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Biomedical subjects

D Elmqvist

Publications and source records attributed to D Elmqvist.

At least 19 recordsLinked to original sources

Sleep and wakefulness after treatment for craniopharyngioma in childhood; influence on the quality and maturation of sleep.

Craniopharyngiomas are situated in immediate vicinity of sleep regulating structures in the basal forebrain area, and the tumor and its treatment might influence the regulation of sleep and wakefulness. In 10 patients treated for craniopharyngioma nighttime sleep quality and daytime vigilance were examined with polygraphic sleep records and multiple sleep latency tests (MSLT). Two girls and 8 boys, 7.1-22.9 years of age, were studied after a follow-up time of 1.5-16.1 years postoperatively. The results were compared to those of 18 normal children. The regulation of the ultradian sleep rhythm was normal but the ability to maintain nighttime sleep was severely disturbed. The patients had an increased number of awakenings and spent long time awake during two recorded nights. Two patients had excessive daytime somnolence during this examination, one after severe sleep disturbance, the other without any known cause. The pattern of sleep and vigilance did not change in puberty in the expected fashion. The disturbances may well have an impact on the psychosocial situation of the patients.

Adolescent

Sleep and wakefulness in preadolescent children with deficits in attention, motor control and perception.

In 10 children with deficits in attention, motor control and perception (DAMP), the relation between daytime vigilance and night-time sleep quality was examined with polygraphic sleep recordings, multiple sleep latency tests and measurements of reaction times. Two girls and eight boys, 6-12 years of age were studied. Eighteen normal children served as controls. Normal sleep regulation and sleep quality was found, but the children with DAMP tolerated the recording procedure less well than the controls. Most patients did not suffer from increased daytime sleepiness, but at MSLT 3, patients had short sleep latencies as in daytime hypersomnolence. Reaction times were significantly longer among the patients than among the controls. It is proposed that the findings may be related to functional changes in the forebrain.

Attention Deficit Disorder with Hyperactivity

Neurophysiologic studies of patients with Crohn's disease on long-term treatment with metronidazole.

Fifty-three patients with Crohn's disease were chosen for this study. They were divided into three groups: the first group (19 patients) was treated with metronidazole and had been receiving the drug for at least 1 year; the second group (13 patients) had previously had the same type of long-term treatment but had been off the drug for at least 3 months before entering the study; the third group (21 patients) had never received treatment with metronidazole. The maximum daily dose of metronidazole used was 800 mg. All patients were examined with a broad set of neurophysiologic investigations devised to reveal signs of peripheral neuropathy. No significant difference was found between the three groups. The conclusion was that a daily dose of metronidazole not exceeding 800 mg is well tolerated by patients with Crohn's disease with regard to objective signs of neurotoxicity. A few patients from all three groups showed a raised perception threshold for changes of temperature in the feet (as compared with the department's normal standard). The results of the test were almost identical in the three groups and thus not connected with the metronidazole treatment. During the study, patients were asked about subjective neurologic symptoms such as tingling and numbness. A few patients from all three groups reported such paresthesias from time to time, but they were of a transient nature, not perpetual, and, in patients taking metronidazole, not aggravated despite continuing treatment with unchanged dose.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult

Effects of single doses of propiomazine, a phenothiazine hypnotic, on sleep and oxygenation in patients with stable chronic obstructive pulmonary disease.

Serious respiratory depression may occur in patients with chronic obstructive pulmonary disease (COPD), receiving hypnotics during acute exacerbations. However, in a previous study on oxygenation during sleep in patients with stable hypoxemic non-hypercapnic COPD, we were unable to demonstrate a significant negative effect from single doses of nitrazepam and flunitrazepam. We have now investigated the effects of propiomazine, a phenothiazine hypnotic, in a double-blind randomized cross-over study of oxygen saturation and apneas during sleep and other sleep variables in 12 non-obese hypoxemic but clinically stable theophylline-treated COPD patients (PaO2 8.1 kPa, PaCO2 5.6 kPa, FEV1 31% of predicted value). None of the respiratory variables were adversely affected by a single oral dose of 25 mg propiomazine, whereas total sleeping time and the sleep efficiency index increased.

Double-Blind Method

Sleep and wakefulness in normal preadolescent children.

Eighteen healthy children, 9 boys and 9 girls, between 8 and 12 years of age were examined with polygraphic sleep records, multiple sleep latency tests (MSLTs), and measurements of reaction times. Sleep was recorded at home on Oxford Medilog 9 channel cassette tape recorders (Oxford Medical Systems, Abingdon, U.K.) and sleep staging was performed from the screen of the display unit. Two consecutive nights were recorded. MSLT was done in the laboratory. The subjects were given 30 min to fall asleep on four occasions during the day after the last recorded night of sleep. Reaction times were measured repeatedly between each MSLT trial. More slow wave sleep was found in this study compared to others. Also, the first night effect was slight. It is proposed that this is due to the fact that the recordings were performed at home. The initial sleep cycle was incomplete in almost all subjects. A sleep stage with traits of both rapid eye movement (REM) and non-REM could be seen in this cycle, probably representing an abortive REM period. MSLT confirmed the low daytime sleepiness in healthy preadolescent children. A sleep latency of 10 min or less on two or more sleep trials, or a daily mean sleep latency of less than 20 min, is rarely seen in this age group. The reaction times were within normal limits for the age of the subjects. Nighttime sleep values, daytime sleep latencies, and reaction times were not correlated in these normal-sleeping children.

Arousal

Delayed decrease in hemispheric cerebral blood flow during Wada test demonstrated by 99mTc-HMPAO single photon emission computer tomography.

We describe how brain regions with a flow (and metabolism) decrease can be visualized after an injection of short-acting barbiturate in one of the internal carotid arteries during a Wada test. An intravenous administration of 99mTc-HMPAO (Ceretec) was used to mark the relative flow distribution. The 99mTc-HMPAO distribution in the brain was recorded three-dimensionally about 1 h later, by means of a single photon emission computer tomograph. We show that the timing of the intravenous 99mTc-HMPAO administration during the Wada test is important for the visualization of the low-flow regions. The administration of the tracer substance should be delayed at least 30 s after the first signs of the barbiturate effect. The rCBF decrease in the barbiturate-injected cerebral hemisphere was associated with a simultaneous decrease in the contralateral, pharmacologically not directly affected, cerebellar hemisphere (crossed cerebellar diaschisis).

Adult

The effects of nitrazepam and flunitrazepam on oxygen desaturation during sleep in patients with stable hypoxemic nonhypercapnic COPD.

Serious respiratory depression has been described in COPD patients receiving hypnotics during acute exacerbations. There are few studies quantifying the effects of hypnotics on oxygenation during sleep in patients with stable hypoxemic COPD. In this study, the effects of single therapeutic doses of nitrazepam and flunitrazepam on SaO2, apneas during sleep and other sleep variables were measured in 14 COPD patients. All patients used theophylline. Sleep-induced decrease in mean SaO2 was 1.3 percent after placebo, 1.4 percent after nitrazepam and 1.9 percent after flunitrazepam (no significant differences). Sleep apneas were not more common or longer after nitrazepam or flunitrazepam, but sleep quality seemed to improve. It is concluded that oxygenation during sleep in these nonobese patients with stable hypoxemic nonhypercapnic COPD, all on maintenance theophylline therapy, was affected very little by single therapeutic doses of nitrazepam or flunitrazepam.

Aged

Automatic versus visual EEG sleep staging in preadolescent children.

Ambulant sleep polygrams were obtained from 14 normal subjects (9 boys and 5 girls) and from 3 boys with attention deficit disorder. The children were aged 8-12 years. Two consecutive nights were recorded with an eight-channel electroencephalographic (EEG) tape cassette recorder. The results were analyzed automatically by the Oxford Medilog 9000 Sleep Stager and by visual scoring from the Medilog Display Unit. Twenty-seven nights were analyzed; 7 nights were excluded because of electrode problems or other technical failures. The main sleep stage shifts and the length of sleep cycles as measured from the hypnogram of the automatic printout agreed well with corresponding values from our visual scoring. In the automatic scoring, rapid eye movement (REM) sleep time was shorter and slow wave sleep was longer than in the visual rating. This can be explained partly by specific properties of the EEG in this age group. The Oxford Medilog 9000 sleep stager can be used to survey sleep quality, but the results must be carefully checked visually. In cases of EEG pathology or sleep abnormalities in childhood it is doubtful if any time or labor is saved by using automatic scoring.

Child

Nocturnal hypoxaemia in severe scoliosis.

The relationship between spirometry and daytime blood gases on the one hand and hypoxaemia during sleep on the other was studied in 13 patients with severe thoracic scoliosis. Eight patients had hypoxaemia (mean Sao2 less than 90%) during sleep. They were characterized by a lower vital capacity (30 versus 50% of predicted, P less than 0.01) and by a greater fall in vital capacity from sitting to supine (26 versus 7% of sitting VC, P less than 0.05). All patients with hypoxaemia during sleep were hypercapnic during the daytime. The fall in Sao2 with sleep was related to the increase in transcutaneous PCO2, indicating hypoventilation as the main mechanism behind hypoxaemia during sleep in scoliosis patients.

Adult

SPECT measurements with 99mTc-HM-PAO in focal epilepsy.

The ability of SPECT measurements with [99mTc]-HM-PAO (Ceretec) to find the location of the epileptic focus was studied in patients under consideration for neurosurgical treatment for therapy-resistant focal epilepsy. The location of low [99mTc]-HM-PAO uptake regions found at interictal measurements, and of high [99mTc]-HM-PAO uptake regions found at ictal measurements, was compared to the findings of extensive ictal and interictal EEG examinations, and to the results of CT and MRT. While EEG revealed focal epileptic activity in all of the 14 patients, SPECT showed regional abnormalities in 13 (93%). CT and MRT showed abnormal findings in 30%.

Adolescent

Risk of seizures after myelography: comparison of iohexol and metrizamide.

A parallel, double-blind, randomized study comparing iohexol and metrizamide--both 180 mg l/ml--in lumbar myelography was carried out in 60 consecutive patients. Eight to 15 ml of contrast medium were administered with the upper level at the middle thoracic column. A detailed neurologic examination was performed before and 24 hr after myelography. EEG recordings--evaluated visually and with fast Fourier transformation analysis--and somatosensory evoked responses were registered before, 6 hr after, and 24 hr after myelography. All patients were observed for adverse reactions for 24-48 hr. Iohexol did not produce any epileptiform activity but epileptiform activity was detected in five patients receiving metrizamide. Iohexol produced significantly less frequent and less severe EEG changes than did metrizamide both at visual evaluation (p less than .0025) and at fast Fourier transformation analysis (p less than .04). No significant changes occurred in the early components of the somatosensory evoked potentials after either contrast medium. Iohexol caused significantly (p less than .002) less frequent and less severe adverse reactions than did metrizamide. The neurologic examination revealed no changes of clinical importance with either contrast agent.

Double-Blind Method

Oxygen desaturation during sleep and exercise in patients with interstitial lung disease.

The relations between mean and maximum fall in arterial oxygen saturation (SaO2) during sleep, hypoxaemia during moderate and maximum exercise, and lung mechanics were studied in 16 patients with interstitial lung disease. Mean and minimum SaO2 during sleep were significantly related to each other and to daytime oxygenation but not to lung mechanics. Although the maximum fall in SaO2 during sleep was similar to the fall during maximum exercise (a level seldom achieved during normal daily activities), profound hypoxaemic episodes during sleep were rare and brief and therefore contributed little to the mean SaO2. The fall in mean SaO2 during sleep was not significant and was considerably less than during moderate exercise (average 0.5 v an estimated 4.5%, p less than 0.05). It is therefore concluded that in patients with interstitial lung disease oxygen desaturation during sleep is mild and less severe than hypoxaemia during exercise.

Humans

Sleep in the surgical intensive care unit: continuous polygraphic recording of sleep in nine patients receiving postoperative care.

Sleep was studied in nine patients for two to four days after major non-cardiac surgery by continuous polygraphic recording of electroencephalogram, electrooculogram, and electromyogram. Presumed optimal conditions for sleep were provided by a concerted effort by staff to offer constant pain relief and reduce environmental disturbance to a minimum. All patients were severely deprived of sleep compared with normal. The mean cumulative sleep time (stage 1 excluded) for the first two nights, daytime sleep included, was less than two hours a night. Stages 3 and 4 and rapid eye movement sleep were severely or completely suppressed. The sustained wakefulness could be attributed to pain and environmental disturbance to only minor degree. Sleep time as estimated by nursing staff was often grossly misjudged and consistently overestimated when compared with the parallel polygraphic recording. The grossly abnormal sleep pattern observed in these patients may suggest some fundamental disarrangement of the sleep-wake regulating mechanism.

Adult

Pressures recorded in ulnar neuropathy.

The pressure between the ulnar nerve and the arcade bridging the two heads of the flexor carpi ulnaris muscle was recorded peroperatively in ten patients with electrophysiologically confirmed ulnar neuropathy at the elbow. At rest, with the elbow extended, pressures ranged from 0 to 19 mm Hg but increased in flexion and during isometric contraction of the flexor carpi ulnaris muscle to maximal values above 200 mm Hg.

Adult

Acetylcholine receptor protein. Neuromuscular transmission in immunized rabbits.

Rabbits injected with purified acetylcholine (ACh) receptor protein produce antibodies against the receptor and develop generalized muscle weakness. The compound muscle action potentials show a decremental fall in amplitude with repetitive nerve stimulation. Both the weakness and the decrement is counteracted by reversible cholinesterase inhibitors. Intracellular recordings from muscle endplates show that the amplitude of the miniature end-plate potentials is considerably reduced. A reduced binding of neurotoxin to muscles from immunized rabbits was observed. Nerve impulses release a normal number of ACh packages (quanta) from the motor nerve terminals. The muscle weakness in immunized rabbits thus has the same features as the muscle weakness in myasthenia gravis and may be a good animal model of myasthenia gravis.

Acetylcholine