Neuropsychological deficits in scuba divers: an exploratory investigation.

Objective: To investigate whether divers with varying levels of experience and without a history of reported decompression sickness (DCS) show neuropsychometric alterations possibly as a result of so-called repetitive "silent" paradoxical gas embolisms.

Methods: Using reaction time as a psychometric measure, 17 experienced military divers (ED, logging between 150 and 1,200 diving hours) and eight very experienced military divers (VED, logging between 2,800 and 9,800 diving hours) with no decompression sickness (DCS) in their medical histories were compared to 23 healthy controls without any diving history, matched as closely as possible with respect to age for the two diving groups. Motor reaction time, decision reaction time and error rates were measured during completion of both simple and complex reaction time tasks.

Prevalence of patent foramen ovale (PFO) and MRI-lesions in mild neurological decompression sickness (type B-DCS/AGE).

Background: Neurological decompression sickness (DCS/AGE) may cover two variants with either severer and probably central nervous (Type A) or milder and sometimes doubtful neurological symptoms (Type B). The pathophysiology of the Type B-DCS/AGE might be different from the Type A-variant. In Type A-DCS/AGE a higher PFO-prevalence (patent foramen ovale) points towards an embolic origin of the Type A-symptomatology.

Viewpoint: the type A- and the type B-variants of Decompression Sickness.

Background: Symptoms of neurological decompression incidents (DCS/AGE) can be severe or mild. It is unknown if these differences of symptom presentation represent different clinical entities or if they represent just the spectrum of DCS/AGE.

Methods: 267 cases with DCS/AGE were compared retrospectively and classified into two subgroups, the Type A-DCS/AGE for cases with a severe and often stroke-like symptomatology and the Type B-DCS/AGE for those with milder and sometimes even doubtful neurological symptoms.

Monitoring of CBFV and time characteristics of oxygen-induced acute CNS toxicity in humans.

Background: Hyperbaric oxygen can cause central nervous system (CNS) toxicity with seizures. We tested the hypothesis that CNS toxicity could be predictable by cerebral blood flow velocity (CBFV) monitoring.

Method: We monitored 369 mandatory oxygen tolerance tests (30 min, 280 kPa O(2)) by video-documentation and since May 2005 by additional CBFV registration (n = 61).

Epidemic conjunctivitis in Germany, 2004.

Epidemic conjunctivitis can be associated with viral or bacterial pathogens, whereas epidemic keratoconjunctivitis is caused mainly by adenoviruses type 8,19 and 37. In Germany, the incidence of adenovirus conjunctivitis cases increased from 0.2 per 100 000 inhabitants (in 2001 and 2002) eventually to 0.

Cerebral autoregulation is temporarily disturbed in the early recovery phase after dynamic resistance exercise.

Aim: To determine cerebral blood-flow velocity (CBFV) and parameters of dynamic cerebral autoregulation (CA) during and after exhausting resistance exercise.

Methods: Strength endurance (23 repetitions) and maximal strength training (8 repetitions) in 16 female and 16 male athletes on a leg curler (m. quadriceps training; approx.

Incidence of abnormal cerebral findings in the MRI of clinically healthy divers: role of a patent foramen ovale.

Background: To investigate incidence and number of abnormal cerebral hyperintensities (ACFs) in Magnet Resonance Imaging (MRI) and its relation to a patent foramen ovale (PFO) in divers with no history of decompression illness.

Methods: Cohort study on 50 divers (21-5500 dives).

Main Outcome Measures: Incidence and number of ACFs visualized by cranial MRI and presence and size of a PFO as documented by echocardiography and transcranial Doppler ultrasound (TCD) with echocontrast.

Noninvasive myocardial contractility monitoring with seismocardiography during simulated dives.

Objective: To determine if bradycardia during hyperbaric exposure is accompanied by a negative influence on myocardial contractility.

Methods: Accelerometer-based registration of myocardial compression waves with Seismocardiography (SCG) for noninvasive contractility monitoring. Comparative pulmonary artery (PA) catheter study (9 ICU-patients, mean = 67ys) with ejection-fraction (EF) equivalent versus sum of g-values of contraction phase in SCG, and Preload (leg-positioning).

Leukotriene-B4 concentrations in exhaled breath condensate and lung function after thirty minutes of breathing technically dried compressed air.

In previous studies it had been shown that leukotriene-B4 [LTB4] concentrations in the exhaled breath mirror the inflammatory activity of the airways if the respiratory tract has been exposed to occupational hazards. In diving the respiratory tract is exposed to cold and dry air and the nasopharynx, as the site of breathing-gas warming and humidification, is bypassed. The aim of the present study was to obtain LTB4-concentrations in the exhaled breath and spirometric data of 17 healthy subjects before and after thirty minutes of technically dried air breathing at normobar ambient pressure.

Respiratory effects of a single dive to 50 meters in sport divers with asymptomatic respiratory atopy.

Increasing popularity of sports diving makes it likely that subjects with allergic respiratory diseases will be involved in diving with self contained underwater breathing apparatus (scuba). The present study evaluated the effects of a single scuba-dive on pulmonary function in subjects with respiratory atopy. Specific airways conductance (sGaw), residual volume (RV), forced vital capacity (FVC), forced expiratory volume in 1 sec (FEV1), mid expiratory flow at 50% of FVC (MEF50), and transfer factor for carbon monoxide (TLCO) were measured in 9 sport divers with a history of hay fever and 9 matched healthy sport divers (control) before, 3 hours and 24 hours after a wet hyperbaric chamber dive to a depth of 50 m.

Respiratory pattern after wet and dry chamber dives to 0.6 MPa ambient pressure in healthy males.

The purpose of this study was to evaluate respiratory effects of wet and dry hyperbaric chamber dives to 0.6 MPa ambient pressure in healthy males. There were 19 and 22 subjects who participated in two series of dives with a bottom time of 15 min and decompression times of 28 and 17 min, respectively.

Magnetic resonance signal abnormalities and neuropsychological deficits in elderly compressed-air divers.

We investigated the association between MR signal abnormalities of the central nervous system, neuropsychologic performance and exposure indices in 20 experienced elderly compressed-air divers who had no history of neurological decompression illness (DCI). Results of MRI of the brain and psychometric testing were compared with 20 matched healthy commercial employees who never dived: 60% of the divers and 45% of the controls had hyperintense MR abnormalities. Among divers, both the number and the size of abnormalities correlated with hours diving in the deep air-diving range of 40-60 m (p < 0.