[Sudden severe headache not always harmless: thunderclap headache as a result of reversible cerebral vasoconstriction].

BACKGROUND

Thunderclap headache may be a symptom of a severe underlying disorder.

CASE DESCRIPTION: A 41-year-old man had recurrent episodes of thunderclap headache triggered by Valsalva-like manoeuvres. His medical history reported cannabis exposure. Angiography showed segmental vasoconstriction of cerebral arteries. He stopped using cannabis and tried to avoid intracranial pressure increasing activities. 3 months later he was no longer experiencing any symptoms and the vascular anomalies had clearly improved. We concluded that reversible cerebral vasoconstriction syndrome (RCVS) was the underlying cause of the thunderclap headache.

CONCLUSION

In contrast with primary thunderclap headache and primary headache due to sex, cough and exertion, RCVS is not harmless, since the characteristic cerebral vasoconstriction can lead to life-threatening neurologic complications. The increasing quality of diagnostic imaging techniques will probably lead to such primary headaches being diagnosed less frequently and, more specifically, to more frequent diagnosis of severe underlying pathology. Because of the differences in prognosis and treatment, proper diagnostic imaging should be performed in all patients with thunderclap headache.