With auriculotherapy, one can diagnose problems and treat patients. Also, there is a reflex relationship between acupuncture points of the ear auricle and the rest of the body through neuroanatomical and neurophysiological pathways. Neuroimaging and clinical neurophysiological research reported such reflexive relationships. For example, Alimi presented evidence supporting a somatotopic organisation of the surface of the auricle of the ear based on functional magnetic resonance imaging. Luparella and Lanza published evidence for such an organisation by means of cerebral-evoked potentials obtained through stimulation of the auricle.
Auriculo-autonomic reflexes have been demonstrated in anesthetised rats. In a cat study, direct intra-operative stimulation of the greater auricular nerve evokes somatic reflex responses in dorsal-neck musculature.
The primary purpose of the study was to demonstrate somatic auriculo-cervical reflex activity produced by electrical stimulation of the human pinna.
In humans, electromyographic (EMG) trigeminocervical reflexes have been described. These are most commonly obtained by stimulating the supraorbital or infraorbital branches of the trigeminal nerve, with EMG surface-electrode or needle recording at the ipsilateral splenius capitis, semispinalis capitis, and sternocleidomastoid muscles.
The mental-nerve stimulation of the face may also result in a trigeminocervical reflex, although this is less consistent than facial supraorbital or infraorbital nerve stimulation. Such reflexes are relevant as the trigeminal nerve provides a significant portion of sensory innervation to the auricle of the ear, particularly through its mandibular division.
The ACR reported herein is distinct from somatic reflexes evoked from direct intra-operative stimulation of the greater auricular nerve in the cat, or from direct stimulation of the supraorbital, infraorbital, and mental branches of the trigeminal nerve in the human face. In addition, the human ACR is different from Snellen’s reflex, sometimes called the “auriculocervical reflex”.
Snellen’s reflex consists of “unilateral congestion of the ear upon stimulation of the distal end of the divided auriculocervical nerve”. Snellen’s reflex is an autonomic reflex of induced vascular congestion of the ear and is not a somatic EMG reflex.
The auricle of the human ear is richly innervated. The principal sensory innervation of the apex region is provided by the mandibular division of the trigeminal nerve. A secondary purpose of this study was to determine if focused, electrical stimulation of these three specific auricular areas of innervation might produce ACRs, and to see if any such evoked somatic reflex activity might vary according to the specific auricular area stimulated in this fashion.
The author is Head of Acupuncture at Sir Ganga Ram Hospital, New Delhi