Sydenhams
Vascular
Increased RBC's (polycythemia)
Toxins: CO, Mg, Hg
Uremia
SLE
Senile chorea
Drugs
APLA syndrome
Neurodegenerative conditions: HD, neuroacanthocytosis, DRPLA
Conception related: pregnancy, OCP's
Endocrine: hyperthyroidism, hypo-, hyperglycemia

 Mnemonic:
St. VITUS'S DANCE