Hello and thank you for your question.
Based on your MRI report you likely have white matter diseases which can be due age, if you have history of diabetes, cholesterol or high blood pressure and as it is periventricular it can also suggest demyelinating diseases like MS.
As it is non specific so it is hard to say what is the cause. Your doctor may order MRI with contrast to evaluate if this lesions are getting enhanced or not for ruling out MS.
Please get back to me if you have any further questions. Thank you.
Periventricular white matter is in form a lesions.