Postmortem analysis of five subjects with Parkinson's disease9-14 years after transplantation of fetal midbrain cell suspensions revealed surviving grafts that included dopamine and serotonin neurons without pathology. These findings are important for the understanding of the etiopathogenesis of midbrain dopamine neuron degeneration and future use of cell replacement therapies.Despite indirect evidence of long-term survival of fetal midbrain dopamine cell suspensions in people with Parkinson's disease 1 , the question remains whether grafted neurons are affected by pathogenic factors intrinsic to the parkinsonian brain.Prominent neuropathological features of Parkinson's disease include dopaminergic neuron loss in the substantia nigra, the presence of dystrophic neurites (Lewy neurites) 2 and the presence of Lewy bodies 3,4 . Ultimately, the durability of transplanted fetal ventral midbrain neurons in therapeutic approaches relies on their resistance to these neurodegenerative processes. Because many aspects of these processes remain unknown, it is important to understand the effects of neurodegeneration in the parkinsonian striatum upon transplanted fetal dopamine neurons. We report histopathological findings in the brains of three subjects (referred to as subjects 4, 5 and 6) with advanced idiopathic Parkinson's disease who had received intracerebral transplantation

The likelihood of rupture of unruptured intracranial aneurysms that were less than 10 mm in diameter was exceedingly low among patients in group 1 and was substantially higher among those in group 2. The risk of morbidity and mortality related to surgery greatly exceeded the 7.5-year risk of rupture among patients in group 1 with unruptured intracranial aneurysms smaller than 10 mm in diameter.

A multicenter, randomized placebo-controlled double-blind trial of nimodipine in poor-grade aneurysm patients was carried out in 17 Canadian hospitals. Of 188 patients enrolled in the trial, 32 were excluded for protocol violations and two were excluded due to statistical considerations, leaving 154 patients for valid outcome analysis. Nimodipine treatment was associated with a significantly better outcome (p less than 0.001): 21 (29.2%) of 72 nimodipine-treated patients had a good outcome at 3 months after subarachnoid hemorrhage (SAH) compared to eight (9.8%) of 82 placebo-treated patients. Delayed ischemic deficits from vasospasm alone were significantly less frequent in the nimodipine group (p less than 0.05) with permanent deficits occurring in five nimodipine-treated patients (6.9%) and in 22 placebo-treated patients (26.8%). Improvement in the good outcome rate and reduction in delayed ischemic deficits from vasospasm alone occurred in both Grade 3 and 4 patients, with no difference between nimodipine- and placebo-treated patients being found in Grade 5 patients. Repeat angiography after Day 4 was carried out in 124 patients. There was no significant difference in the incidence of moderate or severe diffuse spasm, which was seen in 64.3% of nimodipine-treated patients and 66.2% of placebo-treated patients. The authors conclude that nimodipine treatment in poor-grade patients with SAH results in an increase in the number of good outcomes and a reduction in the incidence of delayed neurological deterioration due to vasospasm. This effect occurs by a mechanism other than prevention of large-vessel spasm as visualized on angiography.

A multicenter, randomized, blinded, placebo-controlled trial was conducted to study the possible role of intracisternally administered fibrinolytic agent recombinant tissue plasminogen activator (rt-PA) in preventing delayed onset cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH). The target population was patients with ruptured saccular aneurysms causing severe SAH, placing them at high risk for vasospasm. Treatment consisted of a single 10 ml intraoperative injection of either vehicle buffer solution or rt-PA (1 mg/ml) into the opened basal subarachnoid cisterns immediately following aneurysm clipping. The major efficacy endpoint in this trial was angiographic vasospasm, and the major safety concern was intracranial hemorrhage. One hundred patients were randomized, 49 to placebo and 51 to rt-PA treatment. Baseline population characteristics were similar between the two groups. Severity of intracranial hemorrhage on computed tomographic scans was also similar between groups: 87.2% of both placebo and rt-PA treated patients had thick subarachnoid clots, and the rates for intracerebral and intraventricular hemorrhage were, respectively, 16.3% and 22.5% for placebo and 23.5% and 21.6% for rt-PA. Nine randomized patients did not receive treatment in the operating room, and in 8 this was due to conditions felt unsafe for the administration of a fibrinolytic agent. The overall incidence of angiographic vasospasm measured between the seventh and eleventh day following SAH was similar between the two groups, with arterial narrowing detected in 74.4% of dosed placebo patients and 64.6% of rt-PA treated patients. However, there was a trend toward lesser degrees of vasospasm in the rt-PA treated group. The rates for no or mild, moderate, and severe vasospasm were 69%, 16% and 15% in the rt-PA treated group, versus 42%, 35% and 23% in the placebo group (P = 0.07). When only those patients with thick subarachnoid clots were considered at the treating centers, there was a 56% relative risk reduction of severe vasospasm in the rt-PA treated group, which was significant (P = 0.02).(ABSTRACT TRUNCATED AT 250 WORDS)