Welcome,
From Your query i suspect that you may be suffering from Posterior circulation ischemia.
It is a medical emergency and you need treatment immediately.
You have the symptoms of
1. Severe headache
2. loss of vision
3. hearing loss
4. Numbness on one side of body from face to arm.
5. Change of taste in tongue.
Cause can be atherosclerosis,
connective tissue diseases, dissection and vasculitis.
You need to take the following investigation in addition to CT and MRI
Computed tomography angiography (CTA),
magnetic resonance angiography (MRA)
ultrasound for blood vessels in the brain
complete blood count and blood clotting studies.
ECG and Echocardiogram
Diet changes and medication to lower cholesterol.
Control blood pressure
Blood-thinning medications to lower your risk of stroke, such as aspirin, warfarin or clopidogrel
There is no good
surgical treatment for patients who have narrowing of the vertebrobasilar arteries.
Quit smoking
exercise regularly
Control blood pressure and blood sugar
Follow a healthy diet
Hope this helps.
Take care.
Regards,
Dr.Manjeth