Study of absence of theta oscillation of working memory dysfunction in temporal lobe epilepsy / 国际生物医学工程杂志

Objective Temporal lobe epilepsy (TLE),frequently accompanied by working memory dysfunction,is an important form of adult epilepsy syndrome.Study on neural mechanisms of TLE with working memory dysfunction has important scientific value and clinical significance.Theta oscillations are synchronous activity of the brain in the 4-8 Hz frequency range.It is well recognized that there is a close relationship between the theta oscillations and working memory behavior.TLE patients with working memory dysfunction were taken as the research subjects,and the theta oscillations absence in TLE with working memory behavioral disorder was carried out,which provide the reference for further research into the neural mechanisms of TLE with working memory dysfunction.Methods The 34-channel electroencephalographs (EEGs) were recorded from TLE group (18 TLE patients) and control groups (18 healthy subjects) while subjects were performing visual working memory (delayed matching-tosample) tasks.The EEGs during the 3 s delay period was analyzed as experimental data.Fourier transform was used to assess the EEGs spectrum.The channel with the strongest spectrum was selected as the feature channel.Short-time Fourier transform algosiths was employed to calculate the time-frequency representation of the feature channel for the TLE and control groups.Frequency band with the strongest spectrum was selected for control group as the feature frequency band in working memory.Then,the topographical maps of the feature frequency band spectrum were calculated for the TLE and control groups.Results Compared with the control group,the working memnory behavioral performance of the TLE group was lower:accuracy of the TLE group was significantly lower than that of the control group (P＜0.05),and reaction time of the TLE group was significantly longer than that of the control group (P＜0.001).The feature channel in working memnory was frontal midline (Fz) and the feature frequency band was theta band.The Fz spectrum of the feature frequency for TLE was lower than that for control (P＜0.05).The frontal spectrum (seven channels) of the feature frequency for TLE was lower than that of control (P＜0.01).Conclusions Theta oscillations for TLE with working memory behavioral disorder is absent,which maybe one of the possible neural mechanism of TLE with working memory dysfunction.

Medial Temporal Atrophy and Memory Dysfunction in Poststroke Cognitive Impairment-No Dementia

BACKGROUND AND PURPOSE: It was recently reported that the prevalence of poststroke memory dysfunction might be higher than previously thought. Stroke may exist concomitantly with underlying Alzheimer's disease (AD), and so we determined whether post-stroke memory dysfunction indicates manifestation of underlying subclinical AD. METHODS: Of 1201 patients in a prospective cognitive assessment database, we enrolled subjects with poststroke amnestic vascular cognitive impairment-no dementia (aVCIND; n=48), poststroke nonamnestic vascular cognitive impairment-no dementia (naVCIND; n=50), and nonstroke amnestic mild cognitive impairment (aMCI; n=65). All subjects had cognitive deficits, but did not meet the criteria for dementia. A standardized neuropsychological test battery and magnetic resonance imaging were performed at least 90 days after the index stroke (mean, 473 days). Visual assessment of medial temporal atrophy (MTA) was used as a measure of underlying AD pathology. RESULTS: The MTA score was significantly lower in the naVCIND group (0.64+/-0.85, mean+/-SD) than in the aVCIND (1.10+/-1.08) and aMCI (1.45+/-1.13; p<0.01) groups. Multivariable ordinal logistic regression analysis revealed that compared with naVCIND, aVCIND [odds ratio (OR)=2.69; 95% confidence interval (CI)=1.21-5.99] and aMCI (OR=5.20; 95% CI=2.41-11.23) were significantly associated with increasing severity of MTA. CONCLUSIONS: Our findings show that compared with poststroke naVCIND, the odds of having more-severe MTA were increased for poststroke aVCIND and nonstroke aMCI.

Effect of Dangguishaoyao Powder on three models of memory dysfunction / 中成药

Objective: To observe the effect of DSP on three models of memory dysfunction,so as to provide evidence for its potential therapeuticaction for senile dementia.Methods: Three kinds of memory dysfunction are induced by scopolamine,reserpine and ovariectomy respectively,and memory ability is measured through step through and water maze tests.Meanwhile AchE activity in front cortex, hippocampus,striatum and limlic lobe of rats injected scopalamine is determined.Results: DSP can significantly prolong the step through latency,and decrease AchE activity in different parts of rats injeted scopalamine.And DSP can remarkably prolong latency,and increase uterus index of mice after ovariectomy.On the other hand,DSP can shorten water maze latency,enhance the correction percentage of mice injected reserpine.Conclusions:DSP can improve the memory dysfunction possibly through below pathways:(1)enhance the cholinergic system;(2)antagonize the decrease of monoamino transmitter;(3)has the possible estrogen like action.