Vestibular dysfunction in a Japanese patient with a mutation in the gene OPA1

OPA1-related auditory neuropathy: site of lesion and outcome of cochlear implantation

“…Bilateral vestibular hyporeflectivity was found in Subject 2, who has never complained of vertigo. Similar findings have been obtained in one Japanese patient harbouring the R445H mutation in the OPA1 gene, who showed no response bilaterally on caloric testing in the absence of vestibular symptoms ( Mizutari et al , 2010 ). Impaired vestibular function has previously been reported in other patients with auditory neuropathy, particularly in those with a concomitant peripheral neuropathy, and attributed to degeneration of vestibular nerves ( Starr et al , 1996 ; Fujikawa and Starr, 2000 ; Sinha et al , 2013 ).…”

The genetic basis of auditory neuropathy spectrum disorder (ANSD)

“…However, it can sometimes be associated with sensorineural deafness. ANSDs have also been reported in ADOA, and presented with autosomal dominant inheritance with R445H mutation in OPA1 gene [31][32][33]. Moreover, the results suggest that deafness accompanying this OPA1 mutation is due to altered function of terminal unmyelinated portions of auditory nerve.…”

“…By contrast, congenital ANSD is mainly caused by genetic abnormality, which may be either isolated or associated with other syndromes. For example, Charcot-Marie-Tooth (CMT) disease [9,[22][23][24][25][26][27][28][29], Leber's Hereditary Optic Neuropathy (LHON) [30], Autosomal Dominant Optic Atrophy (ADOA) [31][32][33], Autosomal Recessive Optic Atrophy (OROA) [34], Fredreich's Ataxia [35,36], Mohr-Tranebjaerg Syndrome (MTS) [9,37,38], Refsum's Disease [38,39], Mitochondrial Disease [30,[40][41][42]. However, there might also be occurrences of ANSD with mitochondrial inheritance with associated anomalies, which are outside the boundaries of any existing syndromes.…”

Vestibular test findings in individuals with auditory neuropathy: review

“…Similar findings have been reported in individuals with auditory neuropathy who have a genetic association. 14 Recently, Sharanya et al (unpublished data) studied three patients diagnosed with auditory neuropathy who underwent an extensive vestibular assessment, which consisted of clinical tests of stability (Romberg's, Fukuda stepping test), vestibular-evoked myogenic potential recordings and a standard ENG test battery. All patients showed hypofunctional caloric responses and absent vestibular-evoked myogenic potentials.…”