Michael J. Ebersold

Meningeal hemangiopericytoma: histopathological features, treatment, and long-term follow-up of 44 cases.

Forty-four cases of meningeal hemangiopericytoma that were treated between 1938 and 1987 are reviewed. Fifty-five percent of these tumors occurred in men. The average age of the patients at diagnosis was 42 years. The average duration of preoperative symptoms was 11 months. Symptoms were related to tumor location, which was similar to that of meningioma. The operative mortality was 9% overall, and has been zero since 1974 (18 patients). The average time before the first recurrence was 47 months, with the recurrence rates at 1, 5, and 10 years after surgery being 15, 65, and 76%, respectively. Ten patients have developed extraneural metastasis, mostly to lung and bone, at an average of 99 months after the first operation. The 10- and 15-year rates of metastasis were 33 and 64%, respectively. The average survival period has been 84 months, with survival rates at 5, 10, and 15 years after surgery of 67, 40, and 23%, respectively. The histological diagnosis of the tumor was not related to survival or recurrence and did not change with recurrence. Tentorial and posterior fossa tumors tended to be more lethal. Total tumor resection favorably affected recurrence and survival, as opposed to subtotal resection. Metastasis adversely affected survival, and was followed by death at an average of 24 months after its diagnosis. Radiation therapy after the first operation extended the average time before first recurrence from 34 to 75 months, and extended survival from 62 to 92 months.

A retrospective analysis of pituitary apoplexy.

Thirty-seven patients with pituitary apoplexy were analyzed with an emphasis on clinical presentation and visual outcome. Their mean age was 56.6 years, with a male to female ratio of 2:1. Presenting symptoms included headache (95%), vomiting (69%), ocular paresis (78%), and reduction in visual fields (64%) or acuities (52%). Computed tomographic scanning correctly identified pituitary hemorrhage in only 46% of those scanned. Thirty-six patients underwent transsphenoidal decompression. By immunostaining criteria, null-cell adenomas were the most frequent tumor type (50%). Long-term steroid or thyroid hormone replacement therapy was necessary in 82% and 89% of patients, respectively. Long-term desmopressin therapy was required in 11%, and 64% of the male patients required testosterone replacement therapy. Surgery resulted in improvement in visual acuity deficits in 88%, visual field deficits in 95%, and ocular paresis in 100%. Analysis of the degree of improvement in preoperative visual deficits with the timing of the surgery demonstrated that those who underwent surgery within a week of apoplexy had significant recovery in their visual acuities. In the stable, conscious patient with residual vision in each eye, surgical decompression should be performed as soon as possible, because delays beyond 1 week may retard the return of visual function.

Surgical treatment of spontaneous spinal cerebrospinal fluid leaks

OBJECT Spontaneous spinal cerebrospinal fluid (CSF) leaks are an increasingly recognized cause of intracranial hypotension and may require neurosurgical intervention. In the present report the authors review their experience with the surgical management of spontaneous spinal CSF leaks. METHODS Between 1992 and 1997, 10 patients with spontaneous spinal CSF leaks and intracranial hypotension were treated surgically. The mean age of the seven women and three men was 42.3 years (range 22-61 years). Preoperative imaging showed a single meningeal diverticulum in two patients, a complex of diverticula in one patient, and a focal CSF leak alone in seven patients. Surgical exploration in these seven patients demonstrated meningeal diverticula in one patient; no clear source of CSF leakage could be identified in the remaining six patients. Treatment consisted of ligation of the diverticula or packing of the epidural space with muscle or Gelfoam. Multiple simultaneous spinal CSF leaks were identified in three patients. CONCLUSIONS All patients experienced complete relief of their headaches postoperatively. There has been no recurrence of symptoms in any of the patients during a mean follow-up period of 19 months (range 3-58 months; 16 person-years of cumulative follow up). Complications consisted of transient intracranial hypertension in one patient and leg numbness in another patient. Although the disease is often self-limiting, surgical treatment has an important role in the management of spontaneous spinal CSF leaks. Surgery is effective in eliminating the headaches and the morbidity is generally low. Surgical exploration for a focal CSF leak, as demonstrated on radiographic studies, usually does not reveal a clear source of the leak. Some patients may have multiple simultaneous CSF leaks.

EsthesioneuroblastomaPrognosis and Management

Forty-nine patients with esthesioneuroblastoma were treated at the Mayo Clinic between 1951 and 1990. Their clinical manifestations and treatment results were reviewed to identify possible prognostic factors. The 5-year survival rate for all patients was 69%. Tumor progression occurred in 25 patients (51%; no local control in 6 and local recurrence in 19). Metastasis was found in 15 patients (31%; regional in 10 and distant in 9). Nineteen patients died directly from metastatic or intracranial tumor extension. The pathological grade of the tumor was the most significant prognostic factor identified. The 5-year survival rate was 80% for the low-grade tumors and 40% for the high-grade tumors (P = 0.0001). Surgical treatment alone is effective for low-grade tumors if tumor-free margins can be obtained. Radiation is used for low-grade tumors when margins are close, for residual or recurrent disease, and for all high-grade cancers. The poor prognosis associated with high-grade tumors may also mandate the addition of chemotherapy. Recurrent tumor and regional metastasis should be treated aggressively because this approach has been shown to be worthwhile. A craniofacial resection is now the surgical procedure performed in all cases. Because recurrence can occur after 5 or even 10 years, long-term follow-up is mandatory.

Measurement of cerebrospinal fluid flow at the cerebral aqueduct by use of phase-contrast magnetic resonance imaging: technique validation and utility in diagnosing idiopathic normal pressure hydrocephalus.

OBJECTIVE We analyzed the reliability of a protocol for measuring quantitative cerebrospinal fluid (CSF) flow at the cerebral aqueduct and established the range of CSF flows in normal elderly patients, patients with Alzheimer’s and other forms of dementia, and patients with idiopathic normal pressure hydrocephalus (NPH). METHODS A constant flow phantom was used to establish the accuracy of the CSF flow measurement. The clinical variability of the measurement was estimated by calculating the standard deviations and coefficients of variation of intra- and interobserver and intertrial data sets derived from three normal volunteers. A total of 236 patients were studied, including 47 normal elderly patients, 115 patients with cognitive impairment (9 with mild cognitive impairment, 46 with Alzheimer’s disease, and 60 with other cognitive impairment), 31 patients in whom NPH was suspected but ultimately excluded, and 43 patients with a final clinical diagnosis of NPH. RESULTS The intraobserver, interobserver, and intertrial measurement variations of 6.4, 5.4, and 8.8%, respectively, were substantially smaller than the wide variation observed among subjects. There was no statistically significant difference in flow between normal elderly patients and patients with cognitive impairment (P = 0.91). When these populations were pooled, the average flow was 8.47 ml/min (standard deviation, 4.23; range, 0.9–18.5 ml/min). The average flow rate in patients with a final clinical diagnosis of NPH was 27.4 ml/min (standard deviation, 15.3; range, 3.13–62.2 ml/min). This was significantly higher than the flow rate in each of the other three groups (all, P < 0.001). CONCLUSION CSF flow measurements of less than 18 ml/min with a sinusoidal flow pattern are normal. CSF flow of greater than 18 ml/min suggests idiopathic NPH.

Spinal cord ependymoma: Radical surgical resection and outcome

OBJECTIVE Several authors have noted increased neurological deficits and worsening dysesthesia in the postoperative period in patients with spinal cord ependymoma. We describe the neurological progression and pain evolution of these patients over the 1-year period after surgery. In addition, our favored method of en bloc tumor resection is illustrated, and the rate of complications, recurrence, and survival in this group of patients is addressed. METHODS We operated on 26 patients (12 male and 14 female) with low-grade spinal cord ependymomas between 1975 and 2001. The median age at diagnosis was 42 years. Tumors extended into the cervical cord in 13 patients, the thoracic cord in 7 patients, and the conus medullaris in 6 patients. Eleven patients had previous surgery and/or radiation therapy. RESULTS We achieved a gross total resection in 88% of patients, whereas 8% had a subtotal resection and 4% had a biopsy. Only 1 patient developed a recurrence over a mean follow-up period of 31 months. CONCLUSION We conclude that radical surgical resection of spinal cord ependymomas can be safely achieved in the majority of patients. A trend toward neurological improvement from a postoperative deficit can be expected between 1 and 3 months after surgery and continues up to 1 year. Postoperative dysesthesias begin to improve within 1 month of surgery and are significantly better by 1 year after surgery. The best predictor of outcome is the preoperative neurological status.

Conservative management of acoustic neuroma: an outcome study.

OBJECTIVE This study analyzed selection criteria, clinical outcome, and tumor growth rates in patients with acoustic neuromas in whom the initial management strategy was observation. METHODS A retrospective review of patients with conservatively managed unilateral acoustic neuromas was conducted. Minimum follow-up was 6 months. Patients with neurofibromatosis Type II were excluded. Differences in tumor growth rates were analyzed by use of the Wilcoxon rank sum test. RESULTS Sixty-eight patients (31 men and 37 women) with a mean age of 67.1 years were followed for an average of 3.4 years after diagnosis. The reasons for a trial of observation included advanced age (55%), patient preference (21%), minimal symptoms (9%), poor general medical condition (7%), asymptomatic tumor (4%), and tumor in the only hearing ear (4%). Fifty-eight patients (85%) were successfully managed with observation alone. Ten patients (15%) ultimately required treatment (nine received microsurgical treatment and one patient underwent radiosurgical intervention) at a mean time interval of 4.0 years after diagnosis. Forty-eight tumors (71%) showed no growth and 20 (29%) enlarged during the study period. The mean tumor growth rate at the 1-year follow-up was significantly higher in the group requiring treatment (3.0 mm) than in the group not requiring treatment (0.36 mm) (P < 0.0001). Thus, the tumor growth rate at the 1-year follow-up was a strong predictor of the eventual need for treatment. CONCLUSION Observation is a reasonable management strategy in carefully selected patients with acoustic neuromas. Diligent follow-up with serial magnetic resonance imaging is recommended, because some tumors will enlarge to the point at which active treatment is required.

Aneurysmal Bone Cyst of the Spine: Management and Outcome

Study Design. The clinical records, radiographs, histologic sections, and operative reports of 52 consecutive patients with an aneurysmal bone cyst of the spine were reviewed to evaluate diagnostic and therapeutic options and to correlate treatment and outcome. Objectives. To define the incidence, clinical presentation, diagnostic and therapeutic options, and prognosis of patients with aneurysmal bone cyst of the spine. Summary of Background Data. There are special considerations in the management of spinal lesions: relative inaccessibility of the lesions, associated intraoperative bleeding, necessity of removing the entire lesion to avoid the possibility of recurrence, proximity of the lesion to the spinal cord and nerve roots, and potential postoperative bony spinal instability. Methods. Fifty‐two consecutive patients with an aneurysmal bone cyst of the spine were treated from 1910 to 1993. Forty patients initially treated for a primary lesion had operative treatment (19 intralesional excision and bone grafting and 21 intralesional excision); four also had adjuvant radiation therapy. Preoperative arterial embolization was performed in two. Results. There was a recurrence rate of 10% within 10 years. All recurrences were noted less than 6 months after surgery. Of 12 patients treated for a recurrent lesion, two had a subsequent recurrence (16.7%) within 9 years. At last follow‐up examination, 50 patients (96%) were free of the disease. One patient died of postradiation osteosarcoma, and one died of intraoperative bleeding. Conclusions. Current treatment recommendations involve preoperative selective arterial embolization, intralesional excision curettage, bone grafting, and fusion of the affected area if instability is present.

Improved Preservation of Facial Nerve Function With Use of Electrical Monitoring During Removal of Acoustic Neuromas

Continuous spontaneous electromyographic activity and responses to electrical stimulation of the facial nerve in the surgical field were monitored in 48 patients undergoing primary removal of an acoustic neuroma. The operative and postoperative results in these patients were compared with the results in 48 patients who were matched for age and size of tumor and who underwent the same surgical procedure without intraoperative monitoring. Eighty-three percent of the patients had preoperative evidence of facial neuropathy, which was more severe with larger tumors. Postoperative facial nerve function was most accurately predicted on the basis of the extent of facial neuropathy on preoperative electrophysiologic testing. Anatomic preservation of the facial nerve in patients with large tumors was substantially improved in the monitored patients (67%) in comparison with those without monitoring (33%). No difference was noted in facial nerve function in the two groups of patients immediately postoperatively. By 3 months, the degree of improvement in the monitored group exceeded that in those who were not monitored, particularly in patients with medium-sized and large tumors.

Giant cell tumor of the skull

Background. Most giant cell tumors (GCT) occur at the ends of long bones. There is little information about GCT of the skull bones.