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Biomedical subjects

R Broughton

Publications and source records attributed to R Broughton.

At least 19 recordsLinked to original sources
PubMed1991

Pupillometric assessment of excessive daytime sleepiness in narcolepsy-cataplexy.

Ten untreated patients with narcolepsy-cataplexy and age- and sex-matched normals between the ages of 20 and 71 years underwent pupillometric analyses immediately prior to each of five multiple sleep latency test sessions. Although narcoleptics were sleepier as indicated both by their Stanford Sleepiness Scale ratings and by their latencies to sleep onset, the baseline pupil diameter, pupillary light reflex, and pupillary orienting response did not differentiate between groups. Narcoleptics did, however, exhibit a significantly greater frequency of spontaneous oscillations in the dark-adapted state than did controls. These findings indicate that pupillary stability may serve as a supplementary diagnostic tool for narcolepsy-cataplexy. The results are discussed with the view that psychosensory restoration of alertness, among other extraneous variables, must be controlled when utilizing pupillometric techniques. A review of the literature indicates a variety of methodological and statistical shortcomings that must be amended. Suggestions are made for improving the reliability and validity of the pupillometric approach.

Adult↗
PubMed1991

Motion capture by a frame: global or local processing?

The possibility that frames serve to capture lines within them so that they appear on a coplanar surface was investigated, using coherence in direction of rotary motion (Gillam, 1972) as a quantitative measure of the coplanarity of frame and internal lines. It was found that perceptual coherence between a pair of lines was greatly increased by surrounding them with a frame, if the frame was perspectivally consistent with the lines. A second experiment showed that this grouping can be attributed to a global effect of the frame and cannot be accounted for by local grouping of the internal lines with components of the frame.

Form Perception↗
PubMed1990

Neuropsychological deficits and sleep in myotonic dystrophy.

Eight patients with myotonic dystrophy underwent comprehensive neuropsychological testing and overnight polysomnography to assess whether the waking cognitive impairment might be attributable to sleep structure abnormalities or to sleep-related respiratory problems. Patients showed substantial neuropsychological deficits, fragmented nocturnal sleep and, in half the patients, sleep apnea and/or hypopnea both mainly of central type. There was no statistically significant correlation between the degree of daytime cognitive deficit and the degree of sleep fragmentation or of respiratory problems at night. It was concluded that the neuropsychological deficit in mytonic dystrophy cannot be attributed to a secondary effect of nocturnal sleep apnea or sleep disruption but probably represents a direct effect of CNS lesions.

Adolescent↗
PubMed1990

Triphasic waves in endocarditis.

A 45 year old woman with probable bacterial endocarditis was admitted to hospital having presented with a deteriorating level of consciousness and a febrile illness. Among the numerous investigations she underwent was an EEG which showed classical triphasic waves at the peak of her illness, and which reverted to normal as did the patient after treatment with antibiotics. The association between triphasic waves and bacterial endocarditis has never been previously reported.

Brain↗
PubMed1989

Factors influencing drinking behavior in alcoholic panickers and non-panickers.

Male alcoholics who (a) experienced panic attacks prior to abusing alcohol, (b) experienced panic attacks subsequent to abusing alcohol, and (c) had not experienced panic attacks were compared on three sets of measures: the Panic Attack Questionnaire, the Restrained Drinking Scale, and the Inventory of Drinking Situations. The results showed that two groups of Ss who experienced panic attacks were more likely than non-panickers to use drugs other than alcohol, began drinking at an earlier age, had a greater proportion of parents with panic and alcohol related problems, had higher drinking restraint scores, and drank in more situations. The Ss who experienced panic attacks prior to abusing alcohol were more likely than the other groups to drink in situations similar to those related to agoraphobic fears. It was postulated that alcoholics who experience panic attacks, especially those who experienced panic attacks prior to abusing alcohol may be using alcohol to reduce anxiety or fear related to panic attacks.

Adolescent↗
PubMed1988

Ambulatory 24 hour sleep-wake monitoring in narcolepsy-cataplexy compared to matched controls.

Twenty-four hour ambulatory sleep-wake recordings were made in 10 untreated patients with narcolepsy-cataplexy and 10 matched controls. Nocturnal sleep of narcoleptics was similar to descriptions of laboratory based recordings and was characterized by frequent sleep onset REM periods, high variability of REM latency, increased amounts of wakefulness after sleep onset, and low sleep efficiencies. Daytime portions in narcoleptics showed greater drowsiness and sleep than in controls with significantly higher amounts of stages 1A, 1B, 3, 4 and REM, more sleep episodes longer than 1 and longer than 10 min in duration, and high intersubject variability. On average, only 1.2 daytime sleep episodes began with sleep onset REM periods. There was a strong tendency in both groups towards a long mid-afternoon sleep episode often containing slow wave sleep (SWS) and which was significantly longer in narcoleptics. The mean interval between the onset of nocturnal SWS and the main daytime SWS peak was 14.1 h for narcoleptics and 13.6 h for controls. Daytime waking portions in narcoleptics showed significantly less 'active wakefulness' than in controls. There was no correlation between MSLT measures of sleepiness and amount of daytime sleep in ambulant recordings.

Adult↗
PubMed1988

A comparison of multiple and single sleep latency and cerebral evoked potential (P300) measures in the assessment of excessive daytime sleepiness in narcolepsy-cataplexy.

A direct comparison was made between the amplitude of evoked potential (EP) component P3 (by the P300 paradigm), a known sensitive EP correlate of sleepiness, and sleep latency measures (both to stage 1 or rapid eye movement [REM] and to stage 2 or REM) of the Multiple Sleep Latency Test (MSLT) in 11 untreated narcoleptics and matched controls. Repeated P3 measures were performed immediately prior to standard MSLT naps at 10:00 a.m., 12:00 noon, 2:00 p.m., 4:00 p.m., and 6:00 p.m. Using discriminant analysis and F tests, all three measures (P3 and both by MSLT) were found to distinguish the two groups for collapsed five-nap data, and all showed essentially parallel circadian time-of-day effects, with greatest sleepiness in the midafternoon. The MSLT, however, was somewhat more powerful for collapsed data. Both tests misclassified some subjects as belonging to the other group, with greater misclassification for both tests in the control group and more overall for the P3 measure. Adding the two sleep onset REM period (SOREMP) criteria on MSLT for narcolepsy, one patient was still classified as normal. Analysis of data from individual naps indicated that the MSLT was considerably more powerful in discriminating groups than was P3 amplitude, and it did so for all five naps.

Adult↗
PubMed1986

Excessive daytime sleepiness and the pathophysiology of narcolepsy-cataplexy: a laboratory perspective.

The main disabling symptom of narcolepsy-cataplexy is shown to be the unrelenting excessive daytime sleepiness (EDS) based upon controlled studies of socioeconomic effects and the poor response to treatment. Objective performance deficits mainly involve tests of ability to sustain performance on repetitive boring tasks and are reversible by improved alertness. Physiologically, EDS is seen to represent relatively slow waxing and waning of alertness rather than punctate microsleeps. Evidence is provided for complex cerebral evoked potentials (P300, contingent negative variation) being very sensitive EDS measures comparable to the multiple sleep latency test (MSLT). EDS appears to have qualitatively somewhat different forms mainly reflecting pressure for REM sleep (REM sleepiness) or pressure for NREM sleep (NREM sleepiness), which have different effects on cerebral evoked potentials as well as subjective and objective (MSLT) differences. It is argued that in pathophysiological terms narcolepsy may best be considered a disease of state boundary control.

Cataplexy↗
PubMed1986

Nonconvulsive generalized status epilepticus: clinical features, neuropsychological testing, and long-term follow-up.

We studied 13 episodes of nonconvulsive generalized status epilepticus (NGS) in 10 adults. The syndrome may start in middle or late life and is often mistaken for psychiatric disorders. Some patients have shown good retention of language abilities, except for reduced fluency, despite impairment in other higher functions. In most patients, the syndrome recurs for several years despite anticonvulsant therapy. Transitional cases of NGS with lateralizing EEG features exist, and some cases are probably due to secondary generalization from a temporal or frontal focus.

Adolescent↗
PubMed1985

Excessive fragmentary myoclonus in NREM sleep: a report of 38 cases.

We report 38 consecutive patients referred to a sleep disorder clinic who on diagnostic polysomnography showed excessive amounts of brief fragmentary myoclonus throughout all stages of NREM sleep. Almost all patients were male despite a reasonably equal sex distribution of referral. The phenomenon was found associated with sleep-related respiratory problems, periodic movements in sleep (PMS), narcolepsy, intermittent hypersomnia and (rarely) insomnia. It also occurred associated with excessive daytime sleepiness (EDS) as an isolated polysomnographic finding apart from some degree of sleep fragmentation.

Adult↗
PubMed1985

Does memory impairment exist in narcolepsy-cataplexy?

Approximately one-half of patients with the narcolepsy-cataplexy syndrome suffer from subjective memory problems, mainly involving recent events. Ten untreated narcoleptic patients (7 male, 3 female, aged 28-65 years) with such problems and 10 matched controls were given a battery of tests to study the complaint. Tests included the digit span, Knox cube, recurring figures (verbal and nonverbal), visual reproduction, paired associates learning and logical memory test, plus naming and fluency tests to control for language capabilities. No significant intergroup differences were found. It is concluded that narcoleptics do not have a true organic memory deficit, but rather experience a subjective problem due to drowsiness which they are able to suppress during short testing sessions in a laboratory environment.

Adult↗
PubMed1985

Reappearance of electroencephalogram slow waves in extended sleep with delayed bedtime.

A three-part study using prolonged nights of sleep was undertaken to verify Broughton's hypothesis of an approximate 12-h ultradrian rhythm of human slow wave sleep (SWS). Part I consisted of 2 8-h adaptation nights followed by a prolonged 15-h night of sleep with bedtime at midnight. A significant return of SWS occurred 12 h and 32 min after the first appearance of SWS. In part II, after 1 adaptation night, subjects were asked to sleep for 15 h but bedtime was delayed until 0400 h. A two-peak return of SWS was observed with a first significant return at 1228 h and a second significant return at 1745 h (i.e., 13 h and 32 min after the first appearance of SWS). In part III, bedtime was again delayed to 0400 h; but subjects were given 3 nights to adapt before the 15 h extended sleep. A single significant return of SWS was then observed at 1656 h, i.e., 12 h and 24 min after the first appearance with no peaks around 1200 h, thus exhibiting the same pattern as in part I. These results suggest that the return of SWS seen normally between 1200 and 1500 h is relatively well entrenched since it remained present in the extended night following sudden bedtime delay. It appears, moreover, that SWS does follow a bimodal 12-h rhythm, which is seen immediately upon extended delayed sleep and can be fully phase-shifted with habituation.

Adolescent↗
PubMed1979

The treatment of narcolepsy-cataplexy with nocturnal gamma-hydroxybutyrate.

Sixteen patients with narcolepsy and cataplexy were treated with gamma-hydroxybutyrate (GHB) given at night and tailored to achieve as continuous a night's sleep as possible. The dosage usually consisted of 1.5-2.25 gm orally at bedtime and then one or two further 1.0-1.5 gm doses with awakenings during the night, and totaled about 50 mg/kg. Apart from one patient who took only the bedtime dose, the subjective quality of night sleep improved in all patients and the number of irresistible daytime attacks of sleep and cataplexy substantially diminished. Some residual daytime drowsiness remained and this usually responded well to low doses of methylphenidate. Improvement has been maintained for up to 20 months without the development of tolerance. Two patients experienced adverse side effects necessitating withdrawal of GHB treatment, but no serious toxic effects have occurred.

Adult↗
PubMed1979

A cure for recurrent furunculosis.

A therapy for recurrent boils using antibiotic ointment over the entire integument is described herein. Rather than eradicating the individual nidus of infection, the skin is allowed to muster its own defenses, resulting in fewer, and eventually no, eruptions.

Anti-Bacterial Agents↗
PubMed1978

Sleep patterns in the intensive care unit and on the ward after acute myocardial infarction.

Twelve patients aged 33--70 years (mean 49.5) underwent nightly recordings in the ICU and subsequently on the ward following acute myocardial infarction. Sleep patterns were analyzed according to night after infarct and ICU versus ward environment. Significant differences in nocturnal sleep patterns from matched controls initially after infarction included greater wakefulness, low REM sleep per cent, long REM latency, fewer REM periods, more awakenings, more stage shifts and decreased sleep efficiency. The usual circadian variation in HR was absent, and there was an estimated 8--10 h of unrecorded daytime sleep, which together suggested a quite generalized disruption of biological rhythms. With time, there was loss of daytime sleep, lowered nocturnal wakefulness and increased REM sleep. Slow-wave sleep (sometimes with very long duration delta waves) increased above normal over post-infarction nights 3--9, and sleep was otherwise renormalized by post-infarction night 9. No sudden sleep changes occurred with transfer from ICU to ward. The altered sleep patterns appeared mainly attributable to infarction itself. Twelve nocturnal anginal attacks occurred. Ten began in NREM sleep and two in REM periods without particularly intense phasic activity. Post-infarction nocturnal angina therefore appears to differ in pathogenesis from angina outside this period, which usually occurs in REM sleep. ECG changes could occur during sleep before awakening with pain, and overall decrease in ECG amplitude sometimes accompanied angina. Most attacks (10 of 12) occurred on post-infarction nights 4 and 5, indicating that undetermined that undetermined factors produce a secondary period of heightened risk at that time.

Adult↗
PubMed1978

Effects of sleep deprivation on short duration performance measures compared to the Wilkinson auditory vigilance task.

The effects of one night's total sleep deprivation were examined using the Wilkinson vigilance task and four 10 min duration performance tests. A repeated measures design was used in which eight male subjects experienced one night of sleep loss, the order of sleep loss being balanced across subjects. The four short duration performance tests consisted of choice reaction time, simple reaction time, short-term memory, and a motor task, handwriting. The results confirm the effects of one night's sleep deprivation on the vigilance task and also show that performance on the two reaction time tests was significantly impaired by the loss of sleep, but not at such a high level as for the vigilance. The short-term memory test failed to show any adverse effects of sleep loss and similarly for the handwriting. The experiment shows that two portable and brief (10 min) performance tests are sensitive indices of sleep loss and should be particularly useful for assessing levels of alertness in the field.

Adult↗