A 47-year-old male patient with a known history of arterial hypertension and migraine suffered a sudden right facio-brachial paresis and dysarthria. National Institutes of Health Stroke Scale (NIHSS) score was 6. Emergency computed tomography (CT) showed a recent hemorrhage in the left basal ganglia (Figure 1a) with some subarachnoid hemorrhage in the left insula and the cistern of the middle cerebral artery (Figure 1b). CT angiography (CTA), performed because of the young age of the patient and the presence of subarachnoid blood, showed a small distal lenticulostriate aneurysm (Figures 1c and 1d). This was confirmed a few days later by magnetic resonance angiography (MRA) (Figure 2) and finally by selective left carotid angiography (Figure 3). Because of the distal location of the aneurysm it was decided to remain conservative. During the following weeks there was good recuperation of the clinical symptoms with a persistent slight facial asymmetry. Patient is followed up yearly by MRA.
Basal ganglia hemorrhages in patients with chronic arterial hypertension are frequent. In this context, intravenous contrast is not routinely administered for CT. In our patient, the simultaneous presence of subarachnoid blood in the insular cistern and his young age triggered CTA, which allowed us to detect the small Charcot-Bouchard aneurysm. To date, only approximately 60 cases of Charcot-Bouchard aneurysms are reported. They mostly present at a younger age with a mean of 41.9 years , and not all patients are hypertensive. The primary type of distal lenticulostriate aneurysms is probably dissecting or pseudo-aneurysms, but true saccular aneurysms exist . They mostly lead to solitary hematomas in the basal ganglia mimicking hypertensive hemorrhage . The hematoma in the basal ganglia may be accompanied by subarachnoid hemorrhage as in our case.
Diagnosis of Charcot-Bouchard aneurysms now can be based on CTA showing an enhancing spot in the hematoma. This so-called spot sign is important to recognize, as it indicates active bleeding and predicts rapid hematoma expansion. The lesion can also be shown on MRA  or contrast-enhanced T1-weighted MR, In some cases, however, cross-sectional imaging may fail to display the lesion, which makes catheter angiography the diagnostic standard of reference .
Treatment of Charcot aneurysms would be indicated if the aneurysm is saccular or exceeds 5 mm . Treatment options include surgery or embolisation. Conservative management can be considered if the aneurysm is small and fusiform as in our case. The aneurysm will progressively disappear on follow-up imaging in the following years.
To conclude, as there is no difference on non-contrast CT between Charcot aneurysm and hemorrhage without aneurysm, we recommend to carefully perform CTA when the patient is young, when subarachnoid blood is present and/or when there is no context of arterial hypertension.
The authors have no competing interests to declare.
Nomura M, Baba E, Shirokane K, Tsuchiya A. Aneurysm of lenticulostriate artery in a patient presenting with hemorrhage in the caudate nucleus and lateral ventricle-delayed appearance and spontaneous resolution. Surg Neurol Int. 2018; 21(9): 192. Epub Sept 2018. DOI: https://doi.org/10.4103/sni.sni_126_18