Background/Aims: The relationship between subcortical hyperintensities (SH) on brain MRI and gait parameters in aging and Alzheimer’s disease (AD) is unclear. This study compared gait in 42 mild AD patients to 22 normal controls (NC) based on their SH severity and correlated them to SH burden in these groups. Methods: Gait velocity, stride length, cadence and step width were captured on an automated walkway. Severity of SH on MRI was visually scored, which was used to dichotomize the AD and NC groups into high and low SH severity subgroups. Correlations between gait parameters and total and regional distribution of SH were explored. Results: Compared to both AD subgroups and the NC subgroup with high SH severity, the NC subgroup with low SH severity had a significantly faster velocity (127 cm/s). Overall SH severity correlated significantly with stride length and velocity in the AD (r = –0.4, p = 0.01) and NC (r = –0.4, p = 0.02) groups, respectively, specifically with SH severity in the frontal and basal ganglion regions. Conclusion: SH burden may have a relatively stronger association with slower gait velocity in NC than in patients with mild AD. The fronto-subcortical SH load may influence gait in AD and aging.

This study compared spatial and temporal gait parameters in patients with mild stage of Alzheimer’s Disease [AD] and matched normal controls [NC]. Forty patients with mild AD and 34 NC were asked to walk over-ground, and subsequently on a (harness-secured) treadmill, both at preferred speed. Overground gait-velocity, cycle-time, cadence, stride-length, stride-width and double-support time were averaged over a minimum of three traverses on an automated walkway [GAITRite]. Cadence, cycle-time and double-support time was obtained on the treadmill using footswitches. The groups were well matched on baseline characteristics. The AD group were significantly slower on the Timed-up-and-go task compared to NC [p<0.05]. AD patients differed significantly from the NC on their over-ground gait velocity [99±19 cm/sec vs 119+15 cm/sec, p<0.0001], cadence [101±9 steps/min vs 109±9 steps/min, p<0.001] and stride-length [118±18cm vs 131±17cm, p<0.01]. Preferred speed on the treadmill was significantly slower in the AD group than the NC group [60±20 cm/sec vs 74±23 cm/sec, p=0.01], but at their preferred constant belt speed, no significant differences were observed in gait parameters collected on the treadmill. Patients with mild AD may have subtle changes in gait compared to NC which relate to temporal gait characteristics. At a steady belt-speed on the treadmill, these differences in temporal measures are no longer seen suggesting that early gait changes in AD relate to step-timing and gait-speed.

ObjectivesAlthough antiretroviral therapy (ART) prolongs life and reduces infectiousness, in some contexts, it has been associated with increased sexual risk taking.DesignRetrospective case–control study.SettingNairobi-based dedicated female sex worker (FSW) clinic.ParticipantsHIV-infected FSWs before and after ART initiation (n=62); HIV-infected and -uninfected control FSWs not starting ART during the same follow-up period (n=40).InterventionInitiation of ART.Primary outcome measuresSelf-reported condom use, client numbers and sexually transmitted infection incidence over the study period (before and after ART initiation in cases).ResultsSexual risk-taking behaviour with casual clients did not increase after ART initiation; condom use increased and sexually transmitted infection incidence decreased in both cases and controls, likely due to successful cohort-wide HIV prevention efforts.ConclusionsART provision was not associated with increases in unsafe sex in this FSW population.

No abstract