Brain MRI Findings in Patients in the Intensive Care Unit with COVID-19 Infection.

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Validation of Montreal Cognitive Assessment and Discriminant Power of Montreal Cognitive Assessment Subtests in Patients With Mild Cognitive Impairment and Alzheimer Dementia in Turkish Population.

Montreal Cognitive Assessment (MoCA) is a new cognitive tool developed for screening mild cognitive impairment (MCI). The authors examined validity of MoCA and discriminating power of subtests in a Turkish population comprising of 474 participants (246 healthy controls, 114 subjects with MCI and 114 subjects with dementia). The ANCOVAs showed that age and education had a main effect on MoCA scores. Cut scores were computed according to different education levels. The overall cut-off values for MCI and dementia were found to be lower compared to western studies. MoCA was found to have good internal consistency. The subtests most useful in discriminating MCI from healthy controls were recall, visuospatial and language, while in discriminating dementia from MCI were visuospatial, orientation and attention subtests. The results demonstrated that MoCA is a valid and reliable instrument in screening MCI, and compared with the MMSE, MoCA was proved to have superior sensitivity and specificity in detecting MCI.

A local signature of LTP- and LTD-like plasticity in human NREM sleep.

Paired associative stimulation (PAS) repeatedly pairs electrical nerve stimulation with transcranial magnetic stimulation of the contralateral motor hand area (M1(HAND)). Depending on the interstimulus interval, PAS can induce a long-term potentiation (LTP)-like facilitation or long-term depression (LTD)-like suppression of cortical excitability. In three experimental sessions, 12 awake men received PAS of the right median nerve and left M1(HAND) in the evening before sleep. To optimize the timing of paired stimulation in M1(HAND), the interstimulus interval of PAS was adjusted to the individual N20-latency of the somatosensory evoked potential to induce LTP-like effects (PAS(N20+2ms)), LTD-like effects (PAS(N20-5ms)), or no timing-dependent after-effects (PAS(control)). Motor-evoked potentials (MEPs) showed high interindividual variations in the conditioning effects of PAS(N20+2ms) and PAS(N20-5ms) on cortical excitability. However, PAS(control) allowed us to adjust for any unspecific stimulation effects and the MEP increase after PAS(N20+2ms) differed significantly from the MEP decrease after PAS(N20-5ms). PAS(N20+2ms) and PAS(N20-5ms) also had a differential effect on regional expression of slow waves and slow spindle activity during the first hour of subsequent non-rapid eye movement (NREM) sleep. At the electrode sites overlying the conditioned M1(HAND) and the adjacent premotor cortex, local expression of slow spindle activity was significantly correlated with interindividual differences in the efficacy of PAS(N20+2ms) and PAS(N20-5ms) to potentiate or suppress cortical excitability. This correlation indicates that PAS shapes the local regulation of slow sleep spindles during subsequent NREM sleep.

Treatment differences in cases with venous angioma.

Venous angiomas were found to be the most common cerebral vascular malformations, composing 63% of such lesions in two autopsy series. Annual bleeding risk associated with venous angiomas is about 0.22 % per year. Venous angiomas are generally silent lesions because of their dynamic features, and are low flow and low pressure vascular structures draining normal brain tissue. An angioma rarely causes symptoms such as bleeding, seizure, hemifacial spasm, trigeminal neuralgia, aqueduct compression, nonhemorrhagic infarction and thrombosis of the draining vein. Even if it should bleed, the lesion can be managed conservatively in asymptomatic or mildly symptomatic patients. In this paper we report two venous angioma cases. The first patient bled twice in a short period of time and the angioma was located at the posterior fossa next to the left lateral recess. The second patient recently suffered a cerebral stroke that was located in the vicinity of the right caudate nucleus and not associated with the venous angioma that was located next to the left caudate nucleus. This patient had been under warfarin sodium treatment for 14 years due to his previous coronary artery bypass surgery, but unknowingly there was a venous angioma located next to the caudate nucleus.

Evaluation of the cognitive functions in patients with chronic renal failure before and after renal transplantation.

Chronic renal failure (CRF) and dialysis treatment affect central nervous system and studies have shown that neurocognitive dysfunctions are caused by CRF and dialysis treatment. The aim of this study was to evaluate the changes in cognitive functions of CRF patients after renal transplantation. Neurocognitive functions of 40 renal transplantation patients aged 18-65 years were determined before, 6 and 12 months after transplantation between 2008 and 2010 using neuropsychological tests. Rey Auditory-Verbal Learning Test (RVLT), Rey Complex Figure Test (RCFT), ADAS-cog Test, Stroop Test (ST), Digit Span Test (DST), and Trail Making Test (TMT) were applied. The test results were statistically compared taking into consideration the patients' levels of education, age, gender, donor type, duration of dialysis, dialysis type, and duration of CRF. Neuropsychological test results statistically significantly increased in all the patients after renal transplantation (p < 0.05). The female patients' RVLT test results were statistically higher than the test results of the male patients (p < 0.05). DST, RCFT, RVLT, and (Verbal Fluency Test) VFT results were statistically higher in the patients who were 33 years old or younger (p < 0.05). The patients with high school and college education had statistically significantly higher results in all the tests when compared with the patients that were elementary school graduates (p < 0.05). DST forward task, ST, and RVLT results of the patients, who had received dialysis treatment for 1 year or less, were found to be statistically higher than the results of the patients who had received dialysis for more than 1 year (p < 0.05). The results of RCFT, RVLT, DST backward task, and VFT were statistically higher in the peritoneal dialysis patients than in the hemodialysis patients (p < 0.05). The donor type and the duration of CRF had no significant effects on the results (p > 0.05). The results of this study showed significant improvement in attention, memory, executive functions, pace of data processing and language functions in CRF patients after renal transplantation, as proven with neuropsychological tests.