Pseudoprogression in high-grade glioma.

Pseudoprogression is a treatment-related effect seen on imaging in high-grade glioma. Enhancement of gadolinium contrast on control MRI can be misinterpreted as tumor recurrence and is also difficult to distinguish from radiation necrosis. Pseudoprogression is seen in up to 30% after standard treatment for glioblastoma multiforme (GBM), which is radiotherapy concurrent with chemotherapy with temozolomide (TMZ) and adjuvant cycles of TMZ. In this article, the current literature on pseudoprogression in high-grade glioma is reviewed by searches in PubMed. We also present two clinical cases, one of which had medullary pseudoprogression. No articles on this subentity of pseudoprogression were found in PubMed. Standard MRI with gadolinium contrast cannot differentiate between pseudoprogression, tumor recurrence and radiation necrosis. More advanced imaging techniques are often not available. Pseudoprogression seems to be related to methylated promoter of the O(6)--methyl-guanine methyl transferase (MGMT) gene, which is associated with improved treatment effect. Discontinuation or change of therapy on the basis of misinterpretation of MRI as disease progression is thus unfortunate. MRI should be interpreted with caution the first 6 months after standard treatment of high-grade glioma. In a GBM patient with contrast enhancement on MRI but few or no new symptoms and/or stable steroid doses, treatment should be continued and control imaging performed after 2-3 months.

Analysis of vestibular schwannoma size in multiple dimensions: a comparative cohort study of different measurement techniques.

OBJECTIVES: In this volumetric study of the vestibular schwannoma, we evaluated the accuracy and reliability of several approximation methods that are in use, and determined the minimum volume difference that needs to be measured for it to be attributable to an actual difference rather than a retest error. We also found empirical proportionality coefficients for the different methods. DESIGN/SETTING AND PARTICIPANTS: Methodological study with investigation of three different VS measurement methods compared to a reference method that was based on serial slice volume estimates. These volume estimates were based on: (i) one single diameter, (ii) three orthogonal diameters or (iii) the maximal slice area. Altogether 252 T1-weighted MRI images with gadolinium contrast, from 139 VS patients, were examined. MAIN OUTCOME MEASURES: The retest errors, in terms of relative percentages, were determined by undertaking repeated measurements on 63 scans for each method. Intraclass correlation coefficients were used to assess the agreement between each of the approximation methods and the reference method. The tendency for approximation methods to systematically overestimate/underestimate different-sized tumours was also assessed, with the help of Bland-Altman plots. RESULTS: The most commonly used approximation method, the maximum diameter, was the least reliable measurement method and has inherent weaknesses that need to be considered. This includes greater retest errors than area-based measurements (25% and 15%, respectively), and that it was the only approximation method that could not easily be converted into volumetric units. Area-based measurements can furthermore be more reliable for smaller volume differences than diameter-based measurements. CONCLUSIONS: All our findings suggest that the maximum diameter should not be used as an approximation method. We propose the use of measurement modalities that take into account growth in multiple dimensions instead.

Acoustic neuroma--treatment modalities. Surgery, gamma-knife or observation?

We present our results of 211 patients with acoustic neuroma over a period of 10 years, 1988-97. We operated on 100 and 111 had Gamma-knife (GK) treatment (69 were available to follow-up). The results are excellent for surgery on small and intracanalicular tumours. In tumours of the same size, surgery and GK treatment give comparable, but somewhat different, results. In the GK group of 54 primary treated patients, 3 patients had to be operated on and another 4 developed hydrocephalus. A group of 35 acoustic tumours was observed for more than 3 years. Nineteen did grow (54%). Hearing was unchanged in 23%. We performed surgery in 11 patients and gave 2 patients GK treatment because of tumour growth of > 2 mm in diameter a year. We conclude that either treatment is effective for small and medium-sized acoustic neuromas. Hearing preservation was best in the GK-treated group (80%), compared to only 12.5% in the group operated via the suboccipital route. Larger tumours and most medium-sized tumours should be operated, as should smaller tumours with persistent symptoms of vertigo and pain. Medical contraindications to surgery or reluctance to undergo surgery make GK treatment a good alternative. Treatment of residual tumours with the GK could also be a solution to a difficult problem.

[Cerebral amyloid angiopathy]. / Cerebral amyloid angiopati.

Cerebral amyloid angiopathy affects the cerebral vasculature selectively, and there is no systemic amyloidosis. Amyloid is deposited in small and medium-sized vessels of the cortex and leptomeninges. Cerebral amyloid angiopathy is a common cause of spontaneous lobar haemorrhage in elderly patients. However, cerebral amyloid angiopathy may have atypical clinical and radiological presentations. We report on five patients (three males and two females, aged 43-77 years) with histologically verified cerebral amyloid angiopathy. One patient experienced an acute headache attack and classical lobar haemorrhage. The other patients had various neurological symptoms and signs, such as seizure, disturbed vision, pareses, aphasia, and dementia that were initially diagnosed as cerebral infarction or tumour. Two patients with cerebral amyloid angiopathy and granulomatous angiitis responded to immunosuppressive treatment.

Basilar artery fenestration aneurysms treated with guglielmi detachable coils.

SUMMARY: Four patients with basilar artery fenestration aneurysms at the vertebra basilar junction were admitted after subarachnoid haemorrhage. In two of them attempted surgery failed. Subsequently, all four were embolised with Guglielmi Detachable Coils (GDC), three of them in the acute phase. In one case the initial embolisation was incomplete, but follow-up angiography demonstrated spontaneous total occlusion. In another, partial reopening was treated with further embolisation. Three patients recovered completely after treatment. One patient still has deficits related to surgery of an accompanying aneurysm at the middle cerebral artery. He is clinically improving but still not back at work. In two cases the fenestration was combined with a hypoplastic upper vertebral artery on one side. A hypoplastic veretebral artery on one side may frequently be part of the developmental anomaly of basilar fenestration aneurysms. The anatomical configuration and location of these aneurysms is such that their true nature is sometimes difficult to disclose at cerebral angiography and is only realised during embolisation. Treatment with GDC coils seems superior to surgery in basilar artery fenestration aneurysms.

[Interstitial laser coagulation in the treatment of benign prostatic hyperplasia. Preliminary results]. / Interstitiell laserkoagulasjon ved behandling av benign prostatahyperplasi. Preliminaere erfaringer.

51 patients aged 68 (range 52-81) years with lower urinary tract symptoms compatible with obstruction from benign prostatic hyperplasia were treated with interstitial laser coagulation (ILC). Postoperative urinary retention lasting less than one week was seen in the majority of cases. All patients were followed up for three months and ten cases had further follow-up after one year. Three months after treatment the international prostate symptom score decreased from 23.3 +/- 0.7 to 8.9 +/- 0.8 and was 10.2 +/- 2.1 after one year. Peak urinary flow increased concomitantly from 8.3 +/- 0.4 to 12.2 +/- 0.7 at three months and was 11.5 +/- 1.4 ml/sec after one year. Three patients received other, additional treatment because the ILC-treatment failed. In conclusion, interstitial laser coagulation had marked effects on symptoms, whereas the effects on objective parameters were less pronounced in this selected group of patients. However, more extensive follow-up, is essential for further evaluation of this new treatment procedure.

Expanding cava septi pellucidi and cava vergae in children: report of three cases.

Three children with hydrocephalus and expanding cysts of the cavum septi pellucidi and cavum vergae are reported. In all the patients, the hydrocephalus was present before the persistent cava started to expand. The cava increased gradually, until they became cystic, but their growth did not affect the size of the ventricles. Two of the patients were treated with internal cystoventricular shunts, causing a prompt collapse of the cysts but no change in the concomitant hydrocephalus. In the third patient, the persistent cava started to expand only when a previously implanted ventriculoperitoneal shunt failed temporarily. The cyst disappeared when the shunt resumed its function. The possible mechanisms underlying the expansive growth of persistent cava are discussed. We propose the theory that the growth of the cava in our patients may be the result, rather than the cause, of the hydrocephalus.