[Insomnia and hypnotics]. / Insomni og hypnotika.

This article outlines some of the new developments in the field of insomnia. To obtain a better understanding of insomnia and avoid the diversities of impractical diagnosis, the medical profession must universally agree on the classification of insomnia. This knowledge has to be available to all levels of the medical community, especially general practitioners. The article reviews some new data about classification, diagnosis, and treatment of insomnia. It discusses the definition of insomnia and sets up the accepted criteria for the severity of its various forms. The policy of using hypnotics in Norway is fairly restrictive. Only three hypnotics are available, two benzodiazepins (nitrazepam and flunitrazepam) and the newly introduced cyclopyrrolone (zopiclone). The mechanisms of action of various hypnotics on the gamma-aminobutyric acid system are briefly discussed, and guidelines are given for use and choice of hypnotics, their indications and contraindications. In any modern society like Norway, there should be a clear awareness of the impact of insomnia on the quality of life and the seriousness of the effects it can have on the everyday activities of subjects suffering from this disorder.

Computer detection and analysis of periodic movements in sleep.

Standard polysomnography (PSG) and electromyographic (EMG) recording of the right and left anterior tibial muscles by Medilog 9000 recorder was carried out in 10 patients with periodic movements in sleep (PMS). The analog EMG signals and the sleep data from the Oxford ss90III sleep stager were fed into an IBM compatible personal computer for automatic detection and analysis using specific criteria to define the leg events, the interevent interval, the number of epochs (greater than 30 jerks), and the number of bursts (4 to 29 jerks). The results of automatic analysis were compared with data obtained from visually scored paper PSG. The total number of leg jerks detected by visual scoring was 2,812 and by automatic scoring was 2,789. The mean duration of the leg jerks 2.77 s [standard deviation (SD), 1.22] and the mean inter-interval event duration was 27.3 s (SD, 14.7). The total numbers of epochs scored visually was 35 and scored automatically was 33. The correlation co-efficient to the line of identity was 0.8 (p less than 0.005). The sensitivity of automatic scoring was 94% and the specificity was 85%. Automatic detection and analysis of PMS can provide an objective method for the study of several aspects of this disease that are still not yet fully understood.

The treatment of accessory symptoms in narcolepsy: a double-blind cross-over study of a selective serotonin re-uptake inhibitor (femoxetine) versus placebo.

A randomized, double-blind cross-over trial was carried out in 10 patients with narcolepsy to evaluate the effect of 600 mg femoxetine versus placebo. In comparison to placebo, femoxetine treatment resulted in a significant decrease in both the number and severity score of cataplectic attacks per day. There were also significantly fewer attacks of sleep paralysis, whilst the effects on nightmare and hypnogenic hallucinations were minor. The frequency of sleep attacks decreased slightly during femoxetine treatment, but the overall estimated sleep time during the day and excessive daytime sleepiness remained un-affected. An ambulatory sleep recording for 48 h one week after the start of the femoxetine and placebo period showed that femoxetine treatment resulted in a significant decrease in the total time spent in REM sleep. The side-effects of femoxetine were restricted to transient nausea in 2 patients. It is concluded that femoxetine or other selective serotonin reuptake inhibitors may be a useful alternative for narcoleptic patients who experience troublesome side-effects with tricyclic antidepressants.

Two-segment sural nerve conduction measurements in polyneuropathy.

Sensory conduction velocity of the sural nerve was measured in 50 normal subjects and 100 consecutive patients with suspected or established diagnosis of peripheral neuropathy. The sensory action potential was recorded by the orthodromic technique for the distal and the proximal segments. In the patient group, sensory conduction of the proximal segment appeared to be more consistent and easier to carry out as compared to the distal segment. Measurements of the latter segment alone could sometimes be misleading. Some practical points acquired from our experience with this method that allow considerable reduction of the examination time and the patients's discomfort are reported.

Palatal myoclonus during sleep.

Standard polysomnographic recordings were carried out in three patients with verified diagnoses of palatal myoclonus (PM). Findings showed that PM continued during sleep; its frequency and amplitude varied consistently with different sleep stages. Gradual decrease in rate and amplitude, together with amplitude irregularities, occurred as sleep progressed from light to deep non rapid eye movement sleep. The most characteristic change was seen during rapid eye movement sleep. Here the PM occurred in the form of clusters of two to four high-amplitude movements at rather variable intervals.

Acute multiple brachial neuropathy and Ehlers-Danlos syndrome.

Although acute brachial neuritis is a well-known syndrome, factors that contribute to its pathogenesis are not yet understood. Only once before has this syndrome been reported in connection with Ehlers-Danlos syndrome. We describe here a 24-year-old man who suddenly developed acute multiple brachial neuritis of the right shoulder and on neurologic examination showed an associated finding of Ehlers-Danlos syndrome. The latter syndrome was also confirmed in other members of his family. This combination may have been overlooked previously. Mechanical and traumatic factors may play an important role in both pathogenesis and therapy.

The actioculographic monitor of sleep.

The actioculographic monitor (AOGM) is a newly developed, flexible system for sleep recording using three criteria: eye movements, body movements, and submental electromyogram. The signals are recorded on a four-channel Medilog casette tape and displayed by a mingograph at very low speed. The record is then scored after certain criteria for stages wake, nonrapid eye movement, and rapid eye movement sleep. High statistical correlations were obtained when scoring of the AOGM was compared to scoring of standard polygraphic sleep recordings.

Practical application of patterned visual evoked responses in multiple sclerosis.

Pattern reversal visual evoked potentials (VEP) were studied in a control group of 72 subjects and in 60 patients with multiple sclerosis. The recording system consisted of a visual stimulator for pattern production on a commercial TV connected to an EMG machine for displaying and averaging of the response. The normal values of latency, the upper limit of normality and right-left differences in our control group were compared with those given by different authors. Likewise a comparison of the positive VEP results in MS was carried out. The reasons for the variability of results were briefly discussed and the importance of control studies for each laboratory starting VEP recording was stressed. This test can easily be carried out in every clinical neurophysiological laboratory and it provides an excellent and rapid technique for the investigation of patients with suspected multiple sclerosis.

Central effects of the beta-adrenergic blocking agent acebutolol. A quantitative EEG study using normalised slope descriptors.

The effects of acute intravenous injection of acebutolol 25 mg on the EEG were investigated in 5 normal subjects. On-line EEG analysis was carried out by a special purpose mini-computer using normalised slope descriptors (hjorth parameters). No significant changes were found apart from those due to drowsiness in 2 subjects, although minute to minute ECG frequency was significantly lowered (p = 0.031). The EEG, which is considered to be a sensitive tool, failed to show any conclusive evidence of any central action of the drug. The effects of beta-adrenergic blockers on the CNS are not yet fully understood.