Exclusion of cervical spine instability in patients with blunt trauma with normal multidetector CT (MDCT) and radiography.

The objective of the study was to determine if negative multidetector computed tomography (MDCT) and lateral radiography of the cervical spine effectively excludes patients with unstable cervical spine injuries. Over a period of 40 months, 6558 people were admitted to our trauma service with blunt injury and 447 (6.8%) were found to have cervical fractures. Fractures were identified by CT and/or lateral radiography. In order to rule out clinically significant instability in the absence of fracture, we identified nine patients who required any type of stabilization of the cervical spine including anterior fusion, posterior fusion and external orthosis. These patients also underwent MR of the cervical spine. Radiography, CT, and MR images and reports of these nine patients were reviewed. Nine patients without a fracture required cervical stabilization. These patients had the following abnormalities: disc herniation with canal stenosis in three, unilateral jumped facet in three, and various other soft tissue abnormalities in three, all of which were evident on CT or radiography. All nine patients had evidence for cervical spine injury or instability by MDCT. Normal MDCT and radiography appears adequate to 'clear' the cervical spine. We recommend that patients requiring cervical spine clearance undergo a complete MDCT and lateral radiograph of the cervical spine. If these studies are entirely normal, then the cervical spine may be cleared. If any abnormalities, including disc herniation, soft tissue swelling and bony malalignments are noted by radiography and/or MDCT, further studies, including MR, are indicated prior to clearance of the cervical spine.

Delayed cervical spinal cord tethering following tonsillar resection for Chiari malformation.

Although tethering of the spinal cord in the lumbosacral region, particularly following repair of congenital anomalies, such as myelomeningocele, is a well-known phenomenon, only sporadic reports of tethering along the rest of the neuraxis, including the hindbrain, cervical and thoracic spinal cord have been documented. In this report, we describe a woman who developed symptoms related to tethering of the cervical spinal cord 5 years after suboccipital decompressive surgery of the posterior fossa for Chiari I malformation. The authors discuss the diagnosis, treatment, and postoperative course of this entity.

Epidemiology of ventriculostomy in the United States from 1997 to 2001.

Ventriculostomy is a common practice in neurosurgery, but the annual trend of this procedure in the United States has not been reported in the literature. This study evaluates the annual trend during a recent 5-year period. Between 1997 and 2001, a retrospective review was undertaken concerning all patients in the Nationwide Inpatient Sample (NIS) who had undergone ventriculostomy. The population sample represented approximately a 20% stratified sample of nonfederal hospitals in the United States. The annual number of patients who underwent ventriculostomy during the study period ranged from 20,586 to 25,634. Most patients were male (53.4%), with a mean age of 44.8 years, were commercially insured (46.0%) and had a median annual income above $25,000 (84.4%). Most frequent ICD-9-CM diagnoses were subarachnoid haemorrhage, intracerebral haemorrhage and obstructive hydrocephalus, respectively. The majority of ventriculostomies were performed in large, private, not-for-profit, metropolitan, teaching institutions. Mean length of hospital stay was 19.2 days. Regarding discharge status for patients who had undergone ventriculostomy, approximately one-quarter died in the hospital, one-third were discharged home and one-third were transferred to another institution. No demographic variables changed during the study with the exception of location of ventriculostomy in a teaching hospital, which increased from 64.4% in 1997 to 77.4% in 2001. Patient and hospital demographic characteristics were consistent during the study period. By extrapolation of the data, the prevalence of ventriculostomy in the United States averaged 24,380 per year. This study is the first to comprehensively document data concerning the epidemiology of this common procedure.

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.

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.

Microvascular decompression of cranial nerves: lessons learned after 4400 operations.

OBJECT: Microvascular decompression has become an accepted surgical technique for the treatment of trigeminal neuralgia, hemifacial spasm, glossopharyngeal neuralgia, and other cranial nerve rhizopathies. The senior author (P.J.J.) began performing this procedure in 1969 and has performed more than 4400 operations. The purpose of this article is to review some of the nuances of the technical aspects of this procedure. METHODS: A review of 4415 operations shows that numerous modifications to the technique of microvascular decompression have occurred during the last 29 years. Of the 2420 operations performed for trigeminal neuralgia, hemifacial spasm, and glossopharyngeal neuralgia before 1990, cerebellar injury occurred in 21 cases (0.87%), hearing loss in 48 (1.98%), and cerebrospinal fluid (CSF) leakage in 59 cases (2.44%). Of the 1995 operations performed since 1990, cerebellar injuries declined to nine cases (0.45%), hearing loss to 16 (0.8%), and CSF leakage to 37 (1.85% p < 0.01, test for equality of distributions). The authors describe slight variations made to maximize surgical exposure and minimize potential complications in each of the six principal steps of this operation. These modifications have led to decreasing complication rates in recent years. CONCLUSIONS: Using the techniques described in this report, microvascular decompression is an extremely safe and effective treatment for many cranial nerve rhizopathies.

Intraoperative loss of auditory function relieved by microvascular decompression of the cochlear nerve.

BACKGROUND: Brainstem auditory evoked potentials (BAEP) are useful indicators of auditory function during posterior fossa surgery. Several potential mechanisms of injury may affect the cochlear nerve, and complete loss of BAEP is often associated with postoperative hearing loss. We report two cases of intraoperative auditory loss related to vascular compression upon the cochlear nerve. METHODS: Intra-operative BAEP were monitored in a consecutive series of over 300 microvascular decompressions (MVD) performed in a recent twelve-month period. In two patients undergoing treatment for trigeminal neuralgia, BAEP waveforms suddenly disappeared completely during closure of the dura. RESULTS: The cerebello-pontine angle was immediately re-explored and there was no evidence of hemorrhage or cerebellar swelling. The cochlear nerve and brainstem were inspected, and prominent vascular compression was identified in both patients. A cochlear nerve MVD resulted in immediate restoration of BAEP, and both patients recovered without hearing loss. CONCLUSION: These cases illustrate that vascular compression upon the cochlear nerve may disrupt function, and is reversible with MVD. Awareness of this event and recognition of BAEP changes alert the neurosurgeon to a potential reversible cause of hearing loss during posterior fossa surgery.

Hyperactive rhizopathy of the vagus nerve and microvascular decompression. Case report.

A 37-year-old woman underwent microvascular decompression of the superior vestibular nerve for disabling positional vertigo. Immediately following the operation, she noted severe and spontaneous gagging and dysphagia. Multiple magnetic resonance images were obtained but failed to demonstrate a brainstem lesion and attempts at medical management failed. Two years later she underwent exploration of the posterior fossa. At the second operation, the vertebral artery as well as the posterior inferior cerebellar artery were noted to be compressing the vagus nerve. The vessels were mobilized and held away from the nerve with Teflon felt. The patient's symptoms resolved immediately after the second operation and she has remained symptom free. The authors hypothesize that at least one artery was shifted at the time of her first operation, or immediately thereafter, which resulted in vascular compression of the vagus nerve. To the authors' knowledge, this is the first reported case of a hyperactive gagging response treated with microvascular decompression. The case also illustrates the occurrence of a possibly iatrogenic neurovascular compression syndrome.

Functional outcome and the effect of cranioplasty after retromastoid craniectomy for microvascular decompression.

BACKGROUND: While the efficacy of retromastoid craniectomy for microvascular decompression for hyperactive cranial nerve syndromes is well established, there is no real information regarding the functional outcome of these operations. The purpose of this retrospective questionnaire study is to assess functional outcome regarding presence and duration of postoperative headache, incisional pain, and the time to return to normal activity in patients undergoing retromastoid craniectomy for microvascular decompression. The effect of closure with bone chips or cranioplasty in the defect upon these functional outcomes was studied, as was the influence of the particular nerve that was the object of decompression. METHODS: Four-hundred and ninety-five consecutive patients were contacted and 320 (65%) returned questionnaires with enough information to be suitable for analysis. RESULTS: The incidence of postoperative headache was initially 60.1%, dropping to 28.8% at 1 month and 16.8% at 6 months. Incisional pain likewise declined with time, noted in 25.8% at 1 month and only 13.1% at 6 months. Use of a cranioplasty made no significant difference in influencing either postoperative headache or incisional pain, nor was the nature of the procedure a significant factor. CONCLUSION: Twenty-five percent of patients resumed normal activity by 3 weeks, 50% by 1 month, and 90% by 3 months. Overall, 98% of patients responding reported returning to normal activity. Therefore, although there is an incidence of postoperative headache and incisional pain, these decrease with time and do not seem to interfere with the return to normal activity, nor are they affected by placement of a cranioplasty or the nature of the operation.

Delayed facial weakness after microvascular decompression of cranial nerve VII.

BACKGROUND: Retromastoid craniectomy and microvascular decompression of cranial nerve VII for hemifacial spasm is a well accepted and effective treatment. Risks of the operation relate to the surgical approach in general and to the seventh nerve in particular. Delayed facial weakness is an unusual and little-described complication of the procedure. The purpose of this review is to describe this complication and the characteristics of the patients so affected. METHODS: Between 1972 and 1996, 985 patients have undergone microvascular decompression for hemifacial spasm. During this time, 28 patients (2.8%) undergoing decompression of the facial nerve and 1 patient undergoing decompression of the cochlear nerve for tinnitus developed delayed facial palsy. RESULTS: The weakness was at least a House Grade III or worse and was complete in 11 of the patients. The time to occurrence averaged 12 days, with a tight range of 7 to 16 days. There were no factors such as duration of symptoms, intraoperative findings, or preoperative botulinum injections that were predictive of this postoperative weakness. In all patients there was almost complete recovery (House Grade I or II). CONCLUSIONS: Delayed facial weakness after MVD of CN VII can occur in up to 3% of cases. The onset of weakness after operation is consistent in its timing, occurring on average 12 days after the procedure. Although the etiology of this complication is uncertain, the palsy spontaneously resolves with a good or excellent outcome.

Microvascular decompression for pediatric onset trigeminal neuralgia.

BACKGROUND: Trigeminal neuralgia (TGN) is generally a disease of the elderly. Vascular compression, the causative agent in the majority of cases, is thought to result from atherosclerotic changes within the vessels of the posterior fossa. Rarely, the disease presents during childhood, before the onset of severe atherosclerotic changes. We therefore sought to explore the role of vascular compression in pediatric patients with medically refractory TGN. PATIENTS AND METHODS: Twenty-three patients were identified in whom the onset of typical TGN had occurred during childhood (age 18 yr or younger) and who underwent exploration of the cerebellopontine angle. Twenty-two of 23 underwent microvascular decompression (MVD) of the trigeminal nerve. Twenty-one of these patients were followed for more than 1 year. A retrospective chart review was conducted to determine the efficacy of MVD for the treatment of TGN in this select population. Operative findings were recorded and correlated with patient outcome. RESULTS: Twenty-two of 23 patients (96%) were found to have vascular compression of the trigeminal nerve at the time of exploration. One patient was found to have an epidermoid tumor. MVD resulted in complete pain relief at the time of discharge in 16 of 22 patients (73%), with an additional 4 patients (18%) having a greater than 75% diminution of pain. The 21 patients who were followed for at least 1 year were followed for a mean of 105 months. At the time of their last follow-up, 9 of these patients (43%) continued to have complete pain relief and 3 (14%) had a greater than 75% diminution of pain. The most common operative finding was a vein compressing the nerve, often in combination with a branch of the superior cerebellar artery. DISCUSSION: MVD has been demonstrated to be a safe and efficacious treatment for TGN in the adult population. Patients whose symptoms begin in childhood do not enjoy the same therapeutic response to MVD as do patients with TGN onset in adulthood. An increased incidence of venous compression was noted in this population, as was a longer duration of symptoms before MVD. These factors may be responsible for the decreased efficacy of MVD in this patient population.

Microvascular decompression of the left lateral medulla oblongata for severe refractory neurogenic hypertension.

OBJECTIVE: To demonstrate that microvascular decompression of the left medulla oblongata is a safe and effective modality for treating elevated blood pressure in patients with severe medically refractory "essential" hypertension (HTN). METHODS: Twelve patients with medically intractable HTN with or without autonomic dysreflexia underwent microvascular decompression of the left rostral ventrolateral medulla oblongata. Causes such as pheochromocytoma, carcinoid syndrome, and renal disease were ruled out before surgery. Indications for surgery included systolic blood pressures greater than 180 mm Hg refractory to three or more medications, severe blood pressure lability, or medically resistant HTN at systolic pressures greater than 160 mm Hg associated with autonomic dysreflexia and/or magnetic resonance images demonstrating left medullary compression. The median age and follow-up duration were 51 years and 4.1 years, respectively. RESULTS: Ten of 12 patients experienced reductions in systolic blood pressure greater than 20 mm Hg. Of these 10 patients, pressure reductions were temporary (6 mo) in two. Seven of eight patients experienced improvement in blood pressure lability and/or autonomic dysreflexia, with five patients showing sustained improvements. CONCLUSION: Microvascular decompression of the left rostral ventrolateral medulla oblongata may be an effective treatment modality for patients suffering from severe HTN and/or autonomic dysreflexia refractory to medical management.

The origin and evolution of the University of Pittsburgh Department of Neurological Surgery.

Neurological surgery at the University of Pittsburgh began more than 60 years ago with the arrival of Stuart Niles Rowe. During the years, the department has been led by four men, each of whom guided the department into the future in his unique way. These men and many other dedicated physicians, nurses, and staff members have contributed to this organization and created an environment where neurosurgery flourishes. This article describes the development of neurosurgery within the "Steel City" and outlines the origin and growth of the Department of Neurological Surgery at The University of Pittsburgh Medical Center.

Delayed hearing loss after microvascular decompression of the trigeminal nerve.

OBJECTIVE: The development of sudden postoperative hearing loss as a complication of microvascular decompression (MVD) operations in the cerebellopontine angle has already been reported. A sudden hearing loss of vascular origin may also occur hours or days after such operations, but even in such cases an improvement of hearing over the following weeks is possible. Here we report on a gradual deterioration of hearing over a period of two weeks after MVD which has not been described in the literature up to now. CLINICAL PRESENTATION: A MVD operation was performed twice on a 36 year old patient with trigeminal neuralgia. After the second operation the patient developed a slight hearing impairment 3 days postoperatively which increased over a period of two weeks and ended up with total deafness. The course of intra-operative brainstem auditory evoked potentials and postoperative audiograms is documented. CONCLUSION: Because of gradual development of the delayed hearing loss, we conclude that postoperative tissue scarring may be the underlying pathology.

The surgical management of chronic cluster headache.

OBJECTIVE: Chronic cluster headache occurs in less than 10% of cluster headache sufferers, but remains an intractable medical problem. Surgical treatments have also been limited in their effectiveness. The authors describe their experience with attempted surgical amelioration of chronic cluster headache. DESIGN: Twenty-eight patients, including two with bilateral cluster headache, underwent 39 operations for microvascular decompression of the trigeminal nerve, alone or in combination with section and/or microvascular decompression of the nervus intermedius. Follow-up averaged 5.3 years. RESULTS: Initial postoperative success described as 50% relief or greater was achieved in 22 (73.3%) of 30 first-time procedures and greater than 90% relief in half (15 of 30) of these. Long-term follow-up saw this success rate (excellent or good) drop to 46.6%. Repeat procedures have little success, with 7 of 8 failing at long-term follow-up. Morbidity and neurological deficit from the operations was minimal. CONCLUSIONS: Chronic cluster headache remains a debilitating and poorly controlled syndrome. Although various surgical treatments have had limited success, microvascular decompression of the trigeminal nerve with section of the nervus intermedius compares very favorably to other destructive techniques without the accompanying neurologic deficits. It is, therefore, our recommendation as the first-line operative treatment of chronic cluster headache.

Surgical management of geniculate neuralgia.

BACKGROUND: Geniculate ganglion or nervus intermedius neuraigia is an unusual condition resulting in deep ear pain with or without signs of atypical trigeminal neuralgia, deep face, or throat pain. This article describes an experience with 14 patients who came to the neurosurgical service at the University of Pittsburgh Medical Center with a diagnosis of geniculate neuralgia. METHODS: After failing conservative treatment and after undergoing neurologic, otologic, and dental evaluations, these 14 patients underwent 20 intracranial procedures consisting of retromastoid craniectomies with microvascular decompression of cranial nerves V, IX, and X with section of the nervus intermedius in most cases. RESULTS: At operation, vascular compression of the nerves and nervus intermedius was found, which implicated vascular compression as an etiology of this disorder. Initially, 10 of 14 patients had an excellent outcome (71.5%), 3 experienced partial relief (21.5%), and there was 1 failure (7%). Ten patients were available for long-term (> 12 months) follow-up. Of these 10, 3 retained the excellent result (30%), 6 experienced partial relief (60%), and there was 1 failure (10%). Complications included one transient facial paresis, one facial numbness, one paresis of cranial nerves IX and X, one chemical meningitis, two cerebrospinal fluid leaks, and one superficial wound infection. Of those that fell from the excellent to partial category, this usually involved a return of atypical facial pain, but otalgia remained resolved. CONCLUSIONS: Overall, good results (with excellent or partial relief) were found long term for 90% of patients in this series. The authors recommend microvascular decompression of cranial nerves V, IX, and X with nervus intermedius section for the treatment of geniculate neuralgia.