A population-based study of brain arteriovenous malformation: long-term treatment outcomes

BACKGROUND AND PURPOSE

By undertaking long-term follow-up of a functionally isolated population study group, we sought to achieve a true picture of intrinsic brain arteriovenous malformation (BAVM). We sought to assess the validity of earlier population-based series and to determine the effects of newer treatment methods on the overall morbidity and mortality of BAVM.

METHODS

We excluded other intracranial vascular pathologies by defining criteria. By retrospective and prospective study, 240 patients with BAVM were followed for a mean of 10.11 years from first diagnosis.

RESULTS

Death rates were as follows: all causes, 12.9%; all BAVM related, 8.75%; BAVM related during conservative management, 24.6%; and BAVM related during active management, 3.9% (P=0.031). Mean diagnosis-to-death interval was 10.6 years. Oxford neurological disability scale grades of 209 survivors (July 2001) were as follows: grades 0 to 2, 74.1%; grade 3, 17.2%; and grades 4 to 5, 9.5%. Death rates were higher for patients who had bled or suffered nonhemorrhagic neurological deficit at original presentation. Incidence of first-ever hemorrhage in untreated patients was as follows: 0 to 9 years, 4.6% (P=0.0035); 30 to 39 years, 21% (P=0.02); and 60 to 69 years, 40.0% (P=0.045). The first bleed was fatal in 4.6%.

CONCLUSIONS

We find no evidence of a substantial undiagnosed reservoir of nonsymptomatic BAVM. All BAVM are potentially hazardous. The great majority of BAVM patients become symptomatic during the patient's lifetime, and the majority will bleed. The risk of first hemorrhage is lifelong and rises with age. Compared with earlier population-based series, our low overall patient mortality is predominantly due to higher proportions of active treatment in the 1980s and 1990s.

Detection of an aberrant motile larval form in the brain of a patient with neurocysticercosis

Neurocysticercosis is the most common parasitic infection of the central nervous system in humans. The adult pork tape worm, Taenia solium, resides in the lumen of the intestine, and the only structural element of an adult worm usually found within a tissue cyst in the brain or in muscle is a single invaginated scolex. We report a highly unusual, and perhaps unique, occurrence of neurocysticercosis in which an aberrant worm-like larval form, 12.5 cm in length, was found within a cyst in brain parenchyma.

Photodynamic therapy of brain tumors

Photodynamic therapy (PDT) for the treatment of a variety of brain tumors, particularly gliomas, has been extensively investigated in laboratory studies and has been studied in clinical trials. The main advantage of PDT lies in its ability to select out tumor cells that are infiltrating brain parenchyma and that are responsible for local tumor recurrence, the major therapeutic dilemma in the treatment of gliomas. PDT has been shown to be safe clinically but adequate trials have yet to be undertaken to prove its efficacy and much work remains to be done to optimize treatment. The laboratory studies and clinical trials involving PDT in the treatment of cerebral tumors, particularly the commonest brain tumors, gliomas, are discussed.

Photodynamic therapy of brain tumors

Photodynamic therapy (PDT) is a binary treatment modality suitable for various malignant tumors including brain. It involves the selective uptake of a photosensitizer into tumor followed by intraoperative irradiation of the tumor with light of an appropriate wavelength to cause activation of the sensitizer and subsequent selective tumor destruction. PDT has been extensively investigated in laboratory studies and has been used in clinical trials to treat a variety of brain tumors, particularly gliomas. The main advantage of PDT lies in its ability to select out infiltrating tumor cells that are responsible for local tumor recurrence. The therapy has been shown to be safe clinically but adequate trials have yet to be undertaken to prove its efficacy and much work remains to be done to optimize treatment. The biological basis, laboratory studies, and clinical trials involving PDT in the treatment of cerebral tumors are discussed.

Homozygous deletions of the multiple tumor suppressor gene 1 in the progression of human astrocytomas

The multiple tumor suppressor gene 1 (MTS1) located on chromosome 9p has recently been implicated as a candidate tumor suppressor gene in many different tumor types. Cytogenetic analysis and deletion mapping studies have revealed that deletion of chromosome 9p occurs in a significant number of primary human astrocytomas. Using multiplex PCR with primers for exon 2 of MTS1 and for D9S196 from chromosome 9q, we have analyzed 78 primary astrocytic tumors for the deletion of MTS1. After controlling for the contamination of tumor samples with normal cells, homozygous loss of MTS1 was found in 13 of 25 anaplastic astrocytomas (WHO grade III) and in 27 of 46 cases of glioblastomas (WHO grade IV) but in none of seven astrocytomas (WHO grade II). These data suggest that MTS1 is an important tumor suppressor gene in the malignant progression of astrocytomas.

Mast cell-rich convexity meningioma presenting as chronic subdural hematoma: case report and review of the literature

A 47-year-old woman with a convexity meningioma presenting as a chronic subdural hematoma is reported. This case is unique in that the symptoms were cyclical and stereotypic. The tumor contained an unusually high number of mast cells. A possible etiologic role of histamine-related vasodilation and tumoral hemorrhage is explored. The relationship between meningioma and subdural hematoma is discussed, and the literature is reviewed.

Stereotactic procedures for lesions of the pineal region

During the 7-year period between June 1985 and May 1992, 34 patients with pineal lesions underwent 66 stereotactic procedures (37 biopsies, 19 third ventriculostomies, 6 cyst aspirations, 3 instillations of 32P into cysts, and 1 insertion of an Ommaya reservoir into a cyst) at the Mayo Clinic. Nine patients subsequently also underwent 10 open resections of lesions of the pineal region. In the 34 study patients, the pathologic entities were 9 gliomas (5 astrocytomas, 2 ependymomas, and 2 oligodendrogliomas), 9 germ cell tumors (7 germinomas, 1 entodermal sinus tumor, and 1 malignant teratoma), 8 pineal parenchymal tumors (3 pinealomas, 3 pinealoblastomas, 1 mixed pinealoma-pinealoblastoma, and 1 intermediate differentiation pineal tumor), 4 other malignant tumors (2 undifferentiated carcinomas, 1 malignant melanoma, and 1 non-Hodgkin's lymphoma), 2 meningiomas, and 2 nonneoplastic lesions (1 glial cyst and 1 inflammatory lesion). No mortality or permanent morbidity was associated with the 66 stereotactic procedures; 2 patients had temporary complications--1 neurologic (transient diplopia) and 1 nonneurologic (pulmonary embolism). Diagnostic tissue was obtained in 33 of the 34 patients. An algorithm for the diagnosis and management of patients with lesions of the pineal region is presented. We conclude that stereotactic biopsy of pineal lesions can be performed safely, has a high diagnostic yield, and facilitates rational planning of treatment.

Craniotomy and thoracotomy for non-small cell carcinoma of the lung with cerebral metastasis

Twenty patients with non-small cell carcinoma of the lung who had cerebral metastasis, were treated by craniotomy and thoracotomy. Eighteen of these patients had a solitary metastasis and all were treated as curable. Ten patients presented with synchronous lung and brain disease. Of the remaining 10, nine initially presented with the lung tumour, which was treated first. There was a zero operative mortality rate and median survival was 12 months with reasonable quality of life for this time.

Experience with nimodipine in aneurysmal subarachnoid haemorrhage

OBJECTIVES

To assess the efficacy of nimodipine in preventing delayed ischaemic deficit in aneurysmal subarachnoid haemorrhage.

DESIGN

A continuous prospective audit of all patients with aneurysmal subarachnoid haemorrhage admitted to the joint neurosurgery units of Prince Henry's and Alfred hospitals, Melbourne. Patients were divided into two groups--135 in the pre-nimodipine group during 1986 to 1989, and 73 in the nimodipine group during 1989 and 1990.

MAIN OUTCOME MEASURES

Outcome was measured according to the Glasgow outcome scale and the incidence of delayed ischaemic deficit was recorded.

RESULTS

A substantial reduction in the overall incidence of poor outcome was observed, from 37% of patients in the non-nimodipine group, to 20% in the nimodipine group (P = 0.022). Delayed ischaemic deficit occurred in 41% and 21% (P = 0.005), and poor outcome due to delayed ischaemic deficit occurred in 18% and 8% (P = 0.09) respectively.

CONCLUSIONS

In our experience, nimodipine appears to have substantially reduced the incidence of delayed ischaemic deficits in patients with aneurysmal subarachnoid haemorrhage, with a resultant improvement in overall patient outcome.

Malignant prolactinomas

Six cases of malignant prolactinoma have been reported; an additional two cases are presented here and the literature is reviewed. Diagnosis rests upon evidence of metastasis rather than histological criteria per se. Cases have arisen from known adenomas, particularly the invasive type. Bromocriptine is a useful palliative. The features and treatment of malignant prolactinoma are discussed.

Ruptured intracranial aneurysms: a 12-month prospective study

A prospective study was undertaken of all cases of ruptured intracranial aneurysms that presented to Monash Medical Centre's neurosurgical service over a 12-month period. Forty-seven patients had proved aneurysmal subarachnoid haemorrhages. The management mortality rate over all was 23.4%. Forty patients underwent definitive treatment by craniotomy and clipping of the aneurysm; the operative mortality rate was 12.5%. Excellent results were obtained in all 22 patients whose clinical grade was good on the day of surgery; half these patients underwent operation within 72 hours of the episode. Sixty per cent of all patients were discharged from hospital without any neurological deficit; virtually all the remaining patients' morbidity and mortality were attributable to aneurysmal rebleeding and cerebral vasospasm. Early surgery for aneurysms has been the trend in North America, Europe and Japan and the results that were obtained in this study support early surgery in patients with a good clinical grade; further experience is needed to establish the optimal timing of surgery in patients with a worse clinical grade.