Arterial spasm following perimesencephalic nonaneurysmal subarachnoid hemorrhage in a pediatric patient.

Perimesencephalic nonaneurysmal hemorrhage is a benign form of subarachnoid hemorrhages. This entity is well recognized as a distinct type of subarachnoid hemorrhage in adults. However, perimesencephalic nonaneurysmal subarachnoid hemorrhage in pediatric patients is not well recognized. Angiographic changes such as vasospasm are uncommon in patients, especially in pediatric patients suffering from this type of hemorrhage. This case study reports a 12-year-old male who suffered from perimesencephalic nonaneurysmal subarachnoid hemorrhage. Cerebral carotid angiography performed on the tenth day of the posthemorrhagic period revealed severe vasospasm affecting the basilar artery. The patient, treated symptomatically, was discharged after improvement. One year later, magnetic resonance angiography revealed completely normal features.