Epidermoid cyst of the thoracic spine: case history.

Epidermoid cysts of the spinal cord are very rare tumors. We report a 31 year-old female who presented with a 5 months history of progressive lower extremity weakness and spasticity. Magnetic resonance imaging of the thoracic spine revealed a 2 cm intradural, extramedullary mass at the T4-5 level. A T4 and T5 osteoplastic laminotomy with complete removal of the intradural mass was performed. Intraoperative and final histological examination revealed an epidermoid cyst. Epidermoid cysts must be a consideration for intradural, extramedullary lesions of the spinal cord. Complete surgical resection offers the patient an opportunity for good neurologic outcome.

Microvascular decompression in the treatment of hypertension: review and update.

BACKGROUND: Neurogenic hypertension in association with vascular compression of the left rostral ventrolateral medulla has been documented. A recent group of these clinical reports has raised great interest in decompression of this area of the brainstem as a definitive therapy for essential hypertension. METHODS: To further clarify the mechanism by which decompression of the left rostral ventrolateral medulla relieves neurogenic hypertension, we describe in detail the basic science, animal models, human studies, and most recent clinical trials regarding surgical decompression of this area. CONCLUSION: Multi-disciplinary evidence supports the hypothesis that a sub-population of hypertensive patients achieve significant relief of their hypertension after microvascular decompression. A multi-institutional, prospective, randomized study is necessary to determine the efficacy of microvascular decompression for neurogenic hypertension.

Radiosurgery for childhood intracranial arteriovenous malformations.

OBJECTIVE: The optimal management of intracranial arteriovenous malformations (AVMs) in children remains controversial. Children with intracranial AVMs present a special challenge in therapeutic decision-making because of the early recognition of their future life-long risks of hemorrhage if they are treated conservatively. The goals of radiosurgery are to achieve complete AVM obliteration and to preserve neurological function. We present long-term outcomes for a series of children treated using radiosurgery. METHODS: The findings for 53 consecutive children who underwent at least 36 months of imaging follow-up monitoring after radiosurgery were reviewed. The median age at the time of treatment was 12 years (range, 2-17 yr). Thirty-one children (58%) presented after their first intracranial hemorrhaging episodes, two (4%) after their second hemorrhaging episodes, and one (2%) after five hemorrhaging episodes. Nineteen children (36%) presented with unruptured AVMs, and a total of 25 children (47%) exhibited neurological deficits. AVMs were graded as Spetzler-Martin Grade I (2%), Grade II (23%), Grade III (36%), Grade IV (9%), or Grade VI (30%). The median AVM volume was 1.7 ml (range, 0.11-10.2 ml). The median marginal dose was 20 Gy (range, 15-25 Gy). RESULTS: Results were stratified according to AVM volumes (Group 1, < or =3 ml; Group 2, >3 ml to < or =10 ml; Group 3, >10 ml). Twenty-eight patients (80%) in Group 1 and 11 (64.7%) in Group 2 achieved complete obliteration. The only patient in Group 3 did not achieve obliteration. Complications included brainstem edema (n = 1) and transient pulmonary edema (n = 1). Four patients experienced hemorrhaging episodes, 30, 40, 84, and 96 months after radiosurgery. Multivariate logistic regression analysis demonstrated that only volume was significantly correlated with obliteration rates (P = 0.0109). CONCLUSION: Radiosurgery is safe and efficacious for selected children with AVMs. The obliteration rates and the attendant low morbidity rates suggest a primary role for stereotactic radiosurgery for pediatric AVMs.

Outcome analysis of endoscopic III ventriculostomy.

A retrospective chart review was performed on 54 patients who had undergone endoscopic III ventriculostomy (E3V) in the past 6 years. Patient charts were reviewed to establish age at the time of operation, sex, preoperative diagnosis, preoperative shunt procedures, success or failure of the E3V, duration of success, and complications. Success of an E3V was determined by the resolution of preoperative symptoms and avoidance of a CSF shunt. The most recent clinic visit with adequate documentation of signs and symptoms of hydrocephalus was used as the last date of follow-up. The overall success rate was 74%. Children over the age of 3 years with an acquired CSF obstruction had a significantly greater probability of successful treatment (P=0.05). Younger children, especially those with hydrocephalus attributable to obstruction of the arachnoid villi, as in intraventricular hemorrhage (IVH), were less likely to benefit from E3V.

Remote effects of acute ischemic stroke: A xenon CT cerebral blood flow study.

OBJECTIVE: The purpose of this study was to verify transhemispheric diaschisis in the early hours after an ischemic event. METHODS: XeCT cerebral blood flow (CBF) studies within 8 h of stroke were studied in 23 patients. Mean CBF was evaluated in the ischemic area, contralateral hemisphere and ipsilateral cerebellum. RESULTS: A severe CBF reduction was found in the ischemic area (mean 9 +/- 3 ml/100 g/min). The mean CBF in the unaffected hemisphere (33 +/- 10 ml/100 g/min) was 35% less compared to the normal mean value. CBF was decreased in the cerebellum ipsilateral to the stroke (mean 31 +/- 12 ml/100 g/min) suggesting a blood flow depression of the whole brain. CONCLUSIONS: During the initial hours of cerebral ischemia, the asymptomatic hemisphere demonstrated CBF depression that was part of the global flow reduction.

Recurrent trigeminal neuralgia attributable to veins after microvascular decompression.

OBJECTIVE: To demonstrate the cause of and optimal treatment for recurrent trigeminal neuralgia (TN) in cases where veins were observed to be the offending vessels during the initial microvascular decompression (MVD) procedure. METHODS: An electronic search of patient records from 1988 to 1998 revealed that 393 patients were treated with MVD for TN caused by veins. The pain recurred in 122 patients (31.0%). Thirty-two (26.2%) of these patients underwent reoperations. Clinical presentations, recurrence intervals, surgical findings, and clinical outcomes were analyzed. RESULTS: Analysis of 32 consecutive cases of recurrent TN initially attributable to veins revealed a female predominance (female/male = 26:5), with one female patient exhibiting bilateral TN caused by venous compression. Patient ages ranged from 15 to 80 years, with a prevalence in the seventh decade. The V2 distribution of the face was involved more frequently than other divisions. For 24 patients (75%), recurrence occurred within 1 year after the initial operation. At the time of the second MVD procedure, development of new veins around the nerve root was observed in 28 cases (87.5%). After successful subsequent MVD procedures, the pain was improved in 81.3% of the cases. CONCLUSION: The recurrence rate for TN attributable to veins is high. If pain recurs, it is likely to recur within 1 year after the initial operation. The most common cause of recurrence is the development and regrowth of new veins. Even fine new veins may cause pain recurrence; these veins may be located beneath the felt near the root entry zone or distally, near Meckel's cave. Because of the variable locations of vein recurrence, every effort must be made to identify recollateralized veins. Given the high rate of pain relief after a second operation, MVD remains the optimal treatment for the recurrence of TN attributable to vein regrowth.

Metastatic prostate adenocarcinoma of the dura mater.

A 70-year-old man with known metastatic prostate carcinoma to the long bones of the lower extremities, presented with a several day history of lethargy and confusion. CT was interpreted as showing bilateral acute and chronic subdural hematomas (SDH). Upon opening the dura, a yellowish, firm tumor was layered over the frontal convexity. No hematoma was found. Histological examination revealed prostate carcinoma.

Removal of a thrombus from the sigmoid and transverse sinuses with a rheolytic thrombectomy catheter.

A rheolytic thrombectomy catheter was used to remove thrombus without thrombolytics from the sigmoid and transverse sinuses of a 34-year-old woman. Using small, high-flow fluid jets and Venturi-effect suction, this catheter allowed mechanical removal of thrombus. This technique may obviate the need for thrombolytic agents and the risks associated with their use.

Development of obstructive hydrocephalus with lumboperitoneal shunting following subarachnoid hemorrhage.

Hydrocephalus is a frequent complication of subarachnoid hemorrhage (SAH). The optimum method of treating hydrocephalus in this setting has not been determined. We review our experience with patients developing communicating hydrocephalus secondary to SAH and subsequently treated with lumboperitoneal (LP) shunts. Following hospitalization for the treatment of SAH, patients who developed clinical symptoms and radiologic signs of hydrocephalus were treated with (ventriculoperitoneal) VP or LP shunting. Eighteen patients received an LP shunt, of which seven (28%) developed a non-communicating or obstructive hydrocephalus. These seven patients underwent replacement with a VP shunt and have not had further complications. In the setting of post-SAH communicating hydrocephalus, obstructive hydrocephalus may develop after LP shunt placement. Patients who develop this complication and have their LP shunts converted to VP shunts have a favorable prognosis.

Cervical spine evaluation in obtunded or comatose pediatric trauma patients: A pilot study.

A uniformly accepted protocol for evaluation and clearance of the cervical spine of pediatric trauma patients with altered mental status does not currently exist. We sought to detect cervical spine injuries in this group with minimal risk. Patients were evaluated with standard three-view cervical spine radiographs and CT when necessary. Those patients without radiographic abnormality and altered mental status underwent flexion-extension of the cervical spine using fluoroscopy with somatosensory evoked potential (SSEP) monitoring. Those with abnormal movement by fluoroscopy or changes in SSEP underwent MRI. Fifteen patients were evaluated with this protocol. Two patients had movement on flexion-extension of the cervical spine and 5 had SSEP changes. Three patients had an MRI with only 1 showing injury. Five patients had residual hemiparesis. Evaluation of the cervical spine in obtunded or comatose pediatric trauma patients can be done safely with flexion-extension under fluoroscopy and SSEP monitoring. Further prospective studies are required to determine the efficacy of SSEP monitoring for cervical spine clearance in this select population.

Thyroid carcinoma with isolated spinal metastasis: case history and review of the literature.

An unusual case of metastatic follicular thyroid cancer presenting with symptoms of a radiculopathy at C6 is presented. The patient underwent a laminectomy and removal of tumor with resolution of his symptoms. He was found to have a well differentiated follicular thyroid carcinoma and subsequently had total thyroidectomy and 131I treatment. This patient's presentation raised questions about appropriate preoperative evaluation in this clinical scenario. This case highlights the importance of a thorough pre-operative work up for metastatic spine tumors. This should include evaluation of the thyroid consisting of thorough clinical history with particular attention to prior radiation exposure. Palpation of the thyroid also should be included as part of a routine pre-operative physical in cases of metastatic lesions of unknown origin. Thyroid function studies should not be utilized unless a clinical suspicion for thyroid cancer is raised during the examination.

Communicating hydrocephalus secondary to diffuse meningeal spread of Wegener's granulomatosis: case report and literature review.

OBJECTIVE AND IMPORTANCE: We present a very unusual case of diffuse spread of Wegener's granulomatosis causing hydrocephalus. CLINICAL PRESENTATION: A 53-year-old man presented in 1985 with bilateral middle ear infections requiring myringotomies. During the next 18 months, he went on to develop a left Bell's palsy. The patient then began to develop recurrent occipital headaches along with left sixth and seventh nerve palsies and a green nasal discharge requiring hospitalization. Workup included magnetic resonance imaging showing pronounced enhancement of the tentorium and meninges in the occipital region with normal ventricle size. An x-ray of the chest showed multiple pulmonary nodules. A regimen of prednisone and cyclophosphamide was initiated. The patient did well for 2 years until he again developed middle ear infections and headache. Serial lumbar punctures showed increased pressures. A circulating antineutrophil cytoplasmic antibody was positive. Cyclophosphamide was administered, with acetazolamide added for treatment of the elevated intracranial pressure. The patient stabilized for another 2 years but then presented in 1994 with recurrent headache, bilateral papilledema, and mild left arm and right leg weakness. A lumbar puncture was performed with an opening pressure of 52 cm H2O. Computed tomography of the head revealed moderate enlargement of the lateral third and fourth ventricles, consistent with communicating hydrocephalus. INTERVENTION: A right frontal ventriculoperitoneal shunt was placed. A leptomeningeal biopsy performed at the side of catheter placement (far away from any meningeal enhancement revealed by magnetic resonance imaging) showed chronic meningitis and multinucleated giant cells. Cyclophosphamide therapy was begun again. The patient has not experienced recurrence of headache, cranial nerve deficits, or papilledema for more than 3 years. CONCLUSION: This is the first reported case of diffuse involvement of the meninges from Wegener's granulomatosis. Fortunately, this patient responded well to shunting and sustained medical management. Although rare, Wegener's granulomatosis should be included in the differential diagnosis of chronic aseptic meningitis, communicating hydrocephalus, and papilledema.

Reversible ischemia determined by xenon-enhanced CT after 90 minutes of complete basilar artery occlusion.

Intraarterial thrombolytic therapy decreases mortality in the treatment of acute basilar artery occlusion. An acute decrease in cerebral blood flow (CBF) (<12 mL/100 g per minute) has been reported to invariably result in infarction. We report a case of acute basilar artery occlusion, recanalized within 90 minutes, with reversal of CBF of less than 6 mL/100 g per minute. After reperfusion, areas with persistent CBF of 6 mL/100 g per minute resulted in infarctions on subsequent CT studies. Parenchymal viability is possible after 90 minutes of posterior CBF of 6 mL/100 g per minute.

Carnitine delays rat skeletal muscle fatigue in vitro.

Carnitine has been used to enhance human exercise performance. To test the hypothesis that carnitine can directly modify skeletal muscle function, fatigue of isolated rat skeletal muscle strips was studied in vitro. Carnitine (10 mM) did not modify the initial force of soleus contraction. The time over which force declined by 50% during repetitive electrical stimulation of the soleus muscle (fiber type I) was prolonged 25% in the presence of 10 mM carnitine. In contrast, carnitine had no effect on the fatigue of extensor digitorum longus muscle strips (fiber type II). The beneficial effect of carnitine on soleus muscle strips was not observed if the routine 30-min preincubation in the presence of carnitine was decreased to 5 min; it was associated with a five- to sixfold increase in muscle total carnitine content and a 50-150% increase in muscle long-chain acylcarnitine content. Carnitine did not consistently modify lactate accumulation or glycogen depletion during the fatigue protocol. Incubation with propionyl-L-carnitine resulted in a decreased initial force of contraction and a delay in reaching maximal contractile force. Thus, carnitine can directly improve the fatigue characteristics of muscles enriched in type I fibers.