Hello and welcome to ‘Ask A Doctor’ service. I have reviewed your query and here is my advice.
You've described a patient with many neurological deficits. These deficits can be caused by many diseases including stroke.
Antipsychotic drugs for example typically cause all the symptoms you've mentioned (and more) particularly when the dosage is high (or too high for this particular patient). You haven't mentioned anything about
dementia. What did the doctor tell you about your brother? Patients with dementia (which is very likely for him) will at some point start to refuse eating and drinking and eventually they loose weight and may get dehydrated particularly if the caregivers are not persistent (or skilled) enough when feeding them. Dementia may make a person behave badly and may even lead to self-injury. That's why such patients are usually kept 'calm' with antipsychotic medications. The trade-off is a sleepy patient, who may drool, have slurred speech and difficulty to swallow, etc. Diagnosing a stroke (even if it had occurred in the past) is easy with either an MRI or a
CT scan of the brain. The MRI is more sensitive though and provides more details than the CT scan for this purpose. Some of his symptoms (loosing weight, getting dehydrated, feeling weak, etc) can be partly attributed to
depression which commonly accompanies such situations. Finally other disorders like
renal dysfunction (high urea and
creatinine in the blood), anemia (low
hematocrit), electrolyte disorders and infections may worsen his situation. So in conclusion, your brother requires a careful medical assessment to establish a diagnosis for his symptoms in order to get the appropriate treatment. Perhaps you should discuss your concerns with the treating doctor, as your brother is probably not capable of doing it himself.
Hope I have answered your query. Let me know if I can assist you further.