Neurosurgical management of cavernous malformations located at the foramen of Monro

Cavernous malformations (CMs) located at the foramen of Monro (FM) are relatively rare benign vascular malformations. Knowledge of FM CM is poor. The aims of this study were to describe the incidence, clinical presentation, radiological features, surgical approaches, and neurological outcomes for FM CM patients and to discuss the treatment strategy for this disease. We present a series of nine FM CM patients (four males, five females; mean age 29.3 years) who were treated at a single neurosurgical center. FM CM accounted for 0.56% of the entire series of the central nervous system (CNS) CMs. Headache accompanied by nausea and vomiting was the most common initial symptom (55.6%). The mean preoperative Karnofsky Performance Scale (KPS) score was 84.4 (range 70–100). In all but one patient, the lesions were surgically resected. Postoperatively, two patients developed obstructive hydrocephalus, and one experienced motor aphasia and right hemiparesis. At the time of discharge, the KPS score improved to a mean of 88.9. Follow-up period after diagnosis was 18 to 131 months (mean 69.7 months); all the patients were considered to be in excellent clinical condition. FM CMs are rare and challenging lesions; they have a female predilection. The most common clinical manifestations of FM CM are the symptoms of mass effect. The seizure risk of FM CMs seems to be significantly lower than that of general intraventricular CMs. Early surgical intervention should be offered to symptomatic cases, and gross total resection is associated with favorable neurological outcomes.