Transtympanic management of tinnitus

Transtympanic therapy is becoming and important treatment modality for many inner ear disorders. The current therapies aimed at Meniere's disease, sudden sensorineural hearing loss, noise-induced hearing loss, and the tinnitus associated with these disorders and idiopathic tinnitus, however, represents simply an evolutionary step in this treatment modality and must be validated by further scientific study. A number of promising developments including newer more targeted neuroactive medicines, a better understanding of medicine delivery, and the knowledge of the site, origin, and pathophysiology of the symptoms complex will make this therapy more effective. In the future it is possible that many inner ear disorders will be amenable to inner ear medical therapy. Ideally in the future with knowledge of the disease and its etiology the physician will simply pick the established medicine, the established dose, and the established route of administration and achieve a relatively predictable result

Characterizing and treating dizziness after mild head trauma

The objectives of this study were to characterize patterns of dizziness seen after mild head trauma and to examine the diagnosis and treatment of this disorder. Prospective patient registry. Tertiary referral center. Fifty-eight cases of active duty and retired military personnel who sustained mild head trauma and had resultant dizziness. Vestibular evaluation, characterization by group, and treatment. Outcome measures include characterization of diagnosis types, patient distribution by diagnosis type, and patient outcome. Individuals suffering from dizziness after mild head injury were divided into three diagnostic groups. Forty-one percent of the individuals suffered from posttraumatic vestibular migraines, 28% of the individuals had posttraumatic positional vertigo, and 19% of the individuals were classified as posttraumatic spatial disorientation. The remaining 12% of the patients could not be characterized. The positional group had objective physical examination findings, which cleared with treatment in all cases. The migraine group of patients and the disorientation group of patients had distinct abnormalities of the vestibulo-ocular reflex (VOR) and the vestibulo-spinal reflex (VSR). Eighty-four percent of the migraine group demonstrated an improvement of these test results as compared with 27% of the disorientation group. Mean time to return to work was less than 1 week for the positional group, 3.8 weeks for the migraine group, and greater than 3 months for the disorientation group. Using our patient registry of individuals suffering from dizziness after mild head trauma, we were able to characterize the majority of these cases into one of three more specific diagnostic groups. We present diagnostic criteria, suggested treatment guidelines, and our prognostic data

Microdose gentamicin delivered via the round window microcatheter: A therapeutic option in Menière's disease

Transtympanic gentamicin therapy is becoming an increasingly popular treatment for Menière's disease. Despite its popularity, transtympanic therapy is not without controversy. Vertigo cure rates are high, but hearing loss rates are variable. The best total dose of medicine, the best route of administration, and the best end-point of therapy have not been established. Meanwhile, the mode of action of gentamicin in controlling Menière's disease is still not completely understood. In the last several years, many groups have started to use a variety of sustained release devices to more accurately control the amount of gentamicin administered to the ear. This report discusses the use of one such sustained release device, and the effects of its use with very low doses of gentamicin, on the symptoms of Menière's disease

Kinetics of gentamicin uptake in the inner ear of Chinchilla langier

The search for a safe, effective treatment for the vertigo associated with Meniere's disease has long been an important topic in otolaryngology. In recent years many groups have begun using intratympanic gentamicin to treat this vertigo. Although reported cure rates are as high as 90%, many questions remain regarding this type of treatment. Current limitations are the necessity for repeated treatments and a lack of clear dosing guidelines. In addition, the gentamicin must be delivered in a manner that allows maximal vestibulotoxic effect without injury to hearing. Until investigators can control the exact amount of medicine that is placed in the ear and have an understanding of the kinetics of gentamicin absorption, adequate dosing guidelines will be difficult to establish, and therapy will continue to rely on empiric data. We describe the use of a fibrin-based sustained-release vehicle, impregnated with gentamicin, injected into the middle ear of chinchillas. This allows for a prolonged effect without repeated dosing. Using this model, we studied the absorption kinetics of gentamicin at time points ranging from 8 hours to 1 week after injection. We used our findings to create a kinetics curve of gentamicin absorption. We discuss the shape and characteristics of this kinetics curve and examine the effects of the fibrin-based sustained-release vehicle and gentamicin on the middle ear. We noted no absorption in the contralateral (untreated ear) or blood. Through better understanding of the actions of gentamicin in this animal model, we hope to facilitate safer use of intratympanic medicines in our patient population and initiate programs for the use of this sustained-release vehicle in human beings

The early kinetics of gentamicin uptake into the inner ear

Transtympanic gentamicin administration has become a popular modality in the treatment of Ménière's disease. This modality and other inner-ear medical therapy are gaining increased clinical and scientific attention. We previously described the kinetics and effects of gentamicin uptake into the inner ear after delivery of the medicine into the middle ear using a variety of different techniques and sustained-release modalities [1]. In our previous work, we reported an early peak perilymph concentration and the presence of intracellular gentamicin at the 4-hour time point. We also demonstrated the activation of inner-ear damage pathways at this early time point. In this report, we examine the kinetics of gentamicin at very early time points, 1 and 2 hours after administration. Healthy adult chinchillas underwent implantation of middle-ear sustained-release devices (one to each ear) containing gentamicin. The animals then were maintained in a neutral position and underwent perilymph gentamicin sampling at the two predetermined time points. This technique allowed us to assess accurately very early time point inner-ear gentamicin kinetics and to compare the activity. The samples then were run for concentration using mass spectrometry. The information gained from this study may increase our scientific understanding about the effects of gentamicin on the inner ear and may allow clinicians to treat patients more effectively for inner-ear disorders