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Biomedical subjects

M Amadeo

Publications and source records attributed to M Amadeo.

16 recordsLinked to original sources
PubMed1996

Antiandrogen treatment of aggressivity in men suffering from dementia.

Three demented patients who manifested an aggressive syndrome and motor disturbances including agitation, pacing, and restlessness received a therapeutic trial of the antiandrogen agents medroxyprogesterone acetate and luprolide acetate. Within 4 weeks of the start of the antiandrogen therapy, verbal and physical aggressivity had ceased; activity disturbances such as agitation, pacing, and restlessness were markedly reduced. One patient also manifested marked disinhibited and disruptive sexual behavior. Following treatment, that behavior also ceased. Further control studies assessing the efficacy and safety of antiandrogen agents are recommended.

Aged↗
PubMed1990

Cognitive complaints in elderly depressed and pseudodemented patients.

The cognitive complaints of 11 patients with depressive pseudodementia were compared with those of 22 patients with depression alone. Pseudodemented subjects were defined as depressed inpatients showing reversible cognitive impairment as measured by the Mini-Mental State Examination (MMSE); subjects with depression alone had no such impairment. For each group, cognitive complaints were highly correlated with depressive symptoms and were not related to MMSE scores. The pseudodemented group had significantly higher cognitive complaint scores, complaining more of difficulties with concentration and recent memory. Groups did not differ significantly in complaints of difficulties with remote memory.

Aged↗
PubMed1980

Topography of sensory evoked potentials in depressive disorders.

This study investigated differences in evoked potential (EP) topography between psychotic depressives, nonpatient controls, chronic schizophrenics, and neurotic depressives. Somatosensory (SEP), visual, and auditory EPs were recorded from 14 scalp leads. Locations (latencies) of consecutive EP peaks in a given subject were identified visually in key leads; these latencies were used for computer measurements of amplitude in all leads. Four sets of age- and sex-matched groups were compared by multivariate profile analysis. Amplitude differences between groups agreed well with findings obtained by comparing group sum EPs, indicating convergence between the two measurement methods. Topographic differences involved mainly SEP peaks. Distributions of SEP peaks P90 (positivity at 90 msec), N130, and P290 showed more posterior maxima in psychotic depressives than controls, while P185 was maximal more anteriorly in depressives. Distribution of SEP peaks N20, N60, N130, and P185 differed between psychotic depressives and chronic schizophrenics. The topographic approach appears to provide new EP information of pyschiatric relevance.

Adolescent↗
PubMed1979

Temporal variability of somatosensory, visual, and auditory evoked potentials in schizophrenia.

Previous findings in chronic schizophrenics showed greater than normal somatosensory evoked potential (SEP) waveshape stability before 100-ms after stimulus and reduced stability after 100 ms. To confirm and extend these findings, EPs to left and right median nerve stimuli, visual pattern flashes (VEPs), and auditory clicks (AEPs) were recorded from 14 locations in 86 patients and 33 controls. Three sets of analyses compared different patient groups with age- and sex-matched controls. The results confirmed previous SEP findings in chronic schizophrenics; no other subject group displayed the combination of high early and low late SEP stability. The SEP results did not generalize to VEPs and AEPs. Lead location was important for group differences. In overt schizophrenics, late epoch stability was low in all EPs. The results suggest certain limitations to the hypothesis of an impaired subcortical filtering mechanism in chronic schizophrenics.

Adolescent↗
PubMed1979

Somatosensory and auditory evoked potential studies of functional differences between the cerebral hemispheres in psychosis.

Evidence of lateralized hemispheric dysfunction in schizophrenia was previously found with a measure of visual evoked potential (VEP) wave-shape stability. The purpose of this study was to determine whether the VEP findings would extend to the auditory and somatosensory modalities. Measures of wave-shape stability were computed for auditory (AEP) and somatosensory (SEP) evoked potentials, recorded from one EOG and 14 scalp leads. Subjects were 74 unmedicated patients (49 schizophrenics, 25 nonpsychotics) and 27 nonpatients; two sets of age- and sex-matched comparison groups were formed. Main findings were: (i) Overtly psychotic schizophrenics exhibited lower than normal stability in left hemisphere AEPs (15-100 msec poststimulus). (ii) Both overtly psychotic and latent schizophrenics showed lower than normal wave-form stability, bilaterally, in the later epoch of AEPs (101-450 msec poststimulus). (iii) A subgroup of overt schizophrenics (other than chronic paranoid or chronic undifferentiated) had lower than normal stability in SEPs (15-100 msec) evoked by right median nerve stimuli and recorded from the right (ipsilateral) hemisphere. It was concluded that only the AEP results augment the previous VEP evidence indicating left hemisphere involvement in schizophrenic dysfunction.

Acoustic Stimulation↗
PubMed1978

Evoked potential correlates of psychosis.

Evoked potential (EP) correlates of several psychiatric disorders were investigated by applying a comprehensive EP procedure to 102 psychiatric patients and 28 nonpatients. EPs to left and right median nerve shocks, visual pattern flashes, and auditory clicks were recorded from one EOG and 14 monopolar scalp derivations. Nine age- and sex-matched groups were compared to yield the following main results: (i) EPs of overtly psychotic patients (schizophrenics, depressives, manics) differed markedly from normal, while those of patients without overt psychosis (neurotics, personality disorders, latent schizophrenics) did not; in the overtly psychotic, later EP events (100 msec or more poststimulus) were attenuated. (ii) EPs of neurotic depressives differed greatly from those of psychotic depressives. (iii) A somatosensory negative peak occurring 60-msec poststimulus (N60) was more posteriorly distributed in chronic schizophrenics (paranoid, undifferentiated) than in any other subject group. The attenuated later EP activity associated with overt psychosis was interpreted as a concomitant of cognitive (attention?) impairment, rather than of emotional disturbance.

Acoustic Stimulation↗
PubMed1978

Pattern evoked potential measurements suggesting lateralized hemispheric dysfunction in chronic schizophrenics.

Visual evoked potentials (VEP) were measured to obtain evidence concerning possible lateralized hemispheric dysfunction in schizophrenia. The main results are based on the spatial distribution (12 electrodes) of a measure of VEP wave form stability over time. Subjects were 86 psychiatric inpatients and 33 nonpatients; these were grouped in three ways to permit comparisons of various age- and sex-matched diagnostic classes. Main findings were: (i) VEP wave form stability was generally lower in all types of schizophrenia than in nonpatients, nonpsychotic patients and, probably, psychotic depressives. (ii) VEP stability differed more between the hemispheres in schizophrenics and psychotic depressives than in nonpsychotic subjects; in schizophrenics, left hemisphere stability was lower than normal, whereas it was normal in psychotic depressives. (iii) VEP stability differences between the hemispheres were also greater than normal in latent schizophrenics, with less stability on the left. The results provide a direct demonstration of a left hemisphere involvement in schizophrenic dysfunction.

Adolescent↗
PubMed1977

Evoked potentials of schizophrenics in several sensory modalities.

This is the initial report of results obtained by a comprehensive approach to investigation of evoked potential (EP) characteristics of psychiatric patients. EP to left and right medion nerve, visual (checkerboard flash), and auditory (click) stimuli were obtained for 14 monopolar scalp and one EOG derivation in 32 schizophrenics and 16 nonpatients, matched for age and sex. Results showed amplitude attenuation of EP events 100 msec poststimulus or later in the patients' EPs of all modalities and in most lead locations. Attenuation of later EP events thus appears to be a general characteristic of schizophrenia. Comparisons of chronic paranoid and undifferentiated with other patient subtypes revealed a relatively specific correlate of the chronic subgroup, increased negativity of a negative somatosensory peak occurring 60 msec poststimulus (N60) at contralateral central leads.

Acoustic Stimulation↗
PubMed1977

Can callosal speed of transmission be inferred from verbal reaction times?

Filbey and Gazzaniga (1969) found that verbal reaction times were shorter to right than to left visual field stimuli. They interpreted this reaction time difference (30 to 40 msec) to reflect callosal transmission time, i.e., the delay required for information received in the right hemisphere to be acted upon by the verbal left hemisphere. We have performed four verbal reaction time experiments with normal subjects, utilizing differing hemifield stimulus presentations and task requirements. Stimuli were: small lights (light-emitting diodes); checkerboard pattern briefly flashed; small circles; consonant-vowel-consonant triads, either meaningful or nonsense. Contrary to Filbey and Gazzaniga's observations, we found no difference between verbal reaction times to left and right half-field presentations, or a significantly shorter reaction time with left-field presentations, depending upon experimental conditions. Faster reaction times with left-field stimuli were found in left-handed as well as right-handed subjects. Our data indicate that it may be premature to infer callosal speed of transmission from verbal reaction times to half-field stimuli. The paradoxical finding of faster verbal reactions to right hemisphere visual inputs does not appear to be related to handedness, and it occurs with meaningful stimuli; this finding remains unexplained.

Corpus Callosum↗
PubMed1976

Eye-tracking performance and engagement of attention.

Eye-tracking dysfunction has previously been demonstrated in psychotic patients. To investigate possible influences on this finding of factors related to attention, subjects were required to read numbers while tracking an oscillating pendulum or a pendulum-like target displayed on an oscilloscope tube. Subjects for the pendulum task were 16 nonpatients and 21 patients; 10 nonpatients and 14 patients performed the other task. Introduction of the number-reading maneuver greatly improved tracking performance in both tasks in patients and nonpatients. The results indicate that poor eye-tracking can be improved by facilitating attentional effort; it is suggested that the number-reading maneuver improved tracking by providing extra feedback cues. The poorer the base line performance, the greater the improvement. However, differences between patients and nonpatients were not abolished with number reading.

Adolescent↗
PubMed1976

Spatial distribution of potentials evoked by half-field pattern-reversal and pattern-onset stimuli.

Spatial distributions of visual potentials (VEPs) evoked by half-field checkerboard pattern-reversal and pattern-onset stimuli were studied in 13 subjects, using an 11 lead unipolar array. The main aim was to confirm findings, obtained by previous workers with bipolar recordings, that half-field pattern-reversal VEP's are confined to the contralateral hemisphere and that half-field pattern-onset VEPs are asymmetrical, with greater right hemisphere involvement. Pattern-reversal VEP's contained four consistent peaks, designated here by polarity and peak latency as: (a) P95, positivity contra-lateral and negativity ipsilateral to the field stimulated; (b) P125, predominantly ipsilateral positivity; (c) N165, predominantly ipsilateral negativity; (d) P225; predominantly midline positivity. Pattern-onset VEPs contained three consistent peaks: (a) P125, mainly contraleteral positivity; (B) N175, mainly contralateral negativity; (c) P225, midline positivity. Distributions of pattern-reversal and pattern-onset peaks resembled one another only for P225, suggesting different cortical representation for the other events of the two kinds of VEP. Bipolar pattern-reversal VEPs were largely contralateral, but unipolar recordings showed that this was due to steeper contralateral potential gradients, as ipislateral activity was widespread. Pattern-onset peaks did not differ in amplitude with respect to the half-field stimulated. Previously reported asymmetries were not confirmed. The P125 and N175 pattern-onset peaks were almost entirely restricted to the contralateral hemisphere, but the distributions by half-field were mirror-images of one another. Half-field pattern-onset stimuli could be used to investigate the responsiveness of each hemisphere, although differential hemispheric involvement was not shown. Several differences in amplitude and distribution resulted from varying the width of the vertical central dark strip.

Adolescent↗
PubMedDate not supplied

'Don't know' responses in elderly demented and depressed patients.

The suggestion that patients having depression with reversible dementia make more "don't know" responses to cognitive questions than do demented patients was tested. Inpatients were administered the Mini-Mental Status Examination (MMSE) on admission and shortly before discharge. Errors and "don't know" responses were recorded. Groups were defined as (1) demented (n = 20; diagnosis of dementia, entrance and exit MMSE less than 24) and (2) depressed with reversible dementia (DRD, n = 11; diagnosis of major depression, entrance MMSE less than 24, exit MMSE greater than 24, delta MMSE greater than 3). Groups differed significantly on MMSE scores and errors, with demented patients scoring lower and making more errors than the DRD group. Groups did not differ significantly in "don't know" responses. Comparisons between groups on sections of the MMSE showed that demented patients scored significantly lower and made more errors than DRD patients only on the orientation section of the MMSE. The results suggest that DRD patients do not make more "don't know" responses than demented patients; however, demented patients make more errors on orientation questions.

Age Factors↗