I may be going out on a limb here, but...

The heartsink in question was a thirtyish woman, who presented incessantly with headache.

The headache, though not severe, was utterly unremitting. It was generalised and did not fit into any kind of recognisable pattern.

There were no symptoms referable to neck, eyes, sinuses, teeth or jaw, no apparent stressors and no identifiable ergonomic issues.

Examination was unremarkable and imaging equally unrevealing.

Neurological and psychiatric referrals having led to a dead end, the patient was back in the consulting room with my