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Despite easier recognition of focal developmental cortical anomalies with modern morphological and functional imaging techniques, mechanisms leading to refractory epilepsy are still poorly understood. Recent experimental studies have shown that not only the lesioned cortex, but also the apparently normal adjacent cortex undergoes morphological changes and alterations of its neuronal connections. To further investigate the modifications of the cortex surrounding a focal maldevelopmental lesion, we applied a freezing insult to newborn rat cortex, resulting in a focal cortical malformation similar to human microgyria. Corticocortical associative neurons were retrogradely labeled in a Golgi-like fashion using biotinylated dextran amine combined with NMDA. In addition to previously reported alterations, a considerable spine loss was observed in the basal dendrites of neurons located in the eulaminated cortex adjacent to the lesion. These data demonstrate profound maldevelopmental alterations which are not limited to the macroscopically abnormal lesion, but extend at a cellular level to the surrounding cortex. The observed alterations may contribute to the increased excitability of the cortex harboring a microgyric lesion as well as the frequently associated cognitive impairment.

Few studies on analgesia with remifentanil (Rf) in children are available, and there are no data on the use of this drug in pediatric neurosurgery. Rf is a new μ-receptor opioid agonist, acting through the activation of pain inhibitory mechanisms. We conducted a prospective trial on the analgesic effects of Rf in 20 children less than 1 year of age undergoing a neurosurgical procedure for craniosynostosis repair. Rf was administered at doses of 0.25 μg/kg/min, by continuous infusion, 1 h after admission to the pediatric intensive care unit (PICU). The treatment was prolonged for 12 h after the operation. The postoperative pain was evaluated in our PICU, comparing the changing of behavioral (AFS and CHEOPS score) and hemodynamic (heart rate, respiratory rate, systolic and diastolic blood pressure, oxygen saturation, O2 and CO2 partial pressure) parameters, before and after treatment with Rf. This drug showed a satisfactory pain control in all the children treated. No significant side effects were noticed, except for one episode of urinary retention. In conclusion, Rf appears to be safe and effective for the treatment of acute pain in the very young child submitted to craniosynostosis repair.

Hemispherectomy is required in most cases of hemimegalencephaly in order to control epilepsy refractory to medical treatment. Although there is a general agreement on the effectiveness of the procedure in controlling the seizure disorder, the choice of the surgical technique is still a subject of debate. In particular, anatomical hemispherectomy is blamed to be associated with a higher incidence of surgical complications, namely hydrocephalus and hemosiderosis, than other less ablative operations such as functional hemispherectomies. A series of 15 children with hemimegalencephaly, who had undergone anatomical hemispherectomy (11 cases), functional hemispherectomy (2 cases), and hemidecortication (2 cases) at the Pediatric Neurosurgery Section, Catholic University Medical School, Rome, is reported. Twelve of these patients presented with one or more complications in their postoperative course. Temporary complications, which resolved spontaneously or following medical therapy, included fever, wound breakdown, worsening of preoperative motor deficit, unilateral third cranial nerve deficit, dystonia, and anemia. In 8 patients, postoperative complications led to a second surgical procedure. A CSF shunt was necessary in 5 children, to control a secondary hydrocephalus. Two subjects underwent a toilette of the residual cavity because of persisting chemical abnormalities in CSF parameters. In a child a cranioplasty procedure was necessary as a consequence of an infection of the hemicranial bone flap. There was no apparent correlation between the rate and the type of complications with a specific surgical procedure. On the other hand, the age factor appeared to play an important role in the occurrence of secondary hydrocephalus, as all 5 children with this complication were less than 9 months old at the time of the hemispherectomy. Surgical mortality was nil in this series.

Out of 27 children with intracranial cavernous angiomas observed in a 17-year period of time, 3 presented with their lesion located in the brain stem. A further 19 pediatric cases of brain stem cavernous angiomas sufficiently well described for a reliable analysis were collected from the literature and evaluated for the present study. The widespread use of MR imaging has significantly increased the possibility of recognizing brain stem cavernomas at an early age; indeed, their incidence is nowadays regarded to range between 9 and 15% of pediatric cavernous angiomas. A female predominance was noted in the present study. Focal neurological deficits are the most frequent presenting symptoms; they tend to occur acutely in most cases, although subsequent improvement may then be observed in several patients. Recurrent hemorrhages from the angioma result usually in heavier neurological signs. Surgical approaches have to be planned according to the location of the lesion, and to the site where the angioma is eventually in contact with the pial or ependymal surface. No surgical deaths were observed in these 22 children; only 2 patients presented a mild persistent worsening of their neurological status after the operation. These good results indicate that brain stem cavernous angiomas are actually a surgical lesion in spite of their apparently unfavorable location. The good prognosis is related to the anatomophysiological features of these lesions, which usually displace the brain stem structures rather than invade them, and are characterized by a low-pressure and slow blood flow circle.

Between 1980 and 1992, 10 children affected by tuberous sclerosis and intraventricular subependymal giant cell astrocytomas were surgically treated at the Institute of Neurosurgery, Section of Pediatric Neurosurgery, Catholic University of Rome. Nine patients presented with signs and/or symptoms of intracranial hypertension; in all of them the neuroradiological investigations demonstrated the presence of a space-occupying lesion in the region of the foramen of Monro with secondary ventricular dilation. In the remaining patient, a 5-month-old male infant, an intraventricular mass was discovered by means of an ultrasound examination performed after the first epileptic fit. Three patients underwent a ventriculoperitoneal CSF shunt as first surgical procedure; in 2 of them it was subsequently necessary to remove the intraventricular tumor due to the frequent occlusion of the CSF shunt device. Seven subjects underwent the direct surgical excision of the lesion. In all of them the procedure resulted in the control of the associated hydrocephalus. On the basis of such an experience, the authors conclude that the surgical removal of the intraventricular tumors in patients with tuberous sclerosis and hydrocephalus is the most appropriate treatment. In fact, in the series considered here, the removal of the tumor was not accompanied by significant morbidity, and was followed by improvement in clinical conditions. In particular, in cases in whom the occurrence of hydrocephalus was associated with a worsening in the seizure disorder, the tumor removal and the correction of intracranial hypertension was followed by a significant reduction in frequency or even by the disappearance of the seizures. However, in no case presenting with mental impairment was a significant improvement observed in mental performances as a consequence of the surgical treatment.

18 children having hydrocephalus, which could be regarded clinically as ‘arrested’, underwent cerebral angiography and a constant infusion manometric test. Intracranial pressure was directly recorded in 3 cases. The above examinations indicated that hydrocephalus was still ‘active’ in 8 children. This was confirmed by the good results of the surgical treatment.

Most of the small (50–60 µm) vessels nourish exclusively the cerebral cortex, whereas larger caliber (80–150 µm) arteries penetrate the entirety of the cortical layer to enter the underlying white matter. A single layer of nonfenestrated endothelial cells, surrounded by a continuous layer of basement membrane (which in places splits to envelope a pericyte), and perivascular glial cells attached to the outer surface of this basement membrane, with no pericapillary space, represent the anatomical structure of the blood-brain barrier (BBB). Concentrated electrolyte solutions and increases in mean arterial pressure may reopen the BBB. Water-soluble contrast media used in cerebral angiography are hypertonic solutions of iodinated salts. In cerebritis, one observes a very typical angiographic picture: ‘laminar’ staining of the gyri. The intervening sulci appear as negative images. In brain abscess, one may note angiographic evidence of a space-occupying lesion, a capsular stain in the granulation tissue surrounding the abscess, ‘halo’ formation and ‘pooling’ of contrast media in the sulci, and ‘laminar’ staining of the gyri.