Qualls E. Stevens

Failure rate of frontal versus parietal approaches for proximal catheter placement in ventriculoperitoneal shunts: revisited

Early studies on ventriculoperitoneal shunt malfunctions demonstrated that proximal catheter obstruction was the most common cause for shunt malfunction and choroid plexus was the primary culprit for catheter obstruction. Subsequently, several studies were performed using stereotactic and endoscopic guidance systems to assist with optimal placement of proximal shunt catheters. Surgeons collectively agree that optimum placement of the proximal catheter tip is away from choroid plexus in the frontal horn. To achieve this catheter placement, neurosurgeons typically choose a frontal or parietal approach. Two previous studies comparing parietal and frontal shunt failure rates in the pediatric population have different conclusions. Thus, we decided to compare proximal catheter failure rates of frontal versus parietal approaches on 117 patients (ages ranging from 1 month to 80 years) who had undergone ventriculoperitoneal shunt placement at our institution. Statistical analysis demonstrated a significantly higher malfunction rate in the patients less than 3 years of age and a lower overall malfunction rate in patients shunted for normal pressure hydrocephalus. Surprisingly, there was no significant difference between the two surgical approaches. Thus, we concluded after reviewing the literature, that regardless of the initial surgical approach, the most important variable in shunt malfunction appears to be the final destination of the catheter tip in relation to the choroid plexus.

Intradural extramedullary mature cystic teratoma: not only a childhood disease.

Objective The authors report on the first case of a spinal intradural extramedullary cystic teratoma in an aged patient. These lesions have been reported in adolescents and young adults often with a history of spinal dysraphism. They are believed to be congenital lesions; however, they have also been reported in patients with a history of posterior spinal surgery or lumbar puncture. Method An 85-year-old man was evaluated for persistent and progressive lower extremity paresis. His symptoms began after relatively minor trauma. He had no prior lumbar surgeries. Neuroimaging studies revealed an L1–L2 intradural mass. A putative diagnosis of a cystic intradural extramedullary mass was made. A lumbar laminectomy and durotomy were performed. Results A cystic lesion containing hair follicles, cartilage, adipose, and neural tissue was encountered. Pathologic review corroborated the diagnosis of cystic teratoma. Conclusions The occurrence of cystic teratomas in the absence of previous surgery or lumbar puncture is uncommon. Even rarer are reports of these lesions in aged patients. Of particular interest in this case is the fact that this patient had not undergone any previous lumbar procedures nor did he have a history of spinal dysraphism. Though rare, this entity should be included in the differential of cystic intradural spinal cord lesions.

Reactivation of dormant lumbar methicillin-resistant Staphylococcus aureus osteomyelitis after 12 years

The adequate treatment of methicillin-resistant Staphylococcus aureus (MRSA) osteomyelitis has intrigued clinicians for some time. As the resistance of these pathogens, coupled with the increase in community-acquired cases, continues steadily to rise, clinicians are finding it useful to employ multi-modal approaches for efficacious treatment. The authors present a single case report of a patient with recurrent MRSA osteomyelitis, lumbar paraspinal and epidural abscess. He was found to have decreased muscle strength and was hyporeflexic in the involved extremity. Serum testing demonstrated MRSA bacteremia. Neuroimaging studies revealed evidence of paraspinal abscess and a presumed herniated nucleus pulposus at the L5/S1 interspace with significant nerve root compromise. Despite antimicrobials, his symptoms persisted, necessitating surgical exploration. At surgery, paraspinal and epidural abscesses were encountered and debrided; however, no herniated disc was visualized. This case demonstrates the diagnostic and therapeutic dilemmas with which these lesions present. We postulate that the MRSA osteomyelitis/discitis pathogens were walled off in the disc space and subsequently inoculated the soft tissues with ensuing bacteremia. We concur that antimicrobial treatment should be the first line of therapy for these patients; however, surgical debridements and cautious spinal instrumentation should be employed where appropriate.

Delayed Lateral Rectus Palsy Following Resection of a Pineal Cyst in Sitting Position: Direct or Indirect Compressive Phenomenon?

A rare case of delayed lateral rectus palsy in a patient following resection of a pineal lesion in the sitting position is presented. Postoperative pneumocephalus is common following craniospinal surgical intervention in the sitting position. The sixth cranial nerve is frequently injured because of its prolonged intracranial course. A 13-year-old girl was evaluated for unremitting headaches. No focal deficits were demonstrated on neurological examination. Magnetic resonance imaging revealed a cystlike pineal region mass with peripheral enhancement following intravenous contrast administration. A supracerebellar infratentorial craniotomy was performed in the sitting position, and complete resection of the lesion was achieved. Her postoperative course was complicated by sixth nerve palsy on the third postoperative day. Her symptoms improved with conservative management. The occurrence of sixth cranial nerve palsy secondary to pneumocephalus is a rare entity. Even rarer is the report of this anomaly following craniotomy in the sitting position. This patients symptoms manifested in a delayed fashion. Although uncommon, this complication should be considered in patients undergoing cranial or spinal surgical interventions in this position.

The role of surgical placement and pump orientation in intrathecal pump system failure: a technical report.

Intrathecal pump catheter complications are the most common cause of failure in drug delivery. A previous report has documented that intra-abdominal positioning of the intrathecal pump may predispose the pump-catheter neck to premature catheter breakdown and leakage. Based on this report, we reviewed over 100 intrathecal pump cases to determine the frequency of malpositioning and its role in the pathogenesis of catheter failure. We found three specific cases where a ‘fulcrum effect’ occurred due to intra-abdominal positioning of the pump predisposing the catheter to breakdown. This study demonstrates that intra-abdominal placement of the pump can predispose the catheter to failure/breakdown and that surgeons should attempt to place the pump catheter neck in a superiomedial position, distant from any bony prominences, to prevent the ‘fulcrum effect’ on the pump-catheter neck junction and reducing the likelihood of either internal or external compressive forces.

Use of spinous processes to determine the optimal trajectory for placement of lateral mass screws: technical note.

Study Design Retrospective chart analysis. Objective In the current report, we present a new technique for the placement of lateral mass screws from C3 to C7. The safety, complications, and long-term clinical and imaging follow-up were analyzed. To address potential risk factors for this technique, relevant literature was reviewed and discussed herein. Summary of Background Data Multiple techniques have been reported to place lateral mass screws in the subaxial cervical spine. The trajectory used aims to avoid the vertebral artery and the exiting nerve root. Because of inherent differences in determining the screw trajectory for placement, there can be considerable differences among surgeons. Methods A retrospective analysis of our experience over the period from 2003 to 2006 was undertaken. Standard practices for obtaining institutional review board approval were followed. Radiographs, hospital records, and office charts of 34 patients were reviewed. There was an equal distribution between males and females and the mean age was 56.3 years. Pain was the most frequent presentation. The indications for posterior instrumentation included instability secondary to pseudoarthrosis, infection, spondylosis, osseous metastasis, trauma, and iatrogenic etiologies. Results The follow-up period ranged from 1 to 30 months (average 9.1 mo). Postoperative complications included wound infection (3 cases), malpositioned screw (1 case), cerebrospinal fluid leak (1 case), and dislodged rod (1 case). There were no mortalities directly related to the procedure. Conclusions This technique for placement of lateral mass screws yielded adequate fixation without any appreciable neurovascular complications. It provides a useful alternative for screw placement in patients with intact spinous processes.

Pediatric cranial fixation: a survey of pediatric neurosurgeons.

To date, there are no broad-based studies defining the standard of care for pediatric neurosurgeons in the area of cranial fixation. Thus, the techniques for cranial fixation remain largely surgeon dependent. Over the past few years, there have been several new cranial fixation devices approved for use in the United States. To gain insights into techniques currently in use by pediatric neurosurgeons, we polled all pediatric neurosurgeons listed in either the American Society of Pediatric Neurosurgeons or the International Society of Pediatric Neurosurgeons regarding their techniques for cranial fixation in a variety of age groups. These survey findings may provide a basis for establishing recommendations and lead to a standard of care for cranial fixation techniques among pediatric neurosurgeons.

Umbilical and bilateral inguinal hernias in a veteran powerlifter: is it a pressure-overload syndrome?

Umbilical, inguinal and hiatal hernias are all thought to occur from basically the same etiology, a malformation in the tissue leading to herniation. The mechanisms for these malformations range from congenital to degenerative. Earlier studies proposed that hiatal hernias result from age-related degenerative changes in the phrenoesophageal ligament leading to subsequent herniation. We found that hiatal hernias occur in young power athletes secondary to intra-abdominal pressure overload of the phrenoesophageal ligament. We present a case of umbilical and bilateral inguinal hernias occurring in a veteran powerlifter. The pathogenesis of multiple hernias and the physiological pressure systems involved in the development of multiple hernias in a power athlete are discussed.

Ganglioglioma occurring with glioblastoma multiforme: Separate lesions or the same lesion?

The authors report on the first such case of ganglioglioma and a malignant variant in the same individual without prior irradiation. Gangliogliomas are frequently encountered in children and young adults and have a predilection for the temporal lobes. Sporadic cases of malignant degeneration have been reported; however, most cases have undergone radiation or subtotal resection. A 45-year-old female was seen for speech abnormalities and symptoms referable to elevated intracranial pressure. The patient had no significant past medical history and no history of neurocutaneous disorders. Two separate lesions located in the posterior and anterior temporal lobes were found on imaging. At initial surgery, she underwent gross total resection of the anterior temporal tip ganglioglioma and cyst aspiration of the posterior temporal lobe lesion. The anterior temporal lesion was a ganglioglioma and did not recur. However, the posterior temporal lesion was identified as a malignant ganglioglioma/glioblastoma multiforme variant that recurred multiple times requiring several surgeries, radiation and chemotherapy. The occurrence of these distinct entities is uncommon in patients without a history of prior radiation treatment. Even rarer, is the occurrence of these separate intracranial lesions in a patient without a history of phacomatosis. For benign gangliogliomas, gross total resection can be curative; however, more aggressive variants may be resistant to multimodal therapies.

Nonhemorrhagic Cord Contusion After Percutaneous Fiducial Placement: Case Report and Surgical Recommendations

Abstract Study Design: Single case report and extensive literature review. Objectives: To present the first such report of cervical cord contusion after the percutaneous placement of gold-seed fiducials. The pathomechanics and surgical recommendations are reviewed. Background: Spinal cord injuries are well documented in the medical literature. These injuries range from cord contusion to transection and result primarily from trauma. A single case report of a patient who was found to have a nonhemorrhagic cervical spinal cord contusion after percutaneous fiducial implantation is presented. Methods: Single case report. Results: The patient underwent percutaneous placement of fiducials for stereotactic radiosurgery for a nerve sheath tumor. Postoperatively she had primarily sensory complaints; no motor deficits were detected on neurological examination. Neuroimaging studies demonstrated nonhemorrhagic cervical cord contusion. She was treated conservatively and had complete resolution of her symptoms. Conclusions: The likely mechanism for the contusion was neck hyperextension during thrusting maneuvers during fiducial implantation. This is yet another report of normal intraoperative-evoked potentials with postoperative neurological sequelae. A dedicated team approach involving ancillary staff, anesthesiologists, and surgeons should be utilized to avert this potentially devastating complication.