Surgical treatment of moyamoya disease in pediatric age

Moyamoya is a progressive occlusive cerebrovascular disease which affects the distal internal carotid artery and its main branches, and is characterized, from a clinical point of view, by a variety of ischemic manifestations ranging from transient ischemic attacks (TIA) to stroke. Although considered until recently as almost specific of Japanese population, it can also affect individuals of different origin, and there is an increasing interest for this rare disease in Western medical literature. Nonetheless papers dealing with moyamoya disease in pediatric age are still very rare and almost exclusively limited to isolated case reports. These considerations prompted us to review our experience with the diagnosis and treatment of such unusual disease.

Nine children (seven months to nine years of age) presented with clinical manifestations of occlusive cerebrovascular disease (TIAs or stroke), epilepsy, and/or psychomotor retardation. Neuroradiological investigation, and in particular cerebral angiography, demonstrated the classical pattern of moyamoya disease. Eight of these children underwent cerebral revascularization utilizing the encephalomyosynangiosis (EMS) technique, with a total of 14 operations (six on both sides, two on one side).

There was no mortality neither major morbidity related to surgery. One patient with renovascular hypertension, died at home approximately six months after a successful operation, probably from cerebral hemorrhage. In all the cases postoperative angiography revealed a marked improvement in cerebral circulation. However, in spite of the apparently normalized cerebral blood flow, clinical manifestations were affected less significantly. In fact, there was only minimal if any improvement in children operated on with an already established hemiplegia; whereas improvement in motor ability was obtained in those presenting with hemiparesis or TIAs, as well as in epilepsy and psychomotor retardation.

On the grounds of our results we conclude that cerebral revascularization (by means of a simple operation like the EMS) in children with moyamoya disease is worthwhile, provided that the operation be performed before irreversible cerebral damage is established; however, even under these circumstances the operation can at least stop the progression of the disease.