Stimulated by Liu et al 2020, and Li et al 2021.
EBM – evidence based medicinekey to acronyms
MR angiography – magnetic resonance angiography
PMA – persistent median artery
These are a couple of recent papers, a case report and a letter with a hypothesis, which are linked by virtue of the anatomic region of interest and the involvement of arteries.
The case report is a rather unusual one. Indeed, I have previously never heard of symptomatic nerve compression caused by pressure from an anomalous artery. In this case it was median nerve compression by a superficial brachial artery. An ultrasound image quite convincingly demonstrates indentation of the nerve from the artery. No other vascular anomalies were found in the upper limb using MR angiography.
The median nerve symptoms in this 61-year-old man had been developing over a period of one year and had progressed from aching and weakness of the thumb to involve the first three fingers. These symptoms were substantially improved after 2 months of conservative treatment involving muscle relaxation, acupuncture and moxibustion.
The letter to the Journal of Anatomy (IF 2.72) concerns an arterial variant of the forearm called a persistent median artery (PMA), which occurs in approximately 30% of adults and has been increasing in the last 200 years apparently.
The author of the letter who appears to be an acupuncture practitioner from New Jersey hypothesises that the discovery of the median artery or a third pulse in the middle of the wrist, may have led to the addition of a 12th meridian (the Pericardium meridian).
Eleven meridians were described in the silk scrolls found in Han Tomb No. 3 (dated to 168 BCE) at Mawangdui, Changsha, China. This tomb was discovered in 1970. The 12 meridian system has persisted for the last 2 millenia.
Vivian Shaw suggests that in the Han period, Chinese physicians probably performed anatomical studies on criminals, and the most ancient written description of the meridian system, that from Mawangdui, describes vascular paths through the body. This latest hypothesis concerning the median artery and the addition of the Pericardium meridian would be in complete congruence with her dissertation.
1 Liu J, Zhong K, Lin D. Median nerve compression caused by superficial brachial artery: an unusual clinical case. J Int Med Res 2020;48:030006052096904. doi:10.1177/0300060520969043
2 Li YM. Persistent median artery may explain the transition from 11 to 12 meridians in ancient Chinese medicine. J Anat Published Online First: 13 January 2021. doi:10.1111/joa.13376
3 Lucas T, Kumaratilake J, Henneberg M. Recently increased prevalence of the human median artery of the forearm: A microevolutionary change. J Anat 2020;237:623–31. doi:10.1111/joa.13224
4 Shaw V, Diogo R, Winder IC. Hiding in Plain Sight ‐ ancient Chinese anatomy. Anat Rec Published Online First: September 2020. doi:10.1002/ar.24503