Interactions Between Neurostimulation and Physical Exercise

Inclusion Criteria:

1. Age between 21 and 65 years;

2. Chronic (more than 12 months since injury) incomplete SCI between levels C2-C8 ordiagnosis of definite or probable ALS;

3. Incomplete weakness of left or right hand muscles: score of 2, 3, or 4 (out of 5) onmanual muscle testing of finger extension, finger flexion, or finger abduction;

4. Detectable F-wave responses of the left or right abductor pollicis brevis muscle tomedian nerve stimulation.

Exclusion Criteria:

1. Multiple spinal cord lesions;

2. History of seizures;

3. Ventilator dependence or patent tracheostomy site;

4. Use of medications that significantly lower seizure threshold, such as tricyclicantidepressants, amphetamines, neuroleptics, dalfampridine, and bupropion;

5. History of stroke, brain tumor, brain abscess, or multiple sclerosis;

6. History of moderate or severe head trauma (loss of consciousness for greater than onehour or evidence of brain contusion or hemorrhage or depressed skull fracture on priorimaging);

7. History of implanted brain/spine/nerve stimulators, aneurysm clips, ferromagneticmetallic implants, or cardiac pacemaker/defibrillator;

8. Significant coronary artery or cardiac conduction disease;

9. Recent history (within past 6 months) of recurrent autonomic dysreflexia, defined as asyndrome of sudden rise in systolic pressure greater than 20 mm Hg or diastolicpressure greater than 10 mm Hg, without rise in heart rate, accompanied by symptomssuch as headache, facial flushing, sweating, nasal congestion, and blurry vision (thiswill be closely monitored during all screening and testing procedures);

10. History of bipolar disorder;

11. History of suicide attempt;

12. Active psychosis;

13. Heavy alcohol consumption (greater than equivalent of 5 oz of liquor) within previous 48 hours;

14. Open skin lesions over the face, neck, shoulders, or arms;

15. Pregnancy

16. Unsuitable for study participation as determined by study physician.