Misophonia: A Neurologic, Psychologic, and Audiologic Complex

iStock/nicoletaionescu, misophonia, pain, health.

Figure 1: CBT-based case formulation model in distress caused by misophonia.³⁶ Misophonia, pain, health.

Box: Resources on Misphonia.

Misophonia¹ is a newly described condition that is still not thoroughly understood. To her credit, Marsha Johnson, AuD, was the first to informally discuss sensitivity to specific sounds in online support groups for patients with hyperacusis, and documented about 500 cases of similar sound sensitivity problems in the late 1990s (personal communication, Dec. 3, 2019). She designed the term selective sound sensitivity syndrome (S4), which is still used today to describe misophonia. Later, Margaret Jasterboff, PhD, and Pawel Jastreboff, PhD, coined the term misophonia (which conservatively means dislike of sound),^1,2 and other scientists such as Tyler, et al., refer to essentially the same condition as annoyance hyperacusis.³

Misophonia is considered sound intolerance and oversensitivity to certain sounds, which can result in distraction and annoyance that may limit a person's ability to concentrate, think, and learn.⁴ Some of the trigger sounds include gum popping, lip-smacking, food chewing or crunching, throat clearing, nose sniffing, breathing, tapping, and clicking.^{3, 5-8} Misophonia has yet to be classified in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-V); and unfortunately, the scientific community has not reached a consensus to categorize this condition as an auditory, psychiatric/psychologic, or neurologic ailment. This lack of recognition not only prevents health care providers from officially classifying the disorder but also hinders affected individuals from seeking help.

COEXISTING CONDITIONS

Misophonia can be associated with high levels of anxiety⁹ and comorbid factors, including post-traumatic stress disorder (PTSD), obsessive-compulsive disorder (OCD), and anorexia.^10,11 Autonomous sensory meridian response (ASMR), usually triggered by auditory and visual stimuli, has been associated with heightened levels of misophonia. ASMR is described as a relaxing tingling sensation that starts from the head and neck and spreads through the body.¹² Although sound sensitivity and hyperacusis have been investigated in autism spectrum disorder (ASD),^13,14 misophonia has not been explored in children and adults with ASD. Misophonia can also cause academic difficulties. Connie Porcaro, PhD, a university professor, was concerned about misophonia awareness among her peers in the academic community. In 2019, she designed a study to see how much the university instructors knew about misophonia and what they would do to accommodate students with this condition in their classrooms. Of the 686 survey participants, only 18.4 percent self-reported having knowledge of misophonia. Instructors who knew about this condition indicated that they would be willing to provide classroom accommodations for those who suffer from misophonia.⁴

UNDERLYING CAUSES & NEURAL CORRELATES

The neural correlates of misophonia have been explored, with areas of interest that include the non-classical auditory pathway, limbic system, and auditory cortices.^{7, 15-18} Kumar and colleagues employed fMRI in individuals with misophonia while they were exposed to unpleasant trigger sounds.¹⁶ The researchers found increased neuronal activities in an area referred to as the anterior insular cortex (AIC). Although the findings of this study have been questioned by some researchers,¹⁹ it still is considered as one of the strongest pieces of evidence for a neurological origin of misophonia. It is believed that AIC, in general, is a major player in emotional awareness,²⁰ and one can simply expect the increased responses in this area in individuals with misophonia when they are exposed to trigger sounds. Schröder and colleagues provided additional evidence for a neurobiological basis for misophonia. They studied the response of the N1 component of late auditory evoked potentials to oddball stimuli in a group of subjects with misophonia. Their findings indicated a reduced amplitude in N1 to oddball stimuli. They concluded that a neurobiological deficit in those with misophonia could potentially impair auditory processing of incoming stimuli.¹⁸ Another fMRI study has shown some correlations between misophonia and OCD. fMRI data have indicated that those with misophonia have perfectionist and compulsive behaviors.²¹ These findings may support the clinical observation of annoyance at chewing sounds in those with misophonia.

Additionally, genetics may play a role in misophonia. Although no strong research supports a genetic basis of misophonia, Sanchez and Silva from Brazil have reported a family with 15 members with misophonia and a possible autosomal dominant inheritance.²² Anecdotally, some of our patients have reported a mutation in chromosome 5 when they checked their genetic makeup using commercially available kits. Interestingly, a gene by the name of TENM2, which is involved in brain development, has a cytogenic location at 5q34 (in chromosome 5, longarm region 3 band 4).²³

MISOPHONIA EVALUATION

No standard questionnaire has been developed for misophonia. During the evaluation, patients are usually asked to complete a set of surveys, such as the Misophonia Questionnaire,²⁴ which has three subscales: the Misophonia Symptom Scale, Misophonia Emotions and Behaviors Scale, and Misophonia Severity Scale. Another useful tool is the Amsterdam Misophonia Scale (A-MISO-S),²⁵ which is widely used in many clinics. There are no universally accepted protocols for misophonia evaluation. Dozier, et al., have proposed a set of diagnostic criteria for misophonia that employs a variety of misophonic stimuli, including both auditory and visual modalities.²⁶ Some clinics may measure loudness discomfort levels, particularly if misophonia is associated with hyperacusis. Aazh and colleagues described the loudness level measures in a group of children and adolescents with tinnitus and hyperacusis, and noticed that the uncomfortable loudness levels (ULLs) were at least 20 dB lower at 8 kHz than at 250 Hz.²⁷ These findings also provide important information on the assessment of misophonic triggers, such as high-pitched screeching, that are reported by some patients.

MANAGEMENT PROTOCOLS & METHODS

Misophonia can be managed through tinnitus retraining therapy (TRT), cognitive behavioral therapy (CBT), compassion training, distress tolerance, mindfulness, and acceptance-based treatment, among others.²⁸ Comorbid conditions such as depression and anxiety could be treated with antidepressants and anxiolytics. Brout and colleagues recommended a multidisciplinary care pathway to develop coping skills through CBT, mindfulness, and behavioral change.²⁹ In general, it is understood that mental health and comorbid factors such as anxiety and depression can exacerbate misophonic responses. Parental mental health has also been explored, and the effectiveness of treatment for sound sensitivity disorders has been shown to influence the treatment of people with a history of parental mental health illness.^{30, 31}

TRT. TRT employs extensive counseling and sound therapy. In a study by Margaret and Pawel Jastreboff, on a relatively large number of patients with decreased sound tolerance disorders, 152 out of 184 patients with both misophonia and hyperacusis and 139 out of 167 patients with misophonia alone experienced improvements after TRT.³² In the clinical practice of Ali Danesh, PhD, the use of ear-level sound generators with pleasant signals such as Zen fractal music or other sounds streamed via a smartphone to a Bluetooth hearing device, combined with extensive counseling, were shown to be helpful in managing those with misophonia. However, no solid evidence-based data are available for this observation.

CBT. Since the models describing hyperacusis and tinnitus have significant commonalities with misophonia, it can be presumed that the methods used to treat tinnitus and hyperacusis can also be effective for misophonia. The evidence-based and research-proven protocols for hyperacusis and tinnitus management support CBT.^33-35 The CBT protocol for misophonia is designed to identify negative automatic thoughts (NATs) and examine the validity and truth behind those negative thoughts. After a few sessions, patients realize that most NATs such as anger, isolation, fear, or poor relationships are false perceptions. Aazh and colleagues provide a case formulation model for a CBT plan to manage misophonia.³⁶ This model starts with the exploration of misophonia patients’ initial emotional responses, such as anger and irritation, and their physical complaints, such as tightening of the stomach, static-like tingling sensations on the skin, or pain, when exposed to trigger sounds. These physical sensations and initial emotional reactions to trigger sounds generate a series of negative thoughts that lead to further emotional and physical responses, which in turn result in evaluative thoughts, hence generating a vicious circle of thoughts (Fig. 1).³⁶ The CBT-based interventional model for misophonia aims to break this cycle by assisting the patients in examining and exploring their negative thoughts so they can process and modify them.

Although there is no quick fix or magic pill for misophonia, the use of sound therapies, behavioral modifications, and CBT seems to be promising. Further research will be able to show the effectiveness of other treatment methods, such as electrical and magnetic stimulations, in the search for misophonia management.