Endoscopic treatment of symptomatic septum pellucidum cysts: with some preliminary observations on the ultrastructure of the cyst wall: two technical case reports

OBJECTIVE AND IMPORTANCE

We describe two patients with symptomatic septum pellucidum cysts managed by endoscopic fenestration. In each case, tissue from the cyst wall was studied to define the origin of the cyst wall and fluid.

CLINICAL PRESENTATION

The patients, a 6-year-old boy and a 42-year-old man, each presented with headaches and a syncopal episode. Imaging studies demonstrated large septum pellucidum cysts with obstruction of the foramina of Monro.

INTERVENTION

The patients underwent endoscopic transventricular cyst fenestration with a 4-mm steerable fiberscope. The fenestrations were created to allow communication with the right and left lateral ventricles. In one patient, adhesions between the cyst wall and the foramen of Monro were lysed with endoscopic monopolar cautery. Tissue from the cyst walls was removed for examination by electron microscopy. Postoperatively, the headaches and syncopal episodes resolved in both patients.

CONCLUSION

Endoscopic fenestration of symptomatic septum pellucidum cysts produces immediate relief of the mass effect of the cyst and resolution of associated symptoms. Cannulation of the lateral ventricle before cyst fenestration prevents inadvertent injury to the fornices, thalamus, internal capsule, caudate nucleus, and septal and thalamostriate veins. The endoscopic approach allows the surgeon to ensure communication within the ventricular system, thus avoiding placement of a shunt. Preliminary ultrastructural analysis indicates that the cyst walls derive from the septum pellucidum rather than the choroid plexus or arachnoid. The cellular machinery necessary for fluid secretion was identified in some specimens.

Interventional magnetic resonance imaging guided aspiration and biopsy of a cystic midbrain tumor

Interventional magnetic resonance imaging defines the intraoperative application of magnetic resonance imaging technology, permitting the surgeon to work in an open magnetic field. The application of this technology to pediatric neurosurgery allows precise intraoperative localization of pathology, real-time assessment of the anatomical consequences of surgical and anesthetic interventions, accountability of brain shifts, confirmation of the exact site of biopsy or completeness of lesion removal, and immediate identification of some intraoperative and early postoperative complications. We present the case of a young boy with a cystic left midbrain tumor who underwent interventional magnetic resonance imaging guided aspiration and biopsy to illustrate the surgical advantages of this technology.

Spontaneous dural sinus thrombosis in children

The clinical course of spontaneous dural sinus thrombosis in children varies from indolent to fulminant. Although many different etiologies for the development of dural sinus thrombosis have been described, a full recovery can be anticipated in most children following rehydration and the administration of systemic antibiotics. Steroids, systemic anticoagulation and intrasinus thrombolysis may be beneficial in selected patients, although the efficacy of these therapies has not been established prospectively in children. We reviewed 12 pediatric patients with spontaneous dural sinus thrombosis (1978-1998) to determine the etiology, clinical course and best treatment options. In the absence of a hypercoagulable state, pediatric patients generally recover well with rehydration and antibiotics and do not require anticoagulation.

Anatomy of the shaken baby syndrome

Shaken baby syndrome refers to the constellation of nonaccidental injuries occurring in infants and young children as a consequence of violent shaking. The typical victim of shaken baby syndrome is a male infant younger than six months of age who is alone with the perpetrator at the time of injury. Occurrence of the syndrome is unrelated to race, gender, socioeconomic status, or education. The characteristic injuries observed in shaken baby syndrome include subdural hemorrhages, retinal hemorrhages, and fractures of the ribs or long bones. Although each of these injuries may result from violent shaking of the victim, the most severe brain injuries result from the addition of a forceful impact of the infant's or child's head against a firm surface. The unique anatomic features of the infant's head and skeletal system, which account for the type and pattern of injuries observed in shaken baby syndrome, are emphasized in this article.

Expanding cyst of the septum pellucidum. Case report

Expanding cysts of the septum pellucidum, although rare, may be a cause of significant neurological dysfunction. Most become symptomatic as a result of obstruction of the interventricular foramina and produce headaches, papilledema, emesis, and loss of consciousness. Behavioral, autonomic, and sensorimotor symptoms occur when an expanding cyst impinges on the structures of the hypothalamoseptal triangle or impairs the deep cerebral venous drainage. Neuroophthalmological symptoms may develop as a consequence of hydrocephalus or direct compression of visual structures. The authors describe the case of a young boy with an expanding septum pellucidum cyst who presented with a sudden, severe headache and loss of consciousness. In addition, he had a history of hyperactivity and progressively declining school performance. All symptoms resolved following decompression of the cyst. Seventeen cases from the literature are reviewed. The pathophysiological mechanisms underlying the development of symptoms secondary to expanding septum pellucidum cysts are outlined, and the related clinical neuroanatomy is described. A model is proposed for the natural history of expanding septum pellucidum cysts that provides a rational basis for understanding their clinical behavior and response to intervention. In most cases, fenestration or shunting will relieve the obstructive hydrocephalus and mass effect caused by the cyst and will produce rapid symptomatic improvement.

A new rat spinal cord injury model: a ventral compression technique

A new rat spinal cord injury model, which uses a modification of a DeBakey aortic aneurysm clamp to create the injury, is presented. The model produces a ventral persisting mass (bone and soft tissue) without the requirement of a prior decompressive operation (laminectomy). Modifications of the original technique have resulted in a nil surgical mortality rate. This technique has been applied to 138 animals. It has produced a consistent percentage of animals with complete myelopathies, as well as incomplete myelopathies and animals without apparent injury. The percent of baseline neurological function lost (change in degrees of the angle of tilt as measured by the inclined plane technique) in each group of surviving animals was 58, 36, and 9%, respectively. Sagittal postmortem sections confirmed mass lesions located ventral to the spinal cord. Histological sections confirmed neuronal loss consistent with the neurological findings.

Dose-dependent effects of naloxone and methylprednisolone in the ventral compression model of spinal cord injury

A study of the dose-response effects of naloxone and methylprednisolone after rat ventral spinal cord injury is presented. The spinal cord injury model used herein is unique in that it results in a ventral compression of the spinal cord without the need for a prior laminectomy. This allows for a close approximation of the human clinicopathological situation. There was a statistically significant positive effect on neurological outcome with a naloxone dose of 2.5 mg/kg, whereas higher and lower doses yielded little or no influence on outcome. Methylprednisolone was observed to offer similar results. These results, however, did not achieve statistical significance. The early administration of moderately high doses (45-60 mg/kg), however, offered the best results. The responses to the treatment regimens presented here offer hope for spinal cord injury victims. The observed dose-response relationships indicate that erroneous conclusions may arise from studies using inappropriate doses of narcotic antagonists, as well as other drugs.

Effect of dosage and timing of administration of naloxone on outcome in the rat ventral compression model of spinal cord injury

The effect of the dosage and timing of administration of naloxone after spinal cord injury in rats via the ventral compression technique is presented. The rat ventral compression technique allows for a ventral compression of the spinal cord without the requirement of a previous laminectomy. It therefore facilitates the creation of an experimental lesion that is similar to that observed in the human clinicopathological situation. The first part of the two-part study presented herein involved the determination of the optimal dose of naloxone, administered intraperitoneally 45 minutes after the creation of the lesion. Of the groups studied (control group through 10.0 mg/kg group), 2.0 mg/kg of naloxone proved to be superior to both lesser and greater dosages. The second part of the study involved the administration of a 2.0 mg/kg dose of naloxone at varying intervals ranging from 10 minutes before lesioning to 24 hours after lesioning. A multiphasic response was again demonstrated, with an optimal time of administration occurring 45 minutes after the creation of the lesion. A significant effect was offered by a midrange dose of naloxone (2.0 mg/kg), administered at 45 minutes after injury (P less than 0.02 by analysis of variance and Duncan's multiple range test). These findings are discussed with respect to recent evidence regarding the effects of narcotic antagonists on both mu and kappa narcotic receptors. Past and future experiments must account for these responses to multiphasic dosage and timing of administration. Failure to do so may lead to erroneous conclusions.