Hello,
First and foremost, regular estimation of blood sugar is important as hypoglycemia can lead to dizziness. Also get your blood pressure monitored as orthostatic hypotension due to sudden decrease in systolic BP can also cause dizziness.
Sometimes, there are partial or complete blockages in the arteries that supply the brain with blood. These blockages can cause a temporary loss of blood flow (called transient ischemic attack, or TIA for short), or permanent loss of blood flow (called stroke; also called cerebrovascular accident).This can lead to impaired blood flow through these arteries and so dizziness.
Ear infections and other causes like Meniere’s disease or inner ear diseases can lead to dizziness. If there is any ear pain or tinnitus along with then it may be the possibility.Pls get yourself evaluated for that.
For the numbness,it can be due to diabetes(which your brother already has, hypothyroidism, and hypoparathyroidism, vitamin B12 deficiency or malnutrition and due to some neurological disease.
Get the blood sugar evaluated and an ECG done.CT brain and MRI head also need to be done. The choice of treatment will depend on the diagnosis. I would suggest a neurologist,s evaluation.
Hope it helps.Take care and pls do keep me posted if you have any additional queries.Kind regards.
Has he had a CT scan of his head?