Tks Amanda- It is my wife. She has moderate/severe PH (WHO 3 or 5) & PLCH. On 02 presently 24/7. Diagnosed with small hydropneumothorax which with O2 therapy seems to be getting smaller. Had multiple CTs for lungs/abdomen, blood work & thyroid tests& revealed nothing new to explain tremors which she 1st experienced around onset of pneumothorax in legs & arms (no hands or feet), abdominal area (laterally belly button & below), & with temporary blankness in head. Lasts no more than 1 min, but with regular frequency. Mostly at rest. Has rode stationary bike slowly w/o episode. Had it standing still, but waiting to see if gets it while mobile. No neurological issues in family or with her previously. No PD, MS or essential tremors. Came out of nowhere & can't explain it.