Tehran University Medical Journal

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Normal 0 false false false EN-US X-NONE AR-SA MicrosoftInternetExplorer4 Background: It is a well known fact that language functions are primarily related to the left hemisphere in right handed individuals, there is still no agreement about hemispheric language dominance in left handers. The aim of this study is to evaluate the possibility of using functional Transcranial Doppler ultra sonography (TCD), as a non-invasive method for investigation of hemispheric language dominance and also to explore possible gender influence on hemispheric language representation.
Methods: We performed functional TCD during a word generation task, in 62 healthy volunteers (30 right handers and 32 left handers, 50% male and 50% female). All subjects were medical students in the age range of 22-29 years. Right or left handedness was determined using Edinburgh questionnaire. Two subjects were excluded from the study because of poor temporal windows. Mean blood flow velocity was measured in both right and left middle cerebral arteries (MCA) at rest and during a word generation task, and changes in flow velocities were compared.

Results: Increase of MCA blood flow velocity was observed in 55% (33 subjects) of the students in the left side, and in 45% (27 subjects) of them in the right side. Right hemispheric dominance was observed in 43.3% of right handers and 46.7% of left handers. Left hemispheric dominance was observed in 56.7% of right handers and 53.3% of left handers. Our results showed no significant right hemispheric language dominance in left handed subjects.
Conclusion: This study does not show significant difference in hemispheric language dominance between right and left handers, using functional TCD

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Background: Nonalcoholic Fatty Liver Disease (NAFLD) is one of the most wide-spread human diseases that can impair liver function and sometimes progresses to cir-rhosis. Recently NAFLD has been identified as an independent risk factor for cardio-vascular disease. The aim of this study was to investigate the correlation of fatty liver disease and its sonographic severity on the resistance of the intracranial arteries. Methods: This study was a cross-sectional study of 55 patients referred from Gastroen-trology clinic with diagnosis of NAFLD to Sonodoppler department of Iranian Center of Neurological Research. Pulsaltile index as a Hemodynamic parameter of Middle Cerebral (MCA) and basilar Arteries of NAFLD Patients was measured by Trans Cra-nial Doppler (TCD) sonography and the measurements were compared with normal values. Also the association of these indices with serum liver enzymes and sonographic grading of liver involvement was assessed. The analysis was done by SPSS 16. Fre-quency distribution, mean and standard deviation were used in descriptive analysis and statistical test 2 to compare qualitative variables. Results: Pulsatile Index (PI) were normal (MCA, P= 0.166, Basilar, P= 0.053) and there was no significant difference with relation to severity of fatty liver based on so-nography findings (P= 0.789), but serum liver enzyme levels were inversely correlated with basilar artery PI (P= 0.014). Conclusion: Considering the increase of cerebral arteries PI in advanced liver disease, absence of increase in vascular PI of patients in the present study could be attributed to the short duration of disease from diagnosis to perform TCD, lack of advanced liver involvement (absence of liver dysfunction) and the response effect to treatment before the TCD. Therefore, to assess vascular changes over time, repeating the TCD with assess other parameters such as Fibroscan and K18 factor that has more compatibility of liver function, could help to understand the pathophysiology of liver diseases and its effect on vascular resistance.

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Background: Insomnia is the most common sleep disorder that is associated with cortical hyperexcitability. Potentially transcranial direct current stimulation (tDCS) modifies the cortical state related to insomnia. Therefore, we hypothesized that by using tDCS the intensity of insomnia can be reduced, followed by improvement of the mood symptoms.
Methods: This study was an experimental design with a pre-test and post-test with a control group. The statistical sample included 32 females with chronic insomnia that were randomly divided into an experimental group (active stimulation) and a control group (sham stimulation). Transcranial direct current with an intensity of 2 mA was applied for 30 minutes during 12 sessions (three times in the week) in the active stimulation group. In this protocol, anodal stimulation of left Superior temporal gyrus (STG) and cathodal stimulation of right dorsolateral prefrontal cortex (DLPFC) and left secondary motor cortex (SMA). In the control group, sham stimulation was performed for 30 minutes during 12 sessions (three times in the week). The participants were evaluated before and after of the intervention using the Insomnia Severity Index (ISI) and Positive and Negative Affect Scale (PANAS).