disease: a case report and systematic literature review.
BACKGROUND: Intracranial perivascular/vascular infiltrations and stenoses related to Erdheim-Chester disease (ECD), often associated with ischemic events, are rarely documented. This study aims to characterize intracranial perivascular/vascular infiltrations and stenoses. METHODS: We first report a new case of strokes revealing ECD with intracranial arterial involvement. We then searched all English- and French-language publications from database inception to November 2025 across 12 different search interfaces, including grey literature sources. Vascular involvement was defined by the presence of intracranial perivascular/vascular infiltrations and stenosis on imaging and/or histopathological evidence of small-vessel involvement. Cases with intracranial nodules or masses abutting vessels but without clear longitudinal perivascular infiltration were excluded. RESULTS: We present a case of recurrent strokes with intracranial vertebral and basilar artery wall stenosis, and aortitis. Initially diagnosed as giant cell arteritis, the patient was treated with corticosteroids, cyclophosphamide followed by methotrexate, but relapsed. The identification of tibial osteosclerosis led to the diagnosis of ECD, with a favorable response to anakinra. Twelve relevant articles were retrieved, in addition to our own case. Most patients exhibited focal cerebrovascular signs (11/13) and associated parenchymal involvement (11/13). Intracranial perivascular/vascular infiltrations and stenoses involved the carotid arteries (7/13), the vertebrobasilar arteries (1/13), or both territories (4/13). Aorta was involved in 8/12 cases. Among the nine patients with available follow-up data, five had poor overall or neurovascular outcomes. CONCLUSIONS: Intracranial perivascular/vascular infiltrations and stenoses, which leads to recurrent focal ischemic events, represents a likely underdiagnosed CNS pattern in ECD, referred to as "cerebrovascular ECD", which worsens overall prognosis. Vascular imaging should be included in brain MRI protocols for patients with ECD, given the overlap with parenchymal involvement.