Is brain damage the cause of apraxia?

Sorry to hear that you father is having these difficulties. There are many different questions that I would like to ask and it would be ideal to perform a thorough neurologic exam. You should definitely make an appointment to have him looked at by a neurologist. Apraxia is a term that is used to describe a loss of the ability to execute or carry out learned purposeful movements. This implies as you have mentioned that there has been some damage to the parts of the brain that are in charge of these movements. A common cause of this damage is from stroke (hemorrhagic or embolic), but this is not the only cause. Anything that causes pressure on these particular areas of the brain could have such effect, such as a benign or malignant tumor. It is also possible to develop infection of the brain that cause abnormal changes, and it is possible to have neurologic lesions that disrupt signal pathways. It seems to me that the best thing would be to set up a consultation with a neurologist to get your father examined. I hope this is helpful. Best of luck.