Serial polysomnography in hypnic headache.
BACKGROUND
Hypnic headache (HH) is a rare primary headache disorder characterized by strictly sleep-related headache attacks. Most patients are over the age of 50 and usually awake at the same time at night with dull bilateral head pain. The pathophysiology of this headache disorder is still enigmatic but association with rapid eye movement (REM) sleep and sleep-disordered breathing (SDB) has been suggested.


METHODS
Six patients with HH according to the current International Classification of Headache Disorders (ICHD-II) criteria (code 4.5) were investigated. Serial polysomnography (PSG) was performed in each patient for four consecutive nights.


RESULTS
A total of 22 HH attacks were recorded from all patients during PSG. Six of the monitored headache attacks arose from REM sleep; 16 attacks, however, arose from different non-REM (NREM) sleep stages. Five patients showed an increased apnoea/hypopnoea index (>5), indicating obstructive sleep apnoea (OSA) on some but not the majority of nights. Headache onset and occurrence of SDB were not temporally connected.


CONCLUSIONS
This prospective study shows that the onset of HH was not associated with sleep stage. These results contradict the current belief that REM sleep and SDB play a crucial role in the pathophysiology of HH.
Holle
Dagny
D
Department of Neurology, University of Duisburg-Essen, Hufelandstrasse 55, Essen, Germany. dagny.holle@uk-essen.de
Wessendorf
Thomas E
TE
Zaremba
Sebastian
S
Naegel
Steffen
S
Diener
Hans-Christoph
HC
Katsarava
Zaza
Z
Gaul
Charly
C
Obermann
Mark
M
D000328:Adult; D000368:Aged; D005260:Female; D051270:Headache Disorders, Primary / Q000503:physiopathology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D017286:Polysomnography; D012894:Sleep Stages / Q000502:physiology*