Posture, Gait, Quality of Life, and Hearing with a Vestibular Implant.

BACKGROUND: Bilateral vestibular hypofunction is associated with chronic disequilibrium, postural instability, and unsteady gait owing to failure of vestibular reflexes that stabilize the eyes, head, and body. A vestibular implant may be effective in alleviating symptoms. METHODS: Persons who had had ototoxic (7 participants) or idiopathic (1 participant) bilateral vestibular hypofunction for 2 to 23 years underwent unilateral implantation of a prosthesis that electrically stimulates the three semicircular canal branches of the vestibular nerve. Clinical outcomes included the score on the Bruininks-Oseretsky Test of Motor Proficiency balance subtest (range, 0 to 36, with higher scores indicating better balance), time to failure on the modified Romberg test (range, 0 to 30 seconds), score on the Dynamic Gait Index (range, 0 to 24, with higher scores indicating better gait performance), time needed to complete the Timed Up and Go test, gait speed, pure-tone auditory detection thresholds, speech discrimination scores, and quality of life. We compared participants' results at baseline (before implantation) with those at 6 months (8 participants) and at 1 year (6 participants) with the device set in its usual treatment mode (varying stimulus pulse rate and amplitude to represent rotational head motion) and in a placebo mode (holding pulse rate and amplitude constant). RESULTS: The median scores at baseline and at 6 months on the Bruininks-Oseretsky test were 17.5 and 21.0, respectively (median within-participant difference, 5.5 points; 95% confidence interval [CI], 0 to 10.0); the median times on the modified Romberg test were 3.6 seconds and 8.3 seconds (difference, 5.1; 95% CI, 1.5 to 27.6); the median scores on the Dynamic Gait Index were 12.5 and 22.5 (difference, 10.5 points; 95% CI, 1.5 to 12.0); the median times on the Timed Up and Go test were 11.0 seconds and 8.7 seconds (difference, 2.3; 95% CI, -1.7 to 5.0); and the median speeds on the gait-speed test were 1.03 m per second and 1.10 m per second (difference, 0.13; 95% CI, -0.25 to 0.30). Placebo-mode testing confirmed that improvements were due to treatment-mode stimulation. Among the 6 participants who were also assessed at 1 year, the median within-participant changes from baseline to 1 year were generally consistent with results at 6 months. Implantation caused ipsilateral hearing loss, with the air-conducted pure-tone average detection threshold at 6 months increasing by 3 to 16 dB in 5 participants and by 74 to 104 dB in 3 participants. Changes in participant-reported disability and quality of life paralleled changes in posture and gait. CONCLUSIONS: Six months and 1 year after unilateral implantation of a vestibular prosthesis for bilateral vestibular hypofunction, measures of posture, gait, and quality of life were generally in the direction of improvement from baseline, but hearing was reduced in the ear with the implant in all but 1 participant. (Funded by the National Institutes of Health and others; ClinicalTrials.gov number, NCT02725463.).

Immune Checkpoint Inhibitor-induced Bilateral Vestibulopathy.

Checkpoint inhibitors (CPI), such as anti-programmed death-1 and anti-cytotoxic T-lymphocyte antigen-4antibodies cause serious, rarely fatal immune-related adverse events (irAE) potentially in all organ systems. Neurological immune-related adverse events occur in 1%-5% of patients on CPI therapy and may present with dramatic clinical symptoms of the sensory organs. After exclusion of other causes, a high-dose treatment with corticosteroids is crucial for clinical outcome with lower risk of sequelae. We present a severe case of CPI-related ongoing and most likely irreversible bilateral vestibular affection. A 59-year-old male melanoma patient with brain metastasis undergoing immunotherapy with anti-cytotoxic T-lymphocyte antigen-4 and anti-programmed death-1 antibodies developed severe debilitating rotatory vertigo. Bilateral vestibulopathy was diagnosed as a result of the CPI therapy after a thorough analysis including magnetic resonance imaging, laboratory tests of blood and cerebrospinal fluid as well as neurological and otorhinolaryngology examinations. The vertigo improved slightly during a 10-day course of steroid therapy and intensive balance training but did not resolve completely.

Terapia vestibular en vestibulopatía bilateral por gentamicina: reporte de un caso y revisión de la literatura / Vestibular therapy in a case of gentamicin-induced vestibulopathy: case report and literature revision

La vestibulopatía bilateral es poco frecuente, se caracteriza principalmente por inestabilidad al caminar o al estar de pie, visión borrosa inducida por el movimiento u oscilopsia al caminar o al realizar movimientos rápidos de la cabeza o del cuerpo, empeoramiento de la estabilidad en la oscuridad o terrenos irregulares, reducción de los síntomas al estar en condiciones estáticas, ganancia del reflejo vestíbulo-ocular angular reducida de forma bilateral, entre otros. Existen múltiples causas. Dentro de las causas identificables, se describen principalmente medicamentos ototóxicos, meningitis y enfermedad de Ménière. Se presenta el caso de una paciente de 64 años diagnosticada con vestibulopatía bilateral posterior a tratamiento intramuscular con gentamicina por sobreinfección bacteriana cutánea de las manos. La evaluación vestibular complementada con videonistagmografía y prueba de impulso cefálico asistida por video confirman el diagnóstico y se inicia tratamiento con rehabilitación vestibular enfocada en promover la compensación central a través de estrategias de sustitución principalmente; además de habituación y adaptación vestibular, favoreciendo la estabilización de la mirada, mantención del equilibrio, control postural, marcha y reducción de los síntomas.

Bilateral vestibulopathy is infrequent, and it is characterized mostly by unstable walking or when standing, blurred vision induced by movement, or oscillopsia when walking or performing fast movements; worsening of the stability in darkness or uneven ground, but with lack of symptoms in static conditions. Other symptoms may include bilateral reduction of the oculo-vestibular reflex. Among the identifiable causes, there is the use of ototoxic medication, meningitis, Ménière's disease, although it can be idiopathic or have a neurological cause. We hereby describe the case of a 64-year-old woman, diagnosed with bilateral vestibulopathy secondary to intramuscular treatment with gentamicin due to a bacterial hand infection. Vestibular assessment was complemented with video-nystagmography and video head impulse test which confirmed the diagnosis, and therapy was started with vestibular rehabilitation focused on promoting central compensation mainly, through substitution strategies. Also, habituation exercise and vestibular adaptation strategies were used, thus promoting sight stabilization, balance maintenance, postural control, walking, and reduction of the symptoms.

[Bilateral vestibulopathy after intravenous gentamicin therapy].

This case report is about a 70-year-old man, who developed bilateral vestibulopathy due to intravenous gentamicin for endocarditis, and during admission he developed dizziness and oscillopsia. He was diagnosed with bilateral vestibulop-athy, when saccades were found on a video head impulse test (vHIT). The diagnosis was postponed by the lack of severe vertigo and nystagmus, which is seen in acute unilateral vestibulopathy. When gentamicin-induced vestibulapathy is suspected, a vHIT examination is recommended.

Amiodarone-associated bilateral vestibulopathy.

BACKGROUND: Bilateral vestibulopathy (BVP) is a debilitating disorder characterized by the hypofunction of both vestibular end organs or nerves. The most frequent identifiable causes of BVP are ototoxic drug effects, infectious and autoimmune disorders. The majority of cases, however, remain idiopathic. METHODS: Medical records of patients diagnosed with idiopathic BVP were examined in five dizziness clinics. RESULTS: We identified 126 patients with "idiopathic" BVP. Out of these, 15 patients had a history of Amiodarone treatment before the diagnosis of BVP, resulting in a 12% prevalence. CONCLUSION: The present report supports the hypothesis that Amiodarone can cause BVP. Vestibular examination in patients taking Amiodarone and suffering from balance-related symptoms are recommended, to recognize this adverse effect as early as possible and allow for an informed judgement on a potential dose reduction or withdrawal for recovery of the vestibular function.

Strain and Sex Differences in the Vestibular and Systemic Toxicity of 3,3'-Iminodipropionitrile in Mice.

The nitrile 3,3'-iminodipropionitrile (IDPN) causes a loss of hair cells in the vestibular epithelium of the inner ear in several species of both mammals and nonmammals. It is of interest as a model compound in ototoxicity and vestibular regeneration research, but its effects on the mouse, including the potential relevance of strain and sex differences for susceptibility, have not yet been thoroughly characterized. In this study, we compared the vestibular toxicity of IDPN in dose-response studies (0, 8, 12, 16, and 24 mmol/kg IDPN p.o.) in males and females of 2 different mouse strains (RjOrl:Swiss/CD-1 and 129S1/SvImJ). 3,3'-Iminodipropionitrile caused a dose-dependent loss of vestibular function in all sex and strain groups, as assessed by a specific battery of behavioral tests. However, large differences in systemic toxicity were recorded, with high systemic toxicity in 129S1 mice of both sexes compared to limited effects on the Swiss mice. Both male and female Swiss mice showed a marked increase of hindlimb stride width after exposure. The Swiss, but not the 129S1, mice treated with IDPN showed hyperactivity in the open field. The dose-response relationships in the behavioral effects were matched by the extent of hair cell loss assessed by scanning electron microscopy. Altogether, the data demonstrated prominent strain-dependent differences in the systemic toxicity of IDPN between 129S1 and Swiss mice, in contrast to no differences between the strains and small differences between the sexes in its vestibular toxicity. These results support the use of Swiss mice exposed to IDPN as a mouse lesion model for research in vestibular therapy and regeneration.