Response of the autonomic activity to stress provocation in females with cervicogenic headache compared to asymptomatic controls: a cross-sectional study

BACKGROUND: Because abnormal activity of the autonomic nervous system is associated with chronification of pain, early detection of such dysfunction is important. AIM: Although several studies highlight autonomic dysfunction in the chronification of headache, no study discussed its role in episodic cervicogenic headache. DESIGN: Case-controlled cross-sectional single-blind comparative study between women with episodic cervicogenic headache and matched controls. SETTING: Outpatient setting, Hasselt University. POPULATION: Autonomic activity of 17 females with episodic cervicogenic headache (26.6±11.6 years) was compared with 17 age, gender and socio-economic matched asymptomatic controls (26.8±11.9 years). METHODS: Autonomic activity was compared via repeated measures of the activity of the dermal sweat glands (µmho), peripheral circulation (%), electrical activity of the bilateral upper trapezius (μV) before, during and after cognitive stress provocation. RESULTS: Whereas the autonomic parameters of the control group behaved as expected, participants in the headache group showed: 1) to stress provocation a significant lower dermal sweat gland activity (3.03±0.44 vs. 4.19±0.91 µmho, P<0.0001), higher vasodilatation (-5.56±1.45% vs. -5.61±1.85%, P=0.03), lower activity of the left upper trapezius (0.21±0.44 vs. 0.89±0.59 µV, P=0.03), significant less recuperation of the dermal sweat gland activity (-2.57±0.40 vs. -3.29±0.84 µmho, P<0.0001); 2) no recuperation of the activity (μV) of the left (P=0.83) and right (P=0.99) upper trapezius; 3) from stress provocation to recuperation a significant negative correlation (ρ=0.69, P=0.04) between dermal sweat gland and right upper trapezius activity. CONCLUSIONS: Females with episodic cervicogenic headache reacted less to cognitive stress provocation. Recuperation after such provocation was absent. More research is needed to associate autonomous responses with a possible chronification process. CLINICAL REHABILITATION IMPACT: A dysfunctional reaction to cognitive stress could be a threat to allostasis.