Usefulness of Carotid Arterial Strain Values for Evaluating the Arteriosclerosis.

AIM: We investigated the clinical usefulness of carotid arterial strain and the strain rate for evaluating the progression of arteriosclerosis measured using a two-dimensional speckle-tracking method in carotid ultrasonography. METHODS: We enrolled 259 participants (age: 64±12 years; men: 149; women: 110) in this retrospective analysis. The circumferential strain and the strain rate were measured in bilateral common carotid arteries, and the lowest values were used for the analyses. To assess the characteristics of strain and the strain rate, we investigated the associations between the strain values and gender, age, body mass index (BMI), blood pressure (BP), and the presence of hypertension, diabetes mellitus, and hyperlipidemia. We also examined the explanatory factors for the strain values using clinical parameters along with the intima-media thickness (IMT), the ankle brachial index (ABI), and the cardio-ankle vascular index (CAVI) as possible candidates. Finally, we investigated whether the strain values might be an independent predictor for vascular diseases using multivariate logistic regression analyses. RESULTS: The carotid circumferential strain and the strain rate were significantly correlated with age, IMT, and the CAVI, but not with the BMI, BP, or ABI. Strain and the strain rates were lower in participants with hypertension or cerebrovascular disease and were selected as significant predictive factors for the presence of cerebrovascular diseases, together with diabetes and the CAVI. CONCLUSIONS: Strain and the strain rate of carotid arteries, which could represent local arterial stiffness, might be associated with atherosclerosis and could possibly be used to predict cerebrovascular disease.

Vowel-speech versus pure-tone processing in healthy subjects.

To investigate the characteristics of speech perception, we evaluated the differences in mismatch negativity (MMN) between vowel change and frequency change. Additionally, we examined the effects of gender, age, and educational length on MMN. Forty healthy adults (21 females), who were native Japanese speakers, participated in the study. A Japanese vowel-speech pair (standard/a/vs. deviant/o/) and a pure-tone pair (standard 1000 Hz vs. deviant 1050 Hz) were constructed. MMN elicited by vowel-speech sounds was larger and earlier compared with pure-tone sounds. Larger and earlier MMNs for vowel-speech sounds than for pure-tone sounds suggest different processing of linguistically relevant information at the early stage in the auditory cortex. In conclusion, the factors influencing on MMN are different between vowel-speech sounds and pure-tone sounds.

Aroma helps to preserve information processing resources of the brain in healthy subjects but not in temporal lobe epilepsy.

PURPOSE: Inhalation of ylang-ylang aroma has been shown to reduce the auditory P300, an event-related potential thought to reflect higher-order processing. Because olfactory function is sometimes disturbed in temporal lobe epilepsy (TLE), the objective of the present study was to determine whether the effect of ylang-ylang aroma on the auditory P300 was impaired in patients with TLE. METHOD: Fourteen subjects with TLE and 14 healthy controls participated in this study. Electroencephalograms were recorded during an auditory oddball task, and ylang-ylang aroma or odorless air was delivered through a mask. RESULTS: We found that the ylang-ylang aroma prolonged the latencies of P300 in both groups. The ylang-ylang aroma significantly reduced the P300 amplitudes of healthy subjects as described previously. However, in TLE patients, the P300 was unaffected by the aroma. CONCLUSION: The current results show that exposure to the ylang-ylang aroma reduced information processing resources in healthy subjects but had limited effects in patients with TLE. We suggest that impaired higher-order olfactory processing in TLE patients may inhibit the effects of the ylang-ylang aroma on the P300.

Mismatch negativity for speech sounds in temporal lobe epilepsy.

The mismatch negativity (MMN) is an electrophysiological trace of change detection, measured by electroencephalography (EEG), and is a reliable marker for pre-attentive auditory sensory memory. We used a phonetic oddball paradigm in patients with temporal lobe epilepsy (TLE) to elicit the MMN response at fronto-central sites and the mismatch positivity (MMP) response at mastoid sites. The MMN in 26 patients was compared with that of 26 age- and gender-matched healthy control participants. Electroencephalography responses were recorded during the presentation of speech sounds: the vowels 'a' and 'o' in alternation. Average waveforms were obtained for standard and deviant trials. We found that the MMP response at bilateral mastoid sites was reduced, whereas the MMN response at fronto-central sites did not change significantly. These results support the view that the MMN is generated by separable sources in the frontal and temporal lobes and that these sources are differentially affected by TLE.

Abnormal mismatch negativity for pure-tone sounds in temporal lobe epilepsy.

Auditory processing abnormalities in temporal lobe epilepsy (TLE) were assessed by investigating mismatch negativity (MMN) in a group of 20 TLE patients and 20 healthy control subjects. MMN is an event-related potential (ERP) component that reflects pre-attentive sensory memory function. A passive oddball paradigm using frequency changes in sinusoidal tones was employed to evoke MMN. MMN at frontocentral sites was enhanced in TLE patients relative to controls, while mismatch signals at mastoid sites (i.e., mismatch positivity; MMP) did not differ between the two groups. In the MMP temporal range, greater positivity at mastoid sites in response to standard stimuli was observed in TLE patients than in controls. Both MMN and MMP were significantly delayed in the TLE group. These findings demonstrate that TLE patients have impaired pre-attentive processing of pure-tone sounds. Enhanced frontocentral MMN may reflect hyperexcitability of the frontal lobes in compensation for dysfunction of the temporal lobes. Larger positivity at the mastoids in response to standard stimuli may be attributed to poor neuronal adaptation in the temporal lobe. Taken together, results suggest that evaluation of MMN/P is a useful physiological tool for identifying pre-attentive auditory memory dysfunction in TLE.