Nocturnal vocalization in pure autonomic failure
K. Kashihara, M. Ohno, S. Kawada, T. Imamura
Department of Neurology, Okayama Kyokuto Hospital

Objectives: To evaluate the frequency of sleep-related problems including nocturnal vocalization in patients with pure autonomic failure (PAF).

Background: PAF, as well as idiopathic Parkinson’s disease (IPD) and dementia with Lewy bodies (DLB) have Lewy bodies and Lewy neurites inside nerve cells of the brainstem, limbic area, neocortex, and sympathetic ganglia. These diseases are considered to be three phenotypes of a single disorder. REM sleep behavior disorder (RBD) reportedly can be an indicator of presymptomatic IPD. Vocalization during sleep is frequently observed in patients with RBD.

Methods: We interviewed consecutive patients with PAF, IPD, and caregivers who can tell the sleep status of the patients. Patient/caregiver pairs were assessed for sleep status with the following items: 1. Insomnia, 2. Number of sleep interruptions (more than three times), 3. Daytime somnolence, 4. Nocturnal vocalization, 5. Vivid dreams, 6. Enactment of dreams, and 7. Restless legs syndrome.

Results: Pairs of ten patients (nine men, one woman) with PAF and 169 patients (72 men and 97 women) with IPD could tell the sleep status. The mean age±SD was 73.0±6.4 for PAF and 70.0±9.8 for IPD. Percentages of the sleep-related problems in both diseases are shown in the figure. Nocturnal vocalization was observed frequently in both diseases (80% in PAF and 59% in IPD). Insomnia, sleep interruption, vivid dreams, dream-enactment, and restless legs were also observed to the same extent in both disorders. Daytime somnolence was not observed in PAF, while its frequency was 37% in IPD.

Conclusion: RBD may frequently be complicated in PAF as well as IPD. CNS, at least the brainstem, may be involved in the pathology of PAF.