Transcranial Doppler study in patients with cluster headache
Background: Hemodynamic changes occur in the cerebral blood flow during cluster headache.
Objective: The aim of the present work was to study the middle cerebral artery blood flow velocities and vasoreactivity in cluster headache patients as baseline values and after administration of 100% oxygen during the cluster period.
Materials and methods: Three groups were studied. The 1st consisted of 12 patients with cluster headache, the 2nd consisted of 12 patients with unilateral migraine, and the 3rd one was healthy controls. The three groups had baseline velocity measurement of the MCA bilaterally by transcranial Doppler at standard conditions and after inhalation of 100% O2. Then breath-holding was allowed to calculate the breath holding index.
Results: The breath holding index following administration of oxygen (BHI-O2) was higher in the cluster group compared to the migraine group and the difference was statistically significant (t= 2.811 when P = 0.010). There was a statistically significant inverse correlation between the severity of the cluster attacks and the breath holding index (r = 0.750 when P = 0.005).
Conclusion: Cerebral vessels are more reactive to stimuli after O2 inhalation in patients with cluster headache. Cerebrovascular reactivity may be one of the future predictors of good response to O2 therapy in patients with cluster headache.