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Biomedical subjects

R Broughton

Publications and source records attributed to R Broughton.

At least 37 records · Page 2Linked to original sources
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↗
PubMed1984

Fragmentary pathological myoclonus in NREM sleep.

A 42-year-old patient is reported who presented with marked daytime sleepiness and in whom the only major nocturnal polysomnographic abnormality was intense fragmentary (partial) myoclonus occurring with equal frequency in all stages of NREM sleep associated with some degree of sleep fragmentation. The myoclonus was very brief (less than 150 msec duration), aperiodic and recurred in asynchronous and asymmetrical fashion over the legs, arms and face. It appears unrelated to the clinically similar physiological myoclonus of REM sleep. Other main sleep disorders such as periodic movements, restless leg syndrome, sleep apnea and narcolepsy-cataplexy were excluded by history and polysomnography.

Adult↗
PubMed1984

Gustave Flaubert's illness: a case report in evidence against the erroneous notion of psychogenic epilepsy.

The concept of psychogenic epilepsy was recently revived by Sartre (L'Idiot de la Famille, 1971-2) in relation to Gustave Flaubert's epilepsy, which he believed was secondary to hysterical neurosis and not due to a cerebral lesion. A detailed clinical description of Gustave Flaubert's personal and medical history from birth to death is provided. The relationships between his epileptic seizures and both his personal life and the response of others to the attacks are discussed, as is the interaction between seizure occurrence and his literary work and productivity. The various diagnoses made by medical and nonmedical persons during and after Flaubert's lifetime are then reviewed. Particular emphasis is given to Sartre's purely psychogenic interpretation of the seizures, to his total disinterest in their medical aspects, and to the fact that he did not obtain any medical opinions. It is shown that a definitive diagnosis can be made for Flaubert's illness--that of epilepsy associated with a quite normal psychosocial response by current standards. Moreover, the clinical nature of the seizures and other clinical details permit the more specific diagnosis of "complex partial epilepsy of occipital-temporal origin, secondary to lesion of the left posterior hemisphere with occasional secondary generalization of seizures." The concept of the existence of "psychogenic epilepsy" is reaffirmed as erroneous, despite the occasional precipitation of seizures in some individuals by psychological factors. Finally, Gustave Flaubert's case, like Dostoevski's, points to the possible coexistence of a serious and poorly controlled form of epilepsy with true literary genius without the latter being dependent in any way on the former.

Epilepsy↗
PubMed1984

Corticosteroid injections into the hands and feet.

Sixty-four patients who received corticosteroid injections into the hands and feet were followed up for a period of up to three years. Injections offer a safe, popular, limited advance in the treatment of chronic eczema and psoriasis in these areas. The periods of remission varied from a few weeks to several months. The concurrent use of topical treatment was reduced although most patients continued to use them. No subcutaneous atrophy was observed and no serious side effects occurred. Most patients were willing to receive the injections again.

Eczema↗
PubMed1983

The physiological (EEG) nature of drowsiness and its relation to performance deficits in narcoleptics.

Ten narcoleptics off medication were compared to matched controls to determine the pattern and level of electroencephalographic (EEG) vigilance, and its relation to performance ability on the 1 h Wilkinson auditory vigilance task. The narcoleptics performed significantly more poorly and spent significantly less time in wakefulness than controls. The EEG of the patients revealed continual fluctuations between wakefulness, stage 1A (slowed and diffusing alpha) and stage 1B (theta activity). Stage 2 sleep only occurred briefly in 4 patients. Stages 3, 4 and REM sleep were never encountered. Controls were continually awake aside from very brief appearances of stage 1A in 5 subjects. Narcoleptic performance during stages 1B and 2 was characterized by lapses (response omissions). Patients also demonstrated significantly more lapses as well as false positive responses than controls during wakefulness and stage 1A. Poorer performance even during wakefulness was demonstrated to be related to inability to sustain wakefulness over time. The results clarify the temporal pattern of physiological vigilance during performance in narcoleptics and also demonstrate the insufficiency of the lapse-microsleep formulation in explaining performance deterioration in these patients.

Adult↗
PubMed1983

Life effects of narcolepsy: relationships to geographic origin (North American, Asian or European) and to other patient and illness variables.

A recent questionnaire survey of the life-effects of narcolepsy in 180 patients, 60 each from North American, Asian and European populations, compared to similarly distributed age and sex matched controls, documented multiple and marked effects on work, education, driving, accidents, recreation, personality, memory and other parameters. The data have now been further analysed according to the patients' geographic (culturo-genetic) origin and to a number of other patient and illness variables. The three different geographic populations showed few significant differences for the some 160 life-effects items in the questionnaire. This strongly indicates that these are an integral part of the disease or of the human reactions to it. Most of the few significant population differences appeared cultural in origin (e.g., concerning driving records, personality changes), although a few may possibly reflect genetic differences (e.g., visual problems). Analysis of the pooled data according to respondees' age, sex, age at illness onset, duration of illness and treatment led again to relatively few significant findings. It is concluded that, in general, once the disease has been diagnosed, all the major life effects are present and remain so. The results strongly support the contention that most life-effects are not related to the diagnostic 'tetrad' symptoms themselves but rather to excessive daytime sleepiness, the symptoms most resistant to ant-narcoleptic treatment.

Accidents, Traffic↗
PubMed1982

Auditory evoked potentials compared to performance measures and EEG in assessing excessive daytime sleepiness in narcolepsy-cataplexy.

The AEP to the repetitive stimuli of the Wilkinson auditory vigilance task was compared between untreated patients with narcolepsy-cataplexy and matched controls for periods during which the tones were preceded by 13 sec or more of wakefulness (defined by EEG-polygraphic criteria). During these periods it had been found previously that narcoleptics did not perform worse than did controls. The AEP, nevertheless, showed significant differences for narcoleptics. These were similar to changes described for drowsiness in normals. The AEP, therefore, showed changes related to excessive day time drowsines in narcolepsy-cataplexy when a sensitive performane measure and visual analysis of EEG-polygraphic recordings did not.

Adult↗