contributor dr. janette nesheiwat. tell us about what aphasia is. we know it ims language and multitude of things. what is it from your medical standpoint? >> it affects the language center of the brain, the left side of the brain. patients have difficulty understanding and expressing themselves, have problems reading and writing and speech and it can be debilitating. as we see with bruce willis, he has been diagnosed with this. we see this with other people, sharon stone, dick clark, gabby gifford, it is not rare, but not common. million people in the united states suffer from it. one common cause of aphasia is a stroke, it can be caused by traumatic brain injury, severe blow to the head, an infection,