Sudden paralysis of the arm in an elder

Dear Ask The Doctor: A friend of mine who is 71 spent all night on the toilet leaning across with his arm over i got to him in the morning he raised his arm and i supported him off the toilet. later he atehis breakfast using that arm and lunch. he also raised his arm when he had his personal care. later that day about 4.30 he lost all use of his arm and the neurolgist said it was due to severe brachial plexus injury, would this not have been manifested in the morning. I am totally confused and feel may be i mised something during the day

Dear Veronica: According to your description of the evolution of the events, without an antecedent of trauma in the arm and the age of your friend, it seems to indicate most likely an acute ischemic event in the brain vessels, possibly a TIA. This must be rule out as soon as possible in order to provide your friend the right treatment and follow up and avoid more serious complications.