Burton M. Onofrio

The study involved 77 myxopapillary ependymomas of the spinal cord encountered during a 60-year period (1924-1983). This variant of ependymoma was, with few exceptions, limited to the lumbosacral region, particularly the filum terminale. The male:female ratio was 1.7:1, and the mean age at diagnosis was 36.4 years (range, 6-82); at presentation, 15 (19%) of the patients were in the first two decades of life. The duration of symptoms ranged from 1 month to 30 years; the most frequent complaint was low-back pain, and eight patients had undergone prior "disc surgery." Generally, myelographic block was disclosed. Preoperative cerebrospinal fluid protein levels averaged 2462 mg/dl. Myxopapillary ependymomas are slow-growing tumors that show no significant tendency to histologic dedifferentiation. Despite some variation in cytologic features and the presence of atypia and modest mitotic activity in most cases, the gross characteristics of the tumors appear to be of greater prognostic significance than the histologic features. Tumors that were encapsulated (25%) and amenable to intact, total surgical removal had a recurrence rate of 10%, whereas those that were removed either piecemeal (34%) or subtotally (41%) had recurrence rates of 19%. Overall survival, however, was more closely related to residual disease; total removal of tumor, whether intact (encapsulated) or piecemeal, resulted in longer survival (19 years) than did subtotal resection (14 years). Patients who died (6.5%) did so after a prolonged course marked by multiple recurrences. Radiotherapy may be of particular benefit to patients whose tumors are not amenable to intact total removal.

Fifty-nine cases of vertebral hemangioma were seen at the Mayo Clinic between 1980 and 1990. Vertebral hemangiomas were discovered incidentally in 35 patients, while pain was the presenting complaint in 13 patients. Five patients presented directly with progressive neurological deficit requiring surgery, and six patients had surgery elsewhere for spinal cord compression and were referred for follow-up evaluation. To better define the natural history of these lesions, a historical review of these patients was conducted; progression of an asymptomatic or painful lesion to neurological symptoms was found in only two cases (mean follow-up period 7.4 years, range 1 to 35 years). New-onset back pain followed by subacute progression (mean time to progression 4.4 months, range 0.25 to 12 months) of a thoracic myelopathy was the most common presentation for patients with neurological deficit. Initially, all 11 patients with spinal cord compression underwent decompressive surgery with full neurological recovery. Recurrent neurological symptoms were observed in three of six patients following subtotal tumor resection and postoperative administration of 1000 cGy or less radiation therapy (mean follow-up period 8.7 years, range 1 to 17 years). No recurrences were noted in four patients who had subtotal excision plus radiotherapy between 2600 and 4500 cGy. One other patient had gross total tumor removal without radiotherapy and has not had a recurrence. Based on these patients and a review of the literature, the authors recommend annual neurological and radiological examinations for patients with hemangiomas associated with pain, especially young females with thoracic lesions in whom spinal cord compression is most likely to develop. Radiation therapy or embolization is an effective therapeutic alternative for patients with severe medically refractory pain. Regular follow-up monitoring for patients with asymptomatic lesions is unnecessary unless pain develops at the appropriate spinal level. It is concluded that management of patients with a progressive neurological deficit should include preoperative angiography and embolization, decompressive surgery with the approach determined by the degree of vertebral involvement and site of spinal cord compression, and postoperative radiation therapy in patients following subtotal tumor removal. Operative management and complications are discussed.

A series of 13 patients with synovial or ganglion cysts of the spinal facet joints causing nerve root compression is reported. These cysts were found in both the cervical and the lumbar spine, and the anatomical location of each cyst corresponded to the patient's signs and symptoms. In no case was there evidence of intervertebral disc abnormality found at operation. The patients ranged from 49 to 77 years of age and included 4 men and 9 women. Radiographic evidence of facet degenerative change and degenerative spondylolisthesis was frequently but not invariably noted. The extradural defects defined with positive contrast myelography or postmyelography computed tomographic scanning were usually posterior or posterolateral to the common dural sac and were misinterpreted as extruded discs in the majority of cases. Treatment consisted of laminectomy and surgical excision of cysts. All patients reported improvement or resolution of their presenting symptoms.

In rats with chronically implanted intrathecal catheters, high concentrations of morphine (3 microliters of 50 mg/ml: 150 micrograms) yielded a reliable and striking syndrome of pain behavior that involved intermittent bouts of biting and scratching at the dermatomes innervated by levels of the spinal cord proximal to the catheter tip. In addition, during intervals between bouts of agitation, the animals displayed a clear, marked hyperesthesia where an otherwise innocuous stimuli (brush stroke) evoked significant signs of discomfort and consequent aggressive behavior. These effects were exaggerated rather than reversed by high doses of naltrexone. The effect, perfectly mimicked by a considerably lower dose of morphine-3-glucuronide (15 micrograms) or the glycine antagonist strychnine (30 micrograms), was not produced by equimolar concentrations of sodium sulfate, glucuronide, methadone, or sufentanil. In halothane-anesthetized cats, light brushing of the hindpaw and tail or low-intensity stimulation of the sciatic nerves resulted in prominent elevations in blood pressure and pupil diameter following the intrathecal administration of high concentrations (50 mg/ml; 0.1 ml) of morphine sulfate. This effect, exaggerated by naloxone, was produced by a lower concentration of intrathecal morphine-3-glucuronide (5 mg/ml; 0.1 ml) but not by intrathecal saline. These results suggest the possibility that the effects of high doses of morphine may be characterized by a nonopiate receptor-mediated effect that alters the coding of sensory information in the spinal cord. The authors speculate that high concentrations of spinal opiates, as may be employed in tolerant terminal-cancer patients, could exert an action that physiologically antagonizes the analgesic effects otherwise mediated by the action of morphine on the spinal opiate receptor.(ABSTRACT TRUNCATED AT 250 WORDS)