Endovascular coiling versus neurosurgical clipping in patients with a ruptured basilar tip aneurysm.

OBJECTIVES: To compare endovascular coiling with neurosurgical clipping of ruptured basilar bifurcation aneurysms. METHODS: Patient and aneurysm characteristics, procedural complications, and clinical and anatomical results were compared retrospectively in 44 coiled patients and 44 patients treated by clipping. The odds ratios for poor outcome (Glasgow outcome scale 1, 2, 3) adjusted for age, clinical condition, and aneurysm size were assessed by logistic regression analysis. RESULTS: In the endovascular group, five patients (11%) had a poor outcome v 13 (30%) in the surgical group; the adjusted odds ratio for poor outcome after coiling v clipping was 0.28 (95% confidence interval, 0.08 to 0.99). Procedural complications were more common in the surgical group. Optimal or suboptimal occlusion of the aneurysm immediately after coiling was achieved in 41 patients (93%). Clipping was successful in 40 patients (91%). CONCLUSIONS: The results suggest that embolisation with coils is the preferred treatment for patients with ruptured basilar bifurcation aneurysms.

Risk factors for the development of polyneuropathy and myopathy in critically ill patients.

BACKGROUND: Previously, mainly retrospective and a few important prospective studies postulated the role of sepsis or systemic inflammatory response syndrome (SIRS), multiple organ failure, and the use of medication as causative factors for the development of critical illness polyneuropathy and myopathy (CIPNM). This study aimed to identify the risk factors in the development of CIPNM. METHODS: Prospectively, we studied 98 patients who were on artificial respirators for the development of CIPNM. The Acute Physiology and Chronic Health Evaluation (APACHE) III score, presence of SIRS, and sepsis severity score at entry; the dosage of midazolam, vecuronium, and steroids at entry and day 7 of artificial respiration; and the use of aminoglycosides at entry were related with time to CIPNM or time of last follow-up. The Kaplan-Meier method and log-rank test were used. RESULTS: Thirty-two patients (33%) developed CIPNM. After multivariate analysis, it was found that the APACHE III score and the presence of SIRS were significantly related with risk for the development of CIPNM. No significant relation was found for the use of midazolam, vecuronium, or steroids. Based on a risk index from a Cox regression model with APACHE III score and presence of SIRS as outcomes, three groups could be constructed with low-, medium-, and high-risk patients for the development of CIPNM. CONCLUSIONS: The APACHE III score, a quantitative index of disease severity based on clinical and laboratory physiologic data, is a valuable predictor for the development of CIPNM in patients in the intensive care unit. Together with the presence of SIRS, it can be used to estimate the risk of developing CIPNM for patients on artificial respirators.

[Multidisciplinary treatment of cerebral arteriovenous malformations: preliminary results in 115 consecutive patients]. / De multidisciplinaire behandeling van de cerebrale arterioveneuze malformatie: voorlopige resultaten bij 115 opeenvolgende patiënten.

OBJECTIVE: Preliminary evaluation of the combined treatment (surgery, embolization and stereotactic gamma radiosurgery) of 115 consecutive patients with a cerebral arteriovenous malformation (AVM). DESIGN: Retrospective. SETTING: St. Elisabeth Hospital, Tilburg, the Netherlands. PATIENTS AND METHODS: In a 35-month period 115 consecutive patients presented with an AVM. The mean age was 41.8 years (range: 6-72). The main clinical presentation was haemorrhage in 65 patients (56.5%), seizures in 31 patients (27.0%), neurological deficit in 7 patients (6.1%) and hydrocephalus in 2 patients (1.7%); in 10 patients (8.7%) the AVM was an incidental finding. Treatment consisted of surgery, radiosurgery with the gamma knife and embolization. Embolization was mostly used to reduce the size of an AVM before surgery or radiosurgery. RESULTS: Out of 115 patients 5 were referred for a treatment advice only and treatment was performed elsewhere. Of the remaining 110 patients 84 (76.4%) were treated and 26 (23.6%) were not treated for various reasons. Of the 84 treated patients 17 (20.2%) had surgery only, 17 (20.2%) had radiosurgery only, and 12 (14.3%) were treated with embolization only. Surgery after embolization was performed in 8 patients (9.5%) and radiosurgery after embolization in 26 patients (31.0%). In 4 patients an unusual combination of these treatment methods was used for a variety of reasons. At the time of writing 35 of 84 treated AVMs (41.7%) were completely cured, 39 patients were awaiting the definitive result of radiosurgery. Deliberate partial embolization was performed in 5 patients. In 5 patients (6.0%), the pretreatment objective was not achieved with embolization. Total permanent morbidity was 4.8% (4 patients) and mortality was 1.2% (1 patient). CONCLUSIONS: Given a multidisciplinary combination of treatment methods a treatment is indicated and possible in the majority (76.4%) of patients with an AVM. There is a reasonable chance of a complete cure with an acceptable complication rate.

Safety and pharmacokinetics of the neuroprotective drug lubeluzole in patients with ischemic stroke.

A total of 22 patients with acute ischemic stroke participated in two randomized, single-masked, placebo-controlled studies that evaluated the safety and pharmacokinetics of single escalating intravenous doses of lubeluzole. The first dose of study medication in all patients was given within 6 hours of the first sign of stroke onset. In the first study, 6 patients received a single 1-hour intravenous infusion of 5 mg of lubeluzole; 4 of these patients received an additional 10-mg dose 3 to 4 days later. Two additional patients received placebo. In the second study, 4 patients received a single 1-hour infusion of 10 mg of lubeluzole, and 2 patients received placebo. After a safety evaluation of the second study, 6 additional patients received 15 mg of lubeluzole, and 2 other patients received placebo. Lubeluzole had no clinically relevant effects on any cardiovascular variable compared with placebo. The majority of adverse experiences were mild to moderate and resolved during treatment. No unexpected electroencephalogram abnormalities were observed, and no evidence of epileptiform discharges was found in any of the patients. At the end of the infusion, plasma lubeluzole concentrations decayed biphasically, with mean distribution half-lives of 46.3 to 101.0 minutes and mean terminal half-lives of 20.8 to 27.7 hours. Comparisons of the dose-normalized value of the individual plasma concentrations at the end of the infusion and the total area under the curve from time 0 to infinity suggested that lubeluzole exhibited linear kinetics over the dose range evaluated in patients with ischemic stroke. In the small number of patients studied, lubeluzole's favorable safety profile was demonstrated by the lack of clinically relevant effects on cardiovascular variables and by neurologic examination and clinical laboratory findings.

[Intravascular treatment of inoperable cerebral aneurysms using Guglielmi's spirals; initial results in The Netherlands]. / Endovasculaire behandeling van inoperable cerebrale aneurysma's met Guglielmi-spiraaltjes; eerste ervaringen in Nederland.

OBJECTIVE: Evaluation of endovascular treatment of inoperable cerebral aneurysms using electrolytically detachable platinum coils (Gugliemi Detachable Coils, GDC). DESIGN: Retrospective. SETTING: St. Elizabeth Hospital Tilburg, the Netherlands. METHOD: Fifteen aneurysms in 13 patients were treated using GDC; 14 of these aneurysms were inoperable and in three aneurysms surgical clipping had failed. RESULTS: Twelve of the 15 treated aneurysms were completely occluded. In another two, occlusion was 90% and in one, 70%. One patient with an inoperable basilar bifurcation aneurysm died of progressive thrombosis of both posterior cerebral arteries. One patient with an inoperable aneurysm of the anterior communicating artery developed an infarction of the A. centralis longa (recurrent artery of Heubner). CONCLUSION: GDC treatment of inoperable cerebral aneurysms is currently the only available option with a reasonable chance of success and acceptable risks.

Conduction velocity distributions compared to fiber size distributions in normal human sural nerve.

Compound action potentials (CAPs) were recorded from the sural nerve of healthy volunteers. A mathematical technique (inverse modeling) was used to compute conduction velocity (CV) histograms from the data. Results were compared to the morphology of age-matched normal sural nerve biopsies. Coefficients of variation (CoVs) revealed the statistical relationship between morphological data (diameter histograms) and electrophysiological data (CV histograms and conventional CAP parameters). No differences were found for the thick fiber group when comparing the CoVs of the diameter histogram parameters with the corresponding CV histogram parameters. Apparently, the same inherent biological interindividual variability is encountered. The CoVs of the CVs of the CAP's main phases are in good agreement with the CoVs of the estimated mean velocity of the thick fiber group. Inverse modeling increases the reliability of the estimation of the number of active fibers as compared to direct CAP amplitude interpretation.

[Atrial septal aneurysm and brain infarct: a causal connection?]. / Atriumseptum-aneurysma en herseninfarct: een causaal verband?

In four patients, 2 women aged 24 and 35 and 2 men aged 37 and 47 years, an ischaemic stroke was observed and an atrial septal aneurysm was found as a possible cardiac source of embolism to the brain. Atrial septal aneurysm is a bulging of the fossa ovalis region, that can be visualised by (preferably transoesophageal) echocardiography. In the four patients there were only few other risk factors for ischaemic stroke (migraine, smoking, oral contraceptives). Cerebral angiography was normal in all cases. Recent literature suggests that a causal relationship exists between atrial septal aneurysm and ischaemic stroke. It is still uncertain what treatment is best.

A statistical approach to fiber diameter distribution in human sural nerve.

Fifty-one normal sural nerve biopsies were obtained from 800 diagnostic biopsies. The external diameter distribution of myelinated fibers was described using the sum of two beta probability density functions, describing the thin as well as the thick fiber group. A cross-sectional study using these distribution functions showed increasing values of the peak of the larger fiber group, the diameter of the thickest fibers, and the separation between the smaller and the larger groups until the beginning of adult life. The transition from a uni- into a bimodal histogram occurred gradually between 7 and 13 months. Total transverse fascicular area increased with age, whereas fiber density decreased significantly with age. The number of fibers remained stable over age. The relative proportion of the numbers of fibers in both groups described by one of the beta distributions remained constant over age. This occurred despite a marked decrease in the number of small fibers with a diameter less than, e.g., 6.5 microns. The results indicated an outgrowth of especially the larger myelinated fibers with age. This process continues with decreasing intensity into adult life.

Disturbed frontal regulation of attention in Parkinson's disease.

Parkinson's disease is characterized not only by tremor, akinesia and rigidity, but also by frontal cognitive dysfunction, that can be understood as a disturbance in the 'Supervisory Attentional System' (SAS). This concept refers to a system, located in the frontal cortex, that regulates attentional processes under novel, non-routine conditions. The hypothesis that cognitive dysfunction in Parkinson's disease results from a disturbance in the SAS was investigated by recording 'processing negativity' in 33 parkinsonian patients and 17 controls. Processing negativity is an event-related potential that reflects neuronal activity during selective attention. The contribution of the frontal cortex to selective attention can be studied directly using processing negativity. Parkinsonian patients were also scored for clinical symptoms and subjected to a neuropsychological test battery. Processing negativity was clearly disturbed in the parkinsonian patients. Moreover, parkinsonian patients with the lowest scores on 'frontal' neuropsychological tests such as Stroop, Trail Making and Word Fluency, also had the lowest processing negativity. Our results support the hypothesis that cognitive dysfunction in Parkinson's disease might be understood as a disturbance in the frontal regulation of attentional processes. Degeneration of the dopaminergic mesocortical innervation of the frontal cortex in Parkinson's disease is a possible neurochemical substrate of these frontal attentional disturbances.

Critical illness polyneuromyopathy after artificial respiration.

Up to now, 71 critically ill patients have been reported with neuromuscular complications after artificial respiration. The authors review the literature and present data of a personal series of 22 patients all suffering from severe flaccid tetraparesis and muscle atrophy, which developed after an average of two weeks artificial respiration. The prognosis was relatively good in those surviving the primary disease. The multiconditional causes are discussed with emphasis on the combination of polyneuropathy and myopathy. Tumor necrosis factor (TNF), a key mediator of sepsis, which also has an influence on muscle and nerves, is mentioned as a possible cause of this illness.

Sensory potentials and sural nerve biopsy: a model evaluation.

Compound action potentials (CAPs) were recorded from the sural nerve prior to nerve biopsy in patients with various kinds of polyneuropathy. A previously developed volume conductor model for the CAP is applied to analyze the recorded CAPs in close relation with the morphological findings in the biopsy. First, the fiber diameter histograms obtained from the biopsy are used to simulate CAPs, by assuming a linear relation between fiber diameter and propagation velocity. It is concluded that the simulated CAPs deviate systematically from the recorded CAPs. Next, the assumption of a linear diameter-velocity relation is left, and the assumed fiber velocity distribution is adapted to obtain optimal model reconstructions of the recorded CAPs. It is concluded that the model is capable of reconstructing the recorded CAPs, including slow components and small polyphasic potentials in the case of severe fiber loss. It is demonstrated how the diameter histogram and the optimal velocity distribution can be combined to an empirical estimate of the diameter-velocity relation.