Compression of the lower trunk of the brachial plexus (C8-T1) can cause intrinsic hand muscle weakness and sensory loss along the medial arm and ulnar fingers.
T7-T12 mediate the superficial abdominal reflexes. Loss of these reflexes can indicate a thoracic spinal cord lesion (e.g., multiple sclerosis or transverse myelitis). thoracic spine nerve
The thoracic spinal nerves, with their segmental organization, dual motor-sensory-autonomic roles, and critical contribution to respiration, trunk stability, and sympathetic outflow, are far more than simple "transitional" nerves. While their rigid anatomical environment protects them from many injuries, when dysfunction does occur—whether from herpes zoster, disc disease, or tumor—the clinical presentation is unmistakably a band of pain or numbness wrapped around the torso. A thorough understanding of these nerves is indispensable for neurologists, physiatrists, anesthesiologists, and spine surgeons alike. Compression of the lower trunk of the brachial