Bilateral Decreased Oxygenation During Focal Status Epilepticus in a Neonate With Hemimegalencephaly

Abstract

Early surgical removal of a dysplastic hemisphere appears to be beneficial for neonates with hemimegalencephaly and medically resistant seizures. We analyzed the changes in the cerebral regional oxygen saturation index in a neonate with tuberous sclerosis and right hemimegalencephaly (1) during seven episodes of right hemisphere electroencephalographic status epilepticus with and without clinical manifestations and (2) after right hemispherectomy. The cerebral regional oxygen saturation index demonstrated marked fluctuations and progressive decline in both hemispheres during the episodes and normal values in the remaining hemisphere after surgery. We speculate that decreased oxygenation of the nonepileptic cerebral hemisphere in patients with hemimegalencephaly and medically resistant seizures can contribute to the production of global neurologic impairments in these patients and that the benefits of early hemispherectomy are due to the improved oxygenation of the nondysplastic hemisphere following surgery.

Hemispherectomy in a Premature Neonate with Linear Sebaceous Nevus Syndrome

“…The proposed mechanism of this injury has been decreased oxygenation of the more normal hemisphere by a steal-like phenomenon [18, 19]. Alfonso et al [19], using near-infrared spectroscopy (SPECT), found bilateral decreased oxygen saturation in a 3-week-old with tuberous sclerosis and hemimegalencephaly; this was interpreted as being due to increased oxygen consumption by the abnormal brain with decreased availability of oxygen to the normal hemisphere. Soufflet et al [18] demonstrated earlier return of normal cerebral blood flow in infants who underwent early hemispherectomy compared to their counterparts.…”

“…The intrauterine excessive fetal movement and hiccups were likely manifestations of intrauterine seizure activity [11]. Rapidly progressing clinical and EEG abnormalities raised concern for irreversible injury to the more normal-appearing right hemisphere, as a result of epileptogenic bombardment from the abnormal hemisphere [13,16,17,18,19]. The proposed mechanism of this injury has been decreased oxygenation of the more normal hemisphere by a steal-like phenomenon [18, 19].…”

“…Rapidly progressing clinical and EEG abnormalities raised concern for irreversible injury to the more normal-appearing right hemisphere, as a result of epileptogenic bombardment from the abnormal hemisphere [13,16,17,18,19]. The proposed mechanism of this injury has been decreased oxygenation of the more normal hemisphere by a steal-like phenomenon [18, 19]. Alfonso et al [19], using near-infrared spectroscopy (SPECT), found bilateral decreased oxygen saturation in a 3-week-old with tuberous sclerosis and hemimegalencephaly; this was interpreted as being due to increased oxygen consumption by the abnormal brain with decreased availability of oxygen to the normal hemisphere.…”

“…Our patient’s intracranial hypertension with compression of the more normal hemisphere added to the concern. The potential benefits of early elimination of the ongoing injurious electrical and anatomic influences of the bad hemisphere were considered to outweigh the risks of hemispherectomy [13, 17, 19]. …”

Refractory status epilepticus

“…Es folgte eine Reihe von Einzelfallberichten und kleinen Fallserien mit insgesamt 13 Patienten im Alter von einem Monat bis 31 Jahren [2,33,38,42,56,92,106,116]. Die Dauer der SE lag in den Studien zwischen 6 und 42 Tagen.…”