Symptomatic, Drug-Resistant Narcolepsy Remission After Fenestration of an Arachnoid Cyst - A Case Report.

Objective: The pathogenesis of different narcolepsy phenotypes remains unclear. In rare cases, narcolepsy can be attributable to secondary brain pathologies affecting the midbrain. These cases may elucidate the pathological background and the treatment of narcolepsy, but are often limited by poor objective symptom characterization and effects of therapeutic intervention, especially by modern diagnostic standards. Methods: A young adult presented with excessive daytime sleepiness (EDS) that was refractory to classic narcolepsy medication. Diagnosis of narcolepsy was made based on the pathologically shortened sleep latencies in polysomnography and Multiple Sleep Latency Test (MSLT), together with confirmed sleep-onset REM-sleep (SOREM). Preserved hypocretin levels in cerebrospinal fluid, together with the absence of cataplectic events confirmed the diagnosis of narcolepsy type II. MRI revealed a large arachnoid cyst with compression of the midbrain. Results: Six months after fenestration of the cyst, the patient's EDS had vastly improved. No further SOREM was observed, and polysomnographic and MSLT sleep latencies normalized. No further drug treatment was required. Conclusion: Symptomatic narcolepsy due to space-occupying lesions in the mesencephalon comprises a unique curative treatment option. Here, surgical intervention offers an effective curative therapeutic approach. However, differential diagnosis of symptomatic narcolepsy requires special consideration.

Heart rate variability as a marker and predictor of inflammation, nosocomial infection, and sepsis - A systematic review.

PURPOSE: The autonomic nervous system interacts with the immune system via the inflammatory response. Heart rate variability (HRV), a marker of autonomic activity, is associated with inflammation, and nosocomial infections/sepsis, and has clinical implications for the monitoring of at-risk patients. Due to the vagal tone's influence on anti-inflammatory immune response, this association may predominately be reflected by vagally-mediated HRV indices. However, HRV's predictive significance on inflammation/infection remains unclear. METHODS: 843 studies examining the associations/prognostic value of HRV indices on inflammation, and nosocomial infection/sepsis were screened in this systematic review. According to inclusion and exclusion criteria, 68 associative studies and 14 prediction studies were included. RESULTS: HRV and pro-inflammatory state were consistently associated in healthy subjects and patient groups. Pro-inflammatory state was related to reduced total power HRV including vagally- and non-vagally-mediated HRV indices. Similar, compared to controls, HRV reductions were observed during nosocomial infections/sepsis. Only limited evidence supports the predictive value of HRV in the development of nosocomial infections/sepsis. Reduced very low frequency power HRV showed the highest predictive value in adults, even with different clinical conditions. In neonates, an increased heart rate characteristic score, combining reduced total power HRV, decreased complexity, and vagally-dominated asymmetry, predicted sepsis. CONCLUSIONS: Pro-inflammatory state is related to an overall reduction in HRV rather than a singular reduction in vagally-mediated HRV indices, reflecting the complex autonomic-regulatory changes occurring during inflammation. The potential benefit of using continuous HRV monitoring for detecting nosocomial infection-related states, and the implications for clinical outcome, need further clarification.

The Relationship Between Cognitive Impairments and Sleep Quality Measures in Persistent Insomnia Disorder.

Study Objectives: Persistent insomnia disorder (pID) is linked to neurocognitive decline and increased risk of Alzheimer's Disease (AD) in later life. However, research in this field often utilizes self-reported sleep quality data - which may be biased by sleep misperception - or uses extensive neurocognitive test batteries - which are often not feasible in clinical settings. This study therefore aims to assess whether a simple screening tool could uncover a specific pattern of cognitive changes in pID patients, and whether these relate to objective aspect(s) of sleep quality. Methods: Neurocognitive performance (Montreal Cognitive Assessment; MoCA), anxiety/depression severity, and subjective sleep quality (Pittsburgh Sleep Quality Index: PSQI; Insomnia Severity Index: ISI) data were collected from 22 middle-aged pID patients and 22 good-sleepers. Patients underwent overnight polysomnography. Results: Compared to good-sleepers, patients had lower overall cognitive performance (average: 24.6 versus 26.3 points, Mann-Whitney U = 136.5, p = <0.006), with deficits in clock drawing and verbal abstraction. In patients, poorer overall cognitive performance correlated with reduced subjective sleep quality (PSQI: r(42) = -0.47, p = 0.001; and ISI: r(42) = -0.43, p = 0.004), reduced objective sleep quality (lower sleep efficiency: r(20) = 0.59, p = 0.004 and less REM-sleep: r(20) = 0.52, p = 0.013; and increased sleep latency: r(20) = -0.57, p = 0.005 and time awake: r(20) = -0.59, p = 0.004). Cognitive performance was not related to anxiety/depression scores. Conclusion: Using a simple neurocognitive screening tool, we found that pID patients showed cognitive deficiencies that related to both subjective/self-reported and objective/polysomnographic measures of sleep quality. Furthermore, these cognitive changes resembled those seen in preclinical non-amnestic AD, and thus could indicate incumbent neurodegenerative processes in pID. Interestingly, increased REM-sleep was correlated with better cognitive performance. However, whether REM-sleep is protective against neurodegeneration requires further investigation.

A 37-Year-Old Man With Structural Focal Epilepsy and Paroxysmal Nocturnal Breathing Arrests.

CASE PRESENTATION: A 37-year-old male patient was referred to our sleep laboratory with suspected sleep-disordered breathing. His partner reported periods of breathing arrest accompanied by an odd expiratory noise during sleep, occurring on a near to weekly basis. The patient stated that he was able to sleep well, did not have excessive daytime sleepiness, and was not subjectively aware of any disordered breathing at night. He had a history of structural epilepsy following perinatal trauma, with secondary generalized tonic/clonic seizures, preceded by sensory oral misperceptions. The patient was medicated with phenytoin (100 mg), and reported being seizure-free within the last year. He said that he was otherwise in good health.

Dual Task Effects on Visual Attention Capacity in Normal Aging.

Older adults show higher dual task performance decrements than younger adults. While this is assumed to be related to attentional capacity reductions, the precise affected functions are not specified. Such specification is, however, possible based on the "theory of visual attention" (TVA) which allows for modeling of distinct attentional capacity parameters. Furthermore, it is unclear whether older adults show qualitatively different attentional effects or whether they show the same effects as younger adults experience under more challenging conditions. By varying the complexity of the secondary task, it is possible to address this question. In our study, participants performed a verbal whole report of briefly presented letter arrays. TVA-based fitting of report performance delivered parameters of visual threshold t0, processing speed C, and visual short-term memory (VSTM) storage capacity K. Furthermore, participants performed a concurrent motor task consisting of continuous tapping of a (simple or complex) sequence. Both TVA and tapping tasks were performed under single and dual task conditions. Two groups of 30 younger adults each performed either the simple or complex tapping, and a group of 30 older adults performed the simple tapping condition. In older participants, VSTM storage capacity declined under dual task conditions. While no such effect was found in younger subjects performing the simple tapping sequence under dual task conditions, the younger group performing the complex tapping task under dual task conditions also showed a significant VSTM capacity reduction. Generally, no significant effect on other TVA parameters or on tapping accuracy was found. Comparable goodness-of-fit measures were obtained for the TVA modeling data in single and dual tasks, indicating that tasks were executed in a qualitatively similar, continuous manner, although quantitatively less efficiently under dual- compared to single-task conditions. Taken together, our results show that the age-specific effects of motor-cognitive dual task interference are reflected by a stronger decline of VSTM storage capacity. They support an interpretation of VSTM as central attentional capacity, which is shared across visual uptake and concurrent motor performance. Capacity limits are reached earlier, and already under lower motor task complexity, in older compared to younger adults.