Polysomnography and Other Sleep Testing

Multiple methods are available for evaluating sleep concerns: clinical screening instruments, sleep diaries, polysomnography with multiple sleep latency test and maintenance of wakefulness test, and actigraphy. This chapter reviews the tools used to assess patients with sleep concerns. Screening tools such as questionnaires are used to stratify patients on the basis of their clinical characteristics and risk factors for sleep difficulties. Patients at high risk may need urgent polysomnography or further treatment.

P003 The impact of forced wake from overnight polysomnography on multiple sleep latency test results

Introduction The multiple sleep latency test (MSLT) is used to diagnose disorders of hypersomnolence. Although internationally-recognised protocols do not stipulate whether patients should be woken from the preceding overnight polysomnography (PSG), many labs wake their patients for logistic reasons. This study analyses the impact on PSG and MSLT parameters of forced wake (FW) from the overnight PSG compared with unrestricted sleep (US). Methods 400 consecutive patients (FW=200; US=200) undergoing PSG/MSLT were included and the following parameters were compared: Epworth Sleepiness Scale (ESS), Morningness-Eveningness Questionnaire score (MEQ), PSG total sleep time (TST), wake-up time from the PSG, overall MSLT sleep latency (MSL), individual nap latencies (SLNap 1–4), number of MSLT naps with sleep-onset REM periods (#SOREMP), and percentage of MSLTs with overall MSL<8 minutes (%MSLT<8). Results The 2 groups were well-matched for ESS and MEQ. The FW group had more males (49% vs 39%). When compared to FW, patients with US had longer TST (+38 minutes; p=<0.0001), later wake-up time (+52 minutes; p<0.0001), longer MSL (+1.9 minutes; p=0.0049), 50% fewer #SOREMP (p=0.0224), and 16% fewer %MSLT<8 (p=0.0018). SLNap1 increased by 1.5 minutes (p=0.0623), SLNap2 increased by 2.0 minutes (p=0.0067), SLNap3 increased by 0.75minutes (p=0.0533) and SLNap4 increased by 2.5 minutes (p=0.0059). Discussion Allowing patients to have unrestricted sleep on the night prior to the MSLT resulted in significantly longer TST, longer sleep latencies during the MSLT, fewer SOREMP and fewer tests with MSL<8 minutes. International protocols should stipulate unrestricted sleep on the PSG prior to the MSLT to improve diagnostic accuracy.

Compromised Dynamic Cerebral Autoregulation in Patients With Central Disorders of Hypersomnolence

Objective: We aimed to investigate the dynamic cerebral autoregulation (dCA) in patients with central disorders of hypersomnolence during wakefulness.Methods: Thirty-six patients with central disorders of hypersomnolence were divided into three groups according to polysomnography and multiple sleep latency test results: the idiopathic hypersomnia group (IH), narcolepsy type 1 without rapid-eye-movement sleep behavior disorder group (NT1-RBD), and narcolepsy type 1 with rapid-eye-movement sleep behavior disorder group (NT1 + RBD), with 12 patients in each group. Twelve sex- and age-matched healthy controls were recruited. We assessed the Epworth sleepiness scale (ESS) and dCA of all subjects. dCA was assessed by analyzing the phase difference (PD) using transfer function analysis. The ESS and dCA were analyzed before and after standardized treatment in 24 patients with narcolepsy type 1.Results: The overall PD of the IH, NT1-RBD, and NT1 + RBD groups were lower than that of the control group (P < 0.001). There were no significant differences between the overall PD of the NT1-RBD and NT1 + RBD group (P > 0.05). The ESS scores decreased and the overall PD increased after treatment in 24 patients with narcolepsy type 1 (P < 0.001). Multivariable analysis showed that mean sleep latency in multiple sleep latency test was independently associated with impaired overall PD (P < 0.05).Conclusions: The dCA is impaired in patients with central disorders of hypersomnolence. The impairment of dCA occurs irrespective of NT1-RBD/+RBD. The ESS score and dCA improved in patients with narcolepsy type 1 after medication treatment. The mean sleep latency in multiple sleep latency test was independently associated with impaired dCA.Clinical Trial Registration:www.ClinicalTrials.gov, identifier: NCT02752139.