What Causes Speech Issues In An Elderly Person?

Brief Answer:
Suspect primary progressive aphasia

Detailed Answer:
I read your query carefully and I appreciate your efforts to explain the case in a detailed way by touching on several cognitive functions.

Regarding the MRI I don't see any major change to explain his symptoms, there is no marked atrophy inappropriate for his age. That doesn't exclude early stages of dementia though.

The discrepancy in the MMSE scores is puzzling, of course examination anxiety does play a role but the difference is too much. I am inclined to believe the score is somewhere in between. Since you say he has problems subtracting 50-7, then the 28 score is suspicious given the fact that serial subtraction of seven carries 5 points in the MMSE test. However since you say he's on top of his bills I guess some of that function is retained.

You should know that while Alzheimer's is the most common type of dementia there are also other type of dementias where memory is not the first to be affected.
Also apart from the MRI some other tests should be done, like blood glucose, kidney and liver function tests, electrolytes, Vitamin B12 levels, thyroid function tests. Perhaps they have been done already but I thought I'd make sure.

Also I am assuming a neurological exam for other neurological signs like for example parkinsonism has been done.

If all those showed nothing remarkable then the one diagnosis which could present with isolated language involvement is a neurodegenerative disorder called Primary Progressive Aphasia. It is a rare disorder and its diagnosis especially in the early stages is difficult not only where you live but in any country. Any initial language aspect can initially be involved, but most commonly it's word finding and naming impairment. Tests like MMSE are not adequate, usually it's evaluated by special tests for aphasia like XXXXXXX Diagnostic Aphasia Examination, Western Aphasia Battery, F-A-S test of fluency etc. These are tests performed by specialized neuropsychologists, not by any neurologist.
There are no specific lab tests, at times EEG or PET-SPECT can show asymmetry due to lower metabolism in left hemisphere which deals with language, but not routine examinations and do not exclude the diagnoses especially at these early stages.
As I said it's a difficult diagnosis to be made right-away, often follow-up in time is needed for the evaluation because at early stages not all features are present, so you have to be patient.

Another reason to be evaluated could be an anxiety issue or also depression, although it would have other signs as well, so less likely.

I hope to have been of help.

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Brief Answer:
It is a subtype of frontotemporal dementia

Detailed Answer:
What pulls him away from having Alzheimer's is the fact that you say that he has no visible memory loss. As I said if having language problems MMSE result is not very reliable, MMSE is more of a screening than a diagnostic test.

Frontotemporal dementia (FTD) comprises several types of dementias with prominent behavioural and language functions. The primary progressive dementia which I mentioned is actually a subtype of frontotemporal dementia distinguished by the fact that for a long time language disturbance can be present as the only manifestation. Other subtypes include bvFTD (behavioural variant FTD), semantic dementia or FTD with signs of motor neurone disease.

I am not what you mean by fluid brain build-up. If you mean dementia in the setting of normal pressure hydrocephalus, apart from the demential syndrome affecting other cognitive spheres other than language it also is manifested with gait disturbance as a prominent symptom as well as urinary incontinence later on. Also not suggested by the MRI, there is marked enlargement of the ventricles.

I remain at your disposal for further questions. (If you do not have any other question, you can close the query and rate the answer as you see fit).

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Brief Answer:
I meant in normal pressure hydrocephalus

Detailed Answer:
I meant MRI in normal pressure hydrocephalus.

The ventricles are the fluid filled spaces inside the brain. With age normally there is some degree of atrophy in the brain and so they take more volume, but in normal pressure hydrocephalus this enlargement is more marked more early than the normal ageing or dementia.

That is not your father's case.

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