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Neuroanatomic Structure and Function of Acupuncture Points around the Eye

Narda G. Robinson, DO, DVM, MS, Jessica Pederson, Ted Burghardt, L. Ray Whalen, DVM PhD

ABSTRACT The locations of eight human periocular acupuncture points were transposed to the dog. Canine dissections exposed acupoint-nerve relationships that were compared to those previously identified in the human. Two comparative anatomical differences in periocular points include 1) lack of a complete bony in the dog and absence of cranial nerve foramina, and 2) longer distance between the canine and ipsilateral eye than in the human, requiring a different location for ST 2. Traditional Chinese Veterinary Medicine (TCVM) actions assigned to each point were compared to the neurophysiologic results expected after stimulating these nerves. Nerve structure-function relationships of the periocular acupuncture points explain the theoretical TCVM descriptions of point actions. This finding emphasizes the relevance of ensuring that a transpositional point system is based on comparative neuroanatomical precision. Differences exist in periorbital bony between the dog and the human that call for a re-evaluation of the topographical anatomy of canine periocular acupuncture points.

Key Words: Neuroanatomical acupuncture, transpositional points, veterinary acupuncture, Traditional Chinese Veterinary Medicine, TCVM, ophthalmology

The effects of acupuncture are associated nervous system and out again through somatic and with “neuromodulation”, which involve the autonomic pathways. Predictable neuromodulation physiologic changes caused by acupuncture that depends upon the accuracy of acupuncture point relate directly to the nerves stimulated.1 Peripheral and nerve stimulation. Obtaining a reliable clinical nerves at acupuncture points impact the body as a outcome with acupuncture requires that the target whole through reflex connections into the central acupuncture point affects the appropriate nerves. Since no comprehensive neuroanatomically accurate acupuncture point atlas yet exists for non- human species, developing such an atlas is a critical From: Narda G. Robinson, DO, DVM, MS first step in upgrading the level of clinical practice Shipley Professorship of Complementary and Alternative and scientific research. 2 Medicine Colorado State University Veterinary Medical Center The head region contains a rich network of 300 West Drake Road cranial nerves and abundance of acupuncture Fort Collins, CO 80523 points. Periocular acupuncture points in particular Jessica Pederson, Professional Veterinary Medicine Student, Colorado State University can serve as a worthwhile first step in creating an Ted Burghardt, Professional Veterinary Medicine Student, anatomically based transpositional canine atlas, Colorado State University given their clinical significance for a variety of L. Ray Whalen, DVM PhD University Distinguished Teaching Scholar conditions. Eight points surrounding the eye in the Department of Biomedical Sciences human selected for study in the dog appear in Table Colorado State University Fort Collins, CO 80523 1. Actions assigned to these eight points focus mainly on eye problems; other actions include Funding Acknowledgement craniofacial pain, sinusitis, and migraine. Made possible by the kind support of the Barry and Savannah French-Poodle Memorial Fund. Examples of periocular and other acupuncture point combinations used for the treatment of some ACUC Approval common conditions in humans are listed in Table 2. Animal Care and Use Committee approval was obtained prior to performing the dissections. The objectives of this study were to (1.)

AJTCVM Vol 2, No.1, Summer 2007 33 Table 1: Overview of eight acupuncture points around the eye Acupoint Name Comparative (Chinese Name) Regional Anatomy Associated with the Anatomy Indications TCVM Actions English Translation, Acupoint Concerns Human Location All eye No lacrimal part conditions, of the orbicularis Sensory to upper lid, , and including oculi m has been forehead: redness, found in the dog. Supratrochlear n (CN V1) swelling, In humans, the pain, lacrimal part of Sensory to both , conjunctiva, epiphora, the orbicularis , and , and BL-1 blurred oculi brings the part of the nose: (Jingming) vision, eye eyelids and the Infratrochlear n (CN V1), a branch of the Clarity of pupils itching, Benefits and lacrimal puncta nasociliary n lacrimation brightens the eyes. toward a medial Location: on wind Expels Wind. direction, Tear drainage Slightly medial and exposure, Clears Heat. pressing the superior to the inner aversion to puncta into the of the eye. cold with . Periocular muscles and their nerve supply headache. This allows Orbicularis oculi m, palpebral part (supplied Migraine, lacrimal fluid by palpebral part of auriculopalpebral n, frontal to drain into it (from CN VII) headache, more readily Levator palpebrae superioris m (supplied by rhinitis, through a CN III) frontal capillary action.28 sinusitis. Local pain No supraorbital and swelling, foramen exists in frontal the dog. Instead, headache, the supraorbital lacrimation nerve winds on wind Sensory to upper lid, conjunctiva, frontal BL-2 around the exposure, sinus, and forehead: (Zanzhu) zygomatic blepharospas Supraorbital n (CN V1) Gathered Bamboo process of the m, rhinitis, Dispels Wind. . facial pain, Periocular muscles and their nerve supply Location: Clears Heat. Because of this manic Orbicularis oculi m, orbital part (supplied by Directly superior to BL- Benefits the Eyes. transpositional behavior, palpebral part of auriculopalpebral n, from 1, in a tender depression Alleviates Pain. issue, BL- 2 in pain and CN VII) near the medial end of the dog tends to stiffness of the , at the have a slightly the neck, Frontalis m (supplied by temporalis and supraorbital notch. more lateral blurred auriculopalpebral branch of CN VII) placement on vision. what would be Hallucination the canine s, nightmares, eyebrow. anxiety.

M-HN-6 Redness, Sensory to upper lid, conjunctiva, frontal (Yuyao) pain, swelling sinus, and forehead: As Yuyao resides Fish Waist of the eyes. Supraorbital n (CN V1) lateral to BL 2, Blepharospas there is no bone Relaxes the Location: m. Periocular muscles and their nerve supply beneath this sinews. In the center of the Ptosis, or Orbicularis oculi m, orbital part (supplied by point in the dog, Reduces pain. eyebrow, in the cannot palpebral part of auriculopalpebral n, from unlike in the Benefits the eyes. depression that lies close. CN VII) human. directly above the pupil Frontal

when the eye is looking headache, Frontalis m (supplied by temporalis and forward. migraine. auriculopalpebral br of CN VII) CN V-1 = ophthalmic branch CN V-2 = Trigeminal nerve maxillary branch and CN V-3 = Trigeminal nerve mandibular branch

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Sensory to of lateral upper lid: Lacrimal n (CN V1, CN V2) Supraorbital n (CN V1) TH- 23 No in (Sizhukong) dogs; i.e., there is Sensory to ; carries parasympa- Bamboo Headache. no bony rim to the thetic fibers from CN VII: Thread Pain and red- Resolves Heat. orbit at this loca- Lacrimal n (CN V1, CN V2) ness of the Disperses Wind. tion that contains a Location: eyes. Blepha- Alleviates pain. depression at the In the de- rospasm. Epi- Brightens the eyes. end, which in the Periocular muscles and their nerve supply pression at lepsy. Tooth Frees the channel. human defines Orbicularis oculi m, orbital part (supplied by the lateral pain. palpatory aspects palpebral part of auriculopalpebral n, from CN end of the of the eyebrow. VII) eyebrow.

Frontalis m (supplied by temporalis and auriculo- palpebral br of CN VII) Dogs lack a com- plete bony orbit; instead, GB-1 oc- curs just dorsal to Sensory to skin of lateral canthus region: the frontal process Lacrimal n (CN V-1, CN V-2) of the . Supraorbital n (CN V-1) GB-1 Humans lack a (Tongziliao) retractor anguli Zygomaticotemporal n (CN V-2) Pupil Bone oculi lateralis mus- Hole cle. Branches of the Auriculotemporal n (CN V-3) by way of a small Dispels Heat. differ Headache, eye communicating branch to the zygomaticotemporal Expels Wind. Location: between humans pain, loss of n or zygomaticofacial n Frees the Qi. Lateral to and dogs; humans visual acuity, Alleviates pain. the lateral lack an auriculo- redness in the Zygomaticofacial n (CN V-2) Brightens the eyes. canthus, in a palpebral nerve; eyes, tearing. Facial n (CN VII) by way of an anastomotic con- depression instead, the pe- nection to the zygomaticofacial n on the lateral riocular muscles of side of the facial expression Periocular muscles and their nerve supply orbit. served by the auri- Orbicularis oculi m, orbital part (supplied by culopalpebral nerve palpebral part of auriculopalpebral n, from CN in the dog receive VII) their motor supply from the zygomatic Retractor anguli oculi lateralis m (supplied by and temporal zygomatic br, auriculopalpebral n, from CN VII) branches of the facial nerve. M-HN-8 (Qiuhou) Sensory to skin of lower orbital region: Behind the Auriculotemporal n (CN V-3) by way of a small Ball communicating branch to the zygomaticotemporal Location: All eye condi- n or zygomaticofacial n Along the tions including Dogs do not have inferior rim short- zygomaticofacial Zygomaticofacial n (CN V-2) of the orbit, sightedness, foramina for local- Facial n (CN VII) by way of an anastomotic con- at the junc- optic neuritis, Benefits the eyes. ization of this nection to the zygomaticofacial n tion between optic atrophy, Promotes blood and point. Humans the lateral ¼ glaucoma, Qi flow to the eye. lack a sphincter Periocular muscles and their nerve supply and the me- retinitis pig- colli profundus Orbicularis oculi m, orbital part (supplied by dial ¾ of the mentosa, con- muscle. palpebral part of auriculopalpebral n, from CN orbital rim; vergent strabis- VII) coincides mus. with the Sphincter colli profundus m, palpebral part zygomatico- (supplied by the ventral buccal br, from CN VII) facial fora- men.

AJTCVM Vol 2, No.1, Summer 2007 35 Sensory to skin of lower lid and ventral orbital ST- 1 region: (Chengqi) Infratrochlear n (CN V-1) Container of

Tears Infraorbital n (CN V-2)

Disperses wind. Location: Humans lack a Extinguishes fire. Zygomaticofacial n (CN V-2) Directly sphincter colli Red, painful Controls pathogens. beneath the profundus muscle eyes; tearing in Brightens the eyes. Facial n (CN VII) by way of an anastomotic pupil when but instead have a response to Treats connection to the zygomaticofacial n the eye is levator labii wind exposure, nearsightedness. looking superioris muscle blepharospasm Tonifies the Stomach Periocular muscles and their nerve supply forward, in this region. and Small Intestine. Orbicularis oculi m, orbital and palpebral parts between the (supplied by palpebral part of auriculopalpebral n, globe and from CN VII) the

infraorbital Sphincter colli profundus m, palpebral part ridge (supplied by the ventral buccal br, from CN VII) The infraorbital foramen in dogs lies on the snout ST-2 and is not directly (Sibai) below the pupil, Sensory to skin of lower lid and ventral orbital Four Whites nor is it 1 cun region:

below the pupil. Infratrochlear n (CN V-1) Location: As such, whereas Red, painful Directly this point qualifies eyes; tearing in Infraorbital n (CN V2) beneath the as a periocular response to pupil when point in the human, wind exposure, Relieves pain, Zygomaticofacial n (CN V-2) the eye is it is a nasal point in blepharospasm, Dispels wind, Facial n (CN VII) by way of an anastomotic looking the dog. facial pain, Soothes the sinews, connection to the zygomaticofacial n forward, The levator labii facial spasms, Tonifies the stomach. approximatel superioris muscle headache, Periocular muscles and their nerve supply y 1 cun covers the dizziness, Levator nasolabialis m, (supplied by the beneath the infraorbital sinusitis. auriculopalpebral n, from CN VII) pupil, in the foramen in the depression at human, whereas Motor to nasolabial mm the the levator Ventral buccal br of facial n (CN VII) infraorbital nasolabialis muscle foramen. overlies the dog’s infraorbital foramen. explore the neuroanatomical structures present in underwent formaldehyde fixation. Presumptive the previously presumed acupuncture point locations of periocular acupuncture points, locations around the canine eye, (2.) consider the transposed from the human to dog, were identified relevance of comparative anatomic differences prior to dissection. Figure 1 presents the first seven between the human and dog orbit, and (3) compare points from a frontal perspective. Figure 2 nerve functions to the classically described illustrates all eight points from a lateral view, Traditional Chinese Veterinary Medicine (TCVM) including the two different locations for ST-2 seen effects. in the veterinary acupuncture literature. “ST-2’ ” denotes the topographical location most similar to MATERIALS AND METHODS the human.3 “ST-2” in Figure 2 shows the location After Animal Care and Use Committee where the point would be located approval, a canine cadaver was obtained from a neuroanatomically. The trigeminal nerve was the local animal shelter, having been previously main cranial nerve of interest, as it supplies euthanized for reasons other than this study. sensation to the entire periocular region. Detailed Within thirty minutes after euthanasia, the cadaver dissections were obtained in order to isolate and

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Table 2: Examples of point formulae for treating conditions

Condition Acupuncture Treatment Employed Outcome Reference Treated (Periocular Points in Bold) Dry eye LIV- 3, LIV-8, LIV- 14 88% of 17 patients demonstrated Eliason KJ, Richards SC, and GB-1, GB-41, ST-1 statistically significant Schaumaun GT. Acupuncture improvement in dry eye symptoms treatment for dry eye. Medical Electroacupuncture, after one treatment. Acupuncture. 2007;19(1):25-28. 4Hz for 15 minutes at the following No control group comparison. points: LIV-3, LIV- 8 LIV-14, GB-1. Epiphora BL-1 punctured with pre-warmed 91% of 56 affected eyes improved Ni Y, Shi W, Xu, XX, et al. needle, inserted 10-25 mm until or were cured, compared to 54% Acupuncture treatment for 34 cases sensation of soreness and distension of 35 control eyes that instead of epiphora with dysfunction of elicited, left in place for 5-20 minutes. received norfloxacin eye drops lacrimal duct. Journal of Traditional t.i.d. and lacrimal duct irrigation Chinese Medicine. 2002;22(1):31- daily or on alternate days. 32.

Optic nerve “Commonly used points”: BL-1, Out of 56 patients with optic Huang SY and Zeng Y. Clinical atrophy or GB-1, GB-20, LI-4, KID- 7, SP-6, and neuritis, 47 improved either observation on treatment of disorders optic LIV-3. “moderately” or “markedly” with of the by acupuncture. neuritis either acupuncture alone or in Journal of Traditional Chinese “Reserve points”: BL-2, ST-2, combination with other treatments. Medicine. 1985;5(3):187-190. TH-5, GB-37, ST-36, KID- 3, KID- 6, LIV-8, PC-6, BL-13, Out of 26 patients with optic BL- 18, BL- 21, GV-4, BL-10, SI-6, atrophy, 16 improved BL-58, and BL-23. “moderately” with either acupuncture alone or in combination with other treatments.

Optic Main point: Qiuhou (inserted deeply, 45 out of 55 eyes affected with Ge S and Xu B. 38 cases of optic atrophy 1.5 – 2 cun, or body inches, along the optic atrophy improved, ranging atrophy treated by needling Qiuhou lower rim of the orbit), left in place for from a “clinical cure” to point. Journal of Traditional 5 minutes after patient perceived “improved”. Chinese Medicine. 1989;9(3):171- soreness, distension, or protruding 172. sensation to the eye. Adjunctive point Yiming (inserted 1 cun and left in place for 5 minutes after patient perceived local soreness and distension). Retinitis Three local points: one just below the Retinitis pigmentosa: “Good” Reddy NS and Fouzdar NM. Role of pigmentosa, inner canthus, one just below the outer improvement in vision for 15 out acupuncture in the treatment of myopic canthus, and one just above the mid- of 20 cases, with slight “incurable” retinal diseases. Indian degeneration eyebrow (between Yuyao and GB-14). improvement in the remainder Journal of Ophthalmology. 1983;31 , macular Two distal points: GV-20 and LI-4. (i.e., 5 out of 20). (Spl. 83):1043-1046. choroiditis, Optic atrophy: “Fairly good” or and optic “moderate” improvement in all 12 atrophy cases treated. Myopic degeneration: Some improvement in all of 10 cases treated. Macular choroiditis: Only slight improvement in some of the 8 cases treated. identify these superficial nerves relevant to RESULTS acupuncture and accessible to an acupuncture The dissection revealed several branches of needle inserted at a safe depth. the trigeminal and facial nerves relevant to periocular acupuncture points. The results below

AJTCVM Vol 2, No.1, Summer 2007 37 focus on the trigeminal nerve and its branches, and terminal branches to the skin at the acupuncture mention the facial nerve when pertinent and point known as TH-23. Because this nerve also describe the significant nerves related to each supplies the lacrimal gland, this point can be point. especially beneficial for dry and itching eyes. The The ophthalmic branch of the trigeminal accompanies the into nerve (Cranial nerve V-1) called the ophthalmic the lacrimal gland. It sends branches to the nerve divides into the frontal, lacrimal, and conjunctiva and upper lid and connects to branches nasociliary nerves. 4 The further of the facial nerve.6 The lacrimal nerve divides into two cutaneous branches: the communicates with the zygomaticotemporal nerve, and the . which carries postganglionic parasympathetic fibers The cutaneous territory of the infratrochlear from the sphenopalatine ganglion. These fibers nerve, a branch of the , overlaps provide secretomotor function to the lacrimal with that of the supratrochlear. The lacrimal gland.6 This interneural connection makes TH 23 nerve, which can arise from either the ophthalmic a key location for acupuncture stimulation for or maxillary division, supplies the lacrimal gland conditions impacting lacrimal secretion. with sensation and secretomotor parasympathetic The maxillary division of the trigeminal function through fibers it receives from the nerve (CN V-2) divides into the zygomatic, the by way of the facial pterygopalatine, and the infraorbital nerves. The nerve.5 zygomatic branches into the zygomaticotemporal Infratrochlear and supratrochlear nerves and zygomaticofacial nerves. Both supply skin and BL-1: Nasociliary nerve branches supply the sensation. In addition, the zygomaticotemporal sensation to the nose and eye. One of these nerve provides the lacrimal gland with branches, the , provides secretomotor function, as mentioned previously. sensation to the medial upper and lower lid. It The supplies sensation to the anastomoses with the supratrochlear nerve that skin and upper teeth. arises from the frontal nerve. Together, the Zygomaticotemporal nerve and TH-23 infratrochlear and supratrochlear nerves supply the and GB-1: The human zygomaticotemporal nerve lacrimal sac, caruncle, and duct, the conjunctiva, emerges through the zygomaticotemporal foramen; and the skin at the root of the nose.6 The dogs lack this foramen.1 Certain individuals lack a supratrochlear nerve and only the ventral branch of lacrimal nerve; when this happens, the the infratrochlear nerve appear in Figure 3 in zygomaticotemporal nerve supplies sensation to the relation to BL-1. lacrimal gland.7 A small branch of the Supraorbital nerve and BL-2 and Yuyao: zygomaticotemporal nerve may communicate with The human transmits the the from the mandibular supraorbital nerve. This foramen appears between division of the trigeminal nerve (CN V-3) and/or the medial and middle thirds of the eyebrow. The with the facial nerve.7 The palpebral nerve (from nerve carries postganglionic sympathetic fibers that the facial nerve, CN VII), otherwise known as the supply the local vasculature; it also supplies palpebral branch of the auriculopalpebral nerve, sensation to the upper lid and skin along with the courses through both TH-23 and GB-1, as frontal sinus, galea aponeurotica, and orbicularis illustrated in Figure 5. oculi muscle.1, 6 Branches of the supraorbital nerve and Qiuhou: Like supply the periosteum of the skull as well as the the human zygomaticotemporal nerve, the human frontal and parietal bones.6 Figure 4 shows the zygomaticofacial nerve emerges through a foramen supraorbital nerve (from CN V-1) and the palpebral that bears its name.1 Neither nerve transmits nerve (from CN VII) intersecting at BL 2 and through foramina in the dog, since the orbital rim Yuyao. The palpebral nerve supplies motor does not exist here. Figure 6 illustrates the function to the . relationship between Qiuhou and the Lacrimal nerve, terminal branches and zygomaticofacial nerve and shows the TH-23: The lacrimal nerve (not identified in our auriculotemporal nerve, from the mandibular dissections) supplies the lacrimal gland and sends division of the trigeminal (CN V-3) reaching

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infraorbital foramen of the dog is found on the external nose, whereas the infraorbital foramen of the human is found on the , presenting a major transpositional difference. Figure 8 illustrates ST-2. The facial nerve (Cranial nerve VII) branches into the auriculopalpebral nerve and the ventral buccal branch. The auriculopalpebral nerve relates to BL- 2, Yuyao, TH-23, and GB-1 and forms a plexus between the eye and ear.8 Branches of this plexus supply the rostral auricular, nasolabialis, and palpebralis periocular muscles. The ventral buccal branch of the facial nerve supplies the nasolabial, orbicularis ori, and buccinator muscles. The ventral buccal branch of Figure 1: Periocular acupuncture points on the dog. the facial nerve relates to ST-2.

DISCUSSION toward Qiuhou and the zygomaticofacial nerve. Two notable differences exist between Infraorbital nerve and ST-1 and ST-2: canine and human anatomy related to periocular After the infraorbital nerve emerges from its structures. First, whereas bone completely foramen, it divides into several branches. Palpebral encircles the human orbit, bone incompletely branches ascend to supply sensation to the skin at surrounds the canine orbit.9 (See Figure 9.) ST-1 and conjunctiva of the lower lid; they also Consequently, rather than emanating through communicate with the facial nerve near GB-1. The

Figure 2: Location of the eight periocular points, including the alternate positions for ST-2, denoted as “ST-2” and “ST-2’ ”. The point ST-2’ shows the location most closely resembling that in the human, whereas the location for ST-2 takes into account neuroanatomic relationships.

AJTCVM Vol 2, No.1, Summer 2007 39 Figure 3: Supratrochlear and infra- trochlear nerves in relation to BL-1.

Figure 4: Both the supraor- bital and palpebral nerves supply BL-2 and Yuyao.

Figure 5: The zygomati- cotemporal and auriculo- palpebral nerves both supply TH-3 and GB-1.

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foramina, trigeminal branches instead wind around bony processes of the frontal bone and zygomatic bone. The absence of cranial foramina means that their true transpositional location is less well- defined. From a safety perspective, the presence of ligament, rather than bone, in the dorsolateral orbit elevates safety concerns and inadvertent penetration of the globe if the acupuncturist lacks knowledge of canine anatomy. Second, the maxillary location of the human ST-2 transposes to a nasal location in the dog. Placing ST- 2 below the eye in the dog instead of on the nose misses the infraorbital foramen by possibly several centimeters.

Figure 7: ST-1 relates to both the infraorbital and infratrochlear nerves. Only the infratrochlear nerve appears in this image.

Figure 6: The point Qiuhou associ- ates intimately with the zygomatico- facial nerve. The auriculotemporal nerve resides nearby.

Figure 8: In contrast to the location of ST-2 in the human, just below ST-1 under the eye, ST-2 in the dog lands further from the eye to maintain its relationship with the infraorbital foramen.

AJTCVM Vol 2, No.1, Summer 2007 41 and activating lymphocytes in the gland.12 A desensitized lacrimal gland may atrophy as a result of protein synthesis dysregulation.12 Lacrimal gland overstimulation can also be injurious.12 Thus, a neuromodulatory input such as acupuncture that restores balanced and proper function of the nerves may promote recovery. The TCM syndromes of Liver Fire and Liver Yang Rising pertain neurophysiologically to sympathetic arousal; e.g., irritability, propensity to outbursts of anger, and a Figure 9: This image illustrates the incomplete bony orbit of the dog. rapid, wiry pulse.13 In contrast to the human orbit that possesses a complete bony rim. Excess sympathetic activity also causes eye redness, pain, Unsurprisingly, many of the acupuncture and dryness. Parasympathetic support provides points in Table 1 have a good correlation between calming and moistening benefits that, in TCVM the expected TCVM effects and the terms, promote Yin or reduce Yang. neuromodulation effects seen associated with the In order to access the parasympathetic nerves nerves at that site. Examples of this are TCM and with acupuncture, one method is to stimulate TCVM syndromes for (1.) Heat and Wind Invasion branches of the trigeminal nerve. Communication of the eye, (2.)Benefiting and Brightening the eyes, between the trigeminal and vagus nerves explains (3.)Alleviate pain, Relax the sinews, (4.)Expel why points on the face affect gastrointestinal Wind, (5.)Extinguish Fire , and, (6.)Tonify the motility and cardiopulmonary function.15 16 Input Stomach; Tonify the Small Intestine. from the trigeminal and vagus nerves converge at The TCVM terms Heat and Wind invasion of the spinal nucleus of the trigeminal tract and the the eye equate with conjunctivitis, arising either nucleus tractus solitarius (NTS).14 Neural from exterior pathogens or internal conditions such convergence from trigeminal and spinal inputs to as flaring up of Liver Fire or rising of Liver Yang.10 the nucleus tractus solitarius (NTS) fosters Dry eye, in particular, would fall into this integration of visceral reflexes evoked by incoming classification. Dry eye results from damage to the somatic and visceral signals. Vagal stimulation lacrimal gland, secondary to the dysfunctional can also reduce seizure activity, blood pressure, and neural regulation of lacrimal gland secretion in anxiety. Actions such as these that have been conventional medicine.11 Problems arise in somatic linked to the stimulation of points on the face and afferent transmission, efferent autonomic reflexes, are explained at least in part by the relationship and signaling pathways governing secretion of between the trigeminal and vagus nerves.17 proteins, electrolytes, and water.11 Increased Certain eye conditions benefit from cytokine concentrations in the tear film can damage improved circulation. All of the periocular TCVM corneal nerves, causing diminished corneal point actions mention Benefiting and Brightening sensation and reduced reflex tear formation.12 the eyes. From a TCVM perspective, “moistening” These cytokines may also decrease parasympathetic of the eyes promotes good eyesight; the Blood nerve transmission.13 Lacrimal nerve injures the stored in the Liver produces this effect.18 lacrimal gland by promoting substance P release Trigeminal nerve stimulation causes a reflex

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activation of autonomic ganglia, leading to reflex could benefit an individual by calming the nervous vasodilation of vessels leading to the eye.19 system. Trigeminal stimulation also invokes release of the Reflexes between the trigeminal nerve and vasoactive neuropeptides, calcitonin gene-related the vagus Tonify the Stomach and Tonify the Small peptide (cGRP) and substance P.20 This reflex Intestine. This fact explains how facial acupuncture arc induces the release of vasoactive intestinal point stimulation can improve the signs of colic in polypeptide (VIP) and nitric oxide (NO).20 horses, through restoration of gastrointestinal Stimulation of BL-2 (Zanzhu) and Yuyao motility.26 In fact, part of the trigeminocardiac significantly increases mean blood flow velocity in reflex picture involves gastric hypermotility.27 the middle cerebral and ophthalmic arteries.21 Finally, for safety in needling canine Moreover, acupuncture stimulation of BL-2, Yuyao, periocular acupuncture points, the lack of a TH-23, and GB-1 significantly increases blood complete bony orbit in dogs must be considered. flow velocity in the supratrochlear artery.22 For neuroanatomic accuracy, the canine ST-2 is Several of the periocular acupuncture points located at the infraorbital foramen on the nose. A treat head pain and Alleviate pain, Relax the neuroanatomic perspective can be useful to create a sinews. For tension headache related to the more accurate location for transpositional occipitofrontalis muscle tension, research has acupuncture points in dogs and explain the TCVM documented anatomical and functional convergence effects described centuries ago. of trigeminal and cervical afferent pathways in humans and non-humans.23 24 This communication REFERENCES helps explain how periocular points Relax the 1. Dung HC, Clogston CP, and Dunn JW. sinews. Some headaches arise from irritation of Acupuncture – an Anatomical Approach. Boca the cranial dura, which receives substantial Raton: CRC Press, 2004, p. 3. innervation from the trigeminal nerve, or from 2. Robinson NG. The need for consistency and dysfunction of the trigeminal nerve itself, as in comparability of transpositional acupuncture cluster headaches. 20, 25 Facial autonomic changes of points across species. AJTCVM. 2006; 1 lacrimation and conjunctival injection closely (1):14-21. resemble findings associated with TCVM Liver 3. Still J. Relationship between electrically active conditions. Successful treatment with acupuncture skin points and acupuncture meridian points in may involve neuromodulation accomplished by the dog. American Journal of Acupuncture. stimulating either the ophthalmic or infraorbital 1988;16(1):55-71. divisions of the trigeminal nerve. 4. Ozudogru Z and Aksoy G. A macroscopic In TCVM, seizures arise from Internal Wind investigation of the nerves to the eye and ocular and the treatment strategy is to Expel Wind. The annexes in the Van cat. Veterinary Research approach to epilepsy targets acupuncture points that Communcations. 2005;29:361-371. Expel Internal Wind. From the neuroanatomic 5. Evans HE. Miller’s Anatomy of the Dog, 3rd viewpoint, these acupuncture points send signals to edition. Philadelphia: WB Saunders Co., the NTS by way of the trigeminal nerve. Vagal 1993. Pp. 962-967. nerve stimulators treat seizures by direct vagal 6. Shankland WE. The trigeminal nerve. Part II: nerve stimulation. However, acupuncture can also the ophthalmic division. J Craniomandibular activate the vagus nerve indirectly through the Practice. 2001;19(1):8-12. trigeminal nerve and NTS and thereby reduce 7. Shankland WE. The trigeminal nerve. Part III: seizure activity.17 the maxillary division. J Craniomandibular Besides reducing redness in the eyes, Fire in Practice. 2001;19(2):78-83. TCVM can generate anxiety and treatment is given 8. Evans HE. Op cit. P. 979. that Extinguishes Fire. Given the connections 9. Evans HE. Op cit. P. 157. between the trigeminal pathways and 10. Deadman P and Al-Khafaji M. A Manual of parasympathetic function, as exhibited by Acupuncture. East Sussex: Journal of Chinese trigeminocardiac reflexes, it follows that less Medicine Publications, 1998. P. 130. vigorous stimulation than that caused by surgery

AJTCVM Vol 2, No.1, Summer 2007 43 11. Dartt DA. Dysfunctional neural regulation of neurovascular reflexes in the anaesthetized cat: lacrimal gland secretion and its role in the role of endothelinB receptors in carotid pathogenesis of dry eye syndromes. The vasodilatation. British Journal of Ocular Surface. 2004;2(2):76-91. Pharmacology. 1999;126:485-493. 12. Mathers WD. Why the eye becomes dry: a 21. Goadsby PJ. Trigeminal autonomic cornea and lacrimal gland feedback model. cephalalgias. Pathophysiology and The Contact Lens Association of classification. Rev Neurol. 2005;161(6-7):692- Ophthalmologists Journal. 2000;26(3):159- 695. 165. 22. Litscher G. Computer-based quantification of 13. Schafer M, Carter L, and Stein C. Interleukin 1 traditional Chinese-, ear- and Korean hand beta and corticotrophin-releasing factor inhibit acupuncture: Needle-induced changes of pain by releasing opioids from immune cells in regional cerebral blood flow velocity. inflamed tissue. Proceedings of the National Neurological Research. 2002;24:377-380. Academy of Sciences USA. 1994;91:4223. 23. Litscher G, Wang L, Yang NH, et al. Cited in: Mathers WD. Why the eye becomes Computer-controlled acupuncture®. dry: a cornea and lacrimal gland feedback Quantification and separation of specific model. The Contact Lens Association of effects. Neurological Research. 1999;21:530- Ophthalmologists Journal. 2000;26(3):159- 534. 165. 24. Busch V, Jakob W, Juergens T, et al. 14. Maciocia G. Diagnosis in Chinese Medicine – Functional connectivity between trigeminal and A Comprehensive Guide. Edinburgh: occipital nerves revealed by occipital nerve Churchill Livingstone, 2004. Pp. 632-633. blockade and nociceptive blink reflexes. 15. Menétrey D and Basbaum AI. Spinal and Cephalalgia. 2006;26:50-55. trigeminal projections to the nucleus of the 25. Alstermark B, Pinter MJ, Sasaki S, et al. solitary tract: a possible substrate for Trigeminal excitation of dorsal neck somatovisceral and viscerovisceral reflex motoneurones in the cat. Experimental Brain activation. Journal of Comparative Neurology. Research. 1992;92:183-193. 1987;255:439-450. 26. Bauer DF, Youkilis A, SChenck C, et al. The 16. Yilmaz T, Erol FS, Yakar H, et al. Delayed falcine trigeminocardiac reflex: case report and trigeminocardiac reflex induced by an review of the literature. Surgical Neurology. intraorbital foreign body. Case report. 2005;63:143-148. Ophthalmologica. 2006;220(1):65-68. 27. Shoja MM, Tubbs RS, Ansarin K, et al. 17. Reddy KRM, Chandramouli BA, and Rao Proposal for the existence of a nasogastric GSU. Cardiac asystole during radiofrequency reflex in humans, as a potential cause of upper lesioning of the trigeminal ganglion. J gastrointestinal symptoms. Medical Neurosurg Anesthesiol. 2006;18(2):163. Hypotheses. 2007; in press. 18. Cakmak YO. Epilepsy, electroacupuncture and 28. Schaller B. Trigeminocardiac reflex – a the nucleus of the solitary tract. Acupuncture clinical phenomenon or a new physiological in Medicine. 2006;24(4):164-168. entity? J Neurology. 2004;251:658-665. 19. Maciocia G. Op cit. P. 62. 29. Moore KL and Dalley II AF. Clinically 20. Raval P, Bingham S, Aiyar N, et al. Oriented Anatomy. 4th edition, 1999. P. 856. Trigeminal nerve ganglion stimulation-induced

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