David A. Lundin

OBJECT: Intraoperative stimulation mapping of subcortical white matter tracts during the resection of gliomas has become a valuable surgical adjunct that is used to reduce morbidity associated with tumor removal. The purpose of this retrospective analysis was to assess the morbidity and functional outcome associated with this method, thus allowing the surgeon to predict the likelihood of causing a temporary or permanent motor deficit. METHODS: In this study, the authors report their experience with intraoperative stimulation mapping to locate subcortical motor pathways in 294 patients who underwent surgery for hemispheric gliomas within or adjacent to the rolandic cortex. Data were collected regarding intraoperative cortical and subcortical stimulation mapping results, along with the patient's neurological status pre- and postoperatively. For patients in whom an additional motor deficit occurred postoperatively, its evolution was examined. Of 294 patients, an additional postoperative motor deficit occurred in 60 (20.4%). Of those 60, 23 (38%) recovered to their preoperative baseline status within the 1st postoperative week. Another 12 (20%) recovered from their postoperative motor deficit by the end of the 4th postoperative week, and 11 more recovered to their baseline status by the end of the 3rd postoperative month. Thus, 46 (76.7%) of 60 patients with postoperative motor deficits regained their baseline function within the first 90 days after surgery. The remaining 14 patients (4.8% of the entire study population of 294) had a persistent motor deficit after 3 months. Patients whose subcortical pathways were identified with stimulation mapping were more prone to develop an additional (temporary or permanent) motor deficit than those in whom subcortical pathways could not be identified (27.5% compared with 13.1%, p = 0.003). This was also true when additional (permanent) motor deficits lasted more than 3 months (7.4% when subcortical pathways were found, compared with 2.1% when they were not found; p = 0.041). CONCLUSIONS: In patients with gliomas that are located within or adjacent to the rolandic cortex and, thus, the descending motor tracts, stimulation mapping of subcortical pathways enables the surgeon to identify these descending motor pathways during tumor removal and to achieve an acceptable rate of permanent morbidity in these high-risk functional areas.

OBJECTIVE: Rotational vertebrobasilar insufficiency is a severe and incapacitating condition. Proper investigation and management are essential to reestablish normal posterior circulation hemodynamics, improve symptoms, and prevent stroke. We present a series of 10 patients with rotational vertebrobasilar ischemia who were treated surgically and emphasize the importance of transcranial Doppler in the diagnosis and management of this condition. METHODS: All patients presented with symptoms of vertebrobasilar insufficiency induced by head turning. Transcranial Doppler documented a significant decrease in the posterior cerebral artery velocities during head turning that correlated with the symptoms in all patients. A dynamic cerebral angiogram was performed to demonstrate the site and extent of vertebral artery compression. RESULTS: The surgical technique performed was tailored to each individual patient on the basis of the anatomic location, pathogenesis, and mechanism of the vertebral artery compression. Five patients underwent removal of osteophytes at the level of the subaxial cervical spine, one patient had a discectomy, two patients had a decompression only at the level of C1-C2, and two patients had a decompression and fusion at the C1-C2 level. CONCLUSION: The transcranial Doppler is extremely useful to document the altered hemodynamics preoperatively and verify the return of normal posterior circulation velocities after the surgical decompression in patients with rotational vertebrobasilar ischemia. Surgical treatment is very effective, and excellent long-term results can be expected in the vast majority of patients after decompression of the vertebral artery.

Retained foreign bodies pose a risk to the patient from the perspective of potential morbidity. We describe a previously healthy 8-year-old boy with head and back trauma from a glass picture frame that fell off the wall. He sustained a closed head injury and a back laceration several centimeters lateral to the spine. A persistent drainage from the back laceration contained glucose and protein levels consistent with cerebral spinal fluid. A foreign body was easily visible on subsequent plain radiograph. The glass foreign body was removed by neurosurgeons after computed tomography and magnetic resonance imaging clarified the exact location of the glass fragment. Physicians should have a low threshold for obtaining plain radiographs in patients with glass foreign bodies and consider that projectiles may rest some distance from the laceration site.

Spondylolysis and spondylolisthesis can be associated with significant low back pain, especially in physically active adolescents. Non-operative management is usually successful in improving symptoms, but surgical intervention is occasionally required for those that fail reduction of activity and bracing. In a subpopulation of these patients, direct repair of the pars interarticularis defect can be an effective modality of treatment. The advantage of direct pars repair over intertransverse fusion with or without segmental instrumentation is the preservation of the anatomic integrity and motion of the affected segment. We describe our experience in 5 patients (aged 15-18 years) managed by direct pars interarticularis repair after failing multimodality non-operative treatment. The length of stay averaged 3.2 days (range 3-4 days). All 5 patients were able to return to full activity with either no (60%) or minor (40%) symptoms. No immediate or delayed complications were noted. Patients were followed a minimum of 30 months (range 30-78 months). All 5 patients demonstrated evidence of bony fusion by radiographic criteria. This demonstrates that direct pars repair is a safe and effective modality to treat select groups of patients with spondylolysis and low-grade spondylolisthesis.