Kerry R. Crone

Rapamycin causes regression of astrocytomas in tuberous sclerosis complex

Tuberous sclerosis complex (TSC) is a genetic disorder characterized by the formation of hamartomas in multiple organs. Five to 15% of affected individuals display subependymal giant cell astrocytomas, which can lead to substantial neurological and postoperative morbidity due to the production of hydrocephalus, mass effect, and their typical location adjacent to the foramen of Monro. We sought to see whether therapy with oral rapamycin could affect growth or induce regression in astrocytomas associated with TSC.

Acquired chiari malformations : Incidence, diagnosis, and management

The acquired descent of the cerebellar tonsils radiographically indistinguishable from Chiari I malformations has been previously reported. The relationship between lumbar shunting procedures for hydrocephalus and symptomatic Chiari malformations has been established. We report the cases of 10 children with lumboperitoneal shunts in whom previous radiographic studies had confirmed a normal hindbrain configuration. Seven of the 10 patients acquired tonsillar descent into the foramen magnum, detected by magnetic resonance imaging, whereas the others remained normal. Four of seven patients were symptomatic; two underwent the removal of the lumboperitoneal shunt and conversion to a ventriculoperitoneal shunt, and two underwent posterior fossa decompression. Further magnetic resonance imaging revealed that one of the two patients who underwent conversion shows ascent of the cerebellar tonsils. All four patients became asymptomatic less than 6 months after treatment. In this article, we discuss seven cases of acquired Chiari malformations and the complete reversal of an acquired Chiari malformation after surgical treatment, as documented by magnetic resonance imaging. Cases of asymptomatic acquired Chiari malformations are reported, including those resulting from shunting for intracranial hypertension without hydrocephalus. We conclude that a craniospinal pressure gradient creates a potential for cerebellar tonsil descent and recommend that ventriculoperitoneal shunting be performed in children with communicating hydrocephalus to avoid this potential complication. We also recommend annual surveillance of the cervicomedullary junction in children with lumboperitoneal shunting. Finally, if symptomatic tonsillar descent occurs from lumbar shunting, a trial conversion to ventriculoperitoneal shunting may eliminate the need for posterior fossa decompression.

Traumatic intracranial aneurysms in childhood: two cases and a review of the literature

Traumatic intracranial aneurysms in childhood are rare. To date, 67 well-documented cases in children have been reported. We present 2 additional cases and review the literature. Traumatic aneurysms can best be categorized based on mechanism of injury and location. Aneurysms secondary to penetrating trauma occur most commonly in teenage boys suffering gunshot wounds. Aneurysms secondary to nonpenetrating trauma occur at the skull base or in the periphery, with motor vehicle accidents and falls as the most common modes of injury. Skull base traumatic aneurysms most commonly involve the petrous, cavernous, or supraclinoid carotid artery and also show a predominance in teenage boys. Peripheral traumatic aneurysms can further be divided into distal anterior cerebral artery aneurysms secondary to trauma against the falcine edge and distal cortical artery aneurysms associated with an overlying skull fracture. Peripheral traumatic aneurysms tend to occur in younger patients with a less marked male predominance. Two-thirds of the patients suffered symptomatic aneurysmal hemorrhage, with an associated mortality rate of 31%. The clinical presentation, diagnosis, and treatment of traumatic intracranial aneurysms are discussed.

Acquired Chiari MalformationsIncidence, Diagnosis, and Management

ABSTRACTTHE ACQUIRED DESCENT of the cerebellar tonsils radiographically indistinguishable from Chiari I malformations has been previously reported. The relationship between lumbar shunting procedures for hydrocephalus and symptomatic Chiari malformations has been established. We report the cases of

Hydrosyringomyelia and Its Management in Childhood

Syringomyelia, once regarded as a degenerative disease of adults, is now recognized to be a disorder usually associated with the Chiari malformation and occurring in patients of all ages. We have reviewed 47 patients with syringomyelia treated on the Neurosurgical Service at the Hospital for Sick Children during the years 1977 to 1985. Twelve of these patients had a Chiari I malformation, 30 had a Chiari II malformation, and 5 had an acquired Chiari malformation. Thirty-one of these patients were treated by decompression of the Chiari malformation and plugging of the obex, 5 were treated by a simple posterior fossa decompression, 9 were treated by shunting of the syringomyelic cavity, and 2 were treated by a combined decompression of the posterior fossa and shunting of the syrinx. The Gardner procedure (decompression of the Chiari malformation and plugging of the obex) was the procedure most commonly used in managing our group of patients and resulted in improvement in over 70% of patients.

Sigmoid sinus thrombosis after closed head injury in children.

In the literature, clinical descriptions of sigmoid sinus thrombosis occurring after closed head injury in children are rare. One to 5 days after trauma to the back of the head, five children (aged 1 to 7 yr) presented with gait ataxia, vomiting, and headache. Trauma was mild in four children. Computed tomography of all the children, performed within 5 days after the injury, showed focal hyperdensity in the region of the left sigmoid sinus. Four children had extra-axial hyperdense collections along the left transverse sinus, and three had skull fractures adjacent to the left sigmoid sinus. Magnetic resonance imaging (MRI) of all the children, performed 2 to 6 days after injury, showed left sigmoid-sinus thrombosis and decreased flow or thrombosis within the lateral third of the left transverse sinus. All the children had MRI scans 4 to 6 weeks after their diagnosis and were followed up for 1 to 12 months. In four children whose symptoms subsided completely within 2 to 10 weeks, MRI showed recanalization of the sigmoid sinus within 4 to 6 weeks after injury. In one child whose symptoms resolved after 6 months, sigmoid-sinus thrombosis persisted with the formation of collateral flow. We conclude that traumatic sigmoid-sinus thrombosis should be suspected when a child has persistent or delayed gait ataxia and vomiting after injury to the back of the head. Computed tomography characteristically demonstrated focal hyperdensity within the sigmoid sinus that we term the dense sigmoid-sinus sign. Because the sinus recanalized and the symptoms subsided in most children within 6 weeks, we conclude that prophylactic medical or surgical intervention is not indicated.

Isolated head injuries versus multiple trauma in pediatric patients: do the same indications for cervical spine evaluation apply?

Although the recommendations to evaluate possible cervical spine injuries in patients with isolated head injuries are identical to those with multiple trauma, to date, no such study has confirmed that risk factors are the same for both injuries. We reviewed the charts of 268 pediatric patients with isolated head injuries admitted to the Intensive Care Unit at Childrens Hospital Medical Center (1985-1990) to determine which risk factors were present. In this retrospective study, we divided the patients into two groups: low risk and high risk. The low-risk patients (n = 135) were those capable of verbal communication who did not report cervical discomfort. The high-risk patients (n = 133) either were incapable of verbal communication (preverbal or physically unable due to head injury) or reported neck pain. All patients under 2 years of age were considered preverbal and at high risk. The patients in both groups were indistinguishable by age, sex, mechanism of injury, and type of injury sustained. No patient in the low-risk group suffered cervical spine injury. Cervical spine trauma was present in 10 (7.5%) high-risk patients. Using the method of adjusted odds ratio, we found that high-risk patients had 23 times the likelihood of neck injury when compared with low-risk patients (p = 0.003, 95% confidence limit). Our results indicate that cervical spine X-rays (i.e., anteroposterior, odontoid, lateral views) are indicated only in high-risk pediatric patients with head injuries who either complain of neck pain or cannot voice such complaints because of significant head injury or preverbal age.(ABSTRACT TRUNCATED AT 250 WORDS)

Correlation of admission fibrin degradation products with outcome and respiratory failure in patients with severe head injury.

It has been suggested that concentrations of fibrin degradation products (FDPs) after head injury reflect the extent of brain tissue destruction. In addition, elevated FDP concentrations have been associated with the development of the adult respiratory distress syndrome (ARDS). Coagulation variables, including a FDP screen, were measured on the admission of 33 patients with severe closed head injury (Glasgow coma score 8 or less) to define the prognostic value of FDP concentrations. A Glasgow outcome score was assigned to each patient 6 months after injury, and those patients with higher FDP concentrations had poorer functional outcomes. This correlation of outcome with admission FDP concentration was statistically significant, as was the correlation between outcome and the admission Glasgow coma score. Of 22 patients with FDP concentrations of less than 64 micrograms/ml, only 1 developed early respiratory failure, whereas 9 of 11 patients with FDP concentrations of 64 micrograms/ml or more developed ARDS. These findings were not affected by the presence of multiple system trauma. FDP concentrations seem to have prognostic value similar to the Glasgow coma score and seem to identify those patients with head injury who are at high risk for ARDS.

Relationship between Flow Cytometric Features and Clinical Behavior of Meningiomas

Meningiomas have a wide range of biological potential and clinical behavior. Histological findings are helpful in recognizing the malignant potential of a given tumor, but often fail to correlate with gross features, liability of recurrence, and extent of associated cerebral edema. To find alternate approaches to improve the correlation between biological and clinical behavior, 20 meningiomas were studied by flow cytometry (FC), an assessment that has been applied to meningiomas previously. Such FC features as DNA index (DI) and proliferative index (PI, %G2 + %S) were correlated with size, location, brain invasion, associated edema, and recurrence. Tumors with severe edema had significantly higher PIs (19.5 +/- 4.1) than those with moderate (12.6 +/- 4.5) or minimal (8 +/- 0) edema (P less than 0.05). The PI was greater than 16 in those tumors that recurred (n = 3) or invaded the brain (n = 3). Six tumors were aneuploid (DI, 1.33 +/- 0.17; PI, 17.1 +/- 5.3). These were uniformly large when compared with the diploid tumors, which were more variable in size. All of the aneuploid tumors were associated with moderate to severe cerebral edema. Two partly psammomatous tumors with high PIs and foci of high cellularity suggesting recent growth were associated with severe edema. One of these exhibited brain invasion. These preliminary data indicate that FC may have a potential use in the clinical management of meningiomas.

Achondroplasia and Cervicomedullary Compression: Prospective Evaluation and Surgical Treatment

The association between sudden death and cervicomedullary compression in infants with achondroplasia has been well described. Prospective clinical and imaging evaluations have been recommended to identify those infants with achondroplasia who are at risk of dying suddenly from respiratory arrest secondary to unrecognized cervicomedullary compression. Since 1988, we have prospectively evaluated 11 infants (average age 13 weeks) with achondroplasia who were asymptomatic for cervicomedullary compression on initial clinical evaluation. Craniocervical magnetic resonance imaging (MRI) findings included narrowing of the foramen magnum, effacement of the subarachnoid spaces at the cervicomedullary junction, abnormal intrinsic cord signal intensity and mild to moderate ventriculomegaly. Two patients with severe cord compression underwent immediate decompression. Two patients developed opisthotonic posturing within 3 months of evaluation and underwent foramen magnum decompression, including suboccipital craniectomy and atlantal laminectomy. Surgery in all cases revealed forward extension of the squamous portion of the occipital bone, thickened posterior rim of the foramen magnum and a dense fibrotic epidural band. There were no complications from surgery. Seven patients did not require surgery and were followed closely. All 11 patients remain asymptomatic at follow-up (mean 4.6 years; range 16 months to 7.3 years), and no patient has required a diversionary shunt procedure. The results of this prospective study confirm that early clinical and MRI evaluations are necessary to determine whether infants with achondroplasia have cervicomedullary compression. With early recognition, an immediate decompression can be performed safely to avoid serious complications associated with cervicomedullary compression, including sudden death.