- Auto-antibody against presynaptic side of nmj
- Rare, 50% assoc w/malignancy→ in particular lung
- Can also occur w/other autoimmune dz→ thyroid
- Age ~60 if cancer, 30s & 60s if no malignancy
- Progressive weakness over mos
- Proximal muscles > distal
- Progresses caudal to cranial
- Eye & facial muscles not typically affected
- Autonomic dysfxn→ dry mouth, constipation, orthostatic lightheadedness, etc.
- Proximal weakness
- Diminished or absent reflexes