✓ Five patients had intradural arachnoid cysts of the thoracic spinal canal associated with syringomyelia or posttraumatic intramedullary spinal cord cysts. Three cases were diagnosed 6 to 18 years after spinal surgery and two 14 to 17 years after spinal cord trauma. In each case, delayed progression of symptoms led to the identification of the lesions. The diagnosis was assisted by the use of myelography and delayed computerized tomography scanning in two cases and by magnetic resonance imaging in all five. In each case, the arachnoid cyst appeared to compress the spinal cord or nerve roots; in three cases, the syrinx cavities appeared to exert a significant mass effect. In the two trauma-related cases, the intramedullary cysts were small and may have represented areas of cystic myelomalacia. In four cases, intraoperative real-time ultrasonography helped to localize the arachnoid and intramedullary cavities. All five patients were treated by fenestration of the arachnoid cyst; additional peritoneal shunting of the cyst was performed in one case and of the intramedullary cavity in three. In one patient, the two lesions appeared to have a balancing effect; after drainage of the arachnoid cyst, the syrinx cavity expanded and had to be treated separately. The neurological deficits were reduced in four patients and stabilized in one. Intradural arachnoid cysts and intramedullary cysts may occur together as a late complication of spinal surgery or spinal cord trauma, and either or both lesions may cause delayed neurological deterioration.
Brian T. Andrews, Philip R. Weinstein, Mark L. Rosenblum and Nicholas M. Barbaro
Adam N. Mamelak, Nicholas M. Barbaro, John A. Walker and Kenneth D. Laxer
✓ Corpus callosotomy is valuable for controlling medically intractable generalized seizures in appropriate patients, but postoperative development of language disorders, neuropsychological impairment, and motor dysfunction have all been noted. The extent of callosum resection has been implicated as a possible determinant of outcome, but this hypothesis has not been formally tested. Analysis of the records of all patients who underwent corpus callosotomy at the University of California, San Francisco, from 1986 to 1991 showed that, of 15 patients who underwent anterior or complete callosotomy, seven were entirely or nearly seizure-free, four had at least a 50% reduction in seizure frequency, and four had no change.
To determine callosal size and extent of callosotomy, preoperative and postoperative magnetic resonance images were measured with computer-based planimetry. Seizure outcome was not significantly associated with preoperative callosal size or extent of callosotomy. Intelligence quotient scores did not change significantly after callosotomy. No severe neuropsychological deficits developed after anterior or complete callosotomy, even in patients with mixed cerebral dominance or bilateral language representation. These results indicate that division of the anterior one-half to two-thirds of the corpus callosum is nearly as effective as more extensive anterior sectioning or complete callosotomy in reducing drop-attack and generalized tonic-clonic seizures in appropriate patients, and that the extent of callosotomy is not an important factor on outcome when at least 50% to 65% of the callosum is divided. Mixed cerebral dominance and other unusual patterns of language and memory organization do not appear to increase the postoperative risk for neuropsychological deficits, regardless of the extent of anterior section.
Nicholas M. Barbaro
Nicholas M. Barbaro
Tejas Sankar and Andres M. Lozano
Favorable results with syringoperitoneal shunting
Nicholas M. Barbaro, Charles B. Wilson, Philip H. Gutin and Michael S. B. Edwards
✓ The authors reviewed the clinical findings, radiological evaluation, and operative therapy of 39 patients with syringomyelia. Syringoperitoneal (SP) shunting was used in 15 patients and other procedures were used in 24 patients. Follow-up periods ranged from 1½ to 12 years. During the period of this study, metrizamide myelography in conjunction with early and delayed computerized tomography scanning replaced all other diagnostic procedures in patients with syringomyelia. Preoperative accuracy for the two procedures was 87%.
The most common symptoms were weakness (79%), sensory loss (67%), pain (38%), and leg stiffness (28%). Surgery was most effective in stabilizing or alleviating pain (100%), sensory loss (81%), and weakness (74%); spasticity, headache, and bowel or bladder dysfunction were less likely to be reversed. Approximately 80% of patients with idiopathic and posttraumatic syringomyelia and 70% of those with arachnoiditis improved or stabilized. Better results were obtained in patients with less severe neurological deficits, suggesting the need for early operative intervention. A higher percentage of patients had neurological improvement with SP shunting than with any other procedure, especially when SP shunting was the first operation performed. Patients treated with SP shunts also had the highest complication rate, most often shunt malfunction. These results indicate that SP shunting is effective in reversing or arresting neurological deterioration in patients with syringomyelia.
Devin K. Binder, Paul A. Garcia, Ganesh K. Elangovan and Nicholas M. Barbaro
Prior studies suggest that aura semiology may have localizing value. However, temporal lobe aura characteristics and response to surgery have not been studied in large patient series.
The authors retrospectively analyzed the case records of 182 patients undergoing temporal lobectomy for medically intractable epilepsy at a single institution. They analyzed the frequency and type of auras and seizures preoperatively, and at 3 months and 1 year after temporal lobectomy. Auras were divided into medial semiology (rising epigastric, olfactory/gustatory, experiential, and fear) and lateral semiology (auditory, somatosensory, and visual), or other.
Of 182 patients, 150 were included in this study. The preoperative prevalence of auras was 77%. Multiple types of auras were present in 20% of patients. The most common aura was rising epigastric (26% of all auras). Postoperatively, auras were eliminated in 63% of patients at 3 months and in 64% at 1 year. Seventy-seven patients (51%) were seizure-free and aura-free, 22 (15%) were seizure-free with auras, 26 (17%) had seizures but no auras, and 25 (17%) had seizures with auras. Despite having their auras eliminated, 6.7% of patients continued to have complex partial seizures. Lateral temporal auras were more than twice as likely as medial temporal auras to persist after surgery (p < 0.002).
While the majority of patients in the authors' series became seizure- and aura-free, a significant minority still had persistent auras. Patients with lateral temporal auras appear to be at increased risk for having persistent postoperative auras. The discrepancy between aura and seizure outcomes results in a small group of patients having persistent seizures but losing their auras postoperatively.
Philip A. Starr, Nicholas M. Barbaro, Neil H. Raskin and Jill L. Ostrem
Cluster headache (CH) is the most severe of the primary headache disorders. Based on the finding that regional cerebral blood flow is increased in the ipsilateral posterior hypothalamic region during a CH attack, a novel neurosurgical procedure for CH was recently introduced: hypothalamic deep brain stimulation (DBS). Two small case series have been described. Here, the authors report their technical approach, intraoperative physiological observations, and 1-year outcomes after hypothalamic DBS in four patients with medically intractable CHs.
Patients underwent unilateral magnetic resonance (MR) imaging–guided stereotactic implantation of a Medtronic DBS (model 3387) lead and Soletra pulse generator system. Intended tip coordinates were 3 mm posterior, 5 mm inferior, and 2 mm lateral to the midcommissural point. Microelectrode recording and intraoperative test stimulation were performed. Lead locations were measured on postoperative MR images. The intensity, frequency, and severity of headaches throughout a 1-week period were tracked in patient diaries immediately prior to surgery and after 1 year of continuous stimulation.
At the 1-year follow-up examination, DBS had produced a greater than 50% reduction in headache intensity or frequency in two of four cases. Active contacts were located 3 to 6 mm posterior to the mammillothalamic tract. Neurons in the target region showed low-frequency tonic discharge.
In two previously published case series, headache relief was obtained in many but not all patients. The results of these open-label studies justify a larger, prospective trial but do not yet justify widespread clinical application of this technique.