The incontinence could be do to breaks in the area you describe but as you say you have diminished sensation in the gental region i wonder if it is MS related. One of my earlies symptoms from MS even pre Dx was urunary urgency and the occassional accident. A lesion in the scaral region can cause the symptoms you describe but as your neuro says, the fisrt thing is to rule out simple problems such as urinary tract infections.
Try not to stress to much about it, i know that it is embaressing but it can be managed. here in Australia we have Continence Nurses, RN's with specialist knowledge about dx and treating urinary and bowel incontinence- they are excellent when it comes to management strategies. Its worth seeing if you can get access to one for some advice- you MS society may be able to point you in the right direction.
regards
Karen