is a syrinx bad??

ok i don't have any back pain per se... lucky me! but i have been sick for almost 5 years, since i was 14, with vertigo, muscular atropy and fatigue. i also so floaters on a regular basis. the reason i'm asking you a backrelated question is, i've been told i have a syrinx on my spinal cord. so what exactly is this? is this what's been causing these debilitating symptoms? or is it just a coincidence that it showed up on the scan? i'm waiting to go into hospital for tests atm. i'm curious to know what this is all about. advice and info would be much apreciated. oh and they're also suspecting m.s although i've had no other abonormalities, well i've still to get a LP but... can a syrinx be associated with ms??? is a syrinx another word for lesion??  

oh yes, basic info: female, 19 yrs old, normal weight, good appetite, and i try to excercise gently whenever i can despite right sided muscular atrophy etc.

thank you! xxx