Timing of spontaneous sleep-paralysis episodes

Frequency and Factors of Sleep Paralysis Among Medical Students of Karachi

INTRODUCTION

Sleep paralysis is a prevalent phenomenon characterized by suffocation, immobility, and hallucinations. Its causes remain unknown, although the neurotransmitter imbalance is suggested as a potential factor. This condition is closely associated with hallucinations and a sense of intrusion, often observed in patients with narcolepsy, hypertension, and seizures.

METHODS

A cross-sectional study was conducted in various medical colleges in Karachi, involving 297 participants aged 18 to 30 years. The participants were divided into groups based on gender and year of study. They were surveyed about the frequency of sleep paralysis episodes, their beliefs about the phenomenon, sleep routines, and academic impacts.

RESULTS

Among the respondents, a significant number of females (n=209, 70.3%) reported experiencing sleep paralysis. The overall mean age was 20±2.0 years. Correlation analysis revealed an insignificant relationship between depression and mental anxiety (p=0.147). Similarly, no significant association was found when comparing the occurrence of sleep paralysis (p=0.16). However, a notable finding was the significant link between sleep paralysis and its impact on academics (p=0.043).

CONCLUSION

This study highlighted the frequency of sleep paralysis among medical students, particularly among females. Furthermore, it emphasizes the diverse beliefs held by individuals regarding these frightening episodes. To address this neglected issue, it is essential to conduct awareness sessions aimed at understanding and alleviating sleep paralysis in individuals' lives.

Prevalence and Clinical Picture of Sleep Paralysis in a Polish Student Sample

Sleep paralysis (SP) is a psychobiological phenomenon caused by temporary desynchrony in the architecture of rapid eye movement (REM) sleep. It affects approximately 7.6% of the general population during their lifetime. The aim of this study was to assess (1) the prevalence of SP among Polish students in Lublin (n = 439) using self-reported online surveys, (2) the frequency of SP-related somatic and psychopathologic symptoms, and (3) the factors potentially affecting the occurrence of symptoms among people experiencing SP. We found that the incidence of SP in the Polish student population was slightly higher (32%) than the average prevalence found in other student populations (28.3%). The SP clinical picture was dominated by somatic symptomatology: 94% of respondents reported somatic symptoms (most commonly tachycardia, 76%), 93% reported fear (most commonly fear of death, 46%), and 66% reported hallucinations (most commonly visual hallucinations, 37%). The number of SP episodes was related to sleep duration and supine position during sleep. The severity of somatic symptoms correlated with lifestyle variables and anxiety symptomatology. Our study shows that a significant proportion of students experience recurrent SP and that this phenomenon is associated with fear and physical discomfort. The scale of the phenomenon requires a deeper analysis.

The occurrence and predictive factors of sleep paralysis in university students

The aim of the present study was to assess the occurrence and predictive factors of sleep paralysis (SP) in Czech university students. Our sample included 606 students who had experienced at least one episode of SP. The participants completed an online battery of questionnaires involving questionnaires focused on describing their sleep habits and SP episodes, the 18-item Boundary Questionnaire (BQ-18), the Modified Tellegen Absorption Scale (MODTAS), the Dissociative Experience Scale Taxon, the Beck Depression Inventory II and the State-Trait Anxiety Inventory. The strongest predictive factor for the frequency of SP episodes was nightmares. The strongest predictive factor for the intensity of fear was dream occurrences. In our study sample, SP was more common in women than in men. Those who scored higher in BQ-18 experienced more often pleasant episodes of SP and those who scored higher in MODTAS were more likely to experience SP accompanied with hallucinations. While 62% of respondents answered that their SP was accompanied by intense fear, 16% reported that they experienced pleasant feelings during SP episodes. We suggest that not only the known rapid eye movement sleep dysregulation but also some personality variables may contribute to the characteristics of SP.

Nocturnal aspects of narcolepsy with cataplexy

Even though the most impressive manifestation of narcolepsy is excessive sleepiness, paradoxically a significant number of patients have trouble sleeping at night. A wide array of alterations can affect the night-time sleep of a narcoleptic patient, and the aim of this review is to increase awareness on this issue, thereby enhancing the care of narcoleptic patients by more specific approaches to their disturbed night sleep. This review covers a broad variety of nocturnal sleep features in narcolepsy. Starting from animal models and the clinical features of patients, the paper then discusses the many comorbid conditions found in narcolepsy at night, the most advanced methods of analysis and the few recent advances in the specific treatment of night sleep in narcoleptic patients.

Paranoid delusions and threatening hallucinations: a prospective study of sleep paralysis experiences

Previously we reported a three-factor structure for hallucinations accompanying sleep paralysis (SP). These earlier analyses were, however, based on retrospective accounts. In a prospective study, 383 individuals reported individual episodes online providing further evidence for the three-factor structure as well as clearer conceptually meaningful relations among factors than retrospective studies. In addition, reports of individual episodes permitted a more fine-grained analysis of the internal structure of factors to assess predictions based on the hypothesis that a sensed or felt presence (FP) is a core experience affecting other SP hallucinations. Results were generally consistent with this hypothesis. In particular, associations among, and temporal stability of, sensory hallucinations were largely explained by their common association with FP. The findings are consistent with REM initiation of a threat activated vigilance system with pervasive effects on the SP experience and suggest a potential model for the thematic organization of nightmares and dreams more generally.

Mental representation of space: Insights from an oblique distribution of hallucinations

Three-dimensional spatial distributions of hypnagogic and hypnopompic hallucinations associated with sleep paralysis were used to investigate the internal representation of space. Left-right asymmetries in human preferences and abilities are well established. Parallel effects are also observed as lower-upper asymmetries. These parallels could reflect common underlying mechanisms or additive effects of independently evolved horizontal and vertical asymmetries. This study adds to the growing literature on multidimensional spatial biases in a context free from the influence of task-related factors. We present evidence of an oblique bias in the projection of both sensory and motor hallucinations toward lower-left and especially upper-right external space exceeding that accounted for by an additive model of separate horizontal and vertical biases. These observations are consistent with theories regarding a systematic functional relation of hemispheric with ventral and dorsal cerebral organization.

Parasomnias

Parasomnias are undesirable behaviors that arise from sleep but are not fully under voluntary control. Parasomnias are grouped broadly according to whether they arise from non-rapid eye movement (NREM) or rapid eye movement (REM) sleep. NREM parasomnias are disorders of arousal that occur along a continuum of behavioral, affective, and autonomic activation. REM-related parasomnias include REM sleep behavior disorder, sleep paralysis, and nightmare disorder. Parasomnias can often be managed successfully using behavioral and pharmacologic therapies.