EMDR as a Treatment for Tinnitus

Tinnitus is a common, yet poorly understood condition. In the UK, a large study using data from more than 500,000 people has found a prevalence of tinnitus of 16.2% (defined as any noise in the ear/s lasting longer than five minutes) and a prevalence of bothersome tinnitus as 3.8% (those who were moderately or severely bothered by their tinnitus on a four point Likert scale). Other international studies have also found a high prevalence of 30% with a total of 6% of the study population reporting incapacitating symptoms from tinnitus. Despite the high worldwide prevalence of tinnitus and the large number of proposed therapies available, there is a distinct paucity of well controlled trials in the literature to support an effective treatment.

Tinnitus may be considered as a form of phantom auditory perception and as such parallels may be drawn with other forms of phantom sensation, there has been recent interest in the use of eye movement therapies to treat patients with phantom sensations such as phantom limb pain. Both studies of those with tinnitus and phantom limb pain have suggested a psychological component such as certain premorbid personality traits may also contribute or predispose to these conditions and consequently be helped by psychological therapies.

Eye Movement Desensitisation and Reprocessing (EMDR) was first described by Shapiro in 1989 and requires the subject to perform relatively rapid movements of the eyes. Its application has been particularly documented in the context of post-traumatic stress disorder (PTSD). EMDR has been described as an integrative psychotherapy, due to its assimilation of various elements from diverse psychotherapies. A number of models have been proposed to account for the role of eye movements in EMDR, these include Shapiro's Adaptive Information Processing Model, Dyck's conditioning model, attentional processing accounts and theories of reverse learning . A recurrent mechanism in a number of these accounts is that of the orientating reflex. MacCollock and Feldman argue that lateral eye-movements trigger an investigatory component of this reflex to assess safety with regard to potential external threats . Where threats are positively identified, a flight or flight response is initiated; in situations where no danger is identified a functional reduction in arousal takes place. Support for this reassurance response in non-clinical patients has been demonstrated using auditory stimuli. Overlap between these concepts and theories related to the perception of tinnitus bode well, especially when one considers the neurophysiological model proposed by Jastreboff.

Since its introduction in 1989, numerous controlled studies have been conducted to evaluate EMDR's utility as a treatment for various forms of trauma-related complaints, including PTSD. The positive results have established EMDR as an effective trauma treatment and have prompted numerous professional organisations to recognise its efficacy, beginning with the American Psychological Association's (APA) Division 12 Task Force on Psychological Interventions in 1998. Since then, the NHS the International Society for Traumatic Stress Studies , the Israeli National Council for Mental Health , and the Northern Ireland Department of Health have also supported EMDR. Most recently, the US Departments of Defence and Veterans Affairs stated that EMDR was an effective treatment of trauma, as did the American Psychiatric Association . It has also been found to be helpful in medically unexplained symptoms and somatoform disorders.

Other forms of eye movement therapy have been popularised, such as eye movement integration therapy (EMI) in which eye movements in specific directions provide access strategies to different sensory domains. EMI was originally developed from research in the field of neuro-linguistic programming (NLP) and has also been widely used in the treatment of PTSD. EMI uses slower eye movements that are thought to access internal dialogue or emotional and feeling areas of the brain. Initially the concept of specifically accessing domains associated with auditory-based cue was appealing as a therapy for an auditory based pathology, however, despite initial enthusiasm for EMI the specificity of these associations has been disputed.

The role of eye movements in the propagation and maintenance of tinnitus has been well established, although the exact neurophysiological mechanisms of how eye movements integrate within the central auditory areas is not fully understood, however functional imaging has suggested a number of neuroanatomical sites. Cognitive science has provided neural networks that model tinnitus, these neural network models were inspired by theoretical models that described possible neural mechanisms mediating tinnitus. The majority of these models rely on the lateral-inhibition network (LIN) to simulate tinnitus and focus on the role of central auditory processing regions as possible anatomical locations of the physiological abnormalities that cause tinnitus. Recent work has identified a number of regions responsible for the generation and modulation of tinnitus including limbic, somatosensory and motor areas.

There has been some encouraging work described in the German literature regarding the effectiveness of EMDR for the treatment of tinnitus. The application of eye movement therapies to treat patients with tinnitus would seem logical considering the context our current understanding of tinnitus; the next step would be to test this theory in the setting of a formal randomised controlled clinical study.