Pallesthesia asymetry : a new way to help diagnose of PLMS

Introduction
Periodic Leg Movements during Sleep (PLMS) is one of the sleep movement disorders that can affect the quality of sleep. Diagnostic is actually based on the association of a complaint regarding limb movements during sleep and detection of a periodic limb activity during polysomnography. But some patients could present limb activity without complaint (no bed partner for example). So clinical diagnostic orientation is difficult.

Objective
The aim of our study is to find some subjective or objective criterias to help clinicians in diagnostic, like snoring, neck circumference, macroglossia or signs of ENT obstruction in Sleep Apnea Syndrome.

Material and Method
Data is from a personal database, collected prospectively during sleep consultation. Stored data contain a systematic clinical examination including deep tendon reflexes, sensitivity with a measurement of vibration sense testing (pallesthesia), and sleep recording and diagnostics.

Pallesthesia is evaluated semi-quantitatively using a tuning fork at the ankles and wrists. The duration of perception of vibrations to the four points is recorded in the database. The barycenter of the four measurements is calculated to assess the homogeneity of the measurements.
Distribution of centroid values is analyzed to determine a threshold value above which it is considered that there is an asymmetry of perception and thus determine both groups.
The groups are compared and determined by Khi2 in groups with a syndrome of periodic movements of sleep.

Results
We found a significant association (p = 0.02) between the presence of an asymmetry of the pallesthesia and the presence of a syndrome of periodic movements during sleep.

Conclusion
Pallesthesia could be a new clinical sign to guide the diagnostic towards PLMS in patients who are consulting for a sleep disorder. This results need to be confirmed.