Diagnosis, PD?

Earlier in this placement I came across a patient who presented to me for balance retraining, following several recent falls. Whilst taking his subjective assessment he mentioned that one of his falls came about when he went for a walk, realised he was very far from his car and it was getting late so he started running. When he came close to his car he was unable to stop running, which lead to his fall. On other occasions he noted that it was difficult for him to start walking. He put this down to OA of his foot, and thought nothing more of these symptoms, in fact, had I not asked about his feet, or for details of previous falls he probably wouldn’t have mentioned it at all! Objectively he presented with festinating gait, as well as great difficulty with turning, and rolling. On further assessment cogwheel rigidity was noted. When questioned about these symptoms the patient was unable to tell me how long they had been going on, but they were not new, and it was in the vicinity of ‘years’. I was rather shocked that no one had picked up these symptoms previously, and that the patient hadn’t questioned it. I assumed that as it seems natural for us to question such symptoms the rest of the population should question it too, how soon we forget!

He is to see his doctor soon; as such I need to write a letter to the GP. Is it improper for me to spell out what I think the diagnosis might be? Should I just write the hard facts of what was noted subjective and objectively?