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Biomedical subjects

L Baer

Publications and source records attributed to L Baer.

At least 73 records · Page 4Linked to original sources
PubMed1995

Abnormal excitatory neurotransmitter metabolism in schizophrenic brains.

BACKGROUND: Schizophrenia has been hypothesized to be caused by a hypofunction of glutamatergic neurons. Findings of reduced concentrations of glutamate in the cerebrospinal fluid of patients with schizophrenia and the ability of glutamate-receptor antagonists to cause psychotic symptoms lend support to this hypothesis. N-acetylaspartylglutamate (NAAG), a neuropeptide that is highly concentrated in glutamatergic neurons, antagonizes the effects of glutamate at N-methyl-D-aspartate receptors. Moreover, NAAG is cleaved to glutamate and N-acetylaspartate by a specific peptidase, N-acetyl-alpha-linked acidic dipeptidase (NAALADase). To test the glutamatergic hypothesis of schizophrenia, we studied the NAAG-related glutamatergic variables in postmortem brains from patients with schizophrenia, neuroleptic-treated controls, and normal individuals, with particular emphasis on the prefrontal cortex and hippocampus. METHOD: Different regions of frozen brain tissue from three different groups (patients with schizophrenia, neuroleptic-treated controls, and normal controls) were assayed to determine levels of NAAG, N-acetylaspartate, NAALADase, and several amino acids, including aspartate and glutamate. RESULTS: Our study demonstrates alterations in brain levels of aspartate, glutamate, and NAAG and in NAALADase activity. Levels of NAAG were increased and NAALADase activity and glutamate levels were decreased in the schizophrenic brains. Notably, the changes in NAAG level and NAALADase activity in schizophrenic brains were more selective than those for aspartate and glutamate. In neuroleptic-treated control brains, levels of aspartate, glutamate, and glycine were found to be increased. CONCLUSIONS: The changes in levels of aspartate, glutamate, NAAG, and NAALADase are prominent in the prefrontal and hippocampal regions, where previous neuropathological studies of schizophrenic brains demonstrate consistent changes. These findings support the hypothesis that schizophrenia results from a hypofunction of certain glutamatergic neuronal systems. They also suggest that the therapeutic efficacy of neuroleptics may be related to increased glutamatergic activity.

Adult↗
PubMed1995

The Massachusetts General Hospital (MGH) Hairpulling Scale: 1. development and factor analyses.

We developed the MGH Hairpulling Scale to provide a brief, self-report instrument for assessing repetitive hairpulling. Seven individual items, rated for severity from 0 to 4, assess urges to pull, actual pulling, perceived control, and associated distress. We administered the scale to 119 consecutive patients with chronic hairpulling. Statistical analyses indicate that the seven items form a homogenous scale for the measurement of severity in this disorder.

Adult↗
PubMed1995

Pilot studies of telemedicine for patients with obsessive-compulsive disorder.

OBJECTIVE: Remote video psychiatric assessment holds promise for providing expert consultation to underserved areas. The authors assessed the reliability of rating scales administered in person and over video to patients with obsessive-compulsive disorder. METHOD: Rating scales for obsessive-compulsive, depressive, and anxiety symptoms were administered in person (N = 16) and by means of narrow-bandwidth video transmission over one digital telephone line (N = 10). Interrater reliability was determined for each condition; for the video interviews one rater sat at the local site in front of the videoconsulting apparatus and asked the questions, and the patient and the second rater sat at the remote site. RESULTS: Reliability was excellent in both conditions, and there was no degradation in reliability when the assessment was conducted over video. CONCLUSIONS: Telemedicine resulted in near-perfect interrater agreement on rating scale scores. Its use for other disorders and for more in-depth assessments should be explored.

Anxiety Disorders↗
PubMed1995

Long-term outcome of state hospital patients discharged into structured community residential settings.

OBJECTIVE: This longitudinal study examined various dimensions of the lives of patients with chronic mental illness immediately before and again several years after their discharge from a state hospital into well-staffed structured community residential settings. METHODS: Fifty-three patients with chronic mental illness and long histories of hospitalization were evaluated shortly before their state hospital discharge using a comprehensive structured assessment of nine dimensions of functioning and symptomatology. A follow-up assessment was undertaken a mean of 7.5 years after discharge into four structured group home settings. RESULTS: At follow-up, 57 percent of the patients continued to live in structured community residential settings, 28 percent had moved on to independent living, and 16 percent had returned to an institutional setting. Fifty-five percent needed hospital readmission, but the total sample spent only 11 percent of the time after discharge in the hospital. At follow-up, patients showed significant improvements in cognitive and social functioning, and 94 percent expressed a preference for life in the community. CONCLUSIONS: Many patients discharged to structured community residential settings seem to prefer them to the state hospital, are able to graduate to independent settings, and show improvement in important dimensions of functioning after several years in the community. Other dimensions seem resistant to change despite the structure and support afforded by residential settings.

Activities of Daily Living↗
PubMed1995

Phenomenology of intentional repetitive behaviors in obsessive-compulsive disorder and Tourette's disorder.

BACKGROUND: Recent evidence suggests that obsessive-compulsive disorder (OCD) and Tourette's disorder are related and have overlapping clinical features. The purpose of this study was to test the following hypotheses regarding intentional repetitive behaviors in these two disorders: (1) In OCD without comorbid Tourette's, they are preceded by cognitive phenomena and autonomic anxiety, but not sensory phenomena, and (2) in Tourette's without comorbid OCD, they are preceded by sensory phenomena, but not cognitive phenomena nor autonomic anxiety. METHOD: Fifteen adult OCD outpatients without tics and 17 adult Tourette's outpatients without OCD were evaluated with a structured interview. Questions assessed cognitive, sensory, and affective experiences related to intentional repetitive behaviors. RESULTS: Five of 17 Tourette's subjects were excluded because they had only unintentional or occasionally intentional tics. All OCD patients reported some cognitions preceding their intentional repetitive behaviors, whereas only 2 of 12 Tourette's patients reported cognitions. In comparison, all Tourette's patients reported sensory phenomena preceding repetitive behaviors, and none of the OCD patients reported such sensations. In addition, 13 OCD patients reported at least mild autonomic anxiety associated with their repetitive behaviors, whereas no Tourette's patients reported such symptoms. CONCLUSION: Intentional repetitive behaviors in OCD differ from those in Tourette's and are associated with cognitive and autonomic phenomena. Sensory phenomena preceded intentional repetitive behaviors in Tourette's but not in OCD patients. The dimensions examined in this study (cognition, sensory phenomena, and autonomic anxiety) may represent valid clinical factors for characterization of repetitive behaviors in OCD and Tourette's.

Adult↗
PubMed1994

Low-level sensory processing in obsessive-compulsive disorder: an evoked potential study.

This study used visual and auditory evoked potentials (VEP and AEP) to study low-level sensory processing in a group of 15 unmedicated subjects with obsessive-compulsive disorder (OCD) and 30 age-matched, gender-matched, and handedness-matched normal controls. EPs were recorded to flash (VEP) and binaural click (AEP) stimulation. OCD subjects were found to have significantly shorter latencies on N1 and P2 of the AEP, and no differences were found in the VEP. Results indicate abnormal information processing states in OCD during low-level auditory processing, but not during low-level visual processing. Neural generators of the VEP and AEP are briefly reviewed and results are discussed in relation to current neurobiological models of OCD.

Acoustic Stimulation↗
PubMed1994

Regional cerebral blood flow measured during symptom provocation in obsessive-compulsive disorder using oxygen 15-labeled carbon dioxide and positron emission tomography.

BACKGROUND: The study was designed to determine the mediating neuroanatomy of obsessive-compulsive disorder (OCD). METHODS: The short half-life tracer oxygen 15-labeled carbon dioxide was used to allow for repeated positron emission tomographic determinations of regional cerebral blood flow on each of eight patients with OCD during a resting and a provoked (symptomatic) state. RESULTS: Individually tailored provocative stimuli were successful in provoking OCD symptoms, in comparison with paired innocuous stimuli, as measured by self-report on OCD analogue scales (P = .002). Omnibus subtraction images demonstrated a statistically significant increase in relative regional cerebral blood flow during the OCD symptomatic state vs the resting state in right caudate nucleus (P < .006), left anterior cingulate cortex (P < .045), and bilateral orbitofrontal cortex (P < .008); increases in the left thalamus approached but did not reach statistical significance (P = .07). CONCLUSIONS: These findings are consistent with results of previous functional neuroimaging studies and contemporary neurocircuitry models of OCD. The data further implicate orbitofrontal cortex, caudate nucleus, and anterior cingulate cortex in the pathophysiology of OCD and in mediating OCD symptoms.

Adult↗
PubMed1994

Dissociation, childhood trauma, and the response to fluoxetine in bulimic patients.

Histories of childhood trauma have been reported previously in bulimic subjects but no study to date has assessed how these experiences may affect response to fluoxetine. Thirty outpatient subjects in a placebo-controlled trial of 60 mg of fluoxetine for the treatment of bulimia nervosa completed the Dissociative Experiences Scale and a self-report instrument assessing trauma. Response to treatment was measured with the Hamilton Depression Scale-17 (HAMD-17), the CGI, the PGI, and the change in number of binges per day. Subjects taking fluoxetine with histories of physical abuse showed a significantly greater drop in HAMD-17 scores than those without such histories. No relationship between a reported history of abuse and the response of binging to fluoxetine was found. A history of abuse does not appear to predict the response of binging to fluoxetine but may predict a greater response of nonspecific symptoms like depression.

Adolescent↗
PubMed1994

Psychiatric manifestations of systemic lupus erythematosus: clinical features, symptoms, and signs of central nervous system activity in 43 patients.

Forty-three female inpatients with active systemic lupus erythematosus (SLE) were studied by a multidisciplinary team to answer the following research questions: 1) What are the features of the psychopathology in patients with active SLE? and 2) In these patients, what is the relationship between psychiatric disorders and symptoms and signs suggesting activity of SLE in the CNS? Our a priori hypothesis was that, in patients with active SLE, those with psychiatric manifestations would have more symptoms and signs of CNS activity than those without psychiatric manifestations. Psychiatric evaluation consisted of standardized psychiatric instruments and diagnostic criteria. The assessment of SLE systemic and central nervous system (CNS) activity consisted of rheumatologic, neurologic, and ophthalmologic evaluations; serum and cerebral spinal fluid (CSF) analysis; brain computerized tomography (CT); and electroencephalogram (EEG). Twenty-seven patients (63%) presented psychiatric symptoms (Psychiatric Group), and 16 (37%) patients presented no current psychiatric diagnosis (Nonpsychiatric Group). These groups were compared in terms of the above variables. Depressive syndrome was the most frequent diagnosis (44%) followed by delirium (7%) and dementia (5%). Psychiatric symptoms were associated with subjective cognitive impairment (85%) and neurologic abnormality (85%). Widened cortical sulci was the most frequent CT alteration and was equally common in both groups. No statistical difference was found between the 2 groups regarding their general clinical evaluation, serum and CSF exams, or EEG alterations. To determine whether the severity of psychiatric symptoms was related to CNS activity, we divided the 27 patients with psychiatric manifestations into 2 groups: the Major Group--18 patients with major psychopathology, and the Minor Group--9 patients with mild depressive syndromes.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Long-term follow-up of 85 patients with obsessive-compulsive disorder.

In this study, long-term outcome for patients with obsessive-compulsive disorder treated with serotonin reuptake inhibitor medications was examined. The records of 85 patients who had first been evaluated at least 1 year previously (the mean follow-up period was 773 days) were reviewed. Information was collected on age at onset of symptoms, time since first evaluation, and scores on several scales measuring symptom severity, including the Yale-Brown Obsessive Compulsive Scale. Comparison of these baseline data with Yale-Brown scale scores at the most recent follow-up visit showed that 74 (87%) of the patients had responded to treatment. No predictors of improvement were found.

Adult↗
PubMed1994

Obsessive-compulsive disorder with and without a chronic tic disorder. A comparison of symptoms in 70 patients.

The phenomenological features of 35 obsessive-compulsive disorder (OCD) patients with a lifetime history of tics were compared to 35 age- and sex-matched OCD patients without tics. Seven categories of obsessions and nine categories of compulsions were determined using the symptom checklist of the Yale-Brown Obsessive-Compulsive Scale (YBOCS). Discriminant function analysis revealed that, compared to their counterparts without tics, OCD patients with tics had more touching, tapping, rubbing, blinking and staring rituals, and fewer cleaning rituals, but did not differ on obsessions. These preliminary findings suggest that the types of compulsions present may help to discriminate between two putative subgroups of OCD, i.e. those with and without tics.

Adult↗
PubMed1994

Can patients with obsessive-compulsive disorder discriminate between percepts and mental images? A signal detection analysis.

Signal detection analysis was used to test three hypotheses for repetitive thoughts and behaviors characteristic of obsessive-compulsive disorder (OCD). Patients might have (a) low sensitivity for the difference between having seen something or having imagined seeing it, (b) a high criterion for this discrimination, or (c) difficulty associating context with information in memory. Subjects judged viewed words or imagined words and later indicated which were actually seen. Patients with OCD discriminated seen from imaged words significantly better than normal control subjects, as evidenced by higher d' scores on a recognition memory task. Groups did not differ in response criterion, beta, used to decide whether words had been seen or imaged. Implications for the study of OCD from an information-processing perspective are discussed.

Adolescent↗
PubMed1994

Aberrant snacking patterns and eating disorders in patients with obsessive compulsive disorder.

BACKGROUND: Appetitive symptoms, particularly carbohydrate craving, have been shown to occur in patients whose conditions responded to treatment with drugs that enhance serotonin-mediated neurotransmission. This suggested that patients with obsessive compulsive disorder (OCD) who also frequently respond to serotonergic drugs also might have similar distributions of appetitive and eating patterns. METHOD: A survey study of 170 OCD patients and 920 controls was conducted using a questionnaire that inquired about snacking behavior, including food preference, mood changes after eating, and previous diagnosis of eating disorders. The frequency responses in the two groups were tested for statistical significance. RESULTS: Significant differences were found between the OCD and control groups with respect to the reported incidence of eating disorders, snacking patterns, and mood response to food. CONCLUSION: This finding of different snacking patterns in OCD mirrors that found in other disorders that have been shown to be responsive to serotonergic drugs. The high incidence of carbohydrate snacking among OCD patients compared with the control group provides additional evidence that brain serotonin may be involved in this disorder.

Adult↗