temporal processing
Dotaz
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Ciba Foundation symposium ; 184
[1st ed.] VIII, 347 s. : obr., tab. ; 23 cm
- MeSH
- neurofyziologie MeSH
- oči - fyziologické jevy MeSH
- zrak fyziologie MeSH
- Publikační typ
- kongresy MeSH
- Konspekt
- Lékařské vědy. Lékařství
- NLK Obory
- fyziologie
- neurovědy
- oftalmologie
Age-related hearing loss is manifested primarily by a decreased sensitivity to faint sounds, that is, by elevation of the hearing thresholds. Nevertheless, aging also affects the ability of the auditory system to process temporal parameters of the sound stimulus. To explore the precision and reliability of auditory temporal processing during aging, responses to several types of sound stimuli were recorded from neurons of the auditory cortex (AC) of young and aged anaesthetized Fischer 344 rats. In response to broad-band noise bursts, the aged rats exhibited larger response magnitudes, a higher proportion of monotonic units, and also a larger variability of response magnitudes, suggesting a lower stability of the rate code. Of primary interest were the responses to temporally structured stimuli (amplitude-modulated (AM) noise, frequency-modulated (FM) tones, and click trains) recorded separately in the right and left AC. Significant differences of temporal processing were already found between the neuronal responses in the left and right AC in the young animals: for the click trains, the left hemisphere exhibited a greater responsiveness to higher repetition rates, lower vector strength values, and a lower similarity of responses. The two hemispheres were also affected differently by aging. In the right hemisphere, neurons in the aged animals displayed worse synchronization with the AM noise and clicks, but better synchronization with the FM tone. In the left hemisphere, neuronal synchronization with the stimulus modulation improved at a higher age for all three stimuli. The results show that the ability of the aging auditory system to process temporal parameters of the stimulus strongly depends on the stimulus type and on laterality. Furthermore, the commonly reported age-related decline in the temporal processing ability cannot be regarded as general as, at least at the neuronal level in the AC, objective measures of the temporal representation often exhibit age-related improvement instead of deterioration.
Rozvoj zobrazovacích metód v posledných rokoch významne prispel k spresneniu diagnostiky a klasifikácii epileptických syndrómov. MRI sa už v súčasnosti považuje u týchto pacientov za metódu prvej vofby. MRS sa uvádza ako súčasť diagnostického procesu u kandidátov epileptochirurgickej liečby, pokiaľ výsledky ostatných zobrazovacích metód v korelácii s EEG metódami neumožnia jednoznačnú lokalizáciu epileptogénneho ohniska. V tejto štúdii sa uvádzajú skúsenosti s použitím MRS u pacientov s temporálnou epilepsiou so sporadickými epileptickými záchvatmi. v skupine sledovaných 7 pacientov sa zistila 100% senzitivita vyšetrenia MRS. V 5 prípadoch sa potvrdilo podozrenie z lokalizácie epileptogénneho ohniska stanovené na základe klinického obrazu a EEG vyšetrení, v 2 prípadoch s obojstrannými EEG epileptiformnými prejavmi MRS umožnila lateralizovať proces.
Development of imaging methods was helpful in precising diagnosis and classification of epileptic syndrome. Recently, MRI is the method of the first choice in a diagnostic process of epilepsy. MRS is a part of diagnostic process in patients where we think about epileptosurgery as a possibile treatment. Authors use MRS if there is no clear localization of epileptic focus by other imaging methods. In this study they summarized their experience with the use of MRS in authors group of patients with sporadic epileptic seizures of temporal origin. In this group of 7 patients, 100% senzitivity of MRS was achieved. In 5 cases authors confirmed suspicion of localization of epileptic focus, which correlated well with clinical symptoms and EEG findings. In 2 cases with bilateral EEG epileptic activity, MRS showed the site of pathological process.
- MeSH
- diagnostické techniky neurologické metody MeSH
- dospělí MeSH
- elektroencefalografie metody MeSH
- epilepsie temporálního laloku diagnóza etiologie patologie MeSH
- lidé MeSH
- magnetická rezonanční spektroskopie metody MeSH
- magnetická rezonanční tomografie metody MeSH
- spánkový lalok patologie MeSH
- Check Tag
- dospělí MeSH
- lidé MeSH
- mužské pohlaví MeSH
- ženské pohlaví MeSH
