Effects of sleep deprivation on event-related fields and alpha activity during rhythmic force production

The influence of sleep deprivation (SD) on event-related fields and the distribution of power over the scalp of MEG imaged brain activity was studied during acoustically paced rhythmic force production. At the behavioral level, SD resulted in a reduction of the lag (negative asynchrony) between produced forces and acoustic stimuli at higher movement tempos. Principal component analysis of the accompanying MEG activity showed that auditory- and motor-evoked fields were attenuated after SD and revealed an anterior shift of power towards more frontal channels. These results were interpreted in terms of a change of central processing of afferent sensory input due to SD.     

MEG-compatible force sensor

By use of an insulating material we constructed a strain gauge based sensor to measure isometric forces in parallel with magneto-encephalographic recordings (i.e. without interference). The sensor can be used in different geometries to measure force production in different dimensions. Furthermore, it can easily be adapted or modified for specific experimental applications. Finally, on-line processing of the recorded forces, e.g., for the purpose of feedback, can be realized using standard MEG equipment.     

Wait-and-see policy versus loop excision after two consecutive Pap-2 cervical smears: over time less surgery and an equivalent outcome; no substantial contribution to be expected from the detection of high risk human papillomavirus

OBJECTIVE: To determine the number interventions and outcomes in patients referred with two consecutive Pap 2 cervical smear results who were managed either by a wait-and-see policy or aggressively, and to determine whether triage with high-risk human papillomavirus (hr-HPV) detection, resulting in the referral of only hr-HPV positive patients, would lead to the detection of all patients with cervical intraepithelial neoplasia (CIN). DESIGN: Retrospective comparison and retrospective cohort study. METHOD: 282 patients referred in 1997/'99 with 2 consecutive Pap 2 cervical smears in the screening program were included. Patients referred to the UMC St Radboud Hospital (n = 140; mean age: 45 years) underwent a colposcopy during which only lesions suggestive for CIN 3 were treated. All other colposcopic lesions (CIN 2 or less) were not treated but followed prospectively. Patients referred to the Canisius Wilhelmina Hospital (CWZ) (n = 142; mean age: 44 years) underwent colposcopy during which all colposcopic lesions (including CIN 2 or less) were treated directly. The two groups were compared in terms of the final cytological follow-up, the number of loop excisions, and the number of patients with CIN. The mean follow up was 40 months. In the first group, the effect of triage using hr-HPV detection was also investigated retrospectively. RESULTS: With the wait-and-see approach, statistically significantly fewer diathermic loop excisions were done: 13 versus 124. After the follow-up period there was no statistically significant difference between the two groups in terms of the number of patients with persisting Pap 2: 16 (11%) versus 12 (8%). Triage with hr-HPV detection would identify all patients with CIN 3, 50% of the patients with CIN 2, and none of the patients with CIN 1; of the 48 hr-HPV-positive women, 1 had a CIN 3 lesion and 3 had a CIN 2 lesion; of the remaining 92 women, 2 had a CIN 1 lesion and 3 had a CIN 2 lesion. CONCLUSION: The wait-and-see approach led to fewer interventions, while the number of women with persisting Pap 2 smears was not higher than with the aggressive approach. Triage with hr-HPV may reduce the number of referrals and colposcopies, but follow-up remains necessary in all women regardless of hr-HPV status.     

Employment status, job characteristics, and work-related health experience of people with a lower limb amputation in The Netherlands

OBJECTIVES: To describe the occupational situation of people with lower limb amputations in The Netherlands and to compare the health experience of working and nonworking amputee patients with a nonimpaired reference population. DESIGN: Cross-sectional study in which patients completed a questionnaire about their job participation, type of job, workplace adjustments to their limb loss, their position in the company, and a general health questionnaire. SETTING: Orthopedic workshops in The Netherlands with a population of lower limb amputees. PATIENTS: Subjects were recruited from orthopedic workshops in the Netherlands. They ranged in age from 18 to 60 years (mean, 44.5yr) and had a lower limb amputated at least 2 years (mean, 19.6yr) before this study. MAIN OUTCOME MEASURES: A self-report questionnaire, with 1 part concerning patient characteristics and amputation-related factors, and the other concerning job characteristics, vocational handicaps, work adjustments, and working conditions; and a general health questionnaire (RAND-36) to measure health status. RESULTS: Responses were received from 652 of the 687 patients (response rate, 95%) who were sent the questionnaire. Sixty-four percent of the respondents were working at the time of the study (comparable with the employment rate of the general Dutch population), 31% had work experience but were not presently working, and 5% had no work experience. After their amputations, people shifted to less physically demanding work. The mean delay between the amputation and the return to work was 2.3 years. Many people wished their work was better adjusted to the limitations presented by their disability and they mentioned having problems concerning possibilities for promotion. Seventy-eight percent of those who stopped working within 2 years after the amputation said that amputation-related factors played a role in their decision. Thirty-four percent said that they might have worked longer if certain adjustments had been made. The health experience of people who were no longer working was significantly worse than that of the working people with amputations. CONCLUSIONS: Although amputee patients had a relatively good rate of job participation, they reported problems concerning the long delay between amputation and return to work, problems in finding suitable jobs, fewer possibilities for promotion, and problems in obtaining needed workplace modifications. People who had to stop working because of the amputation showed a worse health experience than working people.     

Physical,mental, and social predictors of functional outcome in unilateral lower-limb amputees

OBJECTIVE: To study the value of physical, mental, and social characteristics as predictors of functional outcome of elderly amputees. DESIGN: Prospective, inception cohort study; comparisons with reference populations. SETTING: Main hospitals, rehabilitation centers, nursing homes, patients' own residence settings in 1 of the 3 northern provinces in the Netherlands. PARTICIPANTS: Forty-six patients older than 60 years, with unilateral transtibial or transfemoral amputation or knee disarticulation because of vascular disease. INTERVENTIONS: Measurement of physical, mental, and social predictors 2 and 6 weeks postamputation. MAIN OUTCOME MEASURES: The Sickness Impact Profile (SIP-68), Groningen Activity Restriction Scale (GARS), Timed up and go (TUG) test, and prosthetic use. RESULTS: A total of 15% of amputees died within the first year after amputation. Seventy percent lived independently at home 1 year postamputation. The functional level of the patients was low, as shown by high scores on the SIP-68 (mean, 23.6), GARS (mean, 41.2), and TUG test (mean, 23.9s). Functionally effective prosthetic use, as measured with the classification of Narang and Pohjolainen, was reached by 49%. For the SIP-68 scores, age, comorbidity, 1-leg balance, and the 15-word test predicted functional outcome in 69% of amputees. For the GARS score, age, 1-leg balance, and the 15-word test predicted functional outcome in 64%. For the TUG test, age and 1-leg balance predicted functional outcome in 42% of amputees. After correction for age, the only significant predictor for prosthetic use was 1-leg balance. CONCLUSIONS: Elderly patients with a leg amputation had a low functional level 1-year postamputation. An important part of functional outcome could be predicted 2 weeks after amputation by age at amputation, 1-leg balance on the unaffected limb, and cognitive impairment. Severe comorbidity probably also played a role. The results may be used in the general policy concerning leg amputees.