Detection of vertebral artery injury after cervical spine trauma using magnetic resonance angiography.

BACKGROUND: We prospectively describe the incidence, magnetic resonance-based diagnosis, and treatment of vertebral artery (VA) injury resulting from closed cervical spine trauma. METHODS: Patients with fracture or dislocation on plain radiographic studies underwent computed tomography. Among these patients, the subset with computed tomographic evidence of foramen transversarium (FT) fracture underwent magnetic resonance angiography as early as possible. RESULTS: During a 16-month period, 38 patients with closed cervical trauma were treated. Twelve patients demonstrated fracture extension through at least one FT by computed tomography. Among these patients, four showed unilateral VA injury by magnetic resonance angiography, all ipsilateral to the fractured FT. Three cases of VA occlusion and one of focal narrowing were demonstrated. All four patients were initially treated with aspirin, and two were systemically anticoagulated. None developed irreversible neurologic deficits from the VA compromise. CONCLUSION: Our data suggest that the incidence of VA injury in closed cervical spine trauma is significant and that FT fractures warrant flow-sensitive magnetic resonance imaging.

Cervical spine fractures in the elderly.

BACKGROUND: Cervical spine fractures in the elderly are relatively common. The management of such injuries may be complicated by underlying medical debility and osteopenia as well as reduced tolerance to halo immobilization. METHODS: Over a 1-year period, 43 cervical spine fractures were treated at our institution. Ten (23%) were in persons 70 years of age or older. This retrospective analysis describe the clinical features, treatment, and outcome of these 10 elderly patients. All fractures in this patient population involved the atlantoaxial complex, including five combination C1-C2 fractures. Six patients were treated with early halo immobilization and three were initially managed with a rigid cervical collar. Three patients required posterior cervical fusion. RESULTS: Of the six patients undergoing halo immobilization, five progressed to osseous union. Three patients were immobilized in a Philadelphia collar resulting in one osseous union, one nonunion, and one death. Three patients underwent posterior cervical fusion with subsequent osseous union in all three. CONCLUSIONS: Although external immobilization with a halo device is our treatment of choice for most C1 and C2 fractures in elderly patients, a Philadelphia collar is useful in select cases when halo immobilization or early surgical fusion is contraindicated. Posterior cervical fusion can be safely and effectively performed in elderly patients and should be strongly considered for initial therapy in the elderly with fracture types unlikely to progress to osseous union with external immobilization alone.

Metastatic melanoma to the spine. Demographics, risk factors, and prognosis in 114 patients.

STUDY DESIGN: One-hundred-fourteen patients with metastatic melanoma of the spine were retrospectively reviewed. OBJECTIVE: The goal was to define the demographics, risk factors, and prognosis for this population. SUMMARY OF BACKGROUND DATA: The incidence of melanoma is increasing faster than any other cancer. Therefore, orthopedic and neurologic surgeons will be increasingly confronted by patients with spinal metastases from melanoma. However, the demographics, risk factors, and prognosis remain unclear. METHODS: From 7010 consecutive patients with melanoma, 114 were identified with clinically or radiographically evident spinal metastases. A comparison was made between these patients and the remainder of the population with melanoma seen at our institution using contingency table analysis with statistical significance determined by a chi-squared test. Survival data were represented by Kaplan-Meier curves, and log-rank testing was used for statistical comparisons. RESULTS: Risk factors associated with the development of these metastases included primary lesions that were ulcerated, deeper than 0.76 mm, or of Clark level II, or located on the trunk or mucosal surfaces. The median survival time for all patients was 86 days, but this was reduced in patients with more than one metastatic site in addition to the spine. CONCLUSION: The prognosis for most patients with spinal metastases from melanoma is dismal. However, patients with metastatic disease limited to the spine and one other organ may survive for a relatively prolonged time and may be candidates for surgical intervention directed toward symptomatic relief.

Unilateral posterolateral decompression without stabilization for neurological palliation of symptomatic spinal metastasis in debilitated patients.

Patients with symptomatic spinal metastases and limited life expectancy are often too debilitated to withstand anterior or posterolateral spinal cord decompression and segmental stabilization. More limited surgery aiming solely at preservation or restoration of neurological function and relief from pain offers the potential for significant improvement in the quality of remaining life without incurring undue perioperative morbidity and mortality. Eight patients with spinal metastases and limited life expectancy underwent a unilateral transpedicular decompression procedure on their most symptomatic side and/or the side of maximum tumor involvement. All patients were neurologically improved within the 1st postoperative week; all were ambulatory and continent postoperatively. Postoperatively, all five patients with preoperative motor deficits demonstrated increased motor strength, and the three patients with predominant radicular pain reported marked improvement. There were no perioperative deaths and two transient perioperative complications. The average length of hospitalization was 6 days for patients without complications and 10 days for the entire group. Unilateral transpedicular decompression without stabilization is an effective and safe method for palliating symptomatic spinal metastases in debilitated patients with widespread malignancy and limited life expectancy. This therapeutic option should be considered in select cases as an alternative to either nonoperative management or anterior or posterolateral decompression and segmental stabilization.

Spinal subdural abscess: successful treatment with limited drainage and antibiotics in a patient with AIDS.

The authors present a case of Staphylococcus aureus spinal subdural abscess in a patient with AIDS. Although complete surgical drainage has been strongly advocated in the literature, this patient made a complete neurologic and symptomatic recovery and radiographically demonstrated resolution of the abscess with only limited surgical drainage and parenteral antibiotics. Magnetic resonance imaging findings of this unusual lesion are discussed. Relevant literature in the management of spinal subdural abscesses is reviewed.

Franz Josef Gall and his contribution to neuroanatomy with emphasis on the brain stem.

Franz Josef Gall, born in 1758, studied medicine in Strasbourg and Vienna and focused his research in two areas. His most notorious research was in craniofacial morphology that gradually evolved into the pseudoscience of phrenology. His second research area was neuroanatomy. Although Gall is usually best remembered for his inglorious introduction of phrenology, his neuroanatomic contributions have more lasting significance. In this vignette we explore Gall's neuroanatomic contributions especially as they relate to brain stem anatomy. By means of blunt dissection he was the first to describe the origins of several cranial nerves, including the trigeminal nucleus. It will be apparent that Gall--his dubious introduction of phrenology notwithstanding--was a pioneer in the description of brain stem anatomy.

The history of trephination in Africa with a discussion of its current status and continuing practice.

Trephination of the skull is one of the most fascinating and, certainly, one of the oldest therapeutic procedures known to man. After Prunières' discovery of the trephined skull at Aiguières in 1868, a plethora of information has been gathered about the procedure. There, however, exits little documentation of African trephination or its history. Using both primary and secondary sources, we have discovered that African trephination was known in the time of Herodotus, has a rich history, and is currently practiced widely throughout Africa for specific reasons. We discuss these findings as they relate to preconceived notions of trephinations in other countries and to the history of neurosurgery.

Extreme lateral lumbar disc herniation. Diagnosis and management.

Extreme lateral disc herniation accounts for about 10% of lumbar disc ruptures and is more common in the elderly. Patients will frequently complain of pain in the groin and anterior thigh but little if any back pain. Because the L4 root is often involved, the physical exam often shows quadriceps weakness and a diminished patellar reflex. Other important signs include a negative Lasèque's sign and reproduction of pain with lateral bending of the back toward the involved extremity. Currently, CT or MRI are the diagnostic procedures of choice. The initial treatment for extreme lateral disc herniation is bed rest and NSAIDs with surgery if conservative therapy fails. Primary care physicians should consider extreme lateral disc herniation when they evaluate patients with low back and leg pain.

The expression of deafferentation dysesthesias reduced by dorsal root entry zone lesions in the rat.

Extensive longitudinal lesions of the dorsal root entry zone (DREZ) are effective in relieving some chronic deafferentation pain in humans. A deafferentation syndrome follows C5-T2 dorsal root ganglionectomies in rats. The syndrome consists of biting and scratching the completely and partially denervated limb areas, respectively. This study examines the effect of DREZ lesions on the deafferentation syndrome in the rat. Of 37 rats, 24 underwent C5-T2 ganglionectomies only, five received C4-T3 micromechanical DREZ lesions only, and eight underwent ganglionectomies plus simultaneous DREZ lesions. The animals were observed for 45 days post-operatively. Histological analysis of the spinal cord lesions was performed. All rats with ganglionectomies alone exhibited the deafferentation syndrome; however, no rats with DREZ lesions alone showed this feature. Only 25% of rats with combined ganglionectomies and DREZ lesions exhibited the deafferentation syndrome in the first 30 days, whereas 80% of the animals with ganglionectomies only did so. Although 75% of the animals with combined lesions eventually bit the insensitive forepaw, this behavior was significantly attenuated: the day of onset was delayed and the extent of self-mutilation was reduced. Postmortem histological examination of the DREZ lesions indicated a close association between the completeness of the dorsal horn destruction and the reduction or prevention of self-mutilation. These data support the validity of the animal model and also the hypothesis stating that the deafferentation syndrome results from abnormal spontaneous neural activity in the dorsal horn. Moreover, the variability of the histological findings in these experiments stresses the importance of making contiguous and complete dorsal horn lesions in human DREZ surgery.

Dorsal root entry zone lesions in the treatment of pain related to radiation-induced brachial plexopathy.

Radiation-induced brachial plexopathy (RBP) is a rare (1-2% of irradiated patients) but serious disorder associated with supramaximal irradiation of the brachial plexus. Nerve compression by radiation-induced fibrosis in the absence of tumor recurrence is the hypothesized mechanism of RBP. It appears as severe pain in up to 20% of cases. Current medical and surgical therapies are ineffective in obtaining long-term pain control. Dorsal root entry zone (DREZ) lesions represent a potential therapy for the pain associated with RBP. The records of two patients with RBP with severe pain successfully treated with DREZ lesions are reviewed. Each received supramaximal radiation to the brachial plexus following resection of the malignancy and had pain within the irradiated area approximately 1 year following radiation without evidence of tumor recurrence by either computed tomography or magnetic resonance imaging. Electromyography patterns consistent with RBP were detected within the irradiated area in both patients. Pain was in the C8-T1 distribution and described as sharp and burning. Both patients failed to obtain pain relief with prior medical and/or surgical procedures. Histologic sections of nerves were taken at surgery and confirmed the diagnosis of radiation-induced injury. Within the immediate postoperative period both patients experienced excellent pain relief and continue to be pain free at 29-48-month follow-up observation. The DREZ lesions provide a safe and effective therapy for the pain associated with RBP.

The history of neurosurgical procedures for the relief of pain.

Pain has been a major medical problem from the beginning of recorded history. Since the earliest medical writings, there have been innumerable procedures designed to relieve pain and its suffering. In this study, we have reviewed both the early medical writings of various civilizations and the first modern publications, to compile a history of neurosurgical procedures for the relief of pain.

Solitary eosinophilic granuloma invading the clivus of an adult: case report.

A 41-year-old white man with facial pain and diplopia was found to have an invasive lesion of the clivus. The final pathological diagnosis was eosinophilic granuloma. The patient's symptoms resolved completely after transsphenoidal resection of the lesion. The pathological and radiological diagnosis and the treatment of solitary eosinophilic granulomas are discussed.

Initial management of pediatric head trauma.

Head injuries are the most common cause of disability and death in children. Identification of children who require specialized management following a head injury will reduce the associated morbidity and mortality. Thus, it is important to differentiate the child who can be safely observed and who will recover spontaneously from the child who will develop a progressive neurologic deficit from a treatable cause. A thorough history, a tailored neurologic examination and limited radiographic studies will assist the family physician in making this determination.

Isolated oculomotor nerve palsy following apoplexy of a pituitary adenoma.

An isolated oculomotor nerve palsy is very rarely the presenting sign of a pituitary adenoma. It may occur slowly due to mechanical compression or rapidly, secondary to pituitary apoplexy. Magnetic resonance imaging (MRI) with and without gadolinium DTPA enhancement provides excellent anatomical detail and is useful in the planning of the operative procedure. When correctly diagnosed and treated, the third nerve dysfunction appears to be reversible. We report a case of a pituitary adenoma presenting with an isolated, partial oculomotor nerve palsy in the setting of apoplexy. The pathophysiology, prognostic factors and MRI findings of this entity are discussed.

Deafferentation syndrome in the rat: effects of sex, age, and lesion type.

A deafferentation syndrome can be produced in Sprague-Dawley rats following dorsal root sections. The behavior may be objective evidence of dysesthesias, thus serving as an experimental model to study chronic dysesthesias caused by deafferentation in humans. This article examines the effects of sex, age, and lesion type on the expression of the deafferentation syndrome in Sprague-Dawley rats. No significant differences were found in the expression of the deafferentation syndrome with respect to age and weight in male rats within the ranges studied. Sex and lesion type did alter the expression of the syndrome.

Perinatal spinal cord injury: clinical, radiographic and pathologic features.

Perinatal spinal cord injury is a relatively uncommon, but a frequently misdiagnosed disorder. Often, the injury is not suspected and an erroneous diagnosis is made. We present five cases of perinatal spinal cord injury. In four, the referring physicians (including pediatric neurologists) misdiagnosed the condition. In view of these diagnostic difficulties, we review the clinical, radiographic and pathologic aspects of these injuries. Serious spinal injuries occasionally occur in the perinatal period. With improving medical care, many infants with less severe injuries are surviving the neonatal period. Therefore, the prompt recognition of neonatal spinal cord damage is essential and allows for optimal treatment of the injured child.

Flow activates an endothelial potassium channel to release an endogenous nitrovasodilator.

Flow-mediated vasodilation is endothelium dependent. We hypothesized that flow activates a potassium channel on the endothelium, and that activation of this channel leads to the release of the endogenous nitrovasodilator, nitric oxide. To test this hypothesis, rabbit iliac arteries were perfused at varying flow rates, at a constant pressure of 60 mm Hg. Increments in flow induced proportional increases in vessel diameter, which were abolished by L,N-mono-methylarginine (the antagonist of nitric-oxide synthesis). Barium chloride, depolarizing solutions of potassium, verapamil, calcium-free medium, and antagonists of the KCa channel (charybdotoxin, iberiotoxin) also blocked flow-mediated vasodilation. Conversely, responses to other agonists of endothelium-dependent and independent vasodilation were unaffected by charybdotoxin or iberiotoxin. To confirm that flow activated a specific potassium channel to induce the release of nitric oxide, endothelial cells cultured on micro-carrier beads were added to a flow chamber containing a vascular ring without endothelium. Flow-stimulated endothelial cells released a diffusible vasodilator; the degree of vasorelaxation was dependent upon the flow rate. Relaxation was abrogated by barium, tetraethylammonium ion, or charybdotoxin, but was not affected by apamin, glybenclamide, tetrodotoxin, or ouabain. The data suggest that transmission of a hyperpolarizing current from endothelium to the vascular smooth muscle is not necessary for flow-mediated vasodilation. Flow activates a potassium channel (possibly the KCa channel) on the endothelial cell membrane that leads to the release of nitric oxide.

Spinal epidural abscess as a complication of Fournier's gangrene.

Fournier's gangrene is a rare, multi-organism infection of the perineum. The disease is most often confined to the groin area with distant spread being extremely unusual. A ase of spinal epidural abscess as a complication of Fournier's gangrene is presented. The infection appears to have spread by the hematogenous route. The patient had several symptoms, including fever, which could have provided an early diagnostic clue. Multiple fever workups were negative, however, and the diagnosis was not made until quadriplegia developed. A lumbar puncture as part of the fever workup might have allowed for an earlier diagnosis and more prompt surgery.

L-arginine normalizes endothelial function in cerebral vessels from hypercholesterolemic rabbits.

We hypothesized that normal vascular reactivity could be restored in vessels from hypercholesterolemic animals by exposing them to L-arginine, the precursor of endothelium-derived relaxing factor (EDRF). Basilar arteries were harvested from New Zealand white rabbits fed normal chow or that supplemented with 2% cholesterol for 10 wk. Vessels were cannulated for perfusion at physiologic pressure. Changes in vessel diameter were monitored by videomicroscopy. In comparison to normal vessels, those from hypercholesterolemic animals vasoconstricted more to KCl, endothelin (E), and 5-hydroxytryptamine (5-HT). Conversely, vasodilation to acetylcholine (ACh) (but not that to verapamil) was significantly impaired in the hypercholesterolemic animals. In vitro administration of L-arginine (3 mM) for 45 min normalized vasodilation to ACh and vasoconstriction to E, 5-HT, and KCl in the isolated vessels from hypercholesterolemic animals. This effect was stereospecific, since D-arginine had no effect. To conclude, these data confirm that hypercholesterolemia attenuates endothelium-derived relaxation, and enhances the sensitivity of these vessels to vasoconstrictors. In vitro administration of L-arginine normalized vascular reactivity of isolated vessels from hypercholesterolemic animals. Thus, hypercholesterolemia induces a reversible endothelial dysfunction that may be corrected by supplying the precursor of EDRF, L-arginine.