<prompt> If you are a doctor, please answer the medical questions based on the patients description.Hi. A friend of mine appeared to be fine, but suddenly could not move his left arm. After 5 or so mins he started to feel a bit better. It turns out he has been having a few bouts of this per year for many years. Sometimes the pain in his heart is great. What could this be ? Your help would be very appreciated.  <response>: Hello, It is necessary performing some tests to investigate for the possible causes underlying your complaints: - a resting ECG- a shoulder and neck X-ray study-complete blood count, PCR, ESR for inflammation. A brain MRI and an EEG may be needed in order to exclude partial seizures that may mimic this clinical situation. Hope I have answered your query. Let me know if I can assist you further. Take care Chat Doctor. 