Ongoing impairments following transient ischaemic attack: retrospective cohort study.

BACKGROUND AND PURPOSE: Clinical management after transient ischaemic attack (TIA) is focused on stroke prevention; however, a number of small studies suggest that patients may experience ongoing residual impairments. METHODS: This was a retrospective matched-cohort study using anonymized electronic primary care records from The Health Improvement Network database, which covers approximately 6% of the UK population. Adults (≥ 18 years old) who experienced a first TIA between 2009 and 2013 were matched in a ratio of 1:5 to controls by age, sex and general practice. The time to first consultation for fatigue, psychological impairment or cognitive impairment was estimated by Kaplan-Meier survivor functions and adjusted hazard ratios. RESULTS: A total of 9419 TIA patients and 46 511 controls were included. The Kaplan-Meier curves showed that TIA patients were more likely than controls to consult for all three impairments (P < 0.0001). Within 7.1 months (95% confidence interval (CI), 6.2-8.2), 25% of TIA patients consulted for psychological impairment compared with 23.5 months (95% CI, 22.5-24.6) for controls. Hazard ratios for TIA patients were 1.43 (95% CI, 1.33-1.54) for consulting for fatigue, 1.26 (95% CI, 1.20-1.31) for psychological impairment and 1.45 (95% CI, 1.28-1.65) for cognitive impairment. CONCLUSIONS: Transient ischaemic attack is associated with significantly increased subsequent consultation for fatigue, psychological impairment and cognitive impairment. These findings suggest that impairments exist after initial symptoms of TIA have resolved, which should be considered by clinicians when treating TIA patients.

Fatigue, psychological and cognitive impairment following transient ischaemic attack and minor stroke: a systematic review.

Transient ischaemic attack (TIA) and minor stroke are characterized by short-lasting symptoms; however, anecdotal and empirical evidence suggests that these patients experience ongoing cognitive/psychological impairment for which they are not routinely treated. The aims were (i) to investigate the prevalence and time course of fatigue, anxiety, depression, post-traumatic stress disorder(PTSD) and cognitive impairment following TIA/minor stroke; (ii) to explore the impact on quality of life (QoL), change in emotions and return to work; and (iii) to identify where further research is required and potentially inform an intervention study. A systematic review of MEDLINE, EMBASE, PSYCINFO, CINAHL, the Cochrane libraries and the grey literature between January 1993 and April 2013 was undertaken. Literature was screened and data were extracted by two independent reviewers. Studies were included of adult TIA/minor stroke participants with any of the outcomes of interest: fatigue, anxiety, depression, PTSD, cognitive impairment, QoL, change in emotions and return to work. Random-effects meta-analysis pooled outcomes by measurement tool. Searches identified 5976 records, 289 were assessed for eligibility and 31 studies were included. Results suggest high levels of cognitive impairment and depression post-TIA/minor stroke which decreased over time. However, frequencies varied between studies. Limited information was available on anxiety, PTSD and fatigue. Meta-analysis revealed that the measurement tool administered influenced the prevalence of cognitive impairment: Mini-Mental State Examination 17% [95% confidence interval (CI) 7, 26]; neuropsychological test battery 39% (95% CI 28, 50); Montreal Cognitive Assessment 54% (95% CI 43, 66). There is evidence to suggest that TIA/minor stroke patients may experience residual impairments; however, results should be interpreted with caution because of the few high quality studies. Notwithstanding, it is important to raise awareness of potential subtle but meaningful residual impairments.

Cardiovascular adaptation in people with multiple sclerosis following a twelve week exercise programme suggest deconditioning rather than autonomic dysfunction caused by the disease. Results from a randomized controlled trial.

BACKGROUND: Guidelines for optimal exercise doses in people with multiple sclerosis (MS) have to be established. We need to ascertain the basic physiological and perceptual response and adaptation to different exercise doses in this clinical population. AIM: The aim of this paper was to explore the response during maximal and sub-maximal exercise in people with MS prior to and following two different twelve week exercise programmes. DESIGN: Sub-analysis of per protocol exercise data of a two group, single blinded, randomised control trial. SETTING: Multicentre (community leisure and rehabilitation centres). POPULATION: Participants with MS assigned to a continuous (N.=12; mean±SE age=52.3±2.08; Barthel index median & range=19&13-20) or interval (N.=9; mean±SE age=49.3±3.5; Barthel index median & range=19&18-20) exercise programme. METHODS: Cardiovascular, respiratory and perceptual exercise response and adaption was measured at maximal and sub-maximal levels of physical exercise prior to and following a twelve week exercise programme, delivered at different intensities. RESULTS: Irrespective of the type of exercise programme followed, there was a significant increase in peak power (z=-1.98; P=0.05) and normalised oxygen uptake during unloaded cycling (z =-2.00; P=0.05). At discharge from the exercise programmes, the cardiovascular response to sub-maximal exercise had significantly changed (t(360) =-4.62; p<0.01). CONCLUSION: The response in people with MS at maximal and sub-maximal levels of physical exercise following a twelve week programme is analogous to non-diseased adults. CLINICAL REHABILITATION IMPACT: Cardiovascular adaptation in people with MS following a twelve week exercise programme suggests deconditioning rather than autonomic dysfunction caused by the disease.

Variables affecting refractive outcome following LASIK for myopia.

AIM: To investigate factors affecting refractive outcome following LASIK for myopia. METHOD: Six hundred and seventy-four consecutive uncomplicated myopic LASIK surgeries, performed by a single surgeon, either using the Technolas 217 planoscan (n=372) or the NIDEK EC 5000 (n=302), were evaluated. Stratified random sampling was used to match the groups for refractive error, patient age, and gender. The final analysis included 302 patients from each treatment group. Conditions were identical for both surgeries, and pre-operative refractive errors were between -1.00 and -14.00 DS and <-1.50 DC. Refractive success was defined as -0.50 to +0.50 DS of the targeted refraction measured 3 months after surgery. A stepwise logistical regression analysis was used to determine variables associated with refractive failure. RESULTS: A successful refractive outcome was achieved in 78% (235/302) of surgeries using the Technolas laser and in 88% (266/302) using the NIDEK laser. Predictor variables for not achieving refractive success were pre-operative refractive error of above -5.00 DS, age more than 40 years, and surgery performed with the Technolas laser. CONCLUSION: Both the Technolas 217 and the NIDEK EC-5000 excimer lasers achieve a successful refractive outcome in the majority of cases. However, patient and surgical factors can influence refractive outcome.

Changes in joint stability with muscle contraction measured from transmission of mechanical vibration.

A non-invasive in vivo technique was developed to evaluate changes in wrist joint stability properties induced by increased co-activation of the forearm muscles in a gripping task. Mechanical vibration at 45, 50 and 55 Hz was applied to the radial head in ten healthy volunteers. Vibrations of the styloid process of the radius and the distal end of the metacarpal bone of the index finger were measured with triaxial accelerometers. Joint stability properties were quantified by the transfer function gain between accelerations on either side of the wrist-joint. Gain was calculated with the muscles at rest and at five force levels ranging from 5% to 25% of maximum grip force (%MF). During contraction the gain was significantly greater than in control trial (0%MF) for all contractions levels at 45 and 50 Hz and a trend for 15%MF and higher at 55 Hz. Group means of contraction force and gain were significantly correlated at 45 (R(2)=0.98) and 50 Hz (R(2)=0.72), but not at 55 Hz (R(2)=0.10). In conclusion, vibration transmission gain may provide a method to evaluate changes in joint stability properties.

Change in central corneal thickness following laser in situ keratomileusis for myopia.

Central corneal thickness alterations may cause residual refractive errors following laser in situ keratomileusis (LASIK). This study reports associations between central corneal thickness alterations and residual refractive error following uncomplicated LASIK. Ninety-one myopic patients with a mean refractive correction of -3.91+/-3.2 DS / -0.66+/-0.3 DC were evaluated. Central corneal thickness was measured prior to, during and following surgery and 2 months later using ultrasound pachometry Results indicate increased tissue removal (94+/-33 microm; mean +/- SD) compared to the nominal Nidek value (52+/-24 microm, P<0.001). Twenty-four hours later the tissue removal was 46+/-27 microm. There was no association between altered central corneal thickness and ablation depth (r = 0.058, P = 0.454). Central corneal thickness change was inversely proportional to residual refractive error (r = -0.364, P<0.01). Increased tissue removal may occur due to rapid stromal dehydration. Central corneal thickness changes between 24 h, and 2 months after surgery were constant over a range of ablation depths, which may partly explain the stability of LASIK procedures over a range of corrections.

Validation of the doubly labelled water technique for bumblebees Bombus terrestris (L.)

The doubly labelled water (DLW) technique was validated for the bumblebee Bombus terrestris (L.) using respirometry (RESP) from tethered roundabout flights. We injected small volumes (1 µl) of a mixture containing low concentrations of deuterium and 18O and withdrew 1-2 µl of haemolymph to determine initial 18O concentration. The injected isotopes were equilibrated with the body water pool after 10 min, and high material turnover allowed the analysis of final blood isotope concentrations after 5-7 h. On average (n=16), values measured using the DLW technique exceeded values measured using RESP by 3.1±9.9 %, a difference that was not statistically significant at the 99 % confidence level. The absolute error was 7.4±7.1 % (mean ± s.d.). Isotope dilution spaces of both deuterium and 18O were almost identical with the body water pool. We corrected for isotope fractionation, using a slightly higher value than usual for one of the fractionation factors. The single most important variable to influence DLW results, which could not be measured with the desired accuracy, was the volume of the final body water pool N. An overestimate of final N possibly resulted in the DLW overestimate.