Alteration of Gut Microbiota in Alzheimer's Disease and Their Relation to the Cognitive Impairment.

BACKGROUND: Dysbiosis of gut microbiota has been reported to be enrolled in the pathogenesis of Alzheimer's disease (AD). However, there is a lack of relevant studies on this topic in Egyptian patients with AD. OBJECTIVE: To investigate different species of gut microbiota in Egyptian patients with AD and correlate microbiota bacterial abundance with clinical data. METHODS: The study included 25 patients with AD and 25 healthy volunteers as age and sex-matched controls. Clinical data was taken for each patient, including medical history and examination; Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) were assessed for each participant. Bacterial DNA was extracted from stool, and abundance quantified via qPCR using 16S rRNA group-specific primers. RESULTS: Akkermansia, Enterobacteria, Bacteroidetes, Bacillus cereus, Prevotella, and Clostridium cluster IV were more abundant in the AD group than in the control group, although there was significantly less abundance of Bifidobacterium spp., Firmicutes, and Actinobacteria in patients with AD than in controls, whereas no such significance was found for lactic acid bacteria between both groups. Lactic acid bacteria and Prevotella abundance was negatively correlated with cognitive impairment (p = 0.03 with MMSE, and p = 0.03 with MoCA). Prevotella abundance was positively correlated with age of onset and duration of illness and negatively correlated with smoking and coronary heart disease (p = 0.007, p = 0.03, p = 0.035, and p = 0.047, respectively). CONCLUSION: The current work highlighted a significant relationship between AD and gut microbiota dysbiosis. A higher abundance of Prevotella species and lactic acid bacteria was correlated with cognition.

Changes in recruitment of motor cortex excitation and inhibition in patients with drug-induced tardive syndromes.

OBJECTIVES: It has recently been suggested that drug-induced tardive syndromes (TS) might be due to maladaptive plasticity, which increases motor excitability in cerebral cortex and basal ganglia. In order to test this hypothesis, we performed the first measurements of cortical excitability in TS. METHODS: Motor cortex excitability was examined using transcranial magnetic stimulation (TMS) in 22 TS patients and compared with that in 20 age and sex-matched healthy individuals. Resting and active motor threshold (RMT, AMT) and input-output curves (I/O curves) assessed corticospinal excitability. The duration of the contralateral silent period (cSP) at a range of stimulation intensities and ipsilateral silent period (iSP) were used as measures of inhibition. RESULTS: There were no significant differences in RMT and AMT between patients and controls, although the input-output curves were significantly steeper in patients. The cSP (at different stimulus intensities) and iSP were both longer in the patients compared to the control group. However, most of this difference could be accounted for by increased recruitment of motor evoked potentials (MEPs) in patients. CONCLUSION: TS is characterized by hyperexcitability of corticospinal output that might contribute to the lack of selectivity in muscle recruitment and contribute to excess involuntary movement. The findings are opposite to those in naturally-occurring hyperkinesia such as Sydenham's and Huntington's chorea, suggesting a fundamental difference in the pathophysiology.

Spectrum of epilepsy - prevalence, impact, and treatment gap: an epidemiological study from Al-Quseir, Egypt.

BACKGROUND: Epidemiology continues to be an important research tool in the study of epilepsy and related disorders, providing a better understanding of the frequency, causes, and natural history of the disorder. OBJECTIVE: To estimate the prevalence of epilepsy in Al-Quseir, Red Sea Governorate, Egypt, and its magnitude of treatment gap. METHODS: The study was part of a door-to-door study, including every door, to screen all inhabitants in Al-Quseir (33,818 inhabitants) by three specialists of neurology and 15 female social workers (for demographic data collection) using a standardized screening questionnaire. All suspected cases were subjected to detailed history, clinical examination, and electroencephalogram. Neuroimaging studies and estimation of serum drug level were done in select cases if needed. RESULTS: The study revealed that the lifetime prevalence rate of epilepsy in Al-Quseir is 5.5/1,000, with the highest peak during early childhood, while that of active epilepsy is 3.3/1,000 population. The annual incidence rate is 48/100,000, and the age-specific incidence rate has a U-shaped pattern with two peaks of incidence in early infancy and elderly life. Localization-related epilepsy is the most frequently encountered type (58.8%). The treatment gap of epilepsy in Al-Quseir is 83.8%. CONCLUSION: The lifetime prevalence of epilepsy in Al-Quseir city, Red Sea Governorate, was 5.5/1000.