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Biomedical subjects

V Krynicki

Publications and source records attributed to V Krynicki.

6 recordsLinked to original sources
PubMed1978

Discriminant analysis of EEG in children with situational, learning and impulse disorders.

Neurological and EEG findings were studied in 113 children diagnosed as adjustment reaction, behavior disorder, and minimal brain dysfunction (MBD). The MBD patients were subdivided into MBD behavior and MBD learning groups, thus yielding four patient groups in all. The presence of soft neurological signs and abnormal EEG examinations increased in stepwise fashion from the adjustment reaction group to the behavior disorder group, to the MBD behavior group, to the MBD learning group. The EEG records were rated on 16 variables, including amounts and frequencies of a variety of normal EEG features as well as abnormal features. The EEG ratings were then subject to a discriminant analysis. Three discriminant functions were found to be necessary to describe the relation of the four groups. The functions were identified as cortical maturity, cortical abnormality, and cortical reactivity. This implies that the groups do not just differ along one dimension, but along three dimensions. The discriminant program correctly classified 53% of the patients.

Attention Deficit Disorder with Hyperactivity↗
PubMed1977

Effect of methylphenidate on sleep stages and ultradian rhythms in hyperactive children.

The effect of methylphenidate on sleep pattern was assessed in four hyperactive children. Two nights of sleep were recorded before drug administration, sleep was again recorded on the 1st and 21st nights during drug administration, and also on the 1st and 2nd nights of drug withdrawal. All patients showed behavioral improvement during drug administration; however, no drug effect was seen when standard sleep variables such as sleep stages and sleep time were examined. This analysis was supplemented by an examination of the REM cycle and computer extraction of the delta cycle; both are ultradian (40 to 140 minutes) rhythms. These rhythms were found to be intact in hyperactive patients. Although the REM cycle was not affected by drug administration or withdrawal, a trend toward lengthening of the delta cycle was found on drug withdrawal.

Child↗
PubMed1976

The temporal and periodic organization of REM eye movements in mental retardation.

Time trends and periodic cycles in REM sleep eye movements were examined in 6 functional and 6 mongoloid adolescent retardates. Both groups of subjects showed approximately equal percentages of linear trends, quadratic trends, linear and quadratic trends, and absence of trend. The eye movement time-series were subject to an orthogonal spectral analysis. In both groups of subjects, peak spectral estimates generally occurred at 10.6- or 21.3-min periods. Following this, the eye movements of the longest REM periods (and one long period of pre-sleep wakefulness) were subject to a least-squares spectral analysis. This analysis yielded estimates ranging from 22 to 44 min. Eye movements lacked the ultradian organization previously reported for eye movements of normal subjects. These results imply that the ultradian organization of REM sleep and the ultradian organization of eye movements may be independent.

Adolescent↗
PubMed1975

Time trends and periodic cycles in REM sleep eye movements.

Eye movements during REM sleep episodes were tabulated in 16 young adults. REM episodes were then broken down into four ranges according to length in min: (1) 11.0-21.3; (2) 21.7-29.7; (3) 30.0-42.3; (4) 42.7 or longer. These data were then analyzed for linear and quadratic trends. Eight episodes had a significant linear trend, 10 had a significant quadratic trend, 7 had both linear and quadratic trends, while 12 had no trend. The residuals from the best-fitting polynomial curve were then subject to a spectral analysis. In addition, 2 long periods of pre-sleep wakefulness (approximately 2 h each) were also analyzed. In general, the spectral analysis revealed the dominant presence of a slow cycle (period of 10 min to about 30 min) the exact period of which varied according to the length of the REM episode. A binomial probability test indicated that the presence of slow cycles was significant in REM episodes except for those in the 21-30 min range. For the episodes of wakefulness, a dominant slow cycle was found in both cases. The results give the impression of similarity in the periodic organization of eye movements during REM sleep and waking. The data also indicated that an ultradian (70-150 min) cycle was present in eye movements during sleep and waking. Further, the finding of a decrease in eye movements before sleep onset, coupled with previous reports of an increase in eye movement after sleep onset, indicate the presence of a circadian cycle.

Adolescent↗