Nilla the mare with right-sided facial and trigeminal nerve injury following trauma
See the video HERE!
by Melissa S Knutzen DVM cVMA, December 11, 2024
Abstract: This case report follows the first 4 medical acupuncture evaluations and treatments for an 18 y/o female Quarter Horse (QH) named Nilla. Nilla suffered an acute trauma to her head and neck when she got her head stuck between a gate and fence post on 9/8/2024. The gate on her right side was applying direct and sustained pressure to her facial nerve along the right side of her face resulting in right-sided facial nerve paralysis. Despite medical therapy including anti-inflammatories and steroids being immediately instituted during the emergency veterinary visit, Nilla was still unable to move her ear, blink her right eye and had a significant muzzle deviation when I first visited her on 10/3/24. Acupuncture treatments were scheduled once per week for 4 weeks and during this time, the clinical signs of facial nerve paralysis noticeably improved. The owner was able to re-introduce dry hay rather than the wet mash and hay pellets she began feeding after the incident. Overall, Nilla returned to almost full facial nerve function and neck discomfort was significantly improved during our treatment period.
History: Nilla is a middle aged QH mare primarily used for trail riding by her owner. She has no significant medical issues prior to this acute injury. On 9/8/2024 Nilla was found by her owner with her head caught between a gate and a fence post. The post was applying direct pressure to the right side of her mandible and below her ear. The owner did not know how long she had been there. The owner called for an emergency veterinarian and was able to get the horse free while waiting. The owner immediately noticed the horse’s right side of her lip drooping and the muzzle deviated to the left. The horse was holding her head and neck rigid. Nilla was treated by the emergency veterinarian for superficial cuts and abrasions on both sides of the face. The veterinarian noted severe facial nerve paralysis of the right side with no voluntary movement of the ear, no palpebral reflex present (unable to blink the eyelids at all) and minimal sensation to the face and muzzle. She was started on a schedule of Banamine and Dexamethasone as well as eye lubrication ointment for the right eye to help prevent dry eye. A soft food diet was started to make eating as easy as possible. Over the course of 2 weeks the anti-inflammatories and steroids were tapered down but the eye lubrication was maintained as the horse still was not blinking reliably. Swelling and neck pain associated with the trauma was noted to be improving. With minimal ongoing improvement to the facial nerve signs, acupuncture was determined to be the next step.
Initial Exams:
Gait analysis: Horse is able to stand comfortably with all 4 feet distributing weight equally. Normal gait when walking away and towards me. No significant lameness observed.
Neuro exam: Normal proprioception of the limbs. No signs of vestibular abnormalities. Right sided facial nerve paralysis consisting of ear drop, minimal blink/palpebral response, lower lip droop on the right side and muzzle deviation to the left. The horse shows retractor bulbi reflex and third eyelid movement with palpation around the right eye. Pain response (as assessed with a finger pinch) is dulled or absent from the TMJ joint on the right side and all along the right masseter muscle and down towards the muzzle. The horse responds to a hard pinch near the muzzle and right ear showing that she can feel these areas but moves her whole body away as she cannot move the individual areas. Nilla appears to have good sensation around the eye and medial side of the ear and forehead as she responds to tapping pressure and a light pinch. In summary, on initial exam Nilla shows severe facial nerve paralysis as evidenced by the lack of voluntary or reflex movement of the muscles of facial expression as well as partial dysfunction of the trigeminal nerve as evidenced by the nonresponse to painful stimuli in certain areas of the right side of her face. All other cranial nerve function is within normal limits.
Myofascial exam: Lower Limb assessment as follows. Normal balance and flexion of all 4 limbs. Decreased scapular lift bilaterally, approximately 75% of what it should be. Restriction of outward rotation of the right shoulder 50% of normal. Normal hind limb circles bilaterally. Myofascia is tight and immobile bilaterally on the neck from poll to scapula. Palpable swelling along the masseter muscle on the right side almost following right along where the facial nerve likely runs. Myofascial tissue of the thoracic spine within normal expectation and thoracic spine mobility and comfort is good. Lumbar spine shows mild restriction of myofascia and approximately 10 % decrease in rotational movement to the right and left hind limb as assessed by lower limb circles. Pelvic assessment is within normal limits for a horse of this age. Good BL 26 drop bilaterally and excellent BL 27 SI flex and tuck bilaterally. Neck flexion was surprisingly good. Perhaps very mild decreased willingness to flex to the right side.
The following acupuncture trigger points were found on exam; on the horse’s right side ST 7 (a and b) points of swollen/ firm myofascia and subcutaneous tissue located distal and rostral from ST 7 along the masseter muscle of the right mandible, BL 10 and TH 16 on the right side of the neck.
Problem List:
- Right-sided facial nerve and trigeminal nerve dysfunction
- Mild discomfort of the neck
- Dry eye of the right eye based on Schirmer Tear test (STT) with the right eye result at 14 and left eye eye at 22 for a 6 second period.
Diagnosis: Right-sided facial nerve paralysis and trigeminal nerve dysfunction with some lingering discomfort and myofascial restriction of the neck (primarily the muscle and myofascial of the right upper cervical area) related to the traumatic event.
Plan: After assessment, I discussed with the owner the need to treat weekly (more was not possible financially) to stimulate the facial nerve, trigeminal nerve and muscles and tissues these nerves serve. Since I am new to this and the horse is new to this, I planned to use fewer needles and no electroacupuncture (e-stim) on the initial visit and try adding in more points and e-stim in follow up visits. Neck discomfort will be addressed with the following points placed bilaterally: GB 21, LI 16, LI 17, TH 16 and SI 16 and BL 10. The nerve paralysis on the right side of the face will be addressed locally using TH 17, ST 7 (plus a and b trigger points as described in the exam), ST 4, ST 2, BL 2, and San Jiang. Midline points of Da Feng Men and GV 14 were also incorporated for neck to poll pain. Ear points including SI 19 and GB 20 may be incorporated as the horse tolerates. I advised the owner to perform gentle massage of the masseter muscle, muzzle and below the ear or to consider getting an at home LASER to continue nerve and tissue stimulation on a daily basis. Continue eye lubricant 3 times daily.
Treatments:
First treatment 10/3/24 (video and still photos): Seirin Purple 0.25 x 30 mm: Bilateral GB 21, LI 16, LI 17. Right side only TH 16 and SI 16; Seirin Red 0.16 x 30 mm: right side only Th 17, ST 7 (*a and b at trigger points in masseter muscle), ST4, ST 2, BL 2; Treatment time 20 minutes. During this treatment, the horse was observed to start voluntarily blinking her right eye (see video).
Second treatment 10/10/24: Seirin Purple 0.25 x 30 mm: Bilateral GB 21, LI 16, LI 17; Seirin Brown 0.3 x 40 mm: GV 14; Seirin Blue 0.2 x 30 mm: right side only Th 17, ST 7, ST 4 and ST 2; Seirin Red 0.16 x 15 mm: Da Feng Men, right side only GB 20, SI 19, BL 2, San Jiang; E-stim at low Hz level 3-3.5 using ITO unit (dial turned up until visible twitch in the tissues) for 15 minutes. Lead 1 TH 17 to ST 2, Lead 2 ST 7 to ST 4; Treatment time 25 minutes.
Third Treatment 10/16/24 (video of improved blinking during treatment): Seirin Purple 0.25 x 30 mm: Bilateral GB 21, LI 16, LI 17, BL 10; Seirin Brown 0.3 x 40 mm: GV 14; Seirin Blue 0.2 x 30 mm: right side only Th 17, ST 7, ST 4 and ST 2; Seirin Red 0.16 x 15 mm: Da Feng Men, right side only GB 20, LI 20, SI 19, BL 2, San Jiang.
E-stim at low Hz level 3.5 -4 using ITO unit (dial turned up until visible twitch in the tissues) for 20 minutes. Lead 1 TH 17 to ST 2, Lead 2 ST 7 to ST 4; Treatment time 25 minutes. Schirmer Tear Test (STT) result right eye 17, left eye 21
Fourth Treatment 10/29/24: Seirin Purple: Bilateral GB 21, LI 16, LI 17; Seirin Brown: GV 14; Seirin Blue: right side only Th 17, ST 7, ST 4 and ST 2; Seirin Red: Da Feng Men, right side only GB 20, LI 20, SI 19, BL 2, San Jiang. E-stim at low Hz level 3.5 -4 using ITO unit (dial turned up until visible twitch in the tissues) for 20 minutes. Lead 1 TH 17 to ST 2, Lead 2 ST 7 to ST 4;Treatment time 25 minutes. Schirmer Tear Test (STT) result right eye 22, left eye 22
Outcome: With each treatment, the owner noted significant improvements throughout the week that followed. The best observed initial improvement was in Nilla’s ability to blink, followed by ear movement and less noticeable muzzle deviation. The lower lip droop lagged behind a bit but did improve markedly by the last session. By the second visit, I noted on exam that the myofascia of the neck was much less rigid and tied down. And by the third visit the previous trigger points at BL 10 and TH 16 were no longer tight and eliciting a pain response. Objectively, the Schirmer Tear Test result improved throughout the treatment period with the marked disparity in the result between the left eye and right eye improving each time until at the last visit they were in fact equal and eye lubricant treatment was discontinued. Additionally, the map of where Nilla responded to painful stimuli (pinch) expanded with each visit. At the last visit, there was a small area of dull response ventral and caudal on the masseter muscle, but sensation seemed to have returned to much of the right side of the face. Additionally, obvious muscle tension had returned to the upper and lower lip, although the lower lip lagged behind somewhat. Nilla was able to eat normal hay rations, and the wet food mash and hay pellets had been discontinued. The plan was to continue treatments at every other week for an additional 2-3 sessions.
Overall, I feel this treatment was incredibly successful and well tolerated by the patient. The acupuncture and e-stim used locally over the facial nerve and trigeminal nerve as well as the muscles of facial expression, allowed biofeedback to the brain to elicit improved peripheral nerve healing, decreased local inflammation, and improved ability to transmit signals of sensation. The points I used and E-stim set up were guided both by material provided in this course and by the published case reports listed in the references. Factors that may have led to greater or quicker success include starting acupuncture in a quicker timeframe after the initial injury, more frequent treatments as is often available in a hospital setting, and a more confidant acupuncturist. This case was quite literally my first one after completing the CuraCore course and I was cautious about placing too many needles and overstimulating the patient or leading to her reluctance to participate in the treatment.
References:
- Fourmestraux C, Tessier C and Touzot-Jourde G. Multimodal therapy including electroacupuncture for the treatment of facial nerve paralysis in a horse. Equine vet. Educ. (2013) doi: 10.1111/eve.12042
- Jeong HS, Kim NS, and Kim MS. Use of Electroacupuncture Treatment on Traumatic Facial Nerve Paralysis in a Horse. J Vet Clin 32(1) : 105-107 (2015) http://dx.doi.org/10.17555/ksvc.2015.02.32.1.105