Other reasons can be cervical spondolysis and vertebrobasilar insufficiency.I feel that MRI neck and MRA(magnetic resonance
angiography) can confirm if there is any compression of the neck veins.
Apart from these,the other causes of lightheadedness are hypoglycemia,orthostatic hypotension,TIA,impending stroke,inner ear diseases,meniere’s disease, endocrine disorders like thyroid, adrenal glands, and pituitary gland disorders and carotid sinus syndrome.