Peer-reviewed article
Periodic limb movements during sleep in Lesch-Nyhan syndrome.
Saito Y, Sumitomo N, Saito T, Kimura A, Fukumizu M et al. ·
Summary
Written by AI, not yet AICS's view · claude-haiku-4-5-20251001This is a medical case study describing periodic limb movements during sleep in three children with Lesch-Nyhan syndrome, a rare genetic metabolic disorder. The study used clinical observation and polysomnography to characterize the movement patterns and timing. While it involves children, the document is a clinical investigation of a neurological symptom rather than an evaluation of child well-being or an intervention to improve children's lives.
Key points
- Three children aged 2-7 years with Lesch-Nyhan syndrome showed repetitive limb movements during sleep
- Movements appeared between ages 1-5 years, before self-injurious behaviors emerged
- Polysomnography confirmed movements as periodic limb movements with indices of 6.9-8.8 events per hour
- Authors hypothesize the movements relate to impaired sensory gating from dopaminergic imbalance
Limitations
This is a case study of only three children with a rare genetic disorder, so findings cannot be generalized. The document focuses on describing a neurological phenomenon rather than testing any intervention or assessing outcomes relevant to broader child well-being.
Abstract
Aim To characterize the periodic limb movements during sleep (PLMS) in children with Lesch-Nyhan syndrome (LNS). Methods Three subjects with LNS aged 2 to 7 years were enrolled. PLMS was diagnosed clinically in one patient, and based on polysomnography (PSG) in two. Results Repetitive, clustered movements during sleep, involving upper and lower extremities, were first observed in each child between 1 and 5 years of age, preceding the onset of self-injurious behaviors (SIB) characteristic of LNS. The movement patterns consisted of either flexion, or a combination of flexion and extension, of all four limbs. Duration of muscle contraction ranged from 0.5 to 5 s, with inter-movement intervals generally of 5 to 20 s. PSG qualified these movements as PLMS, by demonstration of four or more movements in clusters, occurring predominantly during N1 sleep stage. The PLMS index was 6.9 and 8.8 events per sleep hour for each patient. Interpretation PLMS may represent impaired spinal sensory gating in LNS, potentially resulting from reduced dopaminergic activity and/or dopamine receptor hypersensitivity. We propose that SIB in LNS constitutes a maladaptive motor response to aberrant sensory processing or dysesthesia, arising from dopaminergic imbalance across cortico-striatal, trigeminal, and spinal gating systems.