New cerebral microbleeds in ischemic stroke patients on warfarin treatment: two-year follow-up.

OBJECTIVE: Cerebral microbleeds (CMBs) are known to be indicative of bleeding-prone microangiopathy. Little is known about the significance of CMBs in anticoagulated patients. We determined the frequency of new CMBs in ischemic stroke patients who had been receiving warfarin treatment for 2 years. METHODS: A total of 204 ischemic stroke patients on warfarin therapy for 2 years underwent a repeat MRI. We compared demographic features, vascular risk factors, and radiological findings of patients with and without new CMBs. RESULTS: New CMBs on gradient-echo MRI were found in 29 of 204 patients (10%). Of 35 patients who had CMBs in the original study, 9 developed new CMBs after 2 years (26%), compared with 20 of the 169 patients (12%) who did not have CMBs at baseline (p=0.03). Patients with new CMBs were older than patients without CMBs (p=0.04), and the frequency of leukoaraiosis was significantly higher (p=0.02). The mean duration of warfarin treatment was not significantly different between the patients with and without new CMBs (p=0.28). CONCLUSION: This longitudinal study suggested that the presence of CMBs at baseline increased the frequency of new CMBs in patients on warfarin therapy.

Auditory delta event-related oscillatory responses are decreased in Alzheimer's disease.

BACKGROUND: Visual delta event-related (ERO) and evoked oscillations (EO) of Alzheimer patients (AD) are different than healthy. In the present study, the analysis is extented to include auditory ERO and EO in AD. The rationale is to reveal whether the auditory ERO delta responses are also reduced, and whether this is a general phenomenon in Alzheimer patients upon applying stimuli with cognitive load. METHODS: Thirty-four mild AD subjects [17 de-novo and 17 medicated (cholinergic)] and seventeen healthy controls were included. Auditory oddball paradigm and sensory auditory stimuli were applied to the subjects. Oscillatory responses were analyzed by measuring maximum amplitudes in delta frequency range (0.5-3.5 Hz). RESULTS: Auditory delta ERO (0.5-3.5 Hz) responses of healthy controls were higher than either de-novo AD or medicated AD group, without a difference between two AD subgroups. Furthermore, the auditory EO after presentation of tone bursts yielded no group difference. CONCLUSION: Our findings imply that delta ERO is highly unstable in AD patients in comparison to age-matched healthy controls only during the cognitive paradigm. Our results favor the hypothesis that neural delta networks are activated during cognitive tasks and that the reduced delta response is a general phenomenon in AD, due to cognitive impairment.