Diurnal variation of physiological rhythms in a patient with sleepwalking

The association between sleepwalking, a non-rapid-eye-movement parasomnia, and biological rhythms has not been subject of research in the past, although shift work is a known risk factor of the disorder. We present the case of a 36-year-old policeman who suffered for years from sleepwalking and was referred to the hospital for polysomnography. All standard investigations including multiple sleep latency or maintenance wakeful test were normal. On the contrary, chronobiological assessment revealed phase delay of vital functions and body temperature, whereas acrophases of melatonin and cortisol remained stable. We postulate an increase in sleep fragmentation due to shift work, but further research is needed to substantiate the hypothesis.