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Biomedical subjects

J J Askenasy

Publications and source records attributed to J J Askenasy.

At least 19 recordsLinked to original sources
PubMed1992

About the mechanism of hiccup.

Every new empiric observation made over two millenia fueled the dispute as to whether hiccup (Hc) is a digestive or a respiratory reflex. A review of the literature, focusing attention on the probable mechanism of Hc, shows Hc as a neurogenic dysfunction of the 'valve function' between the inspiratory complex and the glottis closure complex.

Glottis↗
PubMed1990

Different laws govern motor activity in sleep than in wakefulness.

A wide range of elementary and complex motor activities are known to occur during sleep, but very little is known about the basic physiologic condition of the skeletal muscle during sleep. The present study provides evidence that a minute electric random activity constitutes the basic physiologic condition of the skeletal muscles during sleep. During the NonREM stages of each sleep cycle a regression of the continuous random minute activity occurs, followed by a sudden increase of the isolated motor unit action potentials during REM sleep. Particular structural features of the anterior tibial (AT) muscle make it the most active skeletal muscle during sleep. During wakefulness, at rest, the random muscle activity disappears.

Adult↗
PubMed1990

Juvenile Parkinson's disease and its response to L-dopa therapy.

Four youngsters, between the ages of 13-27 years, presented dystonic foot. Two to three years following the appearance of the dystonic foot, cogwheel rigidity and tremor appeared on the dystonic foot side. Treatment with low doses of levodopa/carbidopa consistently reversed the symptoms. "On-off" phenomena appeared in the first years of treatment and persisted for the entire period of 5 to 15 years of illness. No parkinsonian signs were present when the dystonic foot appeared. Based on our observations and on a review of the literature, we conclude that responsiveness to low doses of L-dopa is the major marker of juvenile Parkinson's disease.

Adolescent↗
PubMed1989

Is yawning an arousal defense reflex?

Despite the fact that yawning is a reality of everyday life, its study is not included in the curriculum of medical schools, and most medical textbooks barely mention its existence. Two factors may help to explain this puzzling situation: (a) yawning's borderline position between psychology and neurology, and (b) researchers' lack of understanding as to why people yawn. After review of the literature and personal observation, it is concluded that yawning is a complex arousal defense reflex located in the reticular brainstem with a peripheral and central arche, whose aim is to reverse brain hypoxia. Yawning occurs with loss of interest (boredom) and may or may not be associated with fatigue. By reversing drowsiness, yawning avoids a decreased concentration capacity resulting from borderline hypoxia. It is hoped that this article will stimulate further research on the phenomenon.

Arousal↗
PubMed1989

Association of intracerebral bone fragments and epilepsy in missile head injuries.

Twenty young adults sustained missile injuries in the Lebanese war. They underwent repeated clinical electroencephalographical (EEG), computerised tomography scanning (CT-scan) and polysomnographic (PSG) examinations during a 6-year period. All the patients were young adult males with an average age of 23, previously healthy according to their army profiles. Three of 20 developed between 3 to 14 months following injury generalised tonic-clonic convulsions. The unique common epileptogenic feature characterising the 3 epileptics was the presence of bone fragments in lacerated brain tissue. The possible causal relationship between the presence of the bone fragments and epileptogenesis is discussed.

Adult↗
PubMed1989

Sleep tonus inversion: a feature of juvenile dystonic parkinsonism.

Polysomnographic monitoring of a 16-year-old girl suffering from dopa-responsive dystonic parkinsonism showed a change in the distribution of muscle activity in thigh muscles during different stages of sleep. The hamstring muscles were hypertonic at sleep onset compared with the vastus lateralis of the quadriceps muscles. At the third sleep cycle of each of the 2 nights, the time at which sleep benefit becomes clinically evident, the hypertonia in the hamstring muscles was reversed and the vastus lateralis became more hypertonic. It is suggested that the muscle tonus inversion marks the moment at which the sleep process alleviates the dystonic parkinsonian state manifested at wakefulness as a circardian fluctuation. According to our data, the flexor-extensor tonus inversion during sleep was not yet described in the literature, and may be an associated feature of dopa-responsive dystonic parkinsonism.

Adolescent↗
PubMed1988

Is monoamine oxidase inhibitor induced myoclonus serotoninergically mediated?

In the present study a single case observation of myoclonus during sleep-wave transition was monitored in a depressed patient treated with the monoamine oxidase inhibitor, phenelzine. The myoclonus had a rhythm of 1 c/second and lasted for two years, the duration of phenelzine treatment. Myoclonus appeared neither during wakefulness nor during sleep, but at wake-sleep-wake transitions. This "switch" myoclonus was associated with phasic muscle hyperactivity during REM sleep. Methysergide a 5-HT suppressor, decreased the switch myoclonus frequency and the REM muscle hyperactivity, indicating serotoninergic involvement in the mechanism of phenelzine induced myoclonus.

Humans↗
PubMed1988

Sleep hiccup.

The present study is the first to prove the presence of hiccup during sleep polygraphically. Hiccup (Hc) penetrates all sleep stages; in REM sleep, it becomes randomized. The amplitude and frequency of sleep Hc have stage-dependent characteristics, and a linear regression appears with every sleep cycle. Sleep Hc may alternate, but does not coexist with, periodic leg movements. Related to inspiration, sleep Hc presents a right deviation when compared with wake Hc. The sleep pattern in persistent sleep Hc is disturbed in a nonspecific manner. Sleep Hc is not associated with sleep apnea. Sleep synchronizes the breathing rate with the hiccupping rate. During light sleep, the Hc rate exceeds the breathing rate, whereas during deep sleep, the breathing rate exceeds the Hc rate.

Adult↗
PubMed1988

Isolated phasic discharges in anterior tibial muscle: a stable feature of paradoxical sleep.

Phasic muscle discharges known currently as "fasciculations" are more frequently encountered in the limb skeletal muscles and predominate in the lower limbs when compared with the upper limbs. Of the lower limbs, the most active during paradoxical sleep (PS) is the anterior tibial muscle. When quantifying phasic discharges of the eyes versus a lower limb muscle during PS, the former are 14 times more frequent than the latter. During PS there is a sporadic and nonsignificant decrease in the tonus of the antigravitational extensor muscles. Isolated phasic discharges in anterior tibial muscles are a stable feature of PS.

Adult↗
PubMed1988

Postradiation segmental myoclonus selectively inhibited by REM sleep (sleep-wake myoclonus).

A 46-year-old male patient was irradiated following left orchiectomy for seminoma. Three months after radiation, segmental myoclonus appeared involving all skeletal muscle groups up to the level of D10, the area of radiation. Urodynamic testing showed the presence of segmental myoclonus in the urethral sphincter. An around-the-clock 'continuous segmental myoclonus' during sleep and wakefulness with a frequency of 1 c/s and an amplitude of 400 microV selectively inhibited by REM sleep was not found in the literature. This continuous segmental myoclonus caused by a radiation myelopathy at D10-D11 was followed up for 2 years. It was partially controlled by carbamazepine.

Carbamazepine↗
PubMed1988

Sleep apnea as a feature of bulbar stroke.

Medullary disorders can be associated with a sleep apnea syndrome. The present patient developed a sleep apnea syndrome with approximately 25 episodes of apnea or hypopnea during each hour of sleep following a lateral medullary infarction. The presence of predisposing factors and involvement of respiratory centers in the area of the medullary lesion may determine the appearance of sleep apnea with brainstem infarction. Investigation of breathing during sleep may be helpful in such cases.

Cerebrovascular Disorders↗