Suguru Hattori

Preattentive dysfunction in major depression: A magnetoencephalography study using auditory mismatch negativity

Information processing deficits in major depressive disorder have been infrequently examined electrophysiologically. Its preattentive and sensory information processing was examined using mismatch field (MMNm) and P1m components, respectively, by magnetoencephalography. Fourteen major depressive disorder patients and 19 healthy volunteers participated in the study. MMNm was elicited in response to duration and frequency changes of pure-tone stimuli and in response to a vowel across-category change. The magnetic global field power (mGFP) of MMNm was significantly smaller in the major depressive disorder patients than in the healthy volunteers, although that of P1m did not differ between the two groups. Information processing at the preattentive level is impaired functionally in major depressive disorder, and this dysfunction is not due to the dysfunction at the lower level of information processing.

Preattentive dysfunction in bipolar disorder: a MEG study using auditory mismatch negativity.

BACKGROUND Neuropsychological studies have demonstrated that cognitive dysfunction represents pathophysiological mechanisms underlying bipolar disorder. However, information processing deficits in bipolar disorder have not often been examined electrophysiologically. Here, we examined preattentive processing and sensory information processing using mismatch field (MMNm) and P1m components, respectively, using magnetoencephalography. METHODS Ten patients with bipolar disorder and 20 healthy volunteers participated in the study. The participants were presented with auditory stimuli sequences comprising standard and deviant stimuli. MMNm was elicited in response to changes in duration and frequency of pure-tone stimuli and a vowel across-category change. RESULTS The magnetic global field power of MMNm in the right hemisphere under the pure-tone condition was significantly delayed in patients with bipolar disorder compared to healthy volunteers, and that of P1m did not differ between the two groups. The MMNm dipole in the left hemisphere was located inferior in patients with bipolar disorder than in healthy volunteers. This finding did not correlate with clinical symptoms. CONCLUSIONS Information processing at the preattentive level is impaired in patients with bipolar disorder irrespective of clinical symptoms, and this dysfunction is not due to sensory level dysfunction. The quality of preattentive information processing impairment is different between patients with bipolar disorder and patients with major depressive disorder, as shown by the MMNm latency and power differences.

The McGill Pain Questionnaire, Japanese version, reconsidered: confirming the theoretical structure.

BACKGROUND Based on a tripartite theoretical model of pain, the Pain Rating Index (PRI) of the McGill Pain Questionnaire (MPQ) continues to be one of the most frequently used instruments to measure clinical pain. However, language and cultural barriers have hindered its wide use and standardization in Japan. Although a number of exploratory factor analysis studies have failed to support consistently the theoretical structure of the MPQ, a few previous confirmatory factor analysis studies did statistically support the a priori model. OBJECTIVE To test, through confirmatory factor analysis (CFA), the theoretical structure of a Japanese version of the MPQ (JMPQ), which followed a format similar to that of the original MPQ. DESIGN This study used CFA on prospectively collected data from 199 consecutive outpatients with chronic pain at a university hospital to test the theoretical structure of the JMPQ. RESULTS AND CONCLUSIONS CFA was completed on the first 16 PRI subclass scores; this process yielded a well fitting final model that explained 92% of the covariance in the observed data. The results supported the hypothesis that the sensory, affective and evaluative subscales of the PRI are representative of the multidimensionality of the pain experience, with minimal overlap. It is suggested that the theoretical structure of the MPQ is maintained in the JMPQ used in this study. Therefore, this study is the first step toward standardization of the JMPQ, serving as a cultural bridge in the field of pain medicine between Japan and English-speaking nations such as Canada.

A study of the relationship between the seizure focus and 1H-MRS in temporal lobe epilepsy and frontal lobe epilepsy

Abstract Several studies of temporal lobe epilepsy (TLE) patients have investigated the relationship between the seizure focus and 1H magnetic resonance spectroscopy (1H‐MRS). There have also been a few reports in other types of partial epilepsy. We examined the relationship between the seizure focus and the reduction in N‐acetylaspartate : creatine (NAA : Cr) ratio using 1H‐MRS in both TLE and frontal lobe epilepsy (FLE) patients. We studied 21 patients with unilateral TLE and seven patients with unilateral FLE. We used a 1.5 Tesla magnetic resonance unit (Signa Horizon; General Electric). Approximately 15 × 15 × 20 mm3 voxel of interest (VOI) was placed over the anterior portion of the bilateral hippocampus in the TLE patients, and the anterodorsal position of bilateral frontal lobe in the FLE patients. The seizure focus was identified by interictal scalp electro‐encephalogram (EEG). In the TLE patients the NAA : Cr ratios were reduced in the seizure focus, while in the FLE patients they were not always reduced in the seizure focus. In the TLE patients the coincidence rate between the seizure focus and the reduction in the NAA : Cr ratio was 90% (19 of 21 patients), while in the FLE patients the coincidence rate was only 57% (four of seven patients).

A study of the relationship between metabolism using1H-MRS and function using several neuropsychological tests in temporal lobe epilepsy

Abstract Several investigators have reported on the relationship between metabolism, using magnetic resonance spectroscopy (MRS), and function, using neuropsychological tests in temporal lobe epilepsy (TLE) patients , but the opinions regarding the results remain in contention. The aim of this study is to examine the relationship between metabolism, using proton MRS ( 1 H-MRS), and function using several neuropsychological tests in the temporal lobes of TLE patients. We studied 29 TLE patients at our hospital using 1 H-MRS and neuropsychological tests. We used a clinical 1.5 T MR unit. We conducted five neuropsychological tests to examine the function of the left or right temporal lobe. There were significant correlations between the N-acetylaspartate/creatine + phosphocreatine (NAA/Cr) ratios and the scores of almost all of the neuropsychological tests for the temporal lobe function ipsilateral to the spike focus. However, in two Wechsler Memory Scale-Revised (WMS-R) subtests we found no significant correlation in the ipsilateral side. These findings suggest that the NAA/Cr ratios, which reflect neural metabolism, are closely related to function in the temporal lobes of TLE patients . The disparity between the results in two subtests of WMS-R show that several tests may be necessary in order to assess temporal lobe function.

The McGill Pain Questionnaire - Japanese Version, Reconsidered: Confirming the Reliability and Validity

BACKGROUND: The McGill Pain Questionnaire (MPQ) is one of the most widely used instruments in the world to evaluate patients with chronic pain. However, differences in languages and cultural backgrounds have hindered its standardization in Japan.

Magnetoencephalography study of the effect of attention modulation on somatosensory processing in patients with major depressive disorder

Although affective and/or attention modulation of somatosensory processing has been well studied, the biological bases of somatic symptoms in patients with major depressive disorder (MDD) have rarely been examined. To elucidate changes in somatosensory processing underlying somatic symptoms in patients with MDD, we conducted a magnetoencephalography study of patients with MDD and healthy controls.

The Relationship between Proton MRS and Clinical, EEG, or Neuropsychological Features in Temporal Lobe Epilepsy

Purpose: There havc becii few reports on thc seimre rocus lateralimtion in temporal lobe epilcpsy (TLE) using proton magnetic resonance spectroscopy (‘H‐MRS) or studics that investigated the hippocampal function in TLE patients using ‘H‐MRS. We examincd hippoampal ‘H‐MRS studies, clinical symptoms, BEG investigations, and memory tests in TLE paticnts, to investigate whethcr ‘H‐MRS is useful to decide the sciz.urc focus and whethcr it reflects thc clinical rcdturcs or the hippocampal function.

Mapping Epileptic Foci with the Dipole Tracing Method: A Comparison with Intraoperative Electrocorticograms

Purpose: To show the high accuracy of the dipole tracing method (DTM; Homma et al.Electroencephalogr Clin Neurophysiol 1994;91: 374–82), we estimated the position of the epileptic foci in two patients with epileptic seizures by using the DTM and compared the results with electrocorticograms (ECoGs) recorded during surgical resection.