Study: NCT02634658

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Muscle Ultrasound
Description: Ultrasound will be performed using a linear-array transducer with standardized gain and varying depth based on the amount of overlying soft tissue and muscle size. The subjects will be examined in the supine position with extended limbs and relaxed muscles. We will perform bilateral scans of the biceps, anterior forearm, and anterior thigh at standardized sites. For muscle echogenicity measurements, we will scan the same muscles at the same points.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Nerve Conduction Study
Description: Nerve Conduction Studies will be performed using a Nicolet EDX using standard procedures. Repetitive stimulation of the median motor nerve are performed in all subjects. Bilateral sural, radial and median sensory nerves will be analyzed. We will only perform surface, not subdermal sensory recordings. The bilateral peroneal, tibial and median motor responses will be recorded over extensor digitorum brevis, abductor hallucis brevis, and abductor pollicis brevis muscles. The peroneal motor nerve will be stimulated at the fibular head and lateral popliteal fossa, recording from the tibialis anterior muscle. The compound motor action potential (CMAP) responses will be elicited from standard distal and proximal sites.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Nerve Conduction Study
Description: Nerve Conduction Studies will be performed using a Nicolet EDX using standard procedures. Repetitive stimulation of the median motor nerve are performed in all subjects. Bilateral sural, radial and median sensory nerves will be analyzed. We will only perform surface, not subdermal sensory recordings. The bilateral peroneal, tibial and median motor responses will be recorded over extensor digitorum brevis, abductor hallucis brevis, and abductor pollicis brevis muscles. The peroneal motor nerve will be stimulated at the fibular head and lateral popliteal fossa, recording from the tibialis anterior muscle. The compound motor action potential (CMAP) responses will be elicited from standard distal and proximal sites.

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Electromyography
Description: EMG studies will be performed using standard precautions. Insertional activity, spontaneous activity, motor unit potential (MUP) morphology and recruitment/activation pattern will be recorded from some combination of the deltoid, triceps, biceps, first dorsal interosseous, abductor pollicis brevis, iliopsoas, vastus medialis, and tibialis anterior muscles. The specific muscles studied for each patient will vary according to the patient's level of consciousness and ability to activate the muscles either voluntarily or during spontaneous limb movement. If possible, we will try to examine 3 unilateral upper extremity and 3 unilateral lower extremity muscles. If a patient is not able to volitionally participate in EMG testing (by contracting their muscles on command), we will analyze insertional/spontaneous activity and potentially morphology/recruitment (e.g. stroking the sole of the foot to stimulate contraction of the tibialis anterior).

Intervention type: OTHER
Group type: EXPERIMENTAL
Intervention: Electromyography
Description: EMG studies will be performed using standard precautions. Insertional activity, spontaneous activity, motor unit potential (MUP) morphology and recruitment/activation pattern will be recorded from some combination of the deltoid, triceps, biceps, first dorsal interosseous, abductor pollicis brevis, iliopsoas, vastus medialis, and tibialis anterior muscles. The specific muscles studied for each patient will vary according to the patient's level of consciousness and ability to activate the muscles either voluntarily or during spontaneous limb movement. If possible, we will try to examine 3 unilateral upper extremity and 3 unilateral lower extremity muscles. If a patient is not able to volitionally participate in EMG testing (by contracting their muscles on command), we will analyze insertional/spontaneous activity and potentially morphology/recruitment (e.g. stroking the sole of the foot to stimulate contraction of the tibialis anterior).