The relationship between idiopathic intracranial hypertension and obesity.

OBJECTIVE: Idiopathic intracranial hypertension (IIH) is usually considered to result from deficient intracranial absorption of cerebrospinal fluid, but has also been suggested to be caused by decreased cranial venous flow because of increased intrathoracic pressure resulting from intra-abdominal obesity. To test this hypothesis, cerebrospinal fluid pressure (Pcsf), extracranial venous pressure (Pvf), intracranial venous pressure, and body mass index (BMI) were studied in patients with IIH with papilledema compared with patients with chronic tension-type headache (CTTH). DESIGN AND SUBJECTS: The Pcsf and the pressures in frontal veins without (Pvf) and with bilateral compression of the supraorbital branch of the frontal veins and the superficial facial veins (Pvfc), the latter considered to be about equal to Pvfc, were studied in 10 consecutive patients with IIH with papilledema. Ten consecutive CTTH patients were used for controls. Orbital phlebography was performed to confirm that the compression of facial veins other than the frontal veins resulted in adequate communication between the frontal vein used for the studies and the cavernous sinus. RESULTS: Cerebrospinal fluid pressure was between 200 and 250 mm water in 5 of the CTTH patients and above 350 mm water in all IIH patients. Body mass index was >25 in all CTTH patients and similar in the 2 groups. Cerebrospinal fluid pressure was similar to Pvfc in all 10 CTTH patients but significantly greater in 6 of the 10 IIH patients. Pvf was similar in the 2 groups and related to BMI. CONCLUSIONS: Chronic tension-type headache patients may be prone to have Pcsf > 200 mm water and BMI > 25. Papilledema because of intracranial hypertension occurred in the present study at Pcsf > 350 mm water. The findings of Pvfc and Pcsf being similar in all CTTH patients support the suggestion that the techniques used for measuring intracranial venous pressure are adequate. The findings of similar BMI in the CTTH and the IIH patients who differed significantly as to Pcsf refute the hypothesis that obesity precedes, and is the cause of, intracranial hypertension in IIH. The difference between Pcsf and Pvfc in 6 of the IIH patients also does not support such a hypothesis but may indicate that IIH is due to deficient intracranial cerebrospinal fluid absorption. Since a relationship between intracranial hypertension and obesity is established and obesity is not found to cause intracranial hypertension in IIH, intracranial hypertension may be suggested to be the primary cause of weight increase in IIH. Obesity, however, may secondarily increase the preexistent IIH.

Capsulotomy for obsessive-compulsive disorder: long-term follow-up of 25 patients.

CONTEXT: Capsulotomy is sometimes used as a treatment of last resort in severe and treatment-refractory cases of obsessive-compulsive disorder (OCD). OBJECTIVE: To evaluate the long-term efficacy and safety of capsulotomy in OCD. DESIGN: Noncontrolled, long-term follow-up trial (mean of 10.9 years after surgery). SETTING: University hospital referral center. PATIENTS: Twenty-five consecutive patients with OCD who underwent capsulotomy from 1988 to 2000. INTERVENTION: Unilateral or bilateral capsulotomy. Lesions were created by means of radiofrequency heating (thermocapsulotomy) or gamma radiation (radiosurgery, gammacapsulotomy). MAIN OUTCOME MEASURE: Yale-Brown Obsessive-Compulsive Rating Scale (Y-BOCS) score. RESULTS: The mean Y-BOCS score was 34 preoperatively and 18 at long-term follow-up (P < .001). Response (defined as > or = 35% reduction at long-term follow-up compared with baseline) was seen in 12 patients at long-term follow-up. Nine patients were in remission (Y-BOCS score, < 16) at long-term follow-up. Only 3 patients were in remission without adverse effects at long-term follow-up. Response rates did not differ significantly between surgical methods. A mean weight gain of 6 kg was reported in the first postoperative year. Ten patients were considered to have significant problems with executive functioning, apathy, or disinhibition. Six of these 10 patients had received high doses of radiation or had undergone multiple surgical procedures. Results of our magnetic resonance imaging analysis in 11 patients suggest that the OCD symptom reduction may be increased by reducing the lateral extension of the lesions, and a reduction in the medial and posterior extension may limit the risk of adverse effects (ie, smaller lesions may produce better results). CONCLUSIONS: Capsulotomy is effective in reducing OCD symptoms. There is a substantial risk of adverse effects, and the risk may vary between surgical methods. Our findings suggest that smaller lesions are safer and that high radiation doses and multiple procedures should be avoided.

Gamma knife surgery for dural arteriovenous shunts: 25 years of experience.

OBJECT: The aim of this study was to assess the clinical efficacy of gamma knife surgery (GKS) in the treatment of dural arteriovenous shunts (DAVSs). METHODS: From a database of more than 1600 patients with intracranial arteriovenous shunts that had been treated with GKS, the authors retrospectively and prospectively identified 53 patients with 58 DAVSs from the period between 1978 and 2003. Four patients were lost to follow-up evaluation and were excluded from the series. Thus, this study is based on the remaining 49 patients with 52 DAVSs. Thirty-six of the shunts drained into the cortical venous system, either directly or indirectly, and 22 of these were associated with intracranial hemorrhage on patient presentation. The mean prescription radiation dose was 22 Gy (range 10-28 Gy). All patients underwent a clinical follow-up examination. In 41 cases of DAVS a follow-up angiography study was performed. At the 2-year follow-up visit, 28 cases (68%) had angiographically proven obliteration of the shunt and in another 10 cases (24%) there was significant flow regression. Three shunts remained unchanged. There was one immediate minor complication related to the administration of radiation. Furthermore, one patient had a radiation-induced complication 10 years after treatment, although she recovered completely. There was one posterior fossa bleed 2 months after radiosurgery; a hematoma, as well as a lesion, was evacuated, and the patient recovered uneventfully. A second patient had an asymptomatic occipital hemorrhage approximately 6 months postradiosurgery. The clinical outcome after GKS was significantly better than that in patients with naturally progressing shunts (p < 0.01, chi-square test); figures on the latter have been reported previously. CONCLUSIONS: Gamma knife surgery is an effective treatment for DAVSs, with a low risk of complications. Major disadvantages of this therapy include the time elapsed before obliteration and the possibility that not all shunts will be obliterated. Cortical venous drainage from a DAVS, a risk factor for intracranial hemorrhage, is therefore a relative contraindication. Consequently, GKS can be used in the treatment of both benign DAVSs with subjectively intolerable bruit and aggressive DAVSs not responsive to endovascular treatment or surgery.

Optimization of semi-quantification in metabolic PET studies with 18F-fluorodeoxyglucose and 11C-methionine in the determination of malignancy of gliomas.

The treatment of the glioma patient depends on the nature of the lesion and on the aggressiveness of the tumor. The management of gliomas continues to be a challenging task, because morphological neuroimaging techniques do not always differentiate them from nontumoral lesions or high grade tumors from low grade lesions. Positron Emission Tomography (PET) offers the possibility of the in vivo quantitative characterization of brain tumors. Despite decades of useful application of PET in the clinical monitoring of gliomas, no consensus has been reached on the most effective image analysis approach for providing the best diagnostic performance under heavy-duty clinical diagnostic circumstances. The main objective of the present study was to find and validate optimal semi-quantitative search strategies for metabolic PET studies on gliomas, with special regard to the optimization of those metabolic tracer uptake ratios most sensitive in predicting histologic grade and prognosis. 11C-Methionine (11C-Met, n = 50) and/or 18F-Fluorodeoxyglucose (18F-FDG, n = 33) PET measurements were performed in 59 patients with primary and recurrent brain gliomas (22 high grade and 37 low grade tumors) in order to correlate the biological behavior and 11C-Met/18F-FDG uptake of tumors. Data were analyzed by region-of-interests (ROI) methods using standard uptake value calculation. Different ROI defining strategies were then compared with each other for two of the most commonly used metabolic radiotracers, 18F-FDG and 11C-Met, in order to determine their usefulness in grading gliomas. The results were compared to histological data in all patients. Both ANOVA and receiver operating characteristic (ROC) analysis indicated that the performance of 18F-FDG was superior to that of 11C-Met for most of the ratios. 18F-FDG is therefore suggested as the tracer of choice for noninvasive semi-quantitative indicator of histologic grade of gliomas. 11C-Methionine has been suggested as a complimentary tracer, useful in delineating the extent of the tumor. The best diagnostic performance was obtained by calculating the ratio of the peak 18F-FDG uptake of the tumor to that of white matter (p < 0.001; ANOVA). This metabolic tracer uptake ratio is therefore suggested as an easily obtained semi-quantitative PET indicator of malignancy and histological grade in gliomas.

Galanin in pituitary adenomas.

Tumor galanin content was measured in extracts from human pituitary adenomas using a specific RIA method for monitoring human galanin. Twenty-two out of twenty-four tumors contained galanin with notably high levels in corticotroph adenomas, varying levels in clinically inactive tumors, and low levels in GH secreting adenomas. Tumor galanin and ACTH contents were closely correlated in all tumors. In four young patients with microadenomas and highly active Mb Cushing tumor galanin was inversely related to tumor volume. The molecular form of tumor galanin, studied with reverse-phase HPLC, was homogeneous with the majority of tumor galanin coeluting with standard human galanin. In the tumors analysed with in situ hybridization there was a good correlation between galanin peptide levels and galanin mRNA expression. In some tumors galanin mRNA and POMC levels coexisted, in others they were essentially in different cell populations. Levels of plasma galanin-LI were not related to tumor galanin concentration, and galanin levels were in the same range in sinus petrosus close to the pituitary venous drainage as in peripheral blood. Corticotrophin releasing hormone injections in two patients caused ACTH, but no detectable galanin release into sinus petrosus. Our results demonstrate that corticotroph, but not GH adenomas, express high levels of galanin, in addition to ACTH, and that in some tumors both polypeptides are synthesised in the same cell population. However, galanin levels in plasma were not influenced by the tumor galanin content.