Nongalenic cerebral arteriovenous malformations in neonates and infants. Review of 26 consecutive cases (1982-1992).

We present 26 consecutive cases of nongalenic pial arteriovenous malformations (PAVMs) diagnosed in the neonatal period or in infancy. No diagnosis was made antenatally. Presenting symptoms in neonates were systemic cardiac manifestations (54%), seizures (31%), and hemorrhages (15%). In infants, hemorrhagic strokes and hydrodynamic disorders (external or internal hydrocephaly, macrocephaly, atrophy) both occurred in 38% of cases. Systemic cardiac manifestations and seizures were rare at that age (respectively 16% and 8%). Sixty-two percent of neonates and 31% of infants already had neurocognitive disorders (assessed by pediatric neurocognitive testing: Brunet-Leizine and Denver tests) when referred. The venous drainage and its anomalies (ectasias, stenoses, thromboses) were the main causes of symptoms. Atrophy and leukomalacic lesions occurred rapidly; they express local hydrovenous disorders and are specific to this population group. Untreated neonates and infants have a poor prognosis. Endovascular treatment, although partial and challenging in all instances, represents the treatment of choice in our series. Of the eight neonates treated, one improved to normal (12.5%), while four remained stable (50%): two neurologically normal, two with mild neurological deficit. Three (37%) died despite embolization (heart failure, multiorgan failure, postoperative death). Transient neurological complications occurred in two cases (25%): hemiparesis in one patient with a rolandic and in one with a thalamic AVM. Of the eight infants successfully embolized, one was significantly improved (12.5%) and is now neurologically normal, while five remained stable (62.5%): four neurologically normal, one with mild neurological deficit. One died between two sessions of embolization from intracerebral hemorrhage (12.5%). Hemianopsy occurred in one case (12.5%) after embolization of an occipital AVM. In one additional case in a normal child we failed to embolize the last small pial AVM of four after the three others had spontaneously thrombosed. With a minimal follow-up of 18 months and a maximum of 7 years, the review of our series shows 53% of the initial group of neonates and infants growing neurologically normal after therapeutic management in our institution; 23.5% died despite treatment, and the remaining 23.5% present minor neurological deficit. When targeted at the points of angioarchitectural weakness, embolization contributes to stabilizing a lesion. It should be undertaken rapidly to avoid loss of brain substance secondary to hemorrhage, atrophy, or leukomalacia, and to allow neurocognitive recovery and normal brain maturation. In our experience, these lesions are the most aggressive ones for the maturing brain, and the most difficult to approach technically. They represent a new therapeutic field and have their own specific anatomy and physiology.