Visual and speech imagery.
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Auditory Perception↗
Biomedical subjects
M Bach
Publications and source records attributed to M Bach.
Metabolic and electrophoretic studies of rat liver sorbitol dehydrogenase.
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Adrenal Glands↗
Metastatic cerebellar sarcoma (desmoplastic medulloblastoma) with diffuse osteosclerosis and leukoerythroblastic anemia.
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Adult↗
On the movement of an iron particle in a magnetic field.
When moved by a magnetic field, an iron particle does not follow--quite oppositely to a widely held opinion--the field lines of the magnetic field. Rather, the force exerted onto the particle is directed towards the strongest increase of the magnetic field strength. The field lines and the force direction coincide only axially, radially they cross at an angle of 90 degrees. This has implications for ophthalmic surgery, when an extraction of iron splinters by a magnet is required.
Iron↗
Little correlation of the pattern electroretinogram (PERG) and visual field measures in early glaucoma.
Pattern-electroretinograms (PERG) to checkerboard reversal at 16/s. 0.8 degrees and 15 degrees check size and visual fields (Octopus G1) were retrospectively analyzed in 40 eyes of 30 patients with early glaucoma. The mean visual field defect was calculated separately for the central 26 degrees x 34 degrees covered by the PERG stimulus (MDc) and the more peripheral area (MDp) surrounding the stimulus. Deeper field loss was correlated with a reduced pattern electroretinogram amplitude (p < 0.01 for both MDp and MDc), indicating that the pattern electroretinogram deteriorates as glaucoma advances. If the analysis was confined to those 18 eyes (16 patients) that had no field defect within the area covered by the PERG stimulus (normal MDc but abnormal MDp), 13 of these had an abnormal PERG amplitude (p < 0.001). The results suggest that the PERG can reveal impairment of ganglion cell function that is not detected by conventional perimetry.
Adult↗
Check size tuning of the pattern electroretingoram: a reappraisal.
The pattern electroretinogram was recorded to checkerboard stimuli with a wide range of check sizes and two stimulus field sizes. Check sizes ranged from 0.25 degree to 7 degrees (field size, 16 degrees x 14 degrees) and 0.25 degree to 15 degrees (field size, 32 degrees x 27 degrees) in 14 and seven subjects, respectively. Reversal rate was 4.5/s. For minimal intrusion of blink artifacts the interrupted stimulation technique was employed. The P50 and N95 components of the pattern electroretinogram were evaluated separately. With both stimulus field sizes amplitude of P50 and N95 was maximal between 0.75 degree and 1 degree. With smaller check sizes the amplitude dropped monotonically. With larger check sizes field size played a role: with the 16 degrees x 14 degrees field, P50 gradually dropped to 89% from 1 degree to 7 degrees, which was paralleled by N95 only up to 7 degrees, where N95 dropped to 81% (p < 0.05). With the 32 degrees x 27 degrees field, there was no significant difference in size dependency between P50 and N95 for large check, both components staying constant from 1 degree to 15 degrees. We conclude that there is only minor large-check attenuation of the pattern electroretinogram, especially with a large field. The apparent field-size dependency may explain previous discrepancies in the literature.
Electroretinography↗
Retest variability and diurnal effects in the pattern electroretinogram.
Pattern electroretinograms were recorded to phase-reversing checkerboard stimuli with DTL electrodes under conditions close to those of the ISCEV pattern electroretinogram guidelines. Both transient (2 reversals/s) and steady-state (16 reversals/s) stimulation was used. The check sizes were 0.4 degree, 0.8 degree and 16 degrees; the mean luminance 45 cd/m2, the contrast 98%, and the field size 32 degrees x 27 degrees. In 42 eyes of 21 subjects, measurements were repeated at the same time of day after 1 week. For each eye, the intersession coefficient of variation was calculated as a measure of reproducibility. We found a coefficient of variation (+/- standard deviation) of 7% +/- 5% for the amplitude of the steady-state pattern electroretinogram, 9.5% +/- 7% for the transient pattern electroretinogram and 1.5% +/- 2% for the latency of the transient pattern electroretinogram. To assess the diurnal variability, during a 15-h period, three pattern electroretinograms were recorded in 10 subjects. No relationship was found between the P50 latency and the time of day. However, the mean amplitude showed a maximum in the morning (9:30 am) and a minimum in the afternoon (2:30 pm). This small effect (about 7%, p < 0.001) was more pronounced for N95 and steady-state amplitudes than for P50 amplitudes (p < 0.01). Diurnal contributions to the pattern electroretinogram ranged between 3% and 10%. We conclude that pattern electroretinogram amplitude reproduces within +/- 10% with a probability of 70%. The effect size of the diurnal variation is similar and might be relevant for longitudinal studies.
Adult↗
Alexithymia: relationship to personality disorders.
Previous studies suggested an association of alexithymia with other personality models, as well as with various psychiatric syndromes. However, with regard to current diagnostic systems, the clinical validity of alexithymia remains to be established. In a sample of 182 psychiatric outpatients, the lifetime prevalence of DSM-III-R axis I disorders was determined by Structured Clinical Interview for DSM-III-R (SCID) interviews. In addition, DSM-III-R personality disorders were assessed using the Personality Diagnostic Questionnaire-Revised (PDQ-R). On the Toronto Alexithymia Scale (TAS), 17% of the sample scored in the alexithymic range. A series of stepwise multiple regression analyses were performed, exhibiting no relationship between alexithymia and any of the DSM-III-R axis I lifetime diagnoses. In contrast, schizotypal, dependent, and avoidant personality dimensions, as well as a lack of histrionic features, emerged as significant predictors of alexithymia, which further supports the conceptualization of alexithymia as a personality dimension.
Adult↗
Comorbidity of anxiety disorders and hypochondriasis considering different diagnostic systems.
The influence of different hierarchical guidelines in various classification systems on the diagnosis of anxiety disorders and hypochondriasis was investigated. Using a semistructured polydiagnostic interview (including DSM-III, DSM-III-R, and the 1987 draft version of ICD-10), lifetime diagnoses were determined in B2 outpatients with a DSM-III-R anxiety disorder. In all diagnostic systems, half of our patients exhibited the descriptive features of hypochondriasis. As demonstrated, the formulation of restrictive hierarchical rules--as in DSM-III--contributes to the concept of "primary" hypochondriasis, while secondary hypochondriasis remains underdiagnosed. Concordance rates for hypochondriasis were high between DSM-III-R and ICD-10, but not with DSM-III. Although hypochondriasis showed a strong association with the clinical course of panic disorder (PD), it could not be explained as a consequence of greater illness severity of PD with agoraphobia (AP). Our data underline the conceptualization of hypochondriasis as a phenomenologically homogeneous diagnostic category that may be differentiated from comorbid psychiatric conditions.
Adult↗
Clinical utility of DSM-IV pain disorder.
The utility of DSM-IV criteria for pain disorder was investigated within a consecutive sample of 90 chronic pain patients aged between 18 and 65 years. In this sample, 65.6% (n = 59) fulfilled diagnostic criteria for DSM-IV pain disorder. Of the patients with DSM-IV pain disorder, 22% fulfilled additional criteria for depressive disorder, 6.8% for hypochondriasis, and 23.7% for any other DSM-IV diagnosis. Only 54.2% of the patients with DSM-IV pain disorder had no comorbid psychiatric disorder. When assessing somatoform symptoms without hierarchical guidelines, there is a great overlap between the symptomatology of pain disorder and other somatoform disorders. Of 59 patients with DSM-IV pain disorder, 93.2% also met criteria for DSM-IV undifferentiated somatoform disorder and 10.2% for DSM-IV somatization disorder. The mean number of somatoform symptoms was 17 in the total sample. Despite the presence or absence of a general medical condition, there was no significant difference between pain disorder associated with both psychological factors and a general medical condition (code 307.89) and pain disorder associated with psychological factors (code 307.80) with regard to the pain duration, intensity, and type and the level of disability and educational level. The formulation of a distinct psychiatric entity for pain conditions may improve the consideration of psychosocial factors in the pathogenesis and clinical cause of pain. However, with regard to our data, the distinctive validity of different subtypes of pain disorder as provided by DSM-IV awaits further clarification.
Adolescent↗
Independency of alexithymia and somatization. A factor analytic study.
In discussions on the several methodological limitations in the assessment of alexithymia, uncertainty still remains about whether alexithymia and somatization are distinct constructs or whether they share overlapping symptomatology and constructs, as suggested by previous studies. In this study, 379 normal adults completed the newly developed 20-item Toronto Alexithymia Scale (TAS-20) and a screening list for DSM-III-R somatization disorder. Items from both the TAS-20 and the somatization checklist were subjected to factor analysis, resulting in separate factor loadings according to these two scales. These results were replicated and cross-validated in a sample of 125 psychosomatic inpatients, supporting the view of an independency between alexithymia and somatization.
Adolescent↗
Electrophysiological correlates of human texture segregation, an overview.
'Texture segregation' results from parallel processing in the visual cortex. It occurs when the stimulus contains spatial gradients within a visual dimension. We here present an introductory overview of the field, concentrating on electrophysiological correlates in the human EEG ('tsVEPs') of the neuronal processes underlying texture segregation. We describe the isolation of the tsVEP from the background EEG, give examples of the correlation between saliency and tsVEP amplitude and compare texture segregation between visual dimensions.
Animals↗
A case of Asperger's syndrome first diagnosed in adulthood.
A 25-year-old white male patient was admitted to the Department of Psychiatry, Division of Social Psychiatry, of the University of Vienna, Austria, for severe social withdrawal, selective mutism and outbursts of violence with attacks on his mother. Careful examination revealed the presence of all the typical symptoms of Asperger's syndrome. The diagnosis had never been made before, although the patient had a history of a difficult childhood with several admissions to a child psychiatric inpatient unit for 'obsessional neurosis' and an institutional career. It is stressed that, in view of the availability of treatments and the deleterious effect of the untreated condition in the sensitive years of personality development, early recognition and diagnosis of Asperger's syndrome are of utmost importance.
Adult↗
Screening for DSM-IV somatoform disorders in chronic pain patients.
BACKGROUND: The Screening Instrument for Somatoform Symptoms (SOMS) has been developed for selecting subjects with various somatoform disorders. To date, this instrument has not been used for pain patients. The purpose of this study was, therefore, to apply the SOMS to chronic pain patients, and to compare different SOMS cutoff item scores with regard to their sensitivity, specificity and (positive and negative) predictive value for selecting subjects with DSM-IV somatoform disorders among pain patients. METHODS: In a consecutive sample of 105 chronic pain outpatients, the SOMS was administered in addition to an operationalized psychiatric assessment according to DSM-IV. RESULTS: Patients with a somatoform disorder reported significantly more SOMS symptoms than patients without somatoform disorders (p < 0.02). As shown, a cutoff score of >/=4 somatoform items appeared useful for determining a somatoform disorder. However, only a limited number of cases could be correctly classified by the SOMS (range 53-66%). CONCLUSION: Therefore, the applicability of the SOMS as a screening instrument for somatoform disorders in chronic pain patients awaits further clarification.
Adult↗
Clinical validity of ICD-10 neurasthenia.
BACKGROUND: Neurasthenia was defined over a century ago. In view of a questionable clinical validity, it was omitted from the 3rd edition of the American Psychiatric Association's DSM, while it remains as an own diagnostic category in the WHO's ICD-10. The purpose of this study was, therefore, to examine the clinical validity of ICD-10 neurasthenia in a consecutive sample of chronic pain patients. PATIENTS AND METHODS: We included 193 patients (mean age 45.1, SD +/- 10.2, 63% females) in the study. Psychiatric diagnoses were established by the use of ICD-10 Diagnostic Criteria for Research. In addition, the Screening List for Somatization Symptoms was administered: self-rating of 53 medically unexplained somatic symptoms, and 11 additional screening questions concerning weakness after slight mental or physical exertion and disease conviction. RESULTS: Thirty-three percent of the patients who fulfilled the criteria of ICD-10 neurasthenia also fulfilled the criteria of ICD-10 somatization disorder, 69% the criteria of ICD-10 undifferentiated somatoform disorder, 14% the criteria of ICD-10 hypochondriacal disorder, 66% the criteria of ICD-10 somatoform autonomic dysfunction, 85% the criteria of ICD-10 persistent somatoform pain disorder and 14% the criteria for sexual dysfunction not caused by organic disorder or disease. The symptom profile of ICD-10 neurasthenia was not clearly distinguishable from the symptom profiles of ICD-10 somatoform disorders and ICD-10 sexual dysfunction. DISCUSSION: Due to this substantial diagnostic overlap, the clinical validity of ICD-10 neurasthenia remains questionable.
Female↗
Alexithymia in DSM-IV disorder: comparative evaluation of somatoform disorder, panic disorder, obsessive-compulsive disorder, and depression.
The purpose of this study was a direct comparative evaluation of alexithymia in patients with somatoform disorder, panic disorder, obsessive-compulsive disorder, and depression, taking into account the multidimensionality of the alexithymia construct. The authors administered the Structured Clinical Interview for DSM-IV (SCID) and the Toronto Alexithymia Scale (TAS-20) to a sample of 234 subjects. Panic disorder, but no other diagnosis, was significantly related to lower TAS-20 total scores (P=0.000). Regarding TAS-20 subfactors, Factor 1 was significantly associated with somatoform disorder (P=0.006) and depression (P=0.002), Factor 2 was significantly associated with depression (P=0.025), and Factor 3 was significantly associated with obsessive-compulsive disorder (P=0.001), whereas panic disorder showed a significant negative correlation with Factor 3 (P=0.001). The relationships of the three subfactors with various DSM-IV diagnoses and sociodemographic variables emphasize the multidimensionality of alexithymia.
Adult↗
Electrophysiological approaches for early detection of glaucoma.
PURPOSE: While elevated intraocular pressure (IOP) is a major risk factor for glaucoma, only about 1% of patients with 25 mmHg develop the condition each year. Since a sizeable proportion of the ganglion cells are already lost when the visual field losses are apparent, the aim is to identify patients with elevated IOP in whom glaucoma damage is incipient before visual field changes occur. METHODS: This report concerns early diagnosis of glaucoma with electrophysiological techniques, rather than with monitoring the disease using various available psychophysical and morphological methods. Visual electrophysiology offers a wide range of tools to assess function layer-by-layer along the visual pathway. Their clinical value for early detection of glaucoma will be discussed. The pattern electroretinogram (PERG), a direct functional indicator of retinal ganglion cell function, is markedly affected by glaucoma, and in longitudinal studies the PERG correctly indicated eyes at risk before manifest glaucoma occurred. CONCLUSIONS: Consequently, this report will concentrate on the PERG. Less proven, but promising measures like the "photopic negative response", the motion visually evoked potential (VEP) and the multifocal VEP will also be touched upon.
Electroretinography↗
A case of transient organic brain syndrome during quinine treatment.
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Adult↗