Biomedical subjects

P Houck

Publications and source records attributed to P Houck.

25 records · Page 2Linked to original sources

PubMed1991

Hypersomnia in bipolar depression: a comparison with narcolepsy using the multiple sleep latency test.

OBJECTIVE: This study characterized objectively the hypersomnia frequently seen in the depressed phase of bipolar affective disorder. On the basis of previous work in sleep and affective disorders, it has been hypothesized that the hypersomnia is related to greater REM sleep. This hypothesis was tested by using a multiple sleep latency test to compare bipolar affective disorder with narcolepsy, a well-defined primary sleep disorder associated with known REM sleep dysfunction. METHOD: Twenty-five bipolar depressed patients were selected on the basis of complaints of hypersomnia. They underwent 2 nights of polysomnography followed by a multiple sleep latency test. Data on their nocturnal sleep and daytime naps were compared with similar data on 23 nondepressed narcoleptic patients referred for sleep evaluation. RESULTS: Despite their complaints of hypersomnia, no abnormalities were noted for the bipolar group in the results from the multiple sleep latency test. Contrary to the working hypothesis, REM sleep was notably absent during daytime naps in the depressed patients, in marked contrast to the findings for the narcoleptic group. CONCLUSIONS: The complaint of sleepiness in the hypersomnic bipolar depressed patient appears to be related to the lack of interest, withdrawal, decreased energy, or psychomotor retardation inherent in the anergic depressed condition, rather than an increase in true sleep propensity or REM sleep propensity.

Adult↗

PubMed1987

Electroencephalographic sleep of healthy children. Part II: Findings using automated delta and REM sleep measurement methods.

Using earlier developed computer-based measurement methods, delta and REM activity were examined during sleep as a function of age, gender, and time of night in 85 healthy, 6- to 16-year-old children. Chronological age was found to account most strongly for differences in automated delta and REM count measures in this age range. Increasing age was shown to be associated with a significant decline in both automated measures, but the effect was much greater for the delta count measure. The age-related decline in delta wave activity was reflected primarily in a linear decline in 2.0-3.0 Hz delta activity, that is, in the faster end of the delta frequency band. Examination of these measurements in successive NREM and REM sleep periods confirmed that, in children as in adults, delta activity decreases and REM activity increases across the night. Findings are discussed relative to those obtained in the same children using standard measurement methods.

Adolescent↗

PubMed1986

Spontaneous hypercalcemia in patients undergoing dialysis. Etiologic and therapeutic considerations.

Ten dialysis-treated patients with hypercalcemia (11.5 +/- 0.3 mg/dl, mean +/- SE) due to renal osteodystrophy were compared with 30 control dialysis-treated patients who were not hypercalcemic (9.5 +/- 0.1 mg/dl). The hypercalcemic patients were more disabled than the control patients. Fifty percent of the hypercalcemic patients and 37 percent of the control patients had a mineralization defect (p greater than 0.6). In the control group, intact parathyroid hormone level was significantly higher in patients with osteitis fibrosa than in those with osteomalacia (247 +/- 39 pg/ml versus 60 +/- 20 pg/ml, respectively, p less than 0.005) whereas in the hypercalcemic patients, parathyroid hormone measurements did not discriminate between these two types of bone disease. Osteomalacia was more severe and bone aluminum staining was stronger in the hypercalcemic patients than in the control patients (2.02 +/- 0.47 versus 0.35 +/- 0.11 mm/mm2 tissue area, p less than 0.001). The mean serum calcium level fell from 11.2 +/- 0.2 mg/dl to 10.5 +/- 0.3 mg/dl (p less than 0.01) in eight hypercalcemic patients treated with 24,25-dihydroxyvitamin D. It is concluded that hypercalcemia in patients undergoing dialysis is associated with an increase in bone aluminum level, and with more severe osteomalacia. Intact parathyroid hormone levels are useful for predicting bone histomorphometric parameters but only when hypercalcemia is not present. The drug, 24,25-dihydroxyvitamin D, was effective in lowering the serum calcium level.

Adolescent↗

PubMedDate not supplied

Panic-agoraphobic spectrum: reliability and validity of assessment instruments.

DSM IV is a simple, reliable diagnostic system with many advantages. However, DSM diagnostic criteria may not provide sufficient characterization of clinically significant symptoms. We have undertaken a project to assess an array (spectrum) of clinical features associated with different DSM Disorders. The purpose of this paper is to report on reliability of assessment instruments for Panic-Agoraphobic Spectrum (PAS), to document convergent validity of PAS symptom groupings, and to confirm the relationship between PAS and DSM IV Panic Disorder (PD). We studied 22 normal controls and 95 outpatients who met criteria for Panic Disorder with and without lifetime Major Depression, and Major Depression or Obsessive Compulsive Disorder without lifetime Panic Disorder. Assessment instruments had excellent reliability and there was good concordance between interview and self-report formats. PAS scores were highest in subjects with PD, followed by outpatients without PD, and were lowest in normal controls. PAS scores varied among PD patients, and a subgroup of patients without PD scored high on PAS. We conclude that PAS can be reliably assessed, and that it describes a valid, coherent constellation of features associated with DSM IV Panic Disorder, but providing additional important clinical information.

Agoraphobia↗

PubMedDate not supplied

Reliability and validity of the Panic Disorder Severity Scale: replication and extension.

UNLABELLED: The Panic Disorder Severity Scale (PDSS) is a recently developed seven-item instrument to rate overall severity of Panic Disorder. The scale has previously shown good psychometric properties in a sample of Panic Disorder patients with no more than mild agoraphobia. The purpose of this paper is to confirm reliability and validity, to provide an estimate of a cut-score discriminating the presence or absence of current DSM-IV Panic Disorder, and to determine the factor structure of the instrument. PROCEDURES: 104 psychiatric outpatients, including 54 with current Panic Disorder, underwent structured diagnostic assessment and the PDSS interview. The PDSS was repeated within 3-17 days. RESULTS: we confirmed reliability and validity of the instrument and found a one-factor solution fit the data. A cut-off score of eight identifies patients with current panic with a sensitivity of 83.3%, and a specificity of 64%. CONCLUSION: the PDSS is a simple, reliable instrument for use in Panic Disorder studies. A cut-score of eight may be useful as a tool to screen patients in settings such as primary care, for diagnosis-level symptoms.

Adolescent↗

PubMedDate not supplied

Symptoms of stress and depression as correlates of sleep in primary insomnia.

OBJECTIVE: Previous studies have not evaluated the clinical correlates of the electroencephalographic spectral profile in patients with insomnia. In the preliminary study described here, we evaluated the extent to which symptoms of stress and depression are associated with subjective sleep complaints and quantitative measures of sleep in individuals with chronic insomnia. METHODS: Subjects were 14 healthy adults who met criteria for primary insomnia as specified in the fourth edition of the Diagnostic and Statistical Manual of Mental Disorders. Measures of stress, depression, and subjective sleep quality were collected before subjects participated in a two-night laboratory sleep series. We hypothesized that elevated symptoms of stress and depression would be associated with subjective sleep complaints and electroencephalographic evidence of hyperarousal during sleep. Hyperarousal during sleep was defined as decreases in delta power and elevations in alpha and beta power throughout non-rapid eye movement sleep, and symptoms of stress were defined as the tendency to experience stress-related intrusive thoughts and the interaction between intrusion tendency and the number of recent stressful events (subjective stress burden). RESULTS: A stronger tendency to experience stress-related intrusive thoughts was associated with greater sleep complaints and a trend toward higher beta power, whereas increases in subjective stress burden were associated with decreases in delta power. In addition, elevations in subclinical symptoms of depression were associated with greater sleep complaints and elevations in alpha power. CONCLUSIONS: Observed relationships among symptoms of stress, depression, subjective sleep complaints, and electroencephalographic power may be relevant to the discrepancy between subjective and objective measures of sleep in patients with insomnia and may be more broadly applicable to sleep complaints in association with stressful life events and major depression.

Adult↗

PubMedDate not supplied

Epidemiologic characteristics of an outbreak of serogroup C meningococcal disease and the public health response.

An outbreak of serogroup C meningococcal disease occurred in six counties in the State of Washington from January 1989 through mid-1991. This report describes epidemiologic data collected from hospitals and health departments, the results of multilocus enzyme electrophoresis of isolates, and the vaccination of high-risk populations in one county. A total of 45 confirmed or probable cases (10 per 100,000 population) occurred. Infants younger than age 1, Hispanics and American Indians, and low-income populations had high attack rates. Nine (20 percent) patients died. The predominant enzyme type, ET-22, had not been detected previously in Washington. More than 22,000 persons were vaccinated in one of the counties. Major challenges to health care personnel included deciding when and where to employ vaccination, obtaining sufficient vaccine, and responding to public anxiety.

Adolescent↗