Previously used terms:
Primary exertional headache; benign exertional headache.
Exercise-induced migraine is coded under 1. Migraine according to its subtype.
Headache precipitated by any form of exercise in the absence of any intracranial disorder.
A. At least two headache episodes fulfilling criteria B and C
B. Brought on by and occurring only during or after strenuous physical exercise
C. Lasting <48 hr
D. Not better accounted for by another ICHD-3 diagnosis.
4.2 Primary exercise headache occurs particularly in hot weather or at high altitude. Subforms such as “weight-lifters” headache are recognized but not individually classified. Unlike 4.1 Primary cough headache, which can be triggered by short-lasting trains of efforts (ie, Valsalva-like manœuvres), 4.2 Primary exercise headache is usually precipitated by sustained physically strenuous exercise.
Headache had a pulsating character in most repondents with exercise headache in the Vågå study (less so among adolescent sufferers, of whom almost half had headache durations of less than five minutes).
There are reports of prevention in some patients by ingestion of ergotamine tartrate. Indomethacin has been found effective in the majority of the cases.
The pathophysiological mechanisms underlying 4.2 Primary exercise headache are unknown. Most investigators believe it is vascular in origin, hypothesizing that venous or arterial distension, secondary to physical exercise, is the pain-inducing mechanism. The recent finding that patients with primary exercise headache have a significantly higher prevalence of internal jugular venous valve incompetence (70% compared with 20% of controls) suggests that intracranial venous congestion caused by retrograde jugular venous flow may play a role in the pathophysiology of this disorder.
Symptomatic cases occur. On first occurrence of headache with these characteristics, it is mandatory to exclude subarachnoid haemorrhage, arterial dissection and reversible cerebral vasoconstriction syndrome (RCVS).