After going through your case,
I want to know about
1) Presence of Diabetes, high blood pressure
, cholesterol problem, heart disease. Current medication going on if any.
2) Habits like smoking, alcohol.
3) Any recent illness like loose motions, vomiting, excessive sweating
, high grade fever.
4) Any ear problem (pain, decreased hearing, tinnitus- abnormal sound in ear), throat problem.
6) Are symptoms increases after sudden neck movements.
I would like to suggest following test for your father-
1) ECG electrocardiogram.
2) Holter's monitoring, electrophysiological study of heart.
3) 2DEcho (echocardiography)
4) Complete blood count
, hemoglobin, kidney function test, thyroid function test.
5) Blood pressure check in supine position and In standing position to know postural hypotension
6) If all these tests are normal then there may be need of MRI brain with angiography and carotid artery doppler.
In yourcase there may be possibility of
1) Cardiac arrhythmia
(abnormal electrical activity of heart) - it may be a caused by decreased blood supply to heart (vessel blockage) or metabolic abnormalities (abnormalities of kidney or liver function)
2) Postural hypotension which is more likely in your case.
3) Problems related to blood supply of brain.