Periodic Leg Movements' Diagnosis in Spinal Cord Injury: Actigraphy as an Alternative for Polysomnography?

As secondary objectives, the study aims to: * Estimate positive and negative predictive values; * Identify the diagnostic threshold of PLMs index with actigraphy; * Study concordance between actigraphy and polysomnography to detect lower limbs movements; * Evaluate reproducibility between 2 readers and with the new PLMs software; * Study actigraphy reproducibility for this indication over 3 consecutive nights in the same patients (ancillary study); * Compare diagnostic performance according to SCI completeness (AIS-A vs AIS-B, C, D) and underlying pathology (MS, SCI); * Compare installation and interpretation times between actigraphy and PSG. PLMs appropriate diagnosis appeared mandatory in SCI patients however the accessibility and the delay of availability remain challenging for severe SCI complications in care management. The study team hypothesize that actigraphy could be able to diagnose PLMs with sufficient reliability (AUC (area under the curve) around 80%) compared to the gold standard (polysomnography) in patients with spinal cord injuries. Intervention: During a scheduled night recording (polysomnography) 3 actigraphs will be added (1 on the wrist, and 1 on each foot). Equipment: MotionWatch8®, CamNtech® (marking CE Class 1 device; accord FDA (K132764)). Methods: All consecutive eligible patients followed in our tertiary care center (for whom a full night polysomnography is already scheduled) will be informed of the study and proposed to participate. After signing the informed consent form, all subjects will undergo a full-night examinations: polysomnography (already scheduled in usual care) and actigraphy (addition of 3 devices): * 1 classic actigraph on the wrist to detect light and identify inactivity periods compatible with sleep. * 2 new generation Actiwatch actigraphs (MotionWatch) placed on the feet. Polysomnography will incorporate tibialis anterior EMG recording and will be scored by one sleep specialist following American Academy of Sleep Medicine (AASM) scoring criteria. Actigraphy analysis will be provided by: * An automated software specially developed for this indication (PLMsanalysis software, camNtechR). * A nurse reading unaware of both software's and PSG results. * A second reading will be provided by a second nurse, also unaware of the result of the polysomnography. Actigraphy results will not be communicated to patients or physicians and therefore will not affect patient management. At the end of the evaluation period, each patient will be offered, if needed, treatment and follow-up in the sleep unit as in usual care. A study of actigraphy reproducibility will be carried out in a sample of 33 subjects. This study will take place over three consecutive nights during an already scheduled hospitalization (no additional hospitalization night for patients). Statistical analysis: as described in Outcome Measures.