Lateralized nociceptive blink reflex habituation deficit in episodic cluster headache: Correlations with clinical features

Cephalalgia. 2015 Jun;35(7):600-7. doi: 10.1177/0333102414550418. Epub 2014 Sep 16.


Background: We previously observed impaired habituation mechanisms of the conventional blink reflex (BR) in patients with episodic cluster headache (ECH) during the bout, studying only the affected side. Here, we have studied the nociceptive-specific BR (nBR) both on the affected and non-affected sides, and in relation to clinical features.

Participants and methods: We recorded nBR in 18 ECH patients during the bout, and in 18 healthy volunteers (HVs). We compared pain threshold, area, and habituation of the nBR, recorded both for the affected and non-affected sides.

Results: In patients, the pain threshold on the affected side was lower than that of the non-affected side (p = 0.009), and lower than in HVs (p = 0.038). Reflex area was decreased on both sides (p < 0.05) compared with HVs, whereas habituation was significantly impaired only on the affected side (p = 0.025 vs. HVs; p = 0.003 vs. non-affected). The habituation slope was positively correlated with the number of days since the onset of the bout and the daily attack frequency.

Conclusions: Our data reflect lateralized pathological variations in craniofacial nociception in ECH patients over the course of the cluster period. We hypothesized that this is due to malfunctioning of mechanisms that regulate hypothalamic activity and descending aminergic controls.

Keywords: Cluster headache; blink reflex; habituation; lateralization; pain.

MeSH terms

  • Adult
  • Blinking / physiology*
  • Cluster Headache / diagnosis*
  • Cluster Headache / physiopathology
  • Electric Stimulation / adverse effects
  • Female
  • Habituation, Psychophysiologic / physiology*
  • Humans
  • Male
  • Middle Aged
  • Pain Measurement / methods*
  • Pain Threshold / physiology*