Faculty Bibliography

Tourette's syndrome (TS) is a childhood neuropsychiatric disorder characterized by multiple involuntary motor and vocal tics. It is commonly associated with other behavioral disorders including attention-deficit/hyperactivity disorder, obsessive-compulsive disorder, anxiety, depression, and self-injurious behaviors. Tourette's syndrome can be effectively managed with psychobehavioral and pharmacological treatments, and many patients experience an improvement in tics in adulthood. However, symptoms may persist and cause severe impairment in a small subset of patients despite available therapies. In recent years, deep brain stimulation (DBS) has been shown to be a promising treatment option for such patients. Since the advent of its use in 1999, multiple targets have been identified in DBS for TS, including the medial thalamus, globus pallidus internus, globus pallidus externus, anterior limb of the internal capsule/nucleus accumbens, and subthalamic nucleus. While the medial thalamus is the most commonly reported trajectory, the optimal surgical target for TS is still a topic of much debate. This paper provides a review of the available literature regarding the use of DBS for TS.

BACKGROUND AND STUDY AIMS/OBJECTIVE:Postoperative pneumocephalus is commonly observed after neurosurgical intracranial procedures and is usually of little consequence. Intraventricular tension pneumocephalus, however, is a rare complication and a neurosurgical emergency that requires immediate intervention. We describe the first case of intraventricular tension pneumocephalus that developed 1 week following an expanded endoscopic endonasal approach for resection of a suprasellar mass. PATIENT/METHODS:A patient who underwent an endoscopic transplanum transtuberculum approach for resection of a suprasellar epidermoid tumor developed a sudden change in mental status, with imaging consistent with intraventricular tension pneumocephalus. Immediate endotracheal intubation and placement of an external ventricular drain prevented further deterioration. Endoscopic exploration of the skull base reconstruction revealed a one-way ball valve mechanism as the source of pneumocephalus. The skull base reconstruction was revised with autologous fascia lata and repositioning of the pedicled nasoseptal flap. CONCLUSION/CONCLUSIONS:Intraventricular tension pneumocephalus is a rare neurosurgical emergency that may develop after endoscopic skull base surgery. Initial management includes endotracheal intubation and placement of an external ventricular drain to decompress the ventricles. Endoscopic exploration and revision of the skull base repair is imperative to obliterate the ball-valve fistula to prevent further entrapment of air.

OBJECTIVE: The clinical entity of thoracic radiculopathy following spinal cord stimulator (SCS) placement has not been previously described. MATERIALS AND METHODS: A retrospective review of prospectively acquired data on 172 patients, having undergone thoracic SCS placement at our institution, was performed. In addition, four patients were implanted at outside institutions, and were referred for revision. We examine our early experience with placement of thoracic SCS in surgically treated patients with chronic pain and 15 associated specific postoperative radicular pain complications along respective thoracic dermatomes. We postulate that preexisting thoracic spinal pathology affords less compliance in the placement of larger paddles, and subsequent radicular pain in a band-like abdominal fashion. RESULTS: A syndrome of thoracic radiculopathy, presenting as intractable lower thoracic or abdominal wall pain occurring in the immediate postoperative period, was identified in 15 patients. These patients subsequently underwent revision surgery, with either a more extensive laminectomy to further decompress the dorsal nerve roots or lead removal, both of which resulted in near immediate relief of symptoms. CONCLUSIONS: Thoracic radiculopathy may occur following SCS paddle lead placement. This clinical syndrome is characterized by its immediate postoperative development, band-like thoracic or abdominal pain pattern, severe pain that both overwhelms the incisional pain and is refractory to medications, and absence of motor deficit. The lateral placement of paddle leads increases the risk of radicular symptoms. Preoperative thoracic spine magnetic resonance imaging may be helpful in identifying patients who may be susceptible to this syndrome.

An 84-year-old man underwent deep brain stimulation (DBS) for mixed rest-action tremors. One year later, he developed a keratoma where the DBS wire emerged from the insertion cap. It was suspected to be a foreign body reaction and removed by a dermatologist but returned and grew conically over the next 4 years, reaching a height of 4 cm (figure). The surrounding skin began to break down with protrusion of the adjacent extension wire. We recommended removal of the lead but due to continued efficacy and advanced age, he decided to continue with the stimulator in place under observation.

Hangman's fractures are fractures across the pars interarticularis of C2 with possible subluxation of C2 on C3. However, no criteria have been defined for the specific indications for surgical fixation. We describe a 30-year old man who sustained a displaced Hangman's fracture after a motor vehicle accident. The fracture was successfully reduced, in the operating room, by compression across crossed translaminar screws while lifting C1 relative to C2. Intra-operative reduction of a displaced Hangman's fracture by compression across crossed translaminar screws is safe and technically feasible.

BACKGROUND: Abetalipoproteinemia is a rare disorder of fat absorption, characterized by vitamin deficiency, acanthocytosis, and neurologic symptoms including ataxia and tremor. CASE REPORT: A 41-year-old male with abetalipoproteinemia is presented. He underwent staged bilateral thalamic deep brain stimulation (DBS) for the treatment of his tremors. After DBS, the patient achieved significant improvements in his tremors, ataxia, and quality of life. DISCUSSION: Thalamic DBS proved to be both safe and efficacious in the management of ataxia and tremors in a patient with abetalipoproteinemia. This is the first report of DBS in abetalipoproteinemia in the literature.

BACKGROUND:Reconstruction of the thoracolumbar spine after corpectomy is a challenge for fractures, infections, and tumors. OBJECTIVE:To analyze fusion rates, clinical outcomes, and the percent of vertebral body coverage achieved by using stackable carbon fiber-reinforced polyetheretherketone cages in thoracolumbar corpectomies, and to measure the actual size of the cages and compare this measurement with the size of the vertebra(e) replaced by the cage. METHODS:A retrospective study of 40 patients who underwent thoracolumbar corpectomies was performed. Preoperative imaging included plain films, computed tomography scans, and magnetic resonance imaging. Postoperatively, plain films and computed tomography scans were obtained, and the width of decompression and cross-sectional area of the cage were measured. The ratio of the area of the cage to the calculated area of the replaced vertebral body was used to determine the percent of vertebral body coverage. RESULTS:The mean follow-up period was 43 months. Successful fusion was observed in 39 patients. One patient experienced cage subsidence with kyphosis. One additional patient incurred a neurological complication that was corrected without long-term consequence. The mean correction of sagittal alignment was 10°, and the mean width of bony decompression was 20 mm. The mean ratio of the area of the carbon fiber cage to the area of the resected vertebral body was 60%. CONCLUSION/CONCLUSIONS:Stackable carbon fiber cages are effective devices for achieving thoracolumbar fusions. No failures of the cages occurred over long-term follow-up. Excellent clinical and radiographic results were achieved by covering a mean of 60% of the vertebral body with the cage.

Spinal dural meningoceles and diverticula are meningeal cysts that have a myriad of clinical presentations and sequelae, secondary to local mass effect. Our objective is to report a technical case report, illustrating a traumatic spinal injury with multiple pedicle fractures, secondary to atrophic lumbar pedicles as well as the diagnostic workup and surgical management of this problem. Posterior lumbar decompression, resection of the meningeal cyst, ligation of the cyst ostium, instrumentation, and fusion were performed with the assistance of intraoperative isocentric fluoroscopy. The cyst's point of communication was successfully located with intraoperative fluoroscopy and the lesion was successfully excised. We suggest that patients with traumatic spinal injuries, having evidence of pre-existing anomalous bony architecture, undergo advanced imaging studies, to rule out intraspinal pathology. The positive clinical and radiographic results support the removal and closure of the pre-existing meningeal cyst at the time of treatment of traumatic spinal injury. Intraoperative isocentric fluoroscopy is a helpful tool in the operative management of these lesions.

BACKGROUND: Peripheral nerve stimulation for chronic pain states is a safe and efficacious technique, being used with increasing frequency. The incidence of hardware-related complications requiring revision remains high. OBJECTIVES: The authors describe a technique of distal to proximal neurostimulator lead revision, which does not require the changing of generators or extension leads, and thus presumably will minimize further device-related complications. METHODS: The authors present a case series of 3 patients where the distal to proximal neurostimulator lead revision technique was utilized. RESULTS: The technique was well tolerated in each instance and all patients reported >50% pain reduction at long-term follow-up. CONCLUSIONS: The distal to proximal neurostimulator lead revision technique quickly and safely adjusts lead position, including both lead depth and lead tip location, without a need for replacement of components or revision of the entire system.