Stimulation Protocol

Both active and sham groups use 30 Hz frequency and 350 microsecond pulse width. Treatment sessions last 30 minutes and are delivered twice daily for at least five days per week. Active treatment amplitude is set at 90% of the daily maximum tolerable level. The DBS-ON condition uses double monopolar stimulation of ventral electrode contacts at up to 4.5 mA, 60 microseconds, and 150 Hz. Treatment continues for up to 28 days or until ICU discharge. Patients receiving VNS for more than 6 weeks achieved greater motor function gains than those in shorter protocols. Treatment protocols of at least 6 weeks with stimulation intensity of at least 0.8 mA at 30 Hz and at least 300 stimulated movements per session appear to produce greater benefit than shorter, less intensive regimens. Although prolonged stimulation and higher frequency appear to enhance efficacy, optimal stimulation parameters have not yet been definitively established. Existing pharmacological or behavioural treatments can continue, but escalation during the study is not allowed. The sham amplitude is reduced until ultrasound confirms no muscle contraction and then kept fixed for sham sessions. The DBS device stays off duri…