Magnetic resonance imaging in patients with sudden deafness

Is there a relation between sudden sensorineural hearing loss and white matter lesions?

PURPOSE

Sudden sensorineural hearing loss (SSNHL) has similarities to conditions with vascular etiologies such as myocardial infarction and cerebral stroke. Thus, it could be considered as an early sign of a vascular disease and not only a specific local condition. Chronic hypoperfusion in the brain districts leads to a chronic ischemic damage, called cerebral small vessel disease (CSVD), detectable with brain magnetic resonance imaging (MRI).

METHODS

The authors used CSVD to establish the presence of vascular risk factors in individuals with SSNHL and used the Fazekas score scale to classify them.

RESULTS

Our study showed that individuals with SSNHL aged between 48 and 60 years have 26% more probability to have a Fazekas score higher than 1 compared to the general population. Individuals younger than 28 years showed a statistically significant negative correlation to have a Fazekas score higher than 0. The higher is the Fazekas score, the less is the probability of hearing recovery. The medium hearing-recovery probability is 46%. This decreases by 16% for every increase of score in the Fazekas scale. In the present study, the recovery probability decreased from 80% in individuals younger than 48 years with a score of 0 to 14% in individuals with a Fazekas scores of 3 and 4.

CONCLUSIONS

The authors assessed a higher prevalence of CSVD compared to the general population in patients aged between 48 and 60 years with SSNHL. Moreover, they assessed that the presence of CSVD is related to a decreased probability of recovery, as it has already been demonstrated for stroke.

Sudden sensorineural hearing loss associated with inner ear lesions detected by magnetic resonance imaging

Although recent advances in magnetic resonance imaging (MRI) techniques have contributed to the detection of tiny lesions in the internal auditory canal (IAC) that may be responsible for sudden sensorineural hearing loss (SSNHL), there have been relatively few studies on the clinical characteristics of intra-labyrinthine hemorrhage (ILH) and labyrinthitis versus those regarding IAC tumors. Our purpose was to investigate the frequency of those IAC lesions on MRI and their clinical characteristics. Initial MRIs of 200 patients with SSNHL (93 men, 107 women; mean age = 48.61 years, range: 18–84 years), as well as detailed clinical histories, audiological examinations, and thyroid function, lipid battery, and serological tests (for viral agents and autoimmune disease), were performed. All patients were hospitalized at the time of diagnosis of SSNHL and were administered the same treatment protocol. Patients were divided into idiopathic and secondary groups according to their MRI results. After discharge, they underwent follow-up audiometry and clinical examination at predetermined intervals (2 weeks, 1, 2, 4, and 6 months, and 1 and 2 years). Propensity score-matching and receiver operating characteristics curves of the initial parameters were used for estimating clinical characteristics. Of the 200 patients, 25 (12.55%) who had abnormal findings suggesting inner ear lesions on MRI were assigned to the secondary SSNHL group; within this group, 10 patients (10/200, 5%) had a tumor invading the IAC, 7 (7/200, 3.5%) had ILH, 6 (6/200, 3%) had labyrinthitis, and 2 (1%) had a structural deformity of the IAC. The secondary group showed significantly poor recovery of hearing function compared with that in the idiopathic group. Patients with ILH or labyrinthitis showed prognoses that were equally poor as those of patients with tumors in the secondary group. Additionally, patients with such lesions showed significant canal paresis on the lesion side at an early stage and a high prevalence of benign paroxysmal positional vertigo (BPPV). In conclusion, the prevalence of non-tumorous lesions on MRI represents common findings and showed a poorer treatment response than that of vestibular Schwannoma in patients with SSNHL. Abnormal canal paresis (cut-off value of 35% on the lesioned side, sensitivity 65.2% and specificity 67%), spontaneous nystagmus directed to the contralesional side, and positional vertigo would be the clinical presentation of SSNHL with IAC lesions, in which the presence of acute prolonged vertigo or positional vertigo compatible with BPPV suggests the possibility of a non-tumorous lesion, such as ILH or a labyrinthitis rather than an IAC tumor.

Temporal bone imaging

Temporal bone imaging is performed for a variety of clinical conditions addressed in the outpatient and acute care setting ranging from hearing loss to trauma. Recent advances in magnetic resonance technology have enhanced the assessment of fine anatomic temporal bone detail and improved the diagnostic sensitivity for important pathology. For example, non-echo planar diffusion weighted imaging increases detection rate and diagnostic confidence of recurrent cholesteatoma. This chapter will focus on relevant temporal bone clinical entities and new MR developments that have come into clinical practice.

Ressonância magnética em surdez súbita

A surdez súbita é um sintoma cuja etiologia nem sempre é elucidada mesmo dispondo-se de toda propedêutica atual. Neste estudo avaliaremos as alterações encontradas em ressonância magnética de pacientes portadores de surdez súbita. FORMA DE ESTUDO: coorte transversal. MATERIAL E MÉTODO: Estudo prospectivo com realização de RM em 49 dos 61 pacientes com surdez súbita atendidos no pronto socorro de Otorrinolaringologia do Hospital São Paulo, no período de abril de 2001 a maio de 2003. Doze pacientes abandonaram ou não foram submetidos à ressonância magnética por outros motivos. RESULTADOS: 23 (46,9%) pacientes apresentaram alterações à ressonância magnética. Foram encontrados dois tumores sugestivos de meningioma e três schwannomas do oitavo par craniano. Lesões subcorticais e periventriculares esparsas e hiperintensas em FLAIR foram encontradas em 13 pacientes. Cinco (21,7%) pacientes apresentaram alterações periféricas. CONCLUSÃO: A surdez súbita deve ser abordada como um sintoma comum a diferentes doenças. A presença de tumores do ângulo pontocerebelar em 10,2% dos nossos casos, entre outras causas tratáveis, justifica o uso da ressonância magnética com contraste tanto para o estudo do sistema auditivo periférico quanto para o estudo das vias auditivas centrais, incluindo o cérebro.

Magnetic resonance imaging in sudden deafness

The etiology of sudden deafness can remain undetermined despite extensive investigation. This study addresses the value of magnetic resonance imaging in the analysis of sudden deafness patients. Study design: transversal cohort. Material and Method: In a prospective study, 49 patients attended at otolaryngology emergency room of Federal University of Sao Paulo - Escola Paulista de Medicina, from April 2001 to May 2003, were submitted to magnetic resonance imaging. Results: Magnetic Resonance abnormalities were seen in 23 (46.9%) patients and revealed two tumors suggestive of meningioma, three vestibular schwannomas, thirteen microangiopathic changes of the brain and five (21.7%) pathological conditions of the labyrinth. Conclusion: Sudden deafness should be approached as a symptom common to different diseases. The presence of cerebellopontine angle tumors in 10.2% of our cases, among other treatable causes, justifies the recommendation of gadolinium-enhanced magnetic resonance use, not only to study the auditory peripheral pathway, but to study the whole auditory pathway including the brain.

Current concepts in the diagnosis and treatment of sudden sensorineural hearing loss

Sudden hearing loss (SHL) has been a controversial topic in the literature for the past several decades. Although much theoretical work has been done regarding its diagnosis and treatment, no useful practical guidelines exist for application to current patient management. Many authors have discussed the various treatment protocols available to treat this entity, but only a handful of dated, clinical studies supporting these treatments are available. More recent studies applying treatment protocols including vasodilators, plasma expanders, anti-coagulants, and carbogen inhalations have shown no improvement over the rate of spontaneous recovery without therapy. Except in cases of therapy directed toward known predisposing factors, there is insufficient evidence in the literature to support medical treatment for SHL, although steroid therapy appears to be useful in selected patients. Our own review of 14 patients with SHL is presented. A standard diagnostic and therapeutic approach based on a comprehensive review of the literature is described that can be applied to most patients presenting with SHL.