Brain Stroke or MND

Hi,

My grand father is aged 73 years. He is fine till last year but slowly he lost the ability to smell, unable to sense the taste of food, uncontrolled laugh, tears coming up and slowly now he lost ability to speak / couldn't speak. We consulted a couple of neurologists where few of them told that he had storke. Recently we have consulted another neurologist where he told like based on the symptoms it is a MND.

I would like to know the difference between MND and Brain Stroke and what is the exact issue in my grand fathers case.

Below is the medical history of my grand father.
1. Had CABG (Heart Bypass Surgery) 2.5 years back
2. Lost ability smell from last 1 year
3. Unable to sense few tastes for last 6 months
4. Difficulty in eating and swallowing the food and drinking water for last 2 months
5. Uncontrolled laugh and tears from last 6 months
6. Unable to speak for last 2 months.
7. Had sleep disturbances for last two months. however controlled post medications.

Below is the impression identified in the CITI scan

1. MILD ISCHEMIC CHANGES IN BILATERAL PERIVENTRICULAR REGION, CENTRUM SEMIOVALE AND HIGH FRONTOPARIETAL WHITE MATTER, SECONDARY TO SMALL VESSEL DISEASE.
2. DIFFUSE AGE RELATED CEREBRAL ATROPHY
3. NO OBVIOUS ABNORMALITY SEEN IN THE VISUALIZED SECTION OF NASOPHARYNX.

Thanks & Regards,
Venugopal