Thanks for the question.
First of all mild cerebellar atrophy may not produce any symptoms. If it produces symptoms then the symptoms will depend upon whether the whole cerebellum is affected or only part of it is affected etc. If the whole cerebellum is involved then we may see diffuse cerebellar manifestations like all four limb ataxia (incoordination), speech difficulties (dysarthria), truncal ataxia (difficulty in controlling the trunk of the body) etc. If only one side of the cerebellum is involved then the manifestations will be in the limbs on the same side. One sided lesions too can produce speech difficulties. When cerebellum is involved some patients also experience vertigo (spinning type dizziness), nausea, rarely vomiting etc.
If hyper intensity is seen in the right superior cerebellar artery territory then the above mentioned cerebellar manifestations are seen, mainly involving the right limbs and in addition to that if the artery was occluded at its origin then there may be involvement of the brain stem too so patient can experience motor and sensory symptoms too (like muscle weakness, numbness, tingling sensation etc).
Encephalomalacia in the superior aspect of cerebellar hemisphere indicates an old pathology or lesion. It may be secondary to one of the following usually (all the below mentioned examples are old lesions, nothing recent or acute);
Old Head injury
Prior brain surgery
Prior brain infections etc
If T2 hyper intensity signal abnormalities are present in the cerebral white matter in the middle & old aged people generally they do not cause any symptoms. These spots are generally due to high blood pressure, diabetes, high cholesterol, smoking etc, and if any of these risk factors exist then treating them, and quitting smoking will help in preventing formation new spots in the brain. If no such risk factors are present then it is attributed to age related changes.
Please ask if there are any further questions.