Historical Findings: The patient is a 40-year-old female, married with two kids, ages three and six. She complains of ringing in her left ear, impaired hearing, and severe dizziness. She describes the symptoms effecting her left ear as feeling similar to a swimmer’s ear, with pressure, ringing, and impaired hearing as lasting up to a few hours. She complains of these symptoms starting and persisting for the past month. She notes that the start of such episodes started with a frequency of about once a week, but then she began having more episodes in a week as the month progressed. Her longest episodes of ear ringing and dizziness have lasted up to a couple of hours. Other symptoms she has experienced include nausea, occasional throwing up, and sometimes a headache in conjunction with her initial symptoms. When asked if anything is done to alleviate the symptoms, the patient notes that the episodes and symptoms end on their own and nothing seems to cause their onset. She has undergone no recent surgeries or procedures within her head or ears. Besides the patient’s chief complaint, the patient has a very healthy diet and exercise regime though she is unable to exercise when she is having an episode as it just exacerbates the pain to jump or run. The patient is not currently employed, she does not drink or smoke, she sleeps between 6-8 hours a night, and she is not allergic to anything except for seasonal allergies for which she takes Zyrtec (Cetirizine). When asked about any family history of medical conditions and illness, the patient described that her mother used to suffer from migraine headaches. There is no family history of cancer, heart disease, or tuberculosis.
Physical Exam Findings: The patient’s vitals included a temperature of 98.6 degrees Fahrenheit, a pulse of 65 beats per minute, a respiratory rate of 14 breaths per minute, a blood pressure of 112/68. Nothing I observed about the patient’s physical appearance was wrong. There was no visible inflammation in either of her ear canals or tympanic membranes when I examined with an otoscope nor any perforations. The patient’s neurological test was normal. A hearing test showed mild hearing loss in her left ear though the patient noted she was not experiencing an episode of ringing in her ear at the time of the test.
Differential Diagnosis Based on the information provided during the medical interview, my leading hypothesis with the highest pre-test probability is that the patient has Meniere’s Disease. The patient’s experience of recurrent episodes of vertigo or dizziness lasting a couple of hours, more than one occasion of hearing loss or aural fullness in her left ear (unilateral), and tinnitus or ringing in the same affected ear match the triad of symptoms associated with Meniere’s disease. The patient’s description of being asymptomatic in between attacks of vertigo and tinnitus also match the nature of the disease (Rae-Grant, 2017). There are no physical exam findings known to be specific to Meniere’s disease, consistent with my observations of no inflammation or perforations in the patient’s ears during a physical exam. The spontaneous and idiopathic onset of the vertigo and tinnitus episodes associated with nausea match the nature of Meniere’s disease, though a potential trigger can also be responsible for an attack such as the patient’s two young kids, increasing the likelihood for stress, sleep deprivation, or excessive intake of caffeine (Rae-Grant, 2017).
An alternative diagnosis with a lower pre-test probability than my leading hypothesis though still a possible diagnosis for this patient is vestibular migraines which can often be a cause for episodic vertigo (Walker & Daroff, 2018). The patient’s gender and family history indicate that she is at risk for inheriting migraines, with her mother being a migraine sufferer. Common symptoms for vestibular migraines that indicate a possible diagnosis for my patient are nausea and dizziness, decreased ability to function, and aura. The aura is a warning sign that some people get before they get a migraine and can include a ringing in one’s ears similar to what my patient described as having episodically along with dizziness and pressure in her ear on one side of her head. This unilateral nature of her symptoms on the left side of her head is also often an indicator of a migraine (BMJ Publishing Group, 2018, pp.1-4). My patient’s description of her symptoms included that she sometimes experiences the feeling of a headache during an attack. While a possible alternative diagnosis, hearing loss is much less common to be caused by a vestibular migraine making this hypothesis have a lower probability than Meniere’s disease (von Brevern, 2014).
Another alternative diagnosis is Autoimmune Inner Ear Disease (AIED), where the body’s immune system mistakenly attacks the inner ear. Symptoms of AIED include tinnitus, vertigo, nausea and difficulty hearing. AIED usually occurs in the context of an inflammatory condition confined to the inner ear as well as in association with a recognized autoimmune condition (Imboden, Hellmann, & Stone, 2015). The onset of hearing loss with AIED is rapid compared with other diseases, as patients experience hearing loss over the course of weeks to months which reflects the nature of my patient’s very recent onset of symptoms occurring within the past month (Agrawal & Francis, 2010). Often only one ear is affected initially, as with my patient, though bilateral hearing loss occurs in most patients with AIED (Bovo, Aimoni, & Martini, 2006). It is slightly more common in middle-age women, the age range of which my patient is close to, at the age of 40. AIED is much more rare than my leading diagnosis, Meniere’s disease, affecting less than 1% of all cases of hearing impairment or dizziness (Bovo, Aimoni, & Martini, 2006).
Diagnostic Work-Up: In order to help narrow down the differential diagnosis, I first propose a pure tone air audiometry test to provide evidence of hearing impairment and specify the type of hearing loss described by the patient. While sensorineural hearing loss often affects higher frequencies, the exception of Meniere’s disease is characteristically associated with low-frequency sensorineural hearing loss (Lalwani, 2018). Therefore, in the left and affected ear, I would expect thresholds of air and bone conduction indicative of low frequency sensorineural loss if my leading diagnosis of Meniere’s disease is correct (Harcourt, Barraclough, & Bronstein, 2014). Additionally, a contrast-enhanced MRI of the internal auditory canals should be done to both rule out other diagnoses but also to rule in my leading diagnosis and potentially increase its post-test probability. Imaging studies of patients with Meniere’s disease have been identified to show abnormalities of their endolymphatic drainage system such as smaller drainage systems (Zarandy & Rutka, 2010). MRI of the vestibular endolymphatic space has high specificity (96%), sensitivity (81%) and positive predictive value (88%) in differentiating Meniere’s disease ears from other ears, thus ruling in Meniere’s disease in patients with mimicking symptoms (Conte et al., 2018). MRIs are then beneficial to narrowing down this patient’s diagnosis and rule out inflammation that can be secondary to an auto-immune inner ear disease. There are no known adverse effects of MRI and my patient does not have any metal implants or pacemakers that would conflict with the strong magnetic field of the MRI. The MRI is beneficial as compared to an X ray or CT scan as it does not cause radiation exposure to the patient, though it can be more expensive, and the cost must be taken into consideration (Verbist, 2012). Lastly, tests of autoimmunity can detect or rule out the presence of an autoimmune condition such as auto-immune inner ear disease. Such tests would include taking bloodwork from the patient through an Antinuclear Antibody (ANA) blood test. The cost of this test would not be much compared to an exhaustive immunologic work-up study, which is found to not be necessary when evaluating a patient with suspected autoimmune inner ear disease (García-Berrocal et al., 2005).
Final Diagnosis: Given the clinical information collected from the history, physical exam, and results from diagnostic tests, I believe that my patient’s most likely diagnosis is Meniere’s disease. The pure tone air audiometry findings observed low-frequency sensorineural hearing loss in the patient’s left ear. Pure tone measurements of the affected ear at low-frequencies were 50dB at 250 Hz and 45dB at 500 Hz. At higher-frequencies, the pure tone measurements indicated increasingly normal hearing in the affected ear with 25 dB at 1000Hz and 20dB at 2000 Hz. In the contralateral ear, pure-tone measurements ranged from 20 dB at 250 and 500 Hz to 15 dB at 1000 and 2000 Hz, indicating normal hearing (Harcourt, Barraclough, & Bronstein, 2014). These measurements are consistent with the characteristic findings of Meniere’s disease (Rae-Grant, 2017). The MRI of the patient’s internal auditory canals show abnormalities to the endolymphatic drainage system which is a sign to support Meniere’s disease rather than a vestibular migraine or AIED (Zarandy & Rutka, 2010). Lastly, the patient’s bloodwork for the ANA test came back with titres of 1:40 which indicates low probability of an autoimmune disorder (Tan et al., 1997). These diagnostic results, in addition to the specific collection of symptoms expressed by the patient, including multiple spontaneous episodes of vertigo lasting more than 20 minutes and longer, hearing loss documented by an audiogram, and unilateral tinnitus and aural fullness experienced by the patient, are in line with the recommended guidelines for making a diagnosis of Meniere’s disease and distinguishing from my alternative diagnoses (Walker & Daroff, 2018).
Treatment Recommendations: No cure exists for Meniere’s disease, but treatments can help to reduce the frequency and severity of vertigo that the patient is experiencing, as well as to prevent any further hearing loss. My first recommendations for treatment would include behavioral modification by the patient, including dietary modifications. An ear affected by Meniere’s disease is unable to regulate fluid and electrolyte levels within the inner ear; therefore, it is intolerant to variations in sodium levels. As such, dietary modifications including a restriction of sodium and caffeine are recommended (Rae-Grant, 2017). A reduction in sodium may help to reduce the patient’s vertigo spells and a caffeine-free diet may improve over-all functioning in patients (Rae-Grant, 2017). A controlled trial was done and published in 2013 in which patients with Meniere’s disease either received written diet guidelines, were referred for nutritional counseling or sought counseling independently. Those who followed a low sodium and caffeine-free diet longer than 6 months had larger improvement in number of vertigo spells and functional rating. Greater understanding and knowledge of what foods to eat and avoid along with guidance from a dietitian correlated with the levels of hearing loss or improvement. Therefore, in order to avoid risks of patient misinformation or non-compliance with dietary modification suggestions, nutrition education would also be important. I would refer my patient to a registered dietitian to improve the outcomes of the dietary modification in the treatment of her Meniere’s disease and provide greater accountability for adhering to dietary guidelines (Luxford, Berliner, Lee, & Luxford, 2013). However, if dietary restrictions alone do not reduce the patient’s symptoms of vertigo, more treatments can be considered. Oral administration of a steroid such as prednisone can be used as a noninvasive way to help control vertigo for my patient. The frequency and duration of vertigo episodes for patients in a blinded, randomized controlled trial “were reduced by 50% and 30% respectively by prednisone treatment” in addition to a significant reduction in tinnitus (Morales-Luckie, Cornejo-Suarez, Zaragoza-Contreras, Gonzalez-Perez, 2005). However, if the patient’s vertigo is unmanageable through dietary modification or oral glucocorticoids, steroid injections into the ear are recorded as a “safe and effective” treatment for Meniere’s disease. Gentamicin is often considered to be a standard treatment for refractory Meniere’s disease, but has the potential to damage vestibular function and worsen hearing. If the patient has access to repeated injections by a clinician, the use of the steroid, intratympanic methylprednisolone, is an appropriate substitute treatment to gentamicin to reduce vertigo attacks while not contributing to further hearing loss. A clinical trial comparing intratympanic gentamicin with the corticosteroid methylprednisolone showed a decrease in vertigo attacks by 90% in the methylprednisolone group in the last 6 months of treatment as compared to 87% reduction in the gentamicin group (Patel et al., 2016). Indeed, a double-blind randomized controlled clinical trial in 2016 observed that just a single course of injections of corticosteroids such as methylprednisolone (two injections and thereafter further courses were given as-needed) can provide complete vertigo control at 2-years in about 50% of cases (Patel et al., 2016).