Brief Answer:
possible Delirium like symptoms, further neurological check-up required...

Detailed Answer:
Hello there,
Welcome to 'Ask A Doctor' service...
I've gone through your query in details...
I can understand your concerns...

Please note, as per this descriptions, this could be due to a condition called as Delirium (a type of sudden onset disorientation, disorganized thinking, labile mood even causing mild to severe agitation and quite often sleep disturbances)...

A lot of time, this improves spontaneously over a period of a few hours to days. However, a thorough neurological check-up is warranted at this point, based on the findings the Neurologist may also suggest some investigation like an EEG, Serum Vit-B12 levels, Urea and Electrolytes (serum Sodium, Potassium, Calcium and Magnesium), FBS and PPBS levels.

Please discuss this with his doctor and proceed further.
Meanwhile, please vigilant on his condition and ensure that he's drinking an adequate amount of water to stay well hydrated, not getting stressed/agitated due to any particular reason (even if there may be incoherent speech, which could be a part of these symptoms)...

Let me know if I can assist you further...

Take Care
Kind Regards

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