William M. Chadduck

Intraventricular Cavernous Hemangioma: Report of Three Cases and Review of the Literature

The clinical and radiographic presentations of 3 patients with intraventricular cavernous hemangioma are described. The accumulated total of 19 cases from the literature are compared to determine whether there is a common clinical and radiographic presentation for this benign intraventricular lesion. The differential diagnosis of intraventricular cavernous hemangioma includes intraventricular meningioma, choroid plexus papilloma, arteriovenous malformation, low grade astrocytoma, and ependymoma.

Incidence of Seizures in Patients with Myelomeningocele: A Multifactorial Analysis

To determine the role of ventricular shunts as a cause of seizures in children with hydrocephalus, 190 patients with myelomeningoceles were studied. There was a low incidence of seizures (2%) in the nonshunted patients in spite of a high incidence of ventriculomegaly, whereas the overall frequency of seizures in shunted patients was 22%. Further analysis indicated factors accountable for the increase. Only 9% of patients with shunts that had never required subsequent modification had seizures; however, 22% of the patients had seizures if they had required at least one modification for malfunction alone. Patients with a history of a shunt infection had a further increase in their likelihood of developing seizures to 47%. Information concerning the incidence of seizures by location of the shunt indicated no statistical difference between frontal and parietal entry points, with a frequency of 20% and 26%, respectively; however, there was a higher incidence of seizures in a small group of patients with shunts aberrantly placed in the posterior frontal lobe.

Single cervical exostosis: Report of a Case and Review of the Literature

The authors present a rare case of solitary cervical osteochondroma. Because of its rarity and its predilection for the atlantoaxial area, the diagnosis may be overlooked in evaluating patients having cervical myelopathy. Surgical decompression usually improves the patients neurologic status.

Telomeric associations evolving to ring chromosomes in a recurrent pleomorphic xanthoastrocytoma

Telomeric associations observed in a recurrent untreated pleomorphic xanthoastrocytoma were apparently the primary cytogenetic events that evolved by fusion and breakage events, resulting in subclones with ring chromosomes. The telomeric fusions between chromosomes 15pter and 20qter, and between an extra copy of the long arm of chromosome 1 and chromosome 22qter, evolved in a stepwise fashion to ring chromosomes 20 and 22. The findings in this tumor demonstrate that telomeric association is one mechanism that can initiate chromosome instability by generating subclones with unstable chromosome intermediates and result in ring chromosomes and subsequent chromosome loss.

Silastic duraplasty in pediatric patients

The role of adhesions in the retethering of the neural elements after surgical treatment of spinal dysraphism has produced refinements in the technique of the closure of the neural tube. Silastic, because of its relative inert property, has been used for duraplasty, but a few reports of late complications of hemorrhage or fibrotic capsule formation have caused concern over its use. We report 33 patients with the following diagnoses--eight spinal lipomyelomeningoceles, three myelomeningoceles, six symptomatic Chiari II malformations, seven tethered cords, six spinal cord tumors, two diastematomyelia, and one cerebellar astrocytoma--in whom Silastic dural grafts were used to prevent the adherence of neural structures to the overlying tissues. Our surgical technique is presented here. The patients have been observed for up to 6 years. Only one became infected, was treated with antibiotics without graft removal, and has remained without sequelae for over 3 years. One had an incidental pseudomeningocele that was noted on follow-up magnetic resonance imaging scan that was not clinically apparent. There have been no hemorrhages, leakage of cerebrospinal fluid, nor other complications from using nonreinforced Silastic sheeting. In one patient, Dacron-reinforced Silastic was used and, upon reexploration, a marked fibroblastic response was noted. A review of the literature suggests that fibrotic complications are related to this Dacron-reinforced Silastic. The hemorrhagic complications that were reported occurred in instances where Silastic grafts were large and no technical modifications were made preventively. We conclude that the use of nonreinforced Silastic dural grafts, with appropriate technical modifications in surgical technique, is safe and may prevent retethering of neural tissues in a variety of neurosurgical lesions.

Cytogenetic findings in a pleomorphic xanthoastrocytoma

We report a pleomorphic xanthoastrocytoma with an abnormal clonal cell line of 48,XY, +3, +5, -20, -22, +der(7)t(7;?)(p22;?), +der(20)t(15;20)(q11;q13).

Multicentric glioma as a cause of multiple cerebral lesions.

Two new cases of multicentric glioblastoma are presented to re-emphasize the needs (a) to consider this diagnosis in patients with multiple intracerebral lesions suggesting metastases or abscesses and (b) to consider prompt biopsy of accessible lesions in these patients.

Transcranial doppler ultrasonography for the evaluation of shunt malfunction in pediatric patients

Previous studies have demonstrated a high correlation between hydrocephalus and the resistive index (RI), as determined by transcranial Doppler ultrasonography. Measurements of RI, calculated by dividing the difference between the peak systolic velocity and the enddiastolic velocity by the peak systolic velocity, were attempted in 55 pediatric patients during evaluations for ventriculoperitoneal shunt malfunctions; values were obtained in 52. Indications of shunt malfunction included both clinical and radiographic evidence of increased intracranial pressure. Eleven patients, determined to have functional shunts both by clincal criteria and subsequent outcome, had RIs of 47±5 (average±1 standard deviation). Shunt malfunctions were confirmed in 41 patients. Prior to shunt revisions, these 41 patients has RIs of 71±10%; following revision, the RIs fell to 53±12%. Nine patients had had pre-malfunction RIs of 48±11% obtained during routine follow-ups; when they subsequently had shunt malfunctions, their RIs had significantly increased. Four of the 41 patients with shunt malfunctions had essentially normal RIs (52±7%), but had fluid tracking along the shunt; in these, RIs were essentially unaffected by shunt revision. For comparison, 119 pediatric patients with clinically functional ventriculoperitoneal shunts had RIs of 50±9%. The data, statistically significant with a P value of <0.001, showed a correlation between elevated RIs and shunt malfunction; thus, transcranial Doppler ultrasonography is a practical, non-invasive technique useful in the diagnosis of ventriculoperitoneal shunt malfunction.

Cranial doppler ultrasonography correlates with criteria for ventriculoperitoneal shunting

Using pulsed Doppler ultrasound through the sonic window of the anterior fontanelle in infants, 46 children with ventriculomegaly had sequential evaluations of Resistive Index for comparison with the need for ventriculoperitoneal shunting. Hydrocephalus was associated with myelomeningocele in 17 patients and posthemorrhagic, postmeningitic, or congenital hydrocephalus accounted for the rest. The Resistive Index was obtained by dividing the difference between the peak systolic and end diastolic frequencies by the systolic frequency. Criteria for shunting included massive ventriculomegaly, increasing ventriculomegaly with an abnormal increase in head circumference, and clinical evidence of symptomatic hydrocephalus. Those patients requiring shunts had a Resistive Index of 84 +/- 13% prior to shunting. The Resistive Index fell to 72 +/- 11% postshunting with the difference being statistically significant at p less than 0.001. Moreover, the postshunting values compared favorably to data on 29 normal newborns, having Resistive Indices of 71 +/- 7% and to the Resistive Indices of three patients never shunted who had values of 74%, 66%, and 71%. Variations included primarily low Resistive Indices in myelomeningocele patients whose ventricles were decompressed by the leaking spinal lesions. Resistive Index used in conjunction with clinical observations may be extremely helpful not only in predicting the need for ventriculoperitoneal shunt, but also in evaluating children suspected of shunt malfunctions.

Congenital Aneurysmal Hemorrhage and Astrocytoma in an Infant

The authors present the unusual case of an infant who presented at 4 weeks of age with a spontaneous intracerebral hemorrhage due to rupture of a congenital left middle cerebral artery aneurysm. He recovered only to present at 4 months of age with a right frontoparietal desmoplastic cerebral astrocytoma of infancy. The association of brain tumor and aneurysm is discussed, as are the cytogenetic findings associated with this rare form of benign astrocytoma.