Massive symptomatic subependymoma of the lateral ventricles: case report and review of the literature.

Subependymomas are benign intraventricular tumors with an indolent growth pattern, which are usually asymptomatic, and most commonly occur in the fourth and lateral ventricles. When symptomatic, subependymomas often obstruct critical portions of the cerebrospinal fluid (CSF) pathway, causing hydrocephalus, and range from 3 cm to 5 cm in size. We report a case of an unusually massive subependymoma of the lateral ventricles treated with subtotal resection, ventriculoperitoneal shunt, and post-surgical radiation. The clinical course, radiographic and pathologic characteristics of this massive intraventricular subependymoma are discussed, as well as the differential diagnosis of lateral ventricular masses and a review of the literature concerning subependymomas.

Parasagittal ependymoma resembling falcine meningioma.

Presentation, diagnosis, and management of an unusual parasagittal ependymoma, radiographically resembling a falcine meningioma, are described. Despite its radiographic appearance, pathologic evaluation revealed classic features of an ependymoma. The radiographic and pathologic characteristics of this unusual lesion are briefly examined, and the literature is reviewed. Although extraaxial ependymomas are rare, they should be considered in the radiographic differential diagnosis of dural-based lesions, especially for patients within the first 3 decades of life.

Somatotropinoma infarction during octreotide therapy leading to bilateral cavernous sinus syndrome.

The cyclic somatostatin analog, octreotide, forms the mainstay of medical treatment for acromegaly. In addition to lowering circulating growth hormone levels and shrinking tumor size, octreotide may provide symptomatic relief of headaches associated with growth hormone secreting tumors. The majority of reported complications of octreotide therapy are gastrointestinal and metabolic. The present case illustrates the development of acute bilateral cavernous sinus syndrome with loss of eye movement bilaterally during octreotide therapy. Serial MRI examination suggest tumor infarction as the etiology. The symptoms resolved over 2 months as the tumor shrunk in size and growth hormone was dramatically reduced.

Rapid re-expansion of a macroprolactinoma after early discontinuation of bromocriptine.

Prolactin (PRL)-secreting pituitary adenomas are the most common functioning pituitary tumors. Medical treatment with dopamine agonists is the therapy of choice for macroprolactinomas (> or = 10 mm). Withdrawal of bromocriptine after weeks or months of uninterrupted therapy has been associated with rapid tumor re-expansion as evidenced by x-ray and CT scanning of the pituitary region. We report a patient with a giant macroprolactinoma who had a dramatic response to bromocriptine (tumor volume shrinkage of 53% within a month) but rapid re-expansion to its original dimensions one week after discontinuation of bromocriptine. To our knowledge, this is the first time that the rapid shrinkage/re-expansion of a macroprolactinoma has been documented with serial MRI scans.

Pergolide as primary therapy for macroprolactinomas.

The objective of this study is to determine whether pergolide therapy is an effective modality for the de novo treatment of patients with macroprolactinomas. Twenty-two consecutive patients with macroprolactinomas were included in the study and followed prospectively. These included 16 men and 6 women in whom pregnancy was not of concern. Pergolide was administered once or twice a day depending on the patient's preference. Ten patients received 0.1 mg daily as a maintenance regimen and in the others the daily dose ranged from 0.05 to 0.5 mg. Eight patients reported minor but tolerable side effects. One patient had to be switched to cabergoline because of intolerable nausea. After a mean of 12 months (range, 3-36), mean PRL levels declined from 3,135 ng/ml (range, 126-31,513) to 50 ng/ml (3-573), representing a mean PRL suppression of 88% (range, 0-99). PRL levels became normal in 15 patients and decreased to 25-40 ng/ml in 3 others. The mean tumor volume shrinkage was 25% or greater in 19 patients (86%), 50% or greater in 17 patients (77%), and 75% or greater in 10 patients (45%). Visual abnormalities were reversible after pergolide therapy in all but 1 of 12 patients with initially abnormal formal visual testing. Two out of 4 premenopausal women did not normalize PRL levels and had persistent oligomenorrhea. Testosterone was low in 14 men at presentation and normalized in 3 with pergolide therapy. We conclude that pergolide is a safe, inexpensive, and generally well-tolerated dopamine agonist for the treatment of macroprolactinomas in men and women in whom pregnancy is not of concern. In these specific populations, pergolide may become the first-line therapy for treatment of macroprolactinomas.

Extracranial metastatic meningioma.

Meningiomas rarely metastasize outside the intracranial compartment. We report a case of disseminated metastases from a recurrent intracranial meningioma and review the imaging and pathological literature on metastatic meningioma.

Epidural abscess: a delayed complication of esophageal stenting for benign stricture.

A case of anterior cervical epidural abscess associated with perforation of an endoscopically placed esophageal stent is presented. Although delayed esophageal perforation is a known complication of endoscopic stenting, no cases presenting with epidural abscess have yet been reported. The increasing application of endoscopic stenting for benign esophageal strictures provides greater opportunity for this type of delayed complication.

Abducens nerve palsy after radiofrequency rhizolysis for trigeminal neuralgia: case report.

OBJECTIVE AND IMPORTANCE: Abducens nerve palsy is a rare and reversible complication associated with percutaneous radiofrequency trigeminal rhizolysis. CLINICAL PRESENTATION: An 86-year-old man developed an abducens nerve palsy immediately after undergoing percutaneous radiofrequency trigeminal rhizolysis for severe trigeminal neuralgia involving all three divisions of the trigeminal nerve. The palsy resolved spontaneously after 2 months. CONCLUSION: This case, in combination with previous reports, suggests that cases of transient sixth nerve palsy associated with percutaneous radiofrequency trigeminal rhizolysis for trigeminal neuralgia are more likely to occur in elderly patients with ophthalmic division involvement.

Spontaneous chronic epidural pneumocephalus resulting from hyperpneumatization of the cranium causing mass effect: case report.

OBJECTIVE AND IMPORTANCE: We report a rare case of spontaneous epidural pneumocephalus resulting from an unusual boney defect caused by hyperpneumatization of the cranium. The pneumocephalus was also unusual for its chronicity and significant mass effect. CLINICAL PRESENTATION: A 49-year-old man presented with a 3-year history of diffuse headaches and sensation of air movement in his sinuses on the right side. An evaluation for suspected sinusitis using computed tomography determined extensive pneumatization of most of the cranium, a large accumulation of epidural air, and a critical degree of brain shift. INTERVENTION: A right frontoparietal-temporal craniotomy with an osteoplastic bone flap was performed. The floor of the middle cranial fossa and the inner table of the bone flap were extensively debrided of air cells. A large pericranial flap was turned down over the floor of the middle cranial fossa and was held in place by a fat graft. After closing the craniotomy, a tympanostomy tube was placed into the right tympanic membrane. CONCLUSION: The incidence of hyperpneumatization of the cranium seems to be very low. Hyperpneumatization when present, however, can cause spontaneous intracranial pneumocephalus. Based on the literature and the success of this case, the optimal management is surgical obliteration of the involved air cells.

Giant pituitary prolactinoma with falsely low serum prolactin: the pitfall of the "high-dose hook effect": case report.

OBJECTIVE AND IMPORTANCE: We present a case of a giant prolactinoma with a falsely low serum prolactin concentration determined by a two-site chemiluminometric assay. Awareness of the possibility of the "high-dose hook effect" in such cases will prevent preoperative misdiagnosis. CLINICAL PRESENTATION: A patient with a giant invasive pituitary tumor was found preoperatively to have serum prolactin of 31 ng/ml. Pathological examination of the excised tissue, however, demonstrated strong staining for prolactin. INTERVENTION: Serial dilutions of the serum disclosed hyperprolactinemia of 280,000 ng/ml, establishing the presence of the "high-dose hook effect." Treatment with pergolide (Permax; Athena Neurosciences, S. San Francisco, CA) decreased tumor size and lowered serum prolactin by more than 99%. CONCLUSION: A "high-dose hook effect" needs to be suspected in every patient with a giant pituitary adenoma (>3 cm) and normal serum prolactin. Subsequently assaying the diluted serum will reliably disclose this phenomenon and allow correct diagnosis and therapy.

Pituitary irradiation is ineffective in normalizing plasma insulin-like growth factor I in patients with acromegaly.

Pituitary irradiation suppresses GH hypersecretion in patients with acromegaly. Within 10 yr after radiotherapy, up to 80% of patients achieve plasma GH levels below 5 micrograms/L. Whether this is sufficient to normalize plasma insulin-like growth factor I (IGF-I) levels, is unknown. We examined the effect of radiotherapy on plasma IGF-I concentrations in patients with acromegaly. We reviewed hospital charts of 140 patients with acromegaly seen in our institution between 1975 and 1996. Data on plasma GH and IGF-I were extracted and tabulated longitudinally together with the information about the concomitant medical therapy. We included data from the patients who received radiotherapy as a part of their treatment and whose IGF-I was monitored for more than 1 yr afterward. To avoid the potential bias, the data for patients who were referred to us for medical therapy, having failed radiation elsewhere, were excluded. A total of 38 datasets were submitted for the final analysis. The average follow-up was 6.8 +/- 0.8 yr (range, 1-19). Only 2 patients achieved age- and sex-adjusted normal IGF-I levels while off medical therapy. Noncured patients had a mean plasma GH level of 4.6 +/- 1.1 micrograms/L but still elevated plasma IGF-I levels (219 +/- 26% of the upper normal limit) at the last follow-up visit. A random GH concentration below 1.5 micrograms/L was associated with a pathologically high plasma IGF-I concentration in 43% of instances. Radiotherapy appears to be ineffective in normalizing plasma IGF-I levels in acromegaly. A multicenter study to reevaluate the future use of this modality in patients with acromegaly is warranted.

Cerebral oximetry during circulatory arrest for aneurysm surgery.

A patient underwent surgical clipping of a complex giant intracranial carotid aneurysm with the aid of extracorporeal circulation and complete hypothermic circulatory arrest. During the entire procedure, cerebrovascular oxygen saturation (ScO2) was spectroscopically measured. The patient experienced circulatory arrest for 34 min; for 15 of the 34 min ScO2 was < 34% (minimum 32%). The patient tolerated the procedure without new neurological deficit, thus demonstrating that the previously suggested "critical" level of 35% ScO2 is not absolute.

Pre- and postoperative MR imaging of craniopharyngiomas.

PURPOSE: To compare the pre- and postoperative MR appearance of craniopharyngiomas with respect to lesion size, tumour morphology and identification of surrounding normal structures. MATERIAL AND METHODS: MR images obtained prior to and following craniopharyngioma resection were evaluated retrospectively in 10 patients. Tumour signal characteristics, size and extension with particular reference to the optic chiasm, the pituitary gland, the pituitary stalk and the third ventricle were evaluated. RESULTS: Following surgery, tumour volume was reduced in all patients. In 6 patients there was further tumour volume reduction between the first and second postoperative images. Two of these patients received radiation therapy between the 2 postoperative studies, while 4 had no adjuvant treatment to the surgical intervention. There was improved visualization of the optic chiasm in 3, the pituitary stalk in one, and the third ventricle in 9 of the 10 patients. The pituitary gland was identified preoperatively only in one patient, postoperatively only in another, pre- and postoperatively in 5, and neither pre- nor postoperatively in 3 patients. In 3 patients MR imaging 0-7 days postoperatively identified tumour remnants not seen at the end of the surgical procedure. The signal intensities of solid and cystic tumour components were stable from pre- to the first postoperative MR images. Optic tract increased signal prior to surgery was gone 28 days postoperatively in one patient, but persisted on the left side for 197 days after surgery in another. CONCLUSION: Postoperative MR imaging of craniopharyngiomas demonstrated tumour volume reduction and tumour remnants not seen at surgery. Early postoperative MR imaging of craniopharyngiomas may overestimate the size of residual tumour. Improved visualization of peritumoral structures may be achieved.

Craniopharyngioma: radiologic and histologic findings and recurrence.

PURPOSE: To identify the CT and MR characteristics of craniopharyngiomas, to evaluate the histologic types of craniopharyngioma, and to compare the radiologic/histologic appearance and type of therapy with tumor recurrence. METHODS: We reviewed the records of 45 patients with craniopharyngiomas for which surgical specimens (n = 45), preoperative MR or CT studies (n = 27), or other MR or CT studies or reports (n = 18) were available. Radiologic appearance, histologic morphology, treatment, and tumor recurrence were studied. RESULTS: Adamantinomatous epithelium was found in 40 of 45 surgical specimens, keratin in 34 of 45, and squamous epithelium in 11 of 45. A continuum of mixed morphology rather than distinct subtypes of tumors was found. The radiologic appearance did not correlate with the histologic features. No statistically significant difference was found between children and adults with respect to tumor size, calcification, histology, or tumor recurrence. Patients treated with radiation after subtotal resection had far fewer tumor recurrences (n = 3) than patients treated with surgery alone (n = 18). CONCLUSION: Craniopharyngiomas could not be divided into distinct histologic types. No differentiating radiologic or histologic characteristics could be established for craniopharyngiomas in children versus adults. Radiation treatment was strongly associated with tumor regression or lack of recurrence.

Use of the extreme lateral approach in the surgical treatment of an intradural ventral cervical spinal cord vascular malformation: technical case report.

Vascular malformations on the ventral aspect of the spinal cord are difficult to access surgically. Recently, selected lesions have been treated with endovascular embolization. However, embolization using currently approved agents may not be permanently effective, and recanalization rates range from 25 to 83% in the literature. Additionally, many of these lesions are not amenable to endovascular treatment because of the inadequate diameter, tortuosity, or lack of collateral flow of the anterior spinal artery from which the feeding arteries arise. Surgical approaches to these lesions have been posterolateral or anterior. The posterolateral approach requires division of the dentate ligaments and occasionally the adjacent nerve root and then rotation of the cord itself to allow visualization of the lesion. The anterior approach involves a multilevel corpectomy requiring subsequent bone grafting and stabilization. Certain lesions are not readily approachable by either method. We describe the use of the extreme lateral approach to successfully access and obliterate a Type IVa perimedullary fistula located adjacent to the midline ventrally at the C1-C2 level in a 72-year-old woman who had suffered a subarachnoid hemorrhage. The extreme lateral approach was originally designed to access neoplasms located ventral to the cord and brain stem; as a result of the posterior displacement of the spinal cord by the neoplasm, intraoperative visualization is improved. No posterior displacement was present with this malformation. Even without such cord displacement, the extreme lateral approach allowed excellent visualization of and access to the arteriovenous fistula, preserved important anatomic structures, and required essentially no rotation or compression of the spinal cord to successfully obliterate the lesion.

Dolichoectasia of the anterior cerebral arteries in an adolescent.

We report a case of bilateral dolichoectasia of the anterior cerebral arteries in a 14-year-old girl as documented by MR imaging and cerebral angiography. Concurrent thickening of the adjacent medial frontal lobes was found, suggesting either a neuronal migrational abnormality or secondary changes attributable to vascular insufficiency.

Craniopharyngiomas--the utility of contrast medium enhancement for MR imaging at 1.5 T.

To evaluate the efficacy of i.v. contrast medium administration in MR imaging at 1.5 T in patients with craniopharyngiomas, MR studies of 10 men and 6 women with pathologically proven craniopharyngiomas were made. The MR images were obtained as 3- to 5-mm-thick coronal (n = 13) or axial (n = 3) Tl-weighted images (T1WI) prior to and following i.v. Gd-DTPA administration. Proton density- (PD) and T2-weighted images (T2WI) were also obtained. Conspicuity of tumor margins, cystic versus solid components, size, location and effect upon adjacent structures were separately characterized in all imaging sequences. In 6 patients contrast medium-enhanced T1WI. PD and T2WI demonstrated cystic tumor components not seen on unenhanced T1WI. There were significant differences (p < 0.004) on 2-tailed Student's t-test comparing tumor conspicuity on contrast medium-enhanced T1WI with unenhanced T1WI, PD and T2WI. Optimal tumor delineation on MR imaging of patients with craniopharyngiomas justifies the use of i.v. contrast medium.

Radiosensitization with carotid intra-arterial bromodeoxyuridine +/- 5-fluorouracil biomodulation for malignant gliomas.

Bromodeoxyuridine (BUdR), a nonhypoxic radiosensitizing drug, is a halogenated pyrimidine analog that is incorporated into the DNA of dividing cells in a competitive process with thymidine. BUdR sensitizes cells to radiation therapy. 5-Fluorouracil (5-FU) inhibits the endogenous synthesis of thymidine, resulting in increased incorporation of the BUdR. Neurons and glial cells have a very low mitotic rate; they will not incorporate BUdR and will not be sensitized. BUdR and 5-FU are best delivered intra-arterially (IA) because of their regional advantage. We infused BUdR +/- 5-FU over 8 1/2 weeks, before and during 59.4-Gy focal conformal external beam radiation therapy, through a permanently implanted pump with a catheter placed retrograde through the external carotid artery to the carotid bifurcation. Sixty-two patients with grades III or IV glioma were entered into one of two trials, with 23 patients receiving BUdR alone and 39 patients receiving BUdR + 5-FU. The maximum tolerated dose (MTD) of BUdR alone was 400 mg/m2/d for 8 1/2 weeks. The Kaplan-Meier median survival (KMS) was 20 months. In the BUdR + 5-FU trial, the MTD of BUdR was also 400 mg/m2/d and 5-FU was 5 mg/m2/d with a KMS of 17 months. The KMS of all 62 patients in both trials 1 and 2 was 18 months. Pathologic grading used both the original World Health Organization (WHO) and 1993 modified WHO systems. The KMS of grade IV patients was 13.8 months (48 patients) with the original system and 17 months (58 patients) with the modified system.(ABSTRACT TRUNCATED AT 250 WORDS)

Persistence of rapid growth hormone (GH) pulsatility after successful removal of GH-producing pituitary tumors.

GH concentration profiles in patients with acromegaly are characterized by rapid GH pulsatility and high interpulse GH concentrations. Animal and human studies have shown that GH pulses are consequent upon periodic discharges of hypothalamic GHRH, whereas interpulse GH levels might reflect tonic secretion of hypothalamic SRIH. Thus, the pattern of GH secretion in acromegaly may conceivably be attributed to high GHRH pulse frequency and/or SRIH deficiency. If this assumption is correct, removal of a GH-producing tumor should be followed by a persistently high GH pulse frequency and a high recurrence rate. We have studied pulsatile GH secretion in 12 patients with acromegaly before and after apparently complete removal of their pituitary tumors. Despite normalization of GH secretion after surgery, the disease recurred in 3 patients within 3 yr. The other 9 patients had normal insulin-like growth factor-I and basal and dynamic GH concentrations for 24 +/- 4 months postsurgery. Parameters of GH secretion in this group (pre- and postsurgery) were compared to sex-, age-, and body mass index-matched controls. Plasma GH concentrations in the postoperative and control series were analyzed by a chemiluminescent assay with a sensitivity of 0.01 micrograms/L. Removal of the somatotroph tumor led to normalization of mean and interpulse (but not the nadir) GH levels, pulse amplitude, and responses to GHRH. However, GH pulse frequency (14.2 +/- 1.2 vs. 11.8 +/- 0.9 pulses/24 h) did not change and was significantly (P < 0.001) higher than the control value (8.7 +/- 0.9 pulses/24 h). Thus, SRIH secretion in acromegaly is not inherently deficient, and high interpulse GH levels reflect the mass of tumorous somatotrophs. The persistence of rapid GH pulsatility in apparently "cured" patients with acromegaly suggests that abnormally rapid GHRH pulsatility may be an inherent component of the disease process.