RENEW OR SUBSCRIBE TO PPM
Subscription is FREE for qualified healthcare professionals in the US.
4 Articles in Volume 2, Issue #4
An Historical Perspective: A Global View of Evolving Pain Treatment Modalities
Percutaneous Disc Decompression/ Discectomy - A Case Report
Practical Headache Pearls
Temporomandibular Joint Disorder Mimic Ernest Syndrome Diagnosis and Treatment

Temporomandibular Joint Disorder Mimic Ernest Syndrome Diagnosis and Treatment

Often accompanied by other orofacial disorders and capable of mimicking other pain conditions, Ernest Syndrome is often missed or misdiagnosed.

Orofacial pain is a term commonly used to describe pain involving the hard and soft structures of the face, head, oral cavity and neck.1 Ernest Syndrome, one of several orofacial disorders, is often mistaken for temporomandibular disorder (TMD), which is itself a type of orofacial dysfunction that comprises a number of symptoms involving the TM joints, the muscles of mastication and related structures and is often accompanied by TM joint noises, restrictions in opening, lateral jaw deflection to the affected side and impaired functional ability.

Ernest Syndrome, on the other hand, involves the stylomandibular ligament (SML) and its insertion on the posterio-medial aspect of the mandible. The origin of the SML is the styloid process, a bony protuberance that is attached to the temporal bone, just anterior to stylomastoid foramen and extends inferiorly in an antero-medial direction (see Figure 1).1,2 The SML insertion is on the posterio-medial border of the mandibular approximately 10 mm to 15 mm superior to the gonial angle.3,4

Symptoms

The symptoms of Ernest syndrome are temporal headache pain, eye pain, pain in the mandible itself, pain in and around the TM joint, ear pain and fullness, odontalgia, throat pain and pain in other orofacial areas.5 Two different stages of this disorder have been identified by Dr. Ernest. The initial stage has tenderness below the ear and in the posterior mandible near the gonial angle. In the later stages, subjects may have pain in the TMJ, eye and the area behind the eye — possibly with vision changes, mandible, throat, zygomatic arch and coronoid process, temporal region and mandible posterior teeth. Ear symptoms such as pain, fullness and stuffiness are frequently seen along with TMJ clicking or locking, and restricted jaw ranges of motion. Neck and shoulder complaints also occur occasionally.6 These symptoms are similar to the symptoms of internal derangement of the TM joint, temporal tendinitis, and occipital neuralgia, which this disorder can mimic (see Table 1). 5,7

Figure 1. The stylomandibular ligament insertion on the posterior medial aspect of the mandible. Figure 2. The stylomandibular ligament insertion can be located with a blunt probe with a small end. Figure 3. The injection site on the medial side of the mandible.

Diagnosis

Ernest syndrome is best diagnosed utilizing the patient’s history, site palpation, and successful application of an anesthetic block of the SML insertion. The subject must have a positive history of pain in a known referral area. This pain must be present at the SML mandibular attachment, and most importantly, the subject’s pain must be reduced with a local anesthetic injection into the SML insertion. Bell and Mahan recommend diagnostic anesthetic blocks to differentiate pain syndromes.8,9

The injury site is located by palpating 10mm to 15mm superio-medially from the mandibular angle on the painful side. The SML’s insertion is in close proximity to the parotid gland, the posterior belly of the digastric and the medial pterygoid muscle. While the above structures and the transverse process of the atlas are in the area of the SML and are sensitive to firm palpation, a symptomatic SML is very sensitive and on the medial aspect of the mandible. A comparison of Ernest Syndrome symptoms with myofascial trigger point symptoms in the posterior digastric and medial pterygoid are listed in Table 2 to aid the practitioner in isolating the SML insertion.10

A blunt small-headed probe, such as a Hu-Friedy #BB 27/29, can be used to apply pressure antero-medially to a small area during the evaluation (see Figure 2). If the ligament insertion is the source of the complaint, then pressure will produce intense pain and often referral to one or more of the sites previously mentioned. Prior to injecting, the site can be marked and should be cleaned with an antiseptic solution.

A 30-gauge needle with a short-duration, plain anesthetic (i.e. 3% carbocaine) is suggested for diagnostic purposes. Relocate the site with a probe and slowly insert the needle in close proximity to the probe in an antero-medial direction on the medial aspect of the mandible (see Figure 3). Often the patient will relate during the injection that the pain is being referred to one or all of the known referral sites.

Usually, the needle insertion depth is 10 to 15mm and ½ to 1 cc of anesthetic solution is deposited very slowly. Aspiration during the injection is very important because of the close proximity of major vascular structures to the SML attachment. The area is reevaluated after 10 minutes and if the patient has significant or complete pain remission, a diagnosis of Ernest syndrome is suspected. If only partial pain reduction is experienced, a second injection may be indicated, as some SML are very broad.1,4 Prior to the injection, the patient should be advised of the possibility of anesthesia to the facial nerve. Note that the duration of the analgesic effect may often outlast the anesthesia’s duration.11

Symptom Comparison
Symptom   Disorder
  Ernest Syndrome Temporal Tendinitis TM Disorders Occipital Neuralgia
TMJ pain 3 3 3  
Headache 3 3 3 3
Ocular pain 3 3 3 3
Otalgia 3 3 3  
Face pain 3 3 3  
Odontalgia 3 3 3  
Mandibular pain 3     3
Throat pain 3      

Methods

This study identified one hundred and twenty eight subjects with Ernest Syndrome from a group of two hundred and seventeen subjects having orofacial pain and/or TMD complaints (an incidence rate of 59%). Each individual in this study had a history of pain in one of the specific referred pain areas of Ernest syndrome listed previously. They also experienced pain when the insertion of the SML was palpated and had relief of pain when the SML insertion was anesthetized.

The location of the SML injury was determined in each subject as to being unilateral or bilateral and the number and sites of the subject’s pain complaints were charted. The subjects were questioned about the cause of onset of their SML pain and given a comprehensive physical examination with panoramic imaging. Imaging was used to rule out an elongated styloid process and/or ligament calcification. Each subject with positive findings was given an anesthetic injection at the painful SML insertion.

Results

In this prospective study, 128 subjects were found to have Ernest syndrome (59%). Of these subjects, 103 were women (80%) and 25 were men (20%). Ninety-nine subjects (77%) of the Ernest syndrome group could identify an event that initiated their condition (see Table 3). Eighty-eight of these subjects (69%) had Ernest syndrome bilaterally. Of the remainder, 17 subjects (13%) had Ernest syndrome on the right side, while 23 subjects (18%) had it on the left side.

The areas of reported pain are listed in Table 4. Pain in the mandible (angle of the jaw) was the most common reported symptom at 82%. It was followed by pain in the ear (67%), TMJ (65%), temporal (59%), teeth (38%), eye (37%), throat (32%), neck (30%), zygoma (28%), shoulder (5%), and nose (2%).

Anesthetic blocks were successful in significantly reducing the pain and helping to arrive at the diagnosis of Ernest syndrome for each subject.

Discussion

The SML is an accessory ligament of the Temporomandibular Joint articulation3 and has consistently been identified as a distinct stylomandibular ligament structure during human neck dissections.5,12 The SML has been characterized as a protecting, suspensory, and check-rein ligament.13-15 Its function is to resist wide openings of the mandible and limit extreme protrusion and it plays a major role in protecting the TM joint.16,17 Neff suggested that the SML and the sphenomandibular ligament together might influence the envelope of motion within which the mandible articulates.14

Trauma was identified as the most frequent initiating factor... (including) motor vehicle accidents and direct blows to the mandible...

The pathological process may begin when jaw movements exceed the physiological limits of the SML, resulting in micro or macroscopic periosteal tears.18 These events may initiate degenerative changes that begin in the ligament’s attachment where the Sharpey’s fibers insert into the bone. These findings have been confirmed histologically.19,20 As the degenerative changes progress, normal mechanical stress through the Sharpey’s fibers can results in tenderness, limitation of motion and referred pain.1 This disorder has been termed an insertion tendinosis and has been identified in different parts of the body.21,22

Eighty percent of subjects with SML pain in this study were females consistent with women having a higher incident of TMD-type pain. Trauma was identified as the most frequent initiating factor of SML pain in this study, which is consistent with previous studies.19,23 Trauma from motor vehicle accidents and direct blows to the mandible has been found to contribute to this condition in previous studies.1,6,18,19,23,24 Additionally, SML pain has been reported with jaw advancement surgery, difficult mandibular tooth removal, back injury, cervical traction, intubation, and air bag injuries in a small number of cases.4,5

The presence of additional disorders with Ernest syndrome, Table 5, underscores the necessity of anesthetic blocking to confirm the diagnosis.

Comparison with Myofascial Trigger Points Symptoms
Symptom   Myofascial Trigger Point
  Ernest Syndrome Median Pterygoid Posterior Digastric
Mandibular pain 3 3 3
Otalgia 3 3 3
TMJ pain 3 3  
Temporal pain 3    
Odontalgia 3    
Ocular pain 3    
Throat pain 3 3 3

Treatment

A number of methods using both surgical and non-surgical approaches have been used to treat SML disorders. The treatment of choice is anesthetic blocks of the affective ligament insertion at two-week intervals, if necessary. Iontophoresis, for subjects who are needle-phobic, has also been shown to be effective in managing SML pain.25 Ultrasound, cold laser and infrared light therapy have been used successfully for conservative therapy.1,26 Surgery is necessary in 20 percent of the cases and the primary surgery, precutaneous radio-frequency thermoneurolysis, has proven successful for these individuals.18,27 An open retromandibular surgical approach to sever the ligament at its insertion has been reported in addition to an alternative procedure of stripping of the ligament’s attachment to the mandible.1,4

Following diagnostic anesthesia blocking, a soft diet (to reduce the forceful mandibular movements), ice and analgesics are recommended for the first 24 hours to control swelling and pain. The following day, moist heat can be used to promote blood flow and healing. An injection with an anesthetic and 1 ml of synthetic cortisone (e.g., beta-methasone sodium phosphate and betamethasone acetate) with a medrol dose pack may also be necessary for two or three sessions in the event pain continues. Sarapin (a non-steroidal anti-inflammatory) can be used as an alternative to the betamethasone at two weeks intervals.

A flat plane splint is indicated if parafunction (clenching or bruxing the teeth) is evident, because this activity is detrimental to the healing of the ligament’s insertion.

Initiating Events
Events No %
Whiplash 46 35
Automobile accident
(direct trauma)
44 34
Unknown 29 22
Blow to the
mandible
4 3
Slip/dental trauma/
snoring appliance
3 2
Airbag trauma 2 1
Areas of Reported Pain
Areas No. %
Mandible 106 82
Ear 87 67
TMJ 83 65
Temporal 76 59
Teeth 49 38
Eye 47 37
Throat 41 32
Neck 39 30
Zygoma 36 28
Shoulder 7 5
Nose 2 2
Other Disorders
Disorders No. %
Temporal tendonitis 98 76
Internal joint
derangement
96 75
Myofascial pain
dysfunction
88 68
Occipital neuralgia 14 10

Conclusions

Ernest syndrome is a condition that can mimic several different pain disorders and is often missed or misdiagnosed. Injury to the SML can cause TMD-like symptoms. Trauma appears to be the most frequent initiating factor of Ernest syndrome and anesthetic blocking is the best method to confirm the diagnosis.

Last updated on: May 6, 2019
close X
SHOW MAIN MENU
SHOW SUB MENU