Prevalence Of Neurological Symptoms Research Articles

Hyperbaric oxygen for carbon monoxide poisoning

Poisoning with carbon monoxide (CO) remains an important cause of accidental and intentional injury worldwide. Several unblinded non-randomized trials have suggested that the use of hyperbaric oxygen (HBO) prevents the development of neurological sequelae. This has led to the widespread use of HBO in the management of patients with carbon monoxide poisoning. To examine randomised trials of the efficacy of hyperbaric oxygen (HBO) compared to normobaric oxygen (NBO) for the prevention of neurologic sequelae in patients with acute carbon monoxide poisoning. We searched the following electronic databases; Cochrane Injuries Group Specialised Register (searched June 2010), Cochrane Central Register of Controlled Trials (The Cochrane Library 2010, Issue 2), MEDLINE (Ovid SP) 1950 to June 2010, EMBASE (Ovid SP) 1980 to June 2010, ISI Web of Science: Science Citation Index Expanded (SCI-EXPANDED) 1970 to June 2010, ISI Web of Science: Conference Proceedings Citation Index-Science (CPCI-S) 1990 to June 2010. All randomised controlled trials of HBO compared to NBO, involving non-pregnant adults who are acutely poisoned with carbon monoxide (regardless of severity). Two authors independently extracted from each trial information on: the number of randomised patients, types of participants, the dose and duration of the intervention, and the prevalence of neurologic symptoms at follow-up. Seven randomised controlled trials of varying quality were identified; one was excluded because it did not evaluate clinical outcomes. Of the six remaining trials involving 1361 participants, two found a beneficial effect of HBO for the reduction of neurologic sequelae at one month, while four others did not. One of these is an incomplete publication (an abstract of an interim analysis). Although pooled random effects meta-analysis does not suggest a significant benefit from HBOT (OR for neurological deficits 0.78, 95%CI 0.54 to 1.12), significant methodologic and statistical heterogeneity was apparent among the trials, and this result should be interpreted cautiously. Moreover, design or analysis flaws were evident in all trials. Importantly, the conclusions of one positive trial may have been influenced by failure to adjust for multiple hypothesis testing, while interpretation of the other positive trial is hampered by a high risk of bias introduced during the analysis including an apparent change in the primary outcome. Both were also stopped early 'for benefit', which is likely to have inflated the observed effect. In contrast three negative trials had low power to detect a benefit of HBO due to exclusion of severely poisoned patients in two and very poor follow-up in the other. One trial that was said to be finished around eight years ago has not reported the final analysis in any forum. Existing randomised trials do not establish whether the administration of HBO to patients with carbon monoxide poisoning reduces the incidence of adverse neurologic outcomes. Additional research is needed to better define the role, if any, of HBO in the treatment of patients with carbon monoxide poisoning. This research question is ideally suited to a multi-center randomised controlled trial.

Neurological manifestations in patients with Gaucher disease and their relatives, it is just a coincidence?

Gaucher disease (GD) is an autosomal recessive disorder characterized by defective function of glucocerebrosidase. GD presents a wide spectrum of manifestations, and patients and their relatives may develop neurological abnormalities more frequently than the general population. This study aims to determine the presence of neurological symptoms (NS) and Parkinson's disease (PD) in Spanish GD patients and their relatives. We surveyed 87 GD Spanish families and validated the information obtained on the neurological involvement through their physicians, as well as the historical data included in the Spanish Gaucher Disease Registry. Neurological abnormalities were correlated with the genetic characteristics. Statistical analyses included descriptive parameters, ANOVA, t-test, correlation study and Pearson coefficient. Information was obtained from 118 patients and 324 relatives. Out of 110 patients with type 1 GD, 32 (29.1%) reported NS and 7 (6.4%) had PD. In relatives, a total of 39 (13.1%) subjects had NS, including 16 with PD (5.3%). The prevalence of NS in genetic carriers (15.9%) was greater than that in non-carriers (5.9%; p < 0.01). Patients with PD carried the following GBA mutations: S364R, D409H, L444P, R257Q, IVS4-2A > G, c.500insT, and L336P. Relatives with PD exhibited a wide spectrum of mutations: L444P, N370S, V398I, R257Q, G202R, c.1439-1445del7, [E326K; N188S], and c.953delT. We observed a high incidence of PD in type 1 GD and relative's carriers. PD was more frequent in carriers of L444P and other rare GBA mutations. Therefore, it is important to perform a systematic neurological exam in patients with type 1 GD and carriers with high risk mutations.

Cerebral diffusion and perfusion deficits in North Sea divers

Diving is associated with a risk of cerebral decompression illness, and the prevalence of neurological symptoms is higher in divers compared with control groups. Microvascular dysfunction due to gas microembolism and exposure to hyperoxia are possible mechanisms, which may result in cerebral diffusion and perfusion deficits. To investigate if possible functional derangements of the microvasculature and microstructure would be more prevalent among symptomatic divers. Magnetic resonance imaging (MRI) was performed in 91 former divers and 45 controls. Individual parametric images of apparent diffusion coefficient (ADC), cerebral blood flow (CBF), cerebral blood volume (CBV), and mean transit time (MTT) were generated on the basis of diffusion- and perfusion-weighted imaging. To identify regions with statistically significant differences between groups (P < 0.05, corrected for false discovery rate), voxel-wise ANCOVA analysis was performed for each of the four parametric images. Significant regional group differences were found in all four parametric comparisons. Gross regional ADC differences were seen throughout the brain, including large frontal and temporal white-matter regions, the hippocampus, and parts of the cerebellum. Differences in the perfusion maps were localized in fewer and smaller clusters, including parts of the cerebellum, the putamen, and the anterior watershed regions. Regional functional abnormalities as measured by diffusion- and perfusion-weighted imaging were identified in the divers, and there was a partial co-localization of the regions identified in the perfusion and the diffusion images. The findings may explain some of the long-term clinical symptoms reported among professional divers.

Neurological morbidity in survivors of childhood acute lymphoblastic leukemia (ALL)

9529 Background: The majority of children diagnosed with ALL over the past two decades have achieved long-term survival. This remarkable success is attributed in part to intensive central nervous system (CNS)-directed therapy that effectively prevents CNS relapse. Because treatment-related neurological morbidity is recognized but poorly characterized, the objective of this cross-sectional study was to estimate the prevalence of neurological symptoms and signs in long-term survivors of childhood ALL. Methods: After obtaining IRB approval, all long-term ALL survivors (≥ 5 years since diagnosis) aged 6–28 years who remained active patients at our institution were identified. All participants completed a questionnaire consisting of independent (and when possible validated) instruments designed to identify various neurological symptoms, as well as, a comprehensive and standardized neurologic examination by a board-certified neurologist. Results: Of the 433 potentially eligible subjects, 162 (37.4%) were enrolled. Participant demographic information and previous treatment exposure were similar to those not enrolled in the study. The rates of endorsed neurological symptoms were: neuropathy (40.1%), dizziness (33%), back pain (22.8%), fatigue (19.1%), falls (15.4%), headache (14.8%), seizures (10.5%), urinary incontinence (8.6%), and stroke (1.2%). Neurological examination confirmed an underlying sensory neuropathy in 44 patients (27.3%). Otherwise, signs of chronic cranial nerve dysfunction (1.9%) and motor weakness (5.6%) were rare. Conclusions: Symptoms and signs of a chronic sensory neuropathy, presumably from previous vincristine exposure, were evident in many patients. Complaints of fatigue, dizziness, and chronic back pain were also relatively common. The number of patients who routinely fall is of concern. Whether these falls are associated with symptoms/signs of neuropathy, weakness, and/or dizziness will require further analysis. Although headache was a common complaint, its prevalence may not differ significantly from a normal age-matched population. No significant financial relationships to disclose.

Hyperbaric oxygen for carbon monoxide poisoning.

Poisoning with carbon monoxide (CO) remains an important cause of accidental and intentional injury worldwide. Several unblinded nonrandomized trials have suggested that the use of hyperbaric oxygen (HBO) prevents the development of neurological sequelae. This has led to the widespread use of HBO in the management of patients with carbon monoxide poisoning. To assess the effectiveness of hyperbaric oxygen (HBO) compared to normobaric oxygen (NBO) for the prevention of neurologic symptoms in patients with acute carbon monoxide poisoning. We searched MEDLINE (1966-present), EMBASE (1980-present), and the Controlled Trials Register of the Cochrane Collaboration, supplemented by a manual review of bibliographies of identified articles and discussion with recognized content experts. All randomized controlled trials involving non pregnant adults acutely poisoned with carbon monoxide, regardless of severity, with adequate or unclear allocation concealment were examined. Trials with a score of 3 out of 5 or higher on the validity instrument of Jadad were included in the primary analysis. Two reviewers independently extracted from each trial information on the number of randomized patients, types of participants, the dose and duration of the intervention, and the prevalence of neurologic symptoms at follow-up. A pooled odds ratio (OR) for the presence of neurologic symptoms at one month follow-up was calculated using a random effects model. Six randomized controlled trials were identified. The trials were of varying quality. Three trials employing different doses of NBO and HBO were included in the primary analysis. The severity of CO poisoning was inconsistent between trials. At one month follow-up after treatment, symptoms possibly related to carbon monoxide poisoning were present in 81 of 237 patients (34.2%) treated with HBO, compared with 81 of 218 patients (37.2%) treated with NBO (O.R. for benefit with HBO 0.82; 95% CI 0.41-1.66). There is no evidence that unselected use of HBO in the treatment of acute CO poisoning reduces the frequency of neurological symptoms at one month. However, evidence from the available randomized controlled trials is insufficient to provide clear guidelines for practice. Further research is needed to better define the role of HBO, if any, in the treatment of carbon monoxide poisoning. This research question is ideally suited to a multicentre, randomized, double-blind controlled trial.

Cross sectional study of a workforce exposed to hand-arm vibration: with objective tests and the Stockholm workshop scales

OBJECTIVESMedical surveillance of workforces exposed to vibration has been recommended with the Stockholm workshop scales. The aims of this study were (a) to evaluate how the results of the objective...

Persistent Health Effects of Dioxin Contamination in Herbicide Production

A total of 159 cases of chloracne reported in 1969––1975 in TCDD-contaminated production of the herbicide 2,4,5-T have been followed for mortality and morbidity up to 1996 when blood and urine tests were performed on 50 survivors of these exposed chemical workers and matched controls. In exposed, the most frequent cause of sick leave was chloracne which persisted in 32%. Neurological symptoms were reported frequently (44% sleep disturbance, 32% headache, 30% neuralgia). BSR, leucocytes, γ-GT, SGOT, and SGPT were significantly higher in exposed than in controls. The effects of exposure (P=0.002) and alcohol (P=0.002) on γ-GT were found to be independent of each other. Comparisons within the chloracne cohort showed significantly exposed TCDD per gram blood lipid in patients with a history of liver disease (mean 801 pg/g) than without (mean 407 pg/g). Other congeners were not found elevated but some higher chlorinated furans and PCBs were found reduced in patients with liver disease. In multiple regression analysis with the factors age, alcohol, and log TCDD, the effects of TCDD and its interaction with age were found significant, indicative of chronic liver damage after high TCDD exposure at a young age. The prevalence of neurological symptoms and signs of chronic liver disease were related to TCDD in blood and abnormal poryphyrins in urine. In 48% coproporphyrin I>III ratio was elevated, this group showing increased TCDD (mean 719 pg/g). These results contribute to the evidence that chloracne is not the only chronic disease which can be related to TCDD exposure, even 23 years after exposure and despite high intersubject variability of TCDD half-life and other exposures.

Are aluminium potroom workers at increased risk of neurological disorders?

OBJECTIVE: To determine whether long term potroom workers in an aluminium smelter are at increased risk of neurological disorders. METHODS: Cross sectional study of 63 current and former aluminium potroom...

Subjective Symptoms and Neurobehavioral Performances of Ex-Mercury Miners at an Average of 18 Years after the Cessation of Chronic Exposure to Mercury Vapor

In order to determine if there are any residual effects of long-term exposure to mercury vapor, neurobehavioral tests were given to ex-mercury miners about 18 years after the cessation of mercury exposure. Seventy-six male ex-mercury miners who had been exposed to relatively high concentrations of mercury vapor (over 1.0 mg/m 3) and with a past history of mercury intoxication were compared to age (±3 years)-, sex-, and years of education-matched controls. Although the extent of the workers" symptoms caused by mercury poisoning, termed erethismus merculialis, markedly decreased after the cessation of exposure, the prevalence of neurological symptoms (such as hand tremors, headaches, and slurred speech) and symptoms of senility (such as low-back pain, loss of sexual desire) in the exminers was significantly higher than those in the controls. Matched-pair analysis showed that performances of motor coordination, Simple reaction time, and Short-term memory in the exminers were significantly deteriorated compared to those of controls. There are slight but persistent effects on neurobehavioral function, especially on motor coordination function, among mercury miners more than 10 years after the cessation of exposure.

Neurologic Disease in Human Immunodeficiency Virus-Infected Drug Abusers

Previous studies of human immuno-deficiency virus-related neurologic disease have been either retrospective or have included mostly homosexual patients. We sought to determine (1) the true prevalence of neurologic abnormalities in patients with acquired immunodeficiency syndrome or lymphadenopathy acquired immunodeficiency-related complex, and (2) whether differences in prevalence or type of neurological abnormality exist between parenteral drug abusers and non-parenteral drug abusers. We prospectively evaluated 190 adult inpatients with either acquired immunodeficiency syndrome (129) or lymphadenopathy acquired immunodeficiency-related complex (61); 151 (80%) were parenteral drug abusers, and 172 patients (91%) had neurologic symptoms or signs. There was no significant difference in prevalence of neurologic disease between parenteral drug abusers and non-parenteral drug abusers, or between patients with acquired immunodeficiency syndrome and those with lymphadenopathy acquired immunodeficiency-related complex. The prevalence of neurologic symptoms in these patients with lymphadenopathy acquired immunodeficiency-related complex and acquired immunodeficiency syndrome is the highest reported to date and appears to reflect the prospective nature of the study.

Comparative neurobehavioral study of a polybrominated biphenyl-exposed population in Michigan and a nonexposed group in Wisconsin.

An analysis of findings regarding the prevalence and time course of symptoms and the results of neurobehavioral testing among Michigan and Wisconsin dairy farmers, is reported. Reviewed are: (1) differences in the prevalence of neurological symptoms at the time of examination; (2) differences in the incidence and time course of symptoms for the period 1972--1976; (3) differences among populations and subgroups (sex and age) regarding performance test scores; (4) correlations between performance test scores and neurological symptoms; and (5) correlations between serum PBB levels as indicators of exposure and performance tests and neurological symptoms.