Cognitive Dysfunctions in Patients With Severe Obstructive Sleep Apnea Syndrome: Neuropsychological Test and Event-Related Potential Study

Background: Patients with obstructive sleep apnea syndrome (OSAS) show variety of dysfunctions in cognitions including general cognitive function, attention, and frontal lobe and executive function. However, there is no consensus on the main features of the cognitive dysfunction in OSAS patients. So we performed neuropsychological tests and event-related potential (ERP) studies in patients with severe OSAS to evaluate the cognitive dysfunctions and changes of auditory and visual P300. Methods: Twenty-eight men with severe OSAS (apnea hypopnea index (AHI)=63.1±}17.8/hr) and 16 age, sex, educationmatched normal controls (AHI=2.9±}1.8/hr) underwent neuropsychological tests and ERP studies. Results: Patients with severe OSAS showed deficits in corsi block forward and backward test during neuropsychological evaluation, and delayed latency and decreased amplitude of auditory P300. There were significant correlations between auditory P300 amplitudes and digit span forward or corsi block forward test scores, and between visual P300 amplitudes and digit symbol test scores. Conclusions: These findings suggest that severe OSAS patients may have deficits in attention and short-term memory, and abnormal auditory P300.OAIID:oai:osos.snu.ac.kr:snu2008-01/102/2014017262/5SEQ:5PERF_CD:SNU2008-01EVAL_ITEM_CD:102USER_ID:2014017262ADJUST_YN:NEMP_ID:A079623DEPT_CD:801CITE_RATE:0DEPT_NM:의학과SCOPUS_YN:NCONFIRM:

Cortical Representation to Odorant Stimulation: Statistical Non-parametric Mapping of Low Resolution Electromagnetic Tomography (LORETA)

Background: Although olfactory stimulation has been known to produce effects on human mood and cognition, the specific EEG patterns of activity was reported diversely. The purpose of this study was to investigate EEG changes by odorant using low resolution electromagnetic tomography (LORETA) in young healthy subjects. Methods: The EEG's of nineteen (10 males, 9 females) non-smoking right-handed college students were recorded after odorant stimulation. A nineteen-channel EEG was recorded referenced to linked ears before and during olfactory stimulation. Olfactory stimulation was presented with lavender essential oil by blotter method. The LORETA power was computed from ten 2-s epochs, separately for the different EEG frequencies. The power values were logarithmically transformed and paired sample t-tests were done for each voxel and frequency band (1.5-30 Hz). Statistical results were displayed 3-dimensionally on the standard brain template. Results: All subjects experienced positive feelings (relaxed and pleasant) by olfactory stimulation with lavender oil (p<0.01). The LORETA power of theta and alpha band was increased in the dorsolateral and medial frontal areas, predominantly in the posterior cingulate gyri. The alpha LORETA power was also increased in bilateral orbitofrontal regions and the left perisylvian region including the insular cortex. Beta power was increased in the posterior cingulated gyri and mesial temporal region, predominantly on the left side. Conclusions: These results suggest that olfaction associated with emotional feeling might induce brain electrical power changes not only in the limbic system but also in the neocortex with lateralization to the dominant hemisphere.OAIID:oai:osos.snu.ac.kr:snu2004-01/102/2014017262/1SEQ:1PERF_CD:SNU2004-01EVAL_ITEM_CD:102USER_ID:2014017262ADJUST_YN:NEMP_ID:A079623DEPT_CD:801CITE_RATE:0DEPT_NM:의학과SCOPUS_YN:NCONFIRM:

Ictal Hyperperfusion of Brain Structures Related to Ictal Dystonic Posturing in Temporal Lobe Seizures

Although dystonic posturing (DP) during temporal lobe seizures is known to be related to basal ganglia activation, the mechanism of the dystonic posturing has not been investigated in greater details . Methods: Thirty-two patients with mesial temporal lobe epilepsy (TLE) underwent ictal and interictal SPECTs. They were classified into two groups: 1) DP with ictal dystonia during ictal SPECT (N=15) and 2) Non-DP without dystonia (N=17). Ictal-interictal SPECT subtraction was performed as follows: co-registration, intensity normalization, subtraction, thresholding and then an overlay to SPGR MRI. The presence and intensity of ictal hyperperfusion were determined in frontal lobe, basal ganglia, temporal lobe and insular cortex. Results: The incidences of ictal hyperperfusion in DP vs. Non-DP were caudate nucleus [80.0%(12/15 patients) vs. 0% (0/17), p=0.001], putamen [93.3% (14/15) vs. 48.2% (8/17), p=0.005], globus pallidus [53.3% (8/15) vs. 23.5% (4/17), p=0.082], thalamus [80.0% (12/15) vs. 41.2% (7/17), p=0.026], insular cortex [46.7% (7/15) vs.23.5% (4/17), p=0.051], orbitofrontal [46.7% (6/15) vs. 35.3% (7/17), p=0.053], medial frontal [6.7% (1/15) vs. 18.7% (2/17), p=0.621], dorsolateral frontal [13.3% (2/15) vs. 18.7%(2/17), p=0.737] in the hemisphere of epileptic side. In patients who showed ictal hyperperfusion in striatum and thalamus, the average intensity of hyperperfusion in DP vs. Non-DP was caudate nucleus 1.67 vs. 0.0, putamen 2.20 vs. 1.05, globus pallidus 1.2 vs. 0.65, thalamus 2.00 vs. 0.88 in the epileptic hemisphere. Conclusions: Caudate nucleus as well as putamen appeared to be important for producing ictal dystonia during TLE seizures. The greater intensity of ictal hyperperfusion in putamen, caudate nucleus and thalamus seems to be related to ictal dystonia.OAIID:oai:osos.snu.ac.kr:snu2003-01/102/2014017262/5SEQ:5PERF_CD:SNU2003-01EVAL_ITEM_CD:102USER_ID:2014017262ADJUST_YN:NEMP_ID:A079623DEPT_CD:801CITE_RATE:0DEPT_NM:의학과SCOPUS_YN:NCONFIRM:

SIMPLE PARTIAL STATUS EPILEPTICUS LOCLIZED BY SPECT SUBTRACTION IN CHRONIC CEREBRAL PARAGONIMIASIS

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