Medial Antebrachial Cutaneous Nerve Injury During Routine Venous Blood Collection: Could A Low Body Mass Index be A Risk Factor?

The medial antebrachial cutaneous nerve (MACN) is rarely affected on its own. MACN injury may occur as a result of trauma or compression. We present a 23-year-old female patient with neuropathy of the anterior branch of the MACN, associated with venous blood collection from the left antecubital fossa. This case aims to contribute to the understanding of MACN injury by presenting clinical findings, neurophysiological results, and possible risk factors, including low body mass index (BMI). The patient had severe pain in the medial forearm during the blood collection procedure. The patient’s BMI was 17.6 kg/m2. Patients’ score on the Leeds Assessment of Neuropathic Symptoms and Signs scale was 19. In the sensory nerve conduction study, the left MACN amplitude was found to be lower than that of the right. The findings in this case indicate that neuropathic pain may represent a major component of the clinical picture in MACN injury. This case also raises the possibility that a low BMI could increase vulnerability to such neuropathies. Accordingly, procedures involving venipuncture or intravenous access may require greater caution in individuals with low BMI.