This article is a transcription of an electronic symposium held on February 5, 2001 by the Brazilian Society of Neuroscience and Behavior (SBNeC) during which eight specialists involved in clinical and experimental research on sleep and dreaming exposed their personal experience and theoretical points of view concerning these highly polemic subjects. Unlike most other bodily functions, sleep and dreaming cannot, so far, be defined in terms of definitive functions that play an ascribable role in maintaining the organism as a whole. Such difficulties appear quite clearly all along the discussions. In this symposium, concepts on sleep function range from a protective behavior to an essential function for maturation of the nervous system. Kleitman's hypothesis [Journal of Nervous and Mental Disease (1974), 159: 293-294] was discussed, according to which the basal state is not the wakeful state but sleep, from which we awake to eat, to protect ourselves, to procreate, etc. Dreams, on the other hand, were widely discussed, being considered either as an important step in consolidation of learning or simply the conscious identification of functional patterns derived from the configuration of released or revoked memorized information.

Seven cases of sexual behavior during sleep (SBS) have been recently reported. The subjects had histories of behavioral parasomnias as well as positive family histories of parasomnia. A 27 year-old man with a history of sexual behavior during sleep was reported. His sleep history disclosed sleepwalking (SW) since 9 years of age. He also developed episodes of highly disruptive and violent nocturnal behavior with dream enactment at age 20 years, which often resulted in physical injuries either to himself or his wife and infant. His wife also reported episodes of amnestic sexual behavior that began 4 years before referral. During the episodes, the patient typically procured his wife, achieving complete sexual intercourse with total amnesia. Physical and neurological diagnostic workups were unremarkable. Family history disclosed sleepwalking in his brother. He was put on 2mg/day of bedtime clonazepam with a remarkable clinical improvement. This case involves either the combination of violent and non-violent sleepwalking with SBS, or the superimposition of presumed REM sleep behavior disorder (RBD) on top of preexisting SW in a man who also developed SBS in adulthood. Thus, this is a case report of probable parasomnia overlap syndrome.

The authors report the case of a 50 year-old hypertensive male patient with a pontine hematoma. The clinical presentation was characterized by pure pyramidal deficit signs (no other signs or symptoms were present). A pure hemiplegia syndrome, although common in supratentorial lesions, is considered to be a rare event in pontine vascular lesions. The pathophysiologic mechanisms of these neurological findings are unclear. The exclusive involvement of the pyramidal tract in this case is likely due to a variation in the vascular anatomy of the pons but, in some cases, a vascular malformation may be the cause.

Rhythmic movement disorder, also known as jactatio capitis nocturna, is an infancy and childhood sleep-related disorder characterized by repetitive movements occurring immediately prior to sleep onset and sustained into light sleep. We report a 19-year-old man with a history of headbanging and repetitive bodyrocking since infancy, occurring on a daily basis at sleep onset. He was born a premature baby but psychomotor milestones were unremarkable. Physical and neurological diagnostic workups were unremarkable. A hospital-based sleep study showed: total sleep time: 178 min; sleep efficiency index 35.8; sleep latency 65 min; REM latency 189 min. There were no respiratory events and head movements occurred at 4/min during wakefulness, stages 1 and 2 NREM sleep. No tonic or phasic electromyographic abnormalities were recorded during REM sleep. A clinical diagnosis of rhythmic movement disorder was performed on the basis of the clinical and sleep studies data. Clonazepam (0.5 mg/day) and midazolam (15 mg/day) yielded no clinical improvement. Imipramine (10 mg/day) produced good clinical outcome. In summary, we report a RMD case with atypical clinical and therapeutical features.

The Epworth Sleepiness Scale (ESS) measures daytime sleepiness in adults. This paper reports the following data in 616 medical students: 1-ESS scores, 2-its correlation with the declared night sleep time, 3-comparison with ESS values obtained from Australia, 4-comparison of ESS values in a sub-population of 111 students tested early and late 1995. There were 387 males, 185 females and 4 not specified. Age = 20.16 +/- 2.23 (SD), ESS score = 10.00 +/- 3.69 (SD), declared sleep time = 7.04 +/- 1.03 (SD). ESS scores did not statistically correlate with sleep time. Average ESS score was statistically higher than in the Australian sample. Retesting of the medical students showed an increase in ESS values from March to November 1995. Sleep time difference was non-significant. Higher ESS scores in this sample seem to be related to shorter sleep time, but fatigue effects can not be ruled out.

Excessive somnolence can be quite a incapacitating manifestation, and is frequently neglected by physicians and patients. This article reviews the determinant factors, the evaluation and quantification of diurnal somnolence, and the description and treatment of the main causes of excessive somnolence.

Dental devices have been employed in the treatment of snoring and obstructive sleep apnea syndrome (OSAS) of mild to moderate degrees. The authors disclose the preliminary results in 8 patients with clinically diagnosed obstructive sleep apnea polisomnographically confirmed and treated with a dental device (Mandibular-Lingual Repositioning Device--MLRD) developed by one of the authors (RCB). Cephalometrics was performed before usage of MLRD, Epworth Sleepiness Scale (ESS) tests were conducted before and after the MLRD and a questionnaire that subjectively qualified the Overall Subjective Improvement of the patient (OSI) was filled out. The tests were repeated 4 weeks after the application of the MLRD. The average subjective overall improvement was 73.75% and the Epworth Sleepiness Scale was 13.88 (pre-MLRD) and 6.63 (post-MLRD) representing a significant statistical variation (p = 0.05). The authors discuss probable factors involved in the improvement of the subjective measurements of excessive sleepiness.

The authors report a 46 year-old female who was submitted to a right femoral artery coronary arteriography. During the procedure she presented an upward, downward and convergence gaze paresis; an upbeating nystagmus. A NMRI showed a change in T-2 weighted signal of the left paramedian mesencephalic region. A diagnosis of stroke was made and dextran 40 was prescribed. Vertical gaze paresis progressively disappeared. Convergence paresis and nystagmus improved partially only. The possible pathophysiological basis underlying this clinical picture are: catheter-induced dislodgement of an atheromatous plaque; small thrombi formation and release from the catheter tip; catheter-induced vascular lesion with subsequent thromboembolism or dissection of the intima; cardiac arrhythmia; catheter-induced or contrast medium-induced arterial spasm; a combination of two or more of these.

The ubiquitousness of normal yawning and the existence of abnormal yawning warrant an understanding of this reflex. Its mechanisms and functional role are not entirely known. A review of the literature reveals that yawning is a brain stem arousal reflex with both peripheral and central loops subserving reversal of brain hypoxia or hypoxemia. Behaviorally, yawning is a semi-involuntary act that occurs also because of loss of interest in the surroundings and it is not necessarily associated with fatigue. Socio-environmental factors can influence the emergence of yawning. Dopaminergic, acetylcholinergic, ACTHergic and oxytocinergic systems are involved in the generation and modulation of yawning in animal experimentation.

A woman with nocturnal eating syndrome responsive to dexfenfluramine (DXF) is reported. Eating consisted of nightly ingestion of large amounts of high-calorie meals and often sloppy meal consumption or preparation. Amnesia for the episodes was total. Anorexigenic medications produced partial control of her daytime carbohydrate craving and no nocturnal eating change. DXF stopped her eating behavior completely. Nocturnal eating herein meets all 4 DSM-III-R diagnostic criteria for binge eating disorder. 5-HT role in neural process controlling sleep-wakefulness (SW) has been widely shown. A 5-HT agonist like DXF could determine changes in the SW processes producing the therapeutic outcome reported herein. However, a specific DXF effect on the behavioral control of carbohydrate ingestion can not be dismissed.