REM sleep disorder common in PD patients
MedWire News: Nearly half of patients with Parkinson's disease (PD) have rapid eye movement (REM) sleep behavior disorder (RBD), shows a large study.
Data on the 457 patients in the study were drawn from a prospective database of all patients examined in a single hospital's sleep laboratory since 2005. Video-supported polysomnography revealed RBD in 46% of these patients.
The presence of RBD was not associated with PD subtype (tremor-predominant or postural instability/gait disorder), nor did it relate to gender.
However, RBD was more common in patients with more severe PD symptoms. Patients with RBD had a longer duration of symptoms than those without, at 8.7 versus 7.3 years, as well as a more advanced Hoehn & Yahr stage, at 3.2 versus 2.9. They also had more falls and fluctuations.
"Our findings suggest a more advanced stage of neurodegeneration in patients with PD and RBD," Friederike Sixel-Döring (Paracelsus-Elena-Klinik, Kassel, Germany) and colleagues comment in the journal Neurology.
Patients with RBD were taking a higher average levadopa dose than those without, at 733 versus 640 mg/day. They had significantly more hallucinations or psychosis, but most of these were attributed to the effects of medication.
Sleep parameters in PD patients with RBD differed from those without; they spent a significantly greater proportion of total sleep time in the REM stage, at 18% versus 14%, and had higher sleep efficiency, at 68% versus 65% of time in bed.
Patients with RBD also had a significantly increased index of periodic leg movements per hour of sleep, at 35 versus 22.
In an accompanying editorial, Carlos Schenck (University of Minnesota Medical School, Minneapolis, USA) and Bradley Boeve (Mayo Clinic, Rochester, Minnesota) described the study as a "landmark."
They said that the finding "alerts clinicians managing patients with PD about RBD, particularly since there is increased risk for recurrent injury or death."
The editorialists explained that "victim vulnerability factors" in RBD, "such as bleeding disorder, anticoagulant therapy, or osteoporosis, can increase the risk for injury to the patient or bed partner, which should indicate the need for prompt therapy of RBD, even in mild cases."
However, they noted that RBD occurred despite high levodopa doses in many patients, and recommended clonazepam or melatonin as treatments for RBD in PD patients.
By Eleanor McDermid