intercostobrachialnerven

The intercostobrachial nerve (intercostobrachialnerven) is a sensory nerve of the thorax and upper limb. It is typically a lateral cutaneous branch of the second intercostal nerve (T2) and may receive communicating fibers from T1. After arising from the intercostal space, the nerve enters the axilla and commonly traverses the axillary region toward the medial aspect of the arm.

Distribution and course: The intercostobrachial nerve provides cutaneous sensation to the skin on the medial upper arm and portions of the axilla, with some fibers extending to the adjacent medial chest wall near the second intercostal space. It frequently communicates with the medial cutaneous nerve of the arm (medial brachial cutaneous nerve) within the axilla.

Innervation: The nerve is purely sensory, carrying tactile and pain information from its designated skin territories. It has no motor components.

Clinical significance and variations: The intercostobrachial nerve is at particular risk during axillary procedures, such as lymph node dissection for breast cancer, as well as other surgeries involving the axilla or medial chest wall. Injury can result in numbness, paresthesias, or neuropathic pain in its distribution, which can affect comfort and function of the ipsilateral upper limb. Anatomical variations are common; the nerve may receive fibers from T1 or T3, or may be absent in some individuals, with adjacent nerves contributing to its territory. In clinical practice, preserving the intercostobrachial nerve when possible can reduce postoperative sensory loss.