Immersive Virtual Reality to Restore Natural Long-Range Autocorrelations in Parkinson's Disease Patients' Gait During Treadmill Walking

Effects of treadmill walking on Parkinson’s disease (PD) patients’ spatiotemporal gait parameters and stride duration variability, in terms of magnitude [coefficient of variation (CV)] and temporal organization [long range autocorrelations (LRA)], are known. Conversely, effects on PD gait of adding an optic flow during treadmill walking using a virtual reality headset, to get closer to an ecological walk, is unknown. This pilot study aimed to compare PD gait during three conditions: Overground Walking (OW), Treadmill Walking (TW), and immersive Virtual Reality on Treadmill Walking (iVRTW). Ten PD patients completed the three conditions at a comfortable speed. iVRTW consisted in walking at the same speed as TW while wearing a virtual reality headset reproducing an optic flow. Gait parameters assessed were: speed, step length, cadence, magnitude (CV) and temporal organization (evenly spaced averaged Detrended Fluctuation Analysis, α exponent) of stride duration variability. Motion sickness was assessed after TW and iVRTW using the Simulator Sickness Questionnaire (SSQ). Step length was greater (p = 0.008) and cadence lower (p = 0.009) during iVRTW compared to TW while CV was similar (p = 0.177). α exponent was similar during OW (0.77 ± 0.07) and iVRTW (0.76 ± 0.09) (p = 0.553). During TW, α exponent (0.85 ± 0.07) was higher than during OW (p = 0.039) and iVRTW (p = 0.016). SSQ was similar between TW and iVRTW (p = 0.809). iVRTW is tolerable, could optimize TW effects on spatiotemporal parameters while not increasing CV in PD. Furthermore, iVRTW could help to capture the natural LRA of PD gait in laboratory settings and could potentially be a challenging second step in PD gait rehabilitation.

[Clinical case of the month: clostridium difficile colitis]

A 55-year-old patient with mant e cels underwent a cytotoxic chemotherapy (D.H.A.P. + Rituximab). During the medullar aplasia related to the third cycle, diarrhoea due to Clostridium difficile arised and relapsed 15 days later despite normal blood counts. This colitis was very severe with pluribacterial peritonitis, but resolved with intensive medical treatment. The incidence, the patient's risk factors, the iatrogenic and nosocomial characters of cl. difficile colitis are discussed.

National epidemiologic surveys of Enterobacter aerogenes in Belgian hospitals from 1996 to 1998

Two national surveys were conducted to describe the incidence and prevalence of Enterobacter aerogenes in 21 Belgian hospitals in 1996 and 1997 and to characterize the genotypic diversity and the antimicrobial resistance profiles of clinical strains of E. aerogenes isolated from hospitalized patients in Belgium in 1997 and 1998. Twenty-nine hospitals collected 10 isolates of E. aerogenes, which were typed by arbitrarily primed PCR (AP-PCR) using two primers and pulsed-field gel electrophoresis. MICs of 10 antimicrobial agents were determined by the agar dilution method. Beta-lactamases were detected by the double-disk diffusion test and characterized by isoelectric point. The median incidence of E. aerogenes colonization or infection increased from 3.3 per 1,000 admissions in 1996 to 4.2 per 1000 admissions in the first half of 1997 (P < 0.01). E. aerogenes strains (n = 260) clustered in 25 AP-PCR types. Two major types, BE1 and BE2, included 36 and 38% of strains and were found in 21 and 25 hospitals, respectively. The BE1 type was indistinguishable from a previously described epidemic strain in France. Half of the strains produced an extended-spectrum beta-lactamase, either TEM-24 (in 86% of the strains) or TEM-3 (in 14% of the strains). Over 75% of the isolates were resistant to ceftazidime, piperacillin-tazobactam, and ciprofloxacin. Over 90% of the strains were susceptible to cefepime, carbapenems, and aminoglycosides. In conclusion, these data suggest a nationwide dissemination of two epidemic multiresistant E. aerogenes strains in Belgian hospitals. TEM-24 beta-lactamase was frequently harbored by one of these epidemic strains, which appeared to be genotypically related to a TEM-24-producing epidemic strain from France, suggesting international dissemination.

Early identification of Mycobacterium tuberculosis and Mycobacterium avium using the polymerase chain reaction on samples positive by a rapid commercial culture system

A combination of two methods -- a rapid culture method [Mycobacteria Growth Indicator Tube (MGIT); Becton-Dickinson, USA] and a double polymerase chain reaction (PCR) assay -- was assessed for the detection and identification of Mycobacterium tuberculosis and Mycobacterium avium from clinical samples. The aim of the study was to evaluate the ability of the system to offer rapid and accurate diagnosis of mycobacterial infections. After decontamination, clinical samples (n = 554) were stained and cultured in parallel on solid media and in MGITs following standard procedures. The performance of the two culture systems was compared. Positive MGITs were tested for the presence of Mycobacterium tuberculosis and Mycobacterium avium by PCR of IS6110 (Mycobacterium tuberculosis) and the 16S rRNA gene (Mycobacterium avium). A total of 41 mycobacteria -- 27 Mycobacterium tuberculosis isolates, eight Mycobacterium avium isolates, and six other species of mycobacteria -- were isolated by one or both culture media. The MGIT system recovered 36 (87.8%) mycobacteria and the solid media 33 (80.4%). The mean time to detection by the two culture systems did not differ overall, but the mean time to detection of Mycobacterium avium from smear-positive specimens was shorter in MGITs than in solid media (5.25 days vs. 16.25 days, P < 0.05). The double PCR assay performed on the 36 positive MGITs correctly identified all 24 Mycobacterium tuberculosis-positive MGITs and all six Mycobacterium avium-positive vials. Therefore, application of the PCR assay to positive MGITs may mean that Mycobacterium tuberculosis and Mycobacterium avium can be identified at an earlier stage than with current methods.