Basilar perforator Charcot-Bouchard aneurysms (CBA) are a rare etiology of intracerebral hemorrhage (ICH); they are more typically located on lenticulostriate perforators off the middle cerebral artery (MCA) and rupture usually leads to subarachnoid hemorrhage. The prevalence of basilar perforator CBA is less than 1% with less than 100 cases reported in the literature. There are no reported cases of basilar CBA causing ICH—all ruptured cases in the literature have been seen with SAH that are managed in different ways, often conservatively, with ~20-30% risk of re-rupture in those cases.

 

We report a case of pontine hemorrhage caused by rupture of a basilar perforator CBA. A 66-year-old woman with multiple risk factors for spontaneous intracerebral hemorrhage—hypertension, chronic thrombocytopenia, aspirin use, remote ovarian cancer and squamous cell carcinoma of the tongue, and HIV—presented with dizziness and unsteady gait. CT revealed a left pontine hemorrhage with a tiny focus of enhancement on CT angiography. MRI confirmed this finding, showing a corresponding enhancing focus within the hematoma. A subsequent diagnostic angiogram was also done using DynaCT sequences which identified a 1mm CBA arising from a basilar perforator. Given the aneurysm's small size, no intervention was performed. The patient was managed medically with blood pressure control and later discharged to rehabilitation. This case highlights the diagnostic challenge of identifying CBAs, which are often not visible on routine angiography.

This case highlights the diagnostic challenge of identifying CBAs, which are often not visible on routine angiography. Rupture of a basilar perforator aneurysm is a rare cause of pontine hemorrhage. Even in a patient with multiple risk factors for spontaneous intracranial hemorrhage, vascular pathology should be considered. More frequent use of high-resolution imaging techniques, such as DynaCT, may improve detection in the future.