Dear User, Thanks for using health care magic. Although subdural hematoma can be cause of tremor but the tremors are continuous unlike your friends problem. Intermittent tremor in a patent with PTSD is more likely due to emotional arousal and flashbacks. They continue to persist life long if not treated either by medication or psychotherapy. So at this I advice you to see a psychiatrist or psychologist for assessment of problem and get required prescription. Hope I have answered your query. If you have any further questions I will be happy to help . Thanks