Establishment of a Sleep and Sleep-disorder Research Cohort in Patients With Neurological Disorders

Total sleep time is defined as the total amount of time spent asleep during the overnight polysomnography recording, expressed in minutes.

Wake after sleep onset is defined as the total duration of wakefulness after sleep onset and before final awakening during the overnight polysomnography recording, expressed in minutes.

Sleep onset latency is defined as the time from lights off to the first epoch of sleep during overnight polysomnography.

The number of arousal events is defined as the total number of arousals occurring during the overnight polysomnography recording.

Rapid eye movement sleep onset latency is defined as the interval between sleep onset and the first occurrence of rapid eye movement sleep during the overnight polysomnography recording, expressed in minutes.

Non-rapid eye movement (NREM) sleep stages 1, 2, and 3, and rapid eye movement (REM) sleep time are defined as the total duration spent in each sleep stage during overnight polysomnography, expressed in minutes.

The number of awakenings related to respiratory events is defined as the total count of awakenings temporally associated with respiratory events during overnight polysomnography.

The number of respiratory events is defined as the total count of apnea and hypopnea events identified during overnight polysomnography.

The number of respiratory events is defined as the total count of respiratory events identified during overnight polysomnography.

Sleep period heart rate is defined as the average heart rate measured during the sleep period as recorded by overnight polysomnography.

The number of rapid eye movement sleep without atonia events is defined as the total count of rapid eye movement sleep epochs exhibiting increased muscle activity during overnight polysomnography.

Hypoxic burden is a quantitative measure of the cumulative severity of nocturnal hypoxemia, calculated from overnight polysomnography. It represents the total area under the curve of oxygen desaturation events, integrating both the depth and duration of oxygen desaturation across the entire sleep period.

The total score ranges from 0 to 28, and a higher score indicates higher levels of insomnia severity. A score of 8 or greater is the cut point for clinically possible insomnia.

The total score ranges from 0 to 56, and a higher score indicates higher levels of anxiety symptoms. A score of 7 or greater is the cut point for clinically possible anxiety.

The total score ranges from 0 to 52, and a higher score indicates higher levels of depression symptoms. A score of 7 or greater is the cut point for clinically possible depression symptom

The total score ranges from 0 to 30, with higher scores indicating better global cognitive function. A score below 26 is commonly used as the cut-off for cognitive impairment.

Plasma corticotropin-releasing factor concentration was measured as a biomarker of hypothalamic-pituitary adrenal axis activity. Higher levels indicate increased neuroendocrine stress response. Unit of Measure: pg/mL.

Plasma cortisol concentration was assessed as an indicator of hypothalamic-pituitary-adrenal axis function. Higher levels reflect increased physiological stress response. Unit of Measure: μg/dL.

Serum interleukin-6 concentration was measured as a marker of systemic inflammation. Higher levels indicate greater inflammatory activity. Unit of Measure: pg/mL.

Serum brain-derived neurotrophic factor concentration was measured as a biomarker associated with neuroplasticity and neuronal function. Higher levels indicate enhanced neurotrophic activity. Unit of Measure: pg/mL.

Gray matter volume was derived from T1-weighted structural MRI using voxel-based morphometry, reflecting regional brain tissue volume.

Cortical thickness was quantified from T1-weighted MRI as the distance between the white matter and pial surfaces, reflecting cortical integrity.

Hippocampal volume was extracted from T1-weighted MRI using automated segmentation and normalized for intracranial volume.

Functional connectivity was assessed by calculating temporal correlations of blood-oxygen-level-dependent signals between predefined brain regions during rest.

Amplitude of low-frequency fluctuation reflects the amplitude of spontaneous low-frequency BOLD signal oscillations, indicating regional intrinsic neural activity.

Regional homogeneity was calculated to assess the similarity of the time series of a given voxel with its neighboring voxels, reflecting local synchronization of brain activity.

The global blood-oxygen-level-dependent signal represents the average blood-oxygen-level-dependent signal across the whole brain, reflecting the overall amplitude and synchronization of brain activity.

Fractional anisotropy reflects the degree of directional water diffusion and was used to assess white matter microstructural integrity.

Mean diffusivity quantifies the overall magnitude of water diffusion and reflects microstructural tissue changes.

Cerebrospinal fluid flow dynamics were assessed using MRI-based methods to characterize CSF motion and pulsatility.

Dynamic cerebral autoregulation was assessed using the phase difference between cerebral blood flow velocity and arterial blood pressure fluctuations. Larger phase differences indicate better autoregulatory function.

Gain represents the magnitude of cerebral blood flow velocity changes in response to blood pressure fluctuations, with lower gain values indicating more effective autoregulation.