horner's syndrome

I have had a recent episode of Horner's syndrome.  I have been worked up as a probable MS.  Can MS cause Horner's syndrome?  What types of tests would you recommend be performed in addition to Paredrine testing?  I also have a blood vessel abnormality in my pons.  They are not certain , but they believe it to be a "capillary cholangiectasis".  I haven't found a definition of anything like that on the internet.  Could that cause Horner's syndrome?

Thank you for your help.

[CCF-Neuro-M.D.-CS]

Horner's can occur in MS, but is not common. Other causes for Horner's syndrome should be excluded. These include: cervical and thoracic spine problems, injuries to the carotid artery (specifically a dissection), and any massess within the cervical symptathetic chain (this can be done with a MRI or CT scan of the chest). Testing with  cocaine and amphetamine eye drops helps document that this is a disorder of the sympathetic nerves, and helps to determine where the problem may be. I am not familar with the term "capillary cholangiectasis", and therefore could not comment upon it. Good luck.