Cranial trauma

I have had a prospective diving candidate who fell yesterday striking her head and becoming unconscious. She refused hospital treatment . Naturally I refused to conduct the course. If you could advise me as to the requirements necessary before this person can dive. I must point out the accident occurred prior to the commencement of any diving course. I would be grateful for any assistance you can give me to pass on to this individual.

In cases of loss of consciousness caused by cranial trauma - besides the fact that a hospitalization would have been a good thing to do - any post-traumatic complication of a cranial trauma must be excluded.
The exams that should be performed in similar circumstances are normally the following:
Immediate X-ray and, possibly, CAT (Computerize Axial Tomography) scan of the skull, followed by repeated CAT and/or MRI (Magnetic Resonance Imaging) scans during the following days, depending on the clinical evolution.
Electroencephalograms: repeated over the course of some days, depending on the clinical evolution
Careful clinical follow-up to monitor and exclude any neurologically significant complication (headaches, seizures, cranial nerve deficits, etc).
All this may vary significantly, depending on the initial clinical presentation of the case, of the duration of the post-traumatic unconsciousness period, on the possible onset of any complication or sequelae.
The key player in this is a specialist in neurology, who shoul keep the person under clinical observation for the initial 24-48 hour period after the traumatic event and decide for the best course of treatment and further investigation.
I hope this information is useful and please extend my best wishes to your prospective diving course candidate.