Endoscopic management of idiopathic foramen of Monro stenosis

Idiopathic foramen of Monro stenosis (IFOMS) is a rare clinical entity with varied presentations. We present a series of patients treated for IFOMS at our institute from 2000 to 2024. We conducted a retrospective study of all patients operated at our institute. A total of 11 patients with IFOMS were identified from the hospital records. Patients with a history of meningitis or intraventricular hemorrhage were excluded. Most patients presented in the third to fifth decade of life (81%). Most of the patients presented with headaches and one of them presented with features of normal pressure hydrocephalus. Nine patients underwent endoscopic foraminoplasty with septostomy, while two underwent septostomy with ventriculoperitoneal shunt placement. All patients were symptom-free after surgery. Foramen of Monro stenosis is a rare entity but has good outcomes with treatment. Unilateral asymmetric and bilateral lateral ventriculomegaly should raise suspicion of the foramen of Monro stenosis. Endoscopic foraminoplasty with septostomy is an effective treatment for this condition.