E. Cardia

Reversible cerebral perfusion alterations in children with transient mutism after posterior fossa surgery

Abstract Mutism is an infrequent and transitory complication observed following posterior fossa surgery. Patients become mute in the immediate postoperative period, with restoration of speech within a few weeks in the absence of additional neurological alterations. The anatomical structures thought to be involved are the connections between the cerebellar dentate nucleus, the ventrolateral nucleus of the contralateral thalamus and the supplementary motor area. In an attempt to understand the pathophysiology of this syndrome, and to depict the perfusion of different brain areas semiquantitatively, in two children who had become mute after posterior fossa surgery we performed a Tc99M-HM-PAO SPECT study during the period of mutism and again when normal speech had returned. In one patient, who had a left cerebellar astrocytoma, the SPECT study showed a marked reduction of cerebral perfusion in the right fronto-parietal region, and in the other, who had a medulloblastoma, a left fronto-temporo-parietal perfusion alteration was observed. When the patients regained normal speech, the follow-up SPECT studies revealed normalization of the cerebral perfusion. This study demonstrates the occurrence of a focal dysfunction of cerebral perfusion in children with cerebellar mutism after posterior fossa surgery. These observations are useful in extending our understanding of the pathophysiology of this postoperative clinical syndrome.

Intracranial pressure monitoring in children: comparison of external ventricular device with the fiberoptic system.

Several intracranial pressure monitoring devices have been developed in the past several years. We have recently adopted the Camino fiberoptic device that permits subdural, intraparenchymal, and intraventricular monitoring. In this report we compare experiences in monitoring a group of pediatric patients with severe craniocerebral trauma and coma, grouped according to severity of Glasgow Coma Scale score. Patient age ranged from 2 to 16 years. Twelve patients were monitored by a ventricular catheter and 37, treated more recently, by a Camino fiberoptic device. The study demonstrated that the fiberoptic device and the ventricular catheter have the same accuracy and reliability. The fiberoptic method correlates very closely with the ventriculostomy method, but the pressure values are always 3±2 mmHg lower than those obtained with the conventional pressure transducer system, especially in more critically ill patients. This new technique is also easier to implant, safer to use, has minimal drift, and is minimally invasive, which particularly speaks for its use in pediatric patients.

Intracranial solitary-type infantile myofibromatosis

An unusual case of infantile myofibromatosis of the solitary type occurring in an intracranial location in a 48-day-old female infant is presented. To our knowledge, there are no other descriptions in the literature of infantile myofibromatosis with exclusively intracranial involvement. The immunohistochemical and electron microscopic findings confirm the myofibroblastic origin of the proliferation.

Chronic encapsulated intracerebral hematoma: contribution of thallium-201 single photon emission computed tomography in preoperative diagnosis: case report.

OBJECTIVE AND IMPORTANCE Chronic encapsulated intracerebral hematoma is a fairly rare clinical entity. This unique lesion is peculiar for its clinical onset, formation of a capsule, and progressive enlargement. The mechanism for capsule formation and self-perpetuating expansion still remains uncertain, as well as the causal relationship with vascular malformations. Because of their pseudotumoral course and misleading neuroradiological features, these lesions can be misdiagnosed preoperatively as cerebral neoplasms. CLINICAL PRESENTATIONS A 62-year-old man was referred with a 2-month history of generalized tonicoclonic seizures. There was no history of head injury or arterial hypertension. The results of a neurological examination were normal. Computed tomographic scans revealed a slightly hyperdense roundish area in the right parietotemporal region with ring-like enhancement after contrast medium injection, moderate mass effect, and perifocal low attenuation. With the provisional diagnosis of astrocytoma, the patient was admitted for a craniotomy. Before surgery, a thallium-201 single photon emission computed tomographic study was performed, which showed no abnormal uptake of the tracer, raising significant doubt regarding the presumptive diagnosis of a tumor. INTERVENTION Intraoperative findings revealed a hematoma, with a well-demarcated, thick, fibrous-elastic capsule. There was evidence of repeated intracapsular hemorrhages. The lesion was totally removed, and the patient recovered fully. No other pathological findings, including vascular malformations, were noted. CONCLUSION Chronic encapsulated intracerebral hematomas probably occur more frequently than the limited number of reported cases would indicate. This case represents a realistic clinical problem-solving setting in with thallium-201 single photon emission computed tomography was used because of its capacity for functional tumor detection and differential diagnosis.

Spinal cord compression in homozygous beta-thalassemia intermedia

Symptomatic spinal cord compression caused by an epidural mass of extramedullary hematopoietic tissue in patients with beta-thalassemia is a rare occurrence, that becomes exceptional in childhood and adolescence. The literature is not uniform about the optimal treatment of these patients and different modes of therapy have been proposed so far, including surgical excision or decompressing laminectomy followed by local irradiation and/or hypertransfusional regimens. We report the successful treatment of such a complication in an adolescent with homozygous beta-thalassemia by surgery followed by repeated blood transfusions aimed at maintaining hematocrit at normal levels.

Morphological modifications of the choroid plexus in a rodent model of acute ventriculitis induced by gram-negative liquoral sepsis: possible implications in the pathophysiology of hypersecretory hydrocephalus

Gram-negative bacterial infections of the central nervous system are generally associated with high morbidity and mortality rates. In patients with ventriculitis induced by gram-negative liquoral sepsis, a reduction in cerebrospinal fluid formation has been reported, suggesting that gram-negative ventriculitis is able per se to alter the normal functioning of the choroid plexus. The aim of the present study was to analyse, for the first time in the rat, the effects of tcute ventriculitis on the ultrastructure of the choroid plexus. A simple and inexpensive experimental model of acute ventriculitis was developed: we injected into the cisterna magna of rats 103 CFU of liveEscherichia coli, inducing septic ventriculitis without major neurological deficits. Histological examinations of rodent choroid plexus 24 h after the injection revealed patches of altered epithelium, with swollen and vacuolated ependymal cells associated with leukocyte infiltration. Electron microscopy demonstrated a reduced number of microvilli and flattening of the epithelial surface. These results (a) indicate that gramnegative septic ventriculitis is able to induce visible ultrastructural alterations of the choroid plexus which (b) are consitent with a picture of marked reduction of the functioning epithelial choroid plexus surface, and (c) highlight the potential usefulness of our rodent acute ventriculitis model for developing treatment modalities.

Intraoperative monitoring of cerebral blood flow during ventricular shunting in hydrocephalic pediatric patients

Several studies have demonstrated lowered cerebral blood flow (CBF) in patients with hydrocephalus and symptoms of raised intracranial pressure. Ventricular shunting in such cases permits a sudden increase in CBF. The pathophysiology of functional brain deficit secondary to hydrocephalus is little understood. Improvement of the patients clinical status after drainage of CSF suggests that cerebral dysfunction is not necessarily due to permanent brain damage. In fact, it improves rapidly after ventricular taps. In view of this it would be helpful to monitor cerebral perfusion. The transcranial Doppler (TCD) ultrasonography technique allows real-time monitoring of the intracranial circulation and makes it possible to evaluate the physiopathological correlation between ventricular dilatation and CBF. Continuous monitoring of the middle cerebral artery (MCA) by TCD was performed in three hydrocephalic children (2 months, 14 months, and 8 years old) during a ventricular-peritoneal shunt operative procedure. A TC-2000S device provided by an IMP-F fixed probe was utilized. In all patients, when the lateral ventricle was shunted and the CSF could flow away, a clear and sudden increase of flow velocity above 30% was detected. The pulsatility index (PI) was also pathologically increased in all patients. A gradual normalization of this index was revealed after the shunting procedure. Our experience has to be considered preliminary, but nonetheless, it suggests a clear correlation between hydrocephalic disease and concomitant CBF alterations. A more consistent number of monitoring performances by TCD during operative procedures will improve our understanding of the role of CBF in the development of functional deficits in hydrocephalic disease.

Temporal osteoclastoma: an exceptional lesion in infancy

Abstract Osteoclastoma is a rare skeletal lesion, characterized by large multinucleated giant osteoclastic cells; this lesion usually affects young adults with a prevalence of 1 case/1 million population. We report the case of a 9-year-old girl with a right temporal tumescence: X-ray, CT and MRI revealed the presence of a right temporal hyperostotic ring-like area over the lambdoid suture, with irregular margins and calcareous deposits. The tumour was expanding mainly toward the endocranium involving both cranial tables and diploë, without infiltrating the brain parenchyma. The child underwent complete microsurgical removal of the lesion. Histopathological findings revealed the giant cell tumour osteoclastoma. Correct modern preoperative neuroimaging workup, coupled with microneurosurgical technique, allowed successful lesion removal with good outcome. A review of the more recent literature and of mechanisms of pathology together with neuroradiological protocol and results of treatment are discussed.

Xanthomatous posterior pyramid meningioma in a 2-year-old girl

Abstract Meningiomas are common lesions in adults but unusual in infancy and meningiomas located in the posterior cranial fossa are even more rare. Metaplastic changes of meningothelial meningiomas can lead to the rarely observed xanthomatous form. We describe the case of a posterior pyramid xanthomatous meningioma in a 2-year-old girl. After detailed neuroradiological evaluation, the histological diagnosis was confirmed with the aid of immunohistochemical evaluation. A critical case evaluation in the light of the more recent literature, the surgical strategy and technique, and an immunohistological hypothesis are reported.

Outcome of craniocerebral trauma in infants and children

The authors examined 927 patients affected by craniocerebral trauma and analyzed the neurological complications that occurred most frequently. The study confirmed that the percentage of craniocerebral trauma, gravity, and complications were different in relation to the sex and age of the patients. Based on this analysis, a correlation was made between the traumatic pathologies and socioeconomic-environmental conditions.