If Daisy has PSOM, this will be clear on the scan, because they do a picture from the front through the skull, which shows the inside of the ears very clearly. If Daisy has it, Geoff will discuss treatment with you. It sounds, however, as if she may simply have the 'normal' partial deafness that is common in Cavaliers. You can just make allowances for it, or you could ask Chester Gates to give her a BAER test before she has her scan. This will tell you the degree of deafness she has, if indeed she is deaf and not just naughty! It simply involves her sitting on a table wearing comfortable headphones that are plugged into a computer; a noise is sent through the headphones and the computer measures how each ear responds to it. This was how we discovered Oliver is almost totally deaf in one ear. When he had his test (at the same time as his last scan 2 years ago) he was filmed, so you may see him doing his Snoopy as Red Baron imitation on the video that runs in the CG reception!
I think most neurologists take CM as a given in Cavaliers, because almost all of them have it. So the scan will tell you whether the CM is causing any problems, but its main purpose is to discover whether the CM has produced SM; it will tell you (a) whether Daisy has a syrinx, where and how big, (b) how much, if any, herniation there is (the bottom of the brain being pushed down into the spinal cord), and (c) whether her brain ventricles are dilated (enlarged). (b) and (c) can be produced by CM alone, without the presence of a syrinx; and the syrinx itself may or may not be producing symptoms, depending on its size (especially its width). All these factors will affect the amount of pain and discomfort Daisy experiences and what treatments will help. Oliver, for example, has a very small syrinx and moderate herniation, but very enlarged ventricles which cause most of his symptoms (the main one is light phobia and headaches) - so he is on a moderate dose of pain control (gabapentin) but a quite large dose of diuretic (frusemide) to try to reduce the fluid in the ventricles.
Hope this helps,
Kate (and Oliver and Aled on holiday)