I have connective tissue disease. sometimes get debilitating lightheaded, brain fog.it continues until i take short course of low dose prednisone. why?

Fog busters: Disorders of autoimmunity are commonly associated with cognitive dysfunction, so-called "brain fog", which can be steroid responsive. If you also have headaches, you may have cerebrovascular inflammation, for which tests are available. Cognitive functioning can improve with biological treatment used to arrest connective tissue disorders such as RA & are better than long-term steroid treatment.