Is gut microbiota of patients with ALS different from that of healthy individuals?

Background/aim: Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease. Several studies have shown that alterations of microbiota increase the risk of neurodegenerative disorders. We aimed to reveal whether there is a difference in the gut microbiota of patients with ALS. Materials and methods: The participants are divided into three groups. Group 1 comprised patients with ALS. Healthy family members living in the same house of the patients formed Group 2. Lastly, sex- and age-matched healthy people were included in Group 3. Fecal samples were collected in 15-mL falcon tubes and stored at -80 °C. Genomic DNA isolation was performed on samples. Bacterial primers selected from the 16S rRNA region for the bacterial genome and ITS1 and ITS4 (internal transcribed spacer) were used for the identification of DNA. Next generation sequence analysis (NGS) and taxonomic analyses were performed at the level of bacterial phylum, class, order, family, genus, and species. Alpha and beta diversity indexes were used. The linear discriminant analysis (LDA) effect size method (LEfSe) was applied to identify a microbial taxon specific to ALS disease. Results: The relative abundances of the Succinivibrionaceae and Lachnospiraceae families were significantly lower in patients. The dominant families among patients were Streptococcaceae and Ruminococcaceae, while the dominant families among healthy controls were Bacteroidaceae and Succinivibrionaceae. The LEfSe analysis revealed that four families (Atopobiaceae, Actinomycetaceae, Erysipelatoclostridiaceae, Peptococcacceae) differed significantly between the patients and healthy controls (LDA values> 2.5, p < 0.05). Conclusion: Comparison with family members living in the same house is the strength of this study. We found that there were changes in the microbiota of the patients, consistent with the literature. Studies that analyze the composition of the gut microbiota in the predisease period may be needed to understand whether dysbiosis is caused by the mechanisms inherent in the disease or whether it is dysbiosis that initiates the disease.

The impact of transparency on hemispheric lateralization of idiom comprehension: An rTMS study.

Previous neuropsychological data have equivocal suggestions concerning hemispheric involvement during idiom comprehension. The possible contribution of idioms transparency to the lateralization of figurative language comprehension has not been investigated using an interference technique. To analyse the cortical lateralization of idiom transparency processing, we employed inhibitory repetitive transcranial magnetic stimulation (rTMS) to the left and right dorsolateral prefrontal cortex (DLPFC) during the processing of opaque idioms, transparent idioms, and non-idiomatic literal phrases. Based on the Coarse Semantic Coding theory, we predicted a greater right hemisphere involvement when processing opaque than transparent idioms. Eighteen young healthy participants underwent rTMS pulses at 1 Hz frequency, 110% of motor threshold intensity for 15 min (900 pulses) in two sessions at one-week intervals. In a semantic decision task, participants judged the relatedness of an idiom and a target word. The target word was figuratively or literally related to the idiom, or unrelated. The study also included non-idiomatic sentences. We found that left DLPFC functions are more critical for comprehension of opaque rather than transparent idioms when referring to the figurative associations of the idioms. Opaque idioms, in the context of their figurative meaning, rely more heavily on left hemisphere resources. This finding suggests that opaque idioms are seemingly processed as one unit. Taken together, we believe that the transparency of idiomatic expressions may play an important role in modulating hemispheric functions involved in figurative language processing.

Pronation test: eyes closed or open?

BACKGROUND: The pronation test reveals slight paresis in the upper limbs. Patients hold their arms outstretched in front of them with the hands supinated while they keep their eyes closed. Position changes such as pronation, abduction, or drift indicate a positive pronation test. However, proprioceptive disorders also result in position changes when the eyes are closed. AIM: To evaluate the effects of vision on the pronation test and the relation of test results to electrophysiological findings. METHODS: Sixteen patients with slight unilateral paresis due to recent stroke were included in the study. Two pronation tests, one while the patients' eyes were open and the other while the eyes were closed (in randomized order), were performed in all patients and recorded with a video camera. Two neurologists double-blinded to the position of the patients' eyes then assessed the position changes in each recording. Electrophysiological examination included median sensory and motor evoked potentials in both upper limbs. Sensory and motor central conduction times (CCTs) were determined for all patients. RESULTS: Assessments of position changes by two physicians were concordant. Ten patients had position changes more evident in the pronation test with the eyes closed (group 1), while 6 patients had similar position changes in both tests (group 2). Motor CCT difference between two sides was similar in the two groups. However, sensory CCT difference longer than 1.0 ms was significantly more frequent in group 1 (p < 0.01). CONCLUSION: All patients who developed more obvious position changes during the pronation test with eyes closed had sensory CCT abnormalities. Therefore, we suggest that patients should keep their eyes open and then close them during the pronation test in order to distinguish motor or proprioceptive involvement.

Cortical inhibition in first-degree relatives of schizophrenic patients assessed with transcranial magnetic stimulation.

Although cortical inhibition deficit has been shown in schizophrenia patients by transcranial magnetic stimulation (TMS), some controversies remain, possibly due to confounding factors such as medication use and clinical state at the time of assessment. First-degree relatives of schizophrenia patients, who share various degrees of genetic vulnerability with the patients, but are free from confounds related to medication and/or florid psychosis, have not been studied to date. We compared 12 relatives with 14 controls on several paradigms with TMS. Three of the 12 healthy relatives lacked transcallosal inhibition (TI) in one or more of the stimulation levels. There were no significant differences in other parameters. The lack of TI in 25% of the relatives is an important finding that needs to be replicated in larger samples that are heterogeneous in terms of psychosis-proneness.