Differential diagnosis of pituitary tumors.

Many parasellar lesions may mimic pituitary adenomas clinically, endocrinologically, and radiologically. Certain patterns do lead suspicion toward the correct diagnosis, whereas in other cases the diagnosis may be difficult. For most of these lesions, the treatment of choice is different from that for a pituitary tumor, so correct diagnosis is of paramount importance. The presenting signs and symptoms as well as radiologic manifestations of parasellar tumors and conditions are discussed.

Surgical management of dumbbell and paraspinal tumors of the thoracic and lumbar spine.

The lateral extracavitary approach was used for single-staged tumor resection in 12 patients with complex dumbbell or paraspinal tumors of the thoracic and lumbar spine. Six women and six men (age, 28-72 yr) were treated between August 1990 and January 1994. The tumors included schwannoma (6 patients), malignant meningioma (1 patient), hemangioma (1 patient), chondrosarcoma (1 patient), osteocartilaginous exostosis (1 patient), radiation-induced osteogenic sarcoma (1 patient), and metastatic renal carcinoma (1 patient). Gross total resection was achieved in 11 patients. Radical subtotal removal was performed in the remaining patient, who had a malignant osteogenic sarcoma. Concomitant spinal stabilization with internal fixation and anterior interbody strut grafting was performed on two patients. No significant perioperative complications occurred. Ten patients were alive and clinically stable at follow-up visits ranging from 14 to 55 months. Two patients died from systemic tumor dissemination during the follow-up period. The lateral extracavitary approach is useful when extensive or difficult spinal and paraspinal exposure is required. The surgical aspects of these neoplasms and the technique of lateral extracavitary approach are described in detail.

Surgical management of dumbbell tumors of the cervical spine.

Twelve patients with benign dumbbell tumors of the cervical spine were treated surgically between March 1991 and July 1994. Gross total resection was achieved in 11 patients, using a single-stage modified posterior midline exposure with laminectomy and complete unilateral facetectomy. This exposure provides contiguous intraspinal, foraminal, and extraforaminal access that extends up to 4 cm from the lateral dural margin. The surgical considerations of these tumors, including the surgical technique, potential spinal instability, vertebral artery, and risk of nerve root injury, are presented.

Retropleural approach to the thoracic and thoracolumbar spine.

Retropleural thoracotomy was used in 15 patients for the management of ventral thoracic and thoracolumbar spine abnormalities. This approach provides the shortest direct route to the anterior thoracic spine and avoids pleural cavity entry. A detailed description of retropleural thoracotomy and the clinical experiences of 15 patients treated with it are presented.

High cervical split cord malformation and neurenteric cyst associated with congenital mirror movements: case report.

A 48-year-old woman with congenital mirror movements of the hands presented with a high cervical split spinal cord malformation and a ventrally located neurenteric cyst. The clinical, radiological, and surgical features are presented. A brief discussion of the literature and embryology pertaining to split cord malformations and mirror movements is included. To our knowledge, this is the first case of radiographically and surgically proven split cord malformation associated with either mirror movements or a neurenteric cyst presenting in an adult.

Cavernous malformations of the spinal cord.

Six patients with intramedullary cavernous malformations of the spinal cord are presented. Four men and two women presented with acute, subacute, or episodic signs and symptoms of spinal cord dysfunction, ranging in duration from 3 days to 25 years. All patients underwent operative resection of the malformation. Complete removal was achieved in five patients. Neurological function either stabilized or improved postoperatively in all patients; follow-up ranged from 4 to 84 months. The increasing awareness of the propensity for recurrent hemorrhage, clinical features, and resectability of these malformations are discussed.

The posterior approach to a series of glomus (Type II) intramedullary spinal cord arteriovenous malformations.

OBJECTIVE: Intramedullary spinal cord arteriovenous malformations (AVMs) are comprised of those AVMs which in either glomus or nidal form are found partially or entirely within the substance of the spinal cord. An effort to subdivide these lesions into either glomus Type II or juvenile Type III spinal cord AVMs has underscored the diffuse, unresectable nature of the latter but has done little to suggest a logical management paradigm for the more well-defined, low-flow glomus lesion. METHODS: To address this shortcoming, 15 cases of glomus Type II spinal AVMs were identified from a larger series of a variety of spinal AVMs. Computed tomography, magnetic resonance imaging, and superselective angiography rendered the anatomic diagnosis of these lesions accurate in all cases. All lesions were approached posteriorly via a standard laminectomy, with the goal of total extirpation, and all patients underwent immediate postoperative angiography to verify cure. In the vast majority of cases, patients underwent follow-up imaging to confirm the durability of this cure, and long-term outcome was determined using both a subjective quality of life assay and a functional grading scale. Age, sex, mode of presentation, and radiographic features were subsequently analyzed with respect to functional outcome. RESULTS: Most glomus spinal AVMs presented with a rapid cascade of signs and symptoms (73%), often caused by subarachnoid hemorrhage (60%) and often leading to significant neurological deficits (47%). Initially, 14 of 15 patients (94%) were angiographically cured of their malformations. The remaining patient was neurologically improved after a 90% resection, and follow-up angiography demonstrated that the residual was thrombosed. However, not uncommonly, follow-up angiography and magnetic resonance imaging revealed recurrences, with three of the patients who underwent delayed imaging (23%) demonstrating new draining veins. Fortunately, in each case, the recurrence was asymptomatic. Therefore, the long-term cure rate (mean follow-up, 8.5 yr; range, 1-17 yr) was 80%, with no subsequent bleeding or progression of symptoms. Outcomes were generally good, with six patients (40%) demonstrating objective improvement, eight (53%) being neurologically stable, and one (7%) being worse. Sixty-six percent were independent, 20% required moderate assistance, and 14% remained entirely dependent. There were no deaths. Patients possessing lesions with large direct feeders off the anterior spinal artery and occupying a primarily anterior position in the cord fared somewhat worse, as did those with rapidly progressing symptomatology in the absence of subarachnoid hemorrhage. However, even in those with preserved or improved function, chronic pain was a significant problem, affecting one-third of all patients. Chronic pain was especially common in young women who had presented with significant preoperative pain that responded poorly to all subsequent therapeutic manipulations. CONCLUSION: With careful evaluation of high-quality superselective angiography and the judicious use of preoperative embolization, posterior surgical approaches can deliver results comparable with those achieved for other benign intramedullary lesions in terms of long-term cure (80%), control of symptom progression (100%), and good functional outcome (86%). Despite these results, chronic dysesthetic pain syndromes are not uncommon and continue to present a significant management problem.

Trigeminal schwannoma. Surgical series of 14 cases with review of the literature.

A consecutive series of 14 patients with trigeminal schwannoma managed surgically at the Neurological Institute of New York since 1970 is reported. Nine women and five men (mean age 40 years) were diagnosed following a mean symptom duration of 33 months. Abnormalities of trigeminal nerve function were present in 11 patients on admission examination. Facial pain was a prominent feature in eight patients. Two patients, both with schwannomas arising from the trigeminal root, presented initially with typical trigeminal neuralgia. Additional cranial nerve palsies or cerebellar or pyramidal tract signs were noted in eight patients. The surgical approach to these tumors depends on their anatomical location. Four patients had tumors confined to the middle fossa, three patients had tumors limited to the posterior fossa, and seven patients had both supratentorial and infratentorial components of their tumors. Twenty operative procedures were performed on these patients, resulting in complete extirpation in six patients, nearly complete removal in seven patients, and partial removal in one patient. Adherence of the tumor to the lateral wall of the cavernous sinus or the brain stem precluded total removal. There was one postoperative death. In the immediate postoperative period, abnormalities of cranial nerves controlling the extraocular muscles were common. In general, these deficits were transient; however, some permanent loss of trigeminal nerve function occurred in nine patients. Two patients required tarsorrhaphy for neurotropic keratitis, and two patients underwent cerebrospinal fluid (CSF) shunting procedures for hydrocephalus or for a persistent CSF leak. The follow-up period ranged from 4 to 177 months (mean 47 months). The clinical features, anatomical considerations, and surgical approach to these rare tumors are discussed. A clinical review of 106 additional cases of trigeminal schwannoma, reported in the English literature since 1935, is also presented.

Intramedullary ependymoma of the spinal cord.

A consecutive series of 23 patients underwent operative removal of an intramedullary spinal cord ependymoma between January, 1976, and September, 1988. Thirteen women and 10 men between the age of 19 and 70 years experienced symptoms for a mean of 34 months preceding initial diagnosis. Eight patients had undergone treatment prior to tumor recurrence and referral. Mild neurological deficits were present in 22 patients on initial examination. The location of the tumors was predominantly cervical or cervicothoracic. Radiological evaluation revealed a wide spinal cord in all cases. Magnetic resonance (MR) imaging was the single most important radiological procedure. At operation, a complete removal was achieved in all patients. No patient received postoperative radiation therapy. Histological examination revealed a benign ependymoma in all cases. The follow-up period ranged from 6 to 159 months (mean 62 months) with seven patients followed for a minimum of 10 years after surgery. Fourteen patients underwent postoperative MR imaging at intervals ranging from 8 months to 10 years postoperatively. No patient has been lost to follow-up review and there were no deaths. No patient showed definite clinical or radiological evidence of tumor recurrence during the follow-up period. Recent neurological evaluation revealed functional improvement from initial preoperative clinical status in eight patients, no significant change in 12 patients, and deterioration in three patients. The data support the belief that long-term disease-free control of intramedullary spinal ependymomas with acceptable morbidity may be achieved utilizing microsurgical removal alone.

Atlantoaxial degenerative articular cysts.

Cysts associated with spinal joints are not a common cause of neurological symptoms. The authors report a series of five patients with cysts of the atlantodental articulation and review five additional cases from the literature. The patients ranged from 60 to 85 years of age and included three men and seven women. No patient had evidence of rheumatoid arthritis or previous trauma. The cysts caused ventral cervicomedullary compression, did not enhance on magnetic resonance imaging, and were not associated with widening of the anterior atlantodental interval or osseous degeneration of the dens. All patients improved postsurgery. Fusion was required if a transoral procedure was performed. Patients undergoing posterior decompressions were clinically and radiographically stable after operation.

The treatment of associated intracranial aneurysms and arteriovenous malformations.

Cerebral arterial aneurysm associated with arteriovenous malformation (AVM) has been described with a variable incidence, averaging 10% of AVM cases. The present series includes 39 patients with this association, derived from a total of 400 patients with AVM's evaluated and treated since 1970. The aneurysms are classified into four major groups, each carrying particular therapeutic implications. Optimum treatment of these lesions is based in part on a knowledge of the hemodynamic alterations associated with the AVM's. In most of these cases, the symptomatic lesion was treated first; occasionally, when feasible, both lesions were treated during the same operation. All patients had some form of treatment, either surgical or endovascular, directed to at least one of the two types of lesions. All symptomatic lesions were treated and all ruptured aneurysms were obliterated. There were no deaths in this series.

Perioperative management of intracranial catastrophes.

The management and evaluation of neurosurgical intracranial catastrophes require a multidisciplinary approach to optimize outcome. Intracranial pathology must be rapidly evaluated. Clinically, the patient's mental status, the degree and extent of focal neurologic deficits, and the dynamic nature of any changes in clinical status are assessed. The CT scan is invaluable for diagnosing and monitoring the progress and extent of intracranial pathology. Medical therapy for the control of intracranial hypertension must be undertaken simultaneously. This begins with provision of an adequate, protected airway and support of cardiopulmonary function. Specific measures to control intracranial hypertension include hyperventilation, osmotherapy, CSF removal, seizure control, autonomic control, sedation (primarily thiopental), muscle relaxation, mild hypothermia, and, if indicated, steroids. The goal of intraoperative management is physiologic support of systemic and cerebral hemodynamics. There should be a smooth transition from the discovery of the patient in extremis through the period of medical stabilization, operative intervention, and ultimate delivery of the patient to the intensive care facility for extended treatment.

Management of spinal epidural hematoma after tissue plasminogen activator. A case report.

STUDY DESIGN: This case report illustrates a patient with a spontaneous epidural hematoma after tissue plasminogen activator therapy who presented 10 days after the incident with a resolving Brown-Sèquard syndrome. OBJECTIVES: The treatment of this patient involves the principles of conservative follow-up directed by an improving examination and an understanding of the pathophysiology of coagulopathy-induced spontaneous epidural bleeds. SUMMARY OF BACKGROUND DATA: The use of tissue plasminogen activator therapy for thrombolysis in patients with early acute myocardial infarction is becoming increasingly routine. Use is limited most significantly by bleeding complications. Recently, several groups have drawn attention to the neurologic complications associated with intracranial hemorrhage after tissue plasminogen activator therapy. Spontaneous spinal epidural hemorrhage has, by comparison, received little attention. The authors report the second case in the literature and the first without a history of antecedent trauma. METHODS: The onset of the painful myelopathy in this patient was missed in the acute setting because of low suspicion. When the diagnosis was made, coadministered heparin had already been discontinued without reversal, and the patient's examination had already improved. Careful follow-up by neurologic examination and magnetic resonance imaging was obtained without spinal angiography being performed. RESULTS: The patient regained his prehemorrhage neurologic status, experienced no further bleeding, and his coronary ischemia remained subclinical. CONCLUSIONS: Spinal epidural hemorrhage secondary to thrombolytic therapy is becoming increasingly common. Urgent surgical decompression is generally warranted to preserve neurologic function. In cases where the deficit is minimal or resolving, a conservative approach may be warranted with magnetic resonance imaging but not angiographic follow-up.

Clinical evaluation of the spinal cord and nerve roots.

In this article the techniques of clinical neurological evaluation are discussed. It is suggested that correlation of the initial clinical evaluation with radiological investigation remains the most efficient method to determine the type, timing, and appropriateness of surgical intervention. An appreciation of the logical somatotopic organization of spinal cord tracts and cell groups forms the basis of precise localization and provides some insight into the etiology and prognosis of spinal cord dysfunction.

Pregnancy and discogenic disease of the spine.

Low back pain is common during pregnancy and is of moderate or severe intensity in about one fourth of all pregnancies. The etiology is multifactorial but in most cases is related to the physical and physiologic changes brought about by pregnancy. For most women, the pain resolves spontaneously, although they remain at higher risk for increased LBP in future pregnancies and for the development of symptomatic disc disease in later life. Many of the common treatments for LBP are contraindicated or must be modified in this setting. Neurologically symptomatic herniated discs are rare during pregnancy, yet, when indicated, pregnant women can safely undergo surgery.

Infections of the dural spaces.

Suppuration involving the epidural and subdural spaces is a rare occurrence in modern neurosurgical practice. Early diagnosis and appropriate treatment of infections of the dural spaces may avert the high incidence of neurologic disability and death traditionally associated with them, however. Prompt neurosurgical intervention in the treatment of these lesions has been the standard with which all other therapies have been compared.

Functional anatomy of the spinal cord and related structures.

This article reviews the anatomy of the vertebral canal and its contents from a surgical perspective. The normal and pathological relationships of intradural structures are addressed. Spinal cord blood supply, metabolism, and ischemia are discussed in detail. A clinically oriented biomechanical analysis of forces acting within the spinal canal under both physiological and pathological conditions is also presented.

Intramedullary tumors in adults.

The authors review their approach to the surgical management of intramedullary neoplasms. An emphasis is placed on surgical technique and judgment based primarily on the gross characteristics of the tumor. Aggressive removal, irrespective of tumor histology, is recommended for those neoplasms that are clearly demarcated from surrounding spinal cord tissue.

Miscellaneous intradural pathology.

The topics discussed in this article include secondary neoplasia, hemorrhage, meningeal cysts, infectious and inflammatory conditions, and intradural disc herniation. Although they are relatively uncommon in occurrence it is important that these disorders be included in the differential diagnosis of patients harboring intradural pathology. The epidemiology, clinical features, and treatment considerations of these conditions are presented.

Surgical approaches to the thoracolumbar spine.

Surgical treatment of diseases involving the thoracolumbar spine offers a unique challenge to the spine surgeon. Although more familiar posterior techniques are useful for a variety of thoracolumbar problems, the management of disease in this region is often optimized by an anterior approach. Thoracolumbar surgery requires an understanding of the relevant surgical anatomy, the pathologic processes affecting this region, and the relative indications and contraindications for particular operative strategies. It is also essential to be familiar with the management of potential morbidity, methods for avoiding complications, and the selection of particular fusion techniques and instrumentation devices associated with specific operative strategies.