BPPV is the most common cause of vertigo. It most often occurs spontaneously in the 50 to 70 year age group. In younger individuals it is the commonest cause of vertigo following head injury. There is a wide spectrum of severity from inconsistent positional vertigo to continuous vertigo provoked by any head movement. It is likely to be a cause of falls and other morbidity in the elderly. Misdiagnosis can result in unnecessary tests. The cardinal features and a diagnostic test were clarified in 1952 by Dix and Hallpike. Subsequently, it has been established that the symptoms are attributable to detached otoconia in any of the semicircular canals. BPPV symptoms can resolve spontaneously but can last for days, weeks, months, and years. Unusual patterns of nystagmus and nonrepsonse to treatment may suggest central pathology. Diagnostic strategies and the simplest “office” treatment techniques are described. Future directions for research are discussed.

Objective To compare the sensitivity of gadolinium MRI inner imaging with tone burst electrocochleography (EcochG) for diagnosing endolymphatic hydrops. Study Design A prospective study on patients who were to have an MRI scan to exclude retrocochlear pathology. Setting Tertiary care center. Patients One hundred and two patients: 57 patients with Possible, Probable, or Definite Ménière’s Disease, 25 with asymmetrical hearing loss, 18 with sudden sensorineural hearing loss, and 2 with unilateral tinnitus had additional MRI inner ear imaging and click and tone burst stimulus EcochG testing. Intervention Diagnostic. Main Outcome Measure To compare the sensitivity of the two techniques. Results In 30 patients with symptom-based Definite Ménière’s Disease, tone burst EcochG was positive in 25 (83%) and the click EcochG was positive in 9/30 (30%), and gadolinium MRI imaging diagnosed hydrops in 14 (47%). A positive result for either MRI imaging or tone burst EcochG was seen in 26 patients (87%). In 14 subjects with symptom-based Probable Ménière’s Disease, 10 (71%) had either a positive EcochG or MRI. In 13 with Possible Ménière’s Disease, four (31%) had a positive EcochG or MRI. Conclusion This study confirms the greatly enhanced diagnostic sensitivity of tone burst EcochG over click response in diagnosing endolymphatic hydrops in Ménière’s disease. Even though adequate MRI imaging was achieved in 90%, tone burst EcochG was a more sensitive test.

Perilymph fistula (PLF) is defined as a leak of perilymph at the oval or round window. It excludes other conditions with “fistula” tests due to a dehiscent semi circular canal from cholesteatoma and the superior canal dehiscence syndrome. It was first recognized in the early days of stapedectomy as causing disequilibrium and balance problems before sealing of the stapedectomy with natural tissue became routine. It then became apparent that head trauma and barotraumatic trauma from flying or diving could be a cause of PLF. Descriptions of “spontaneous” PLF with no trauma history followed. A large literature on PLF from all causes accumulated. It became an almost emotional issue in Otolaryngology with “believers” and “nonbelievers.” The main criticisms are a lack of reliable symptoms and diagnostic tests and operative traps in reliably distinguishing a perilymph leak from local anaesthetic. There are extensive reviews on the whole topic, invariably conveying the authors' own experiences and their confirmed views on various aspects. However, a close examination reveals a disparity of definitions and assumptions on symptoms, particularly, vestibular. This is an intentionally provocative paper with suggestions on where some progress might be made.

The technique of transtympanic electrocochleography was initially developed as an objective hearing threshold test by Eggermont. In 1977 Gibson and colleagues claimed that an enlarged direct current component of the action potential (AP) called the summating potential (SP) is an indication of endolymphatic hydrops, later confirmed by Coates who proposed an SP/AP ratio measure. This led to numerous publications using diagnostic ratios of 0.33 to 0.35. The insensitivity led to an eventual disenchantment with the test as a reliable objective test for Meniere’s disease. It was further confused by audiologists employing remote canal or ear drum electrodes which give a response about one fourth of the magnitude obtained by an electrode in contact with the cochlea. Subsequently Gibson stated that an SP/AP ratio of <0.5 is not diagnostic for hydrops. He then showed that a tone burst stimulus gave the test a significantly higher sensitivity and specificity, which has been supported by others. On MRI inner ear imaging with gadolinium hydrops can be seen, but the quality of images and what is seen may vary according to brand of scanner, settings, mode of gadolinium administration and the possibility that gadolinium entry may favour the vestibule. Transtympanic tone burst electrocochleography is to date the simplest, cheapest and sensitive technique for detecting cochlear endolymphatic hydrops to confirm a diagnosis of Meniere’s disease.