MTHFR polymorphism: associated intralabyrinthine hemorrhage.

udden sensorineural hearing loss (SSNHL) is a diagnosticand therapeutic challenge for the clinician. While in mostcases the etiology and pathogenesis remain unknown and treat-ment protocols are mainly empiric, meticulous laboratory andimaging evaluation might reveal a specific cause requiring a dif-ferent therapeutic approach. We describe a case study of SSNHLsecondary to intralabyrinthine hemorrhage associated with meth-yleneretrahydrofolate (MTHFR) polymorphism.The publication of this case report was approved by theInstitutional Review Board of Hillel Yaffe Medical Center.A 53-year-old woman presented with right sudden hear-ing loss accompanied by tinnitus and vertigo. She had noprevious hearing or vestibular symptoms, concurrent infec-tion, history of head trauma, or exposure to rapid changes inambient pressure. The patient was in general good healthand received no prescribed medications. The only patho-logic finding on otoneurological examination was a seconddegree right beating rotatory nystagmus, which resolvedseveral hours from presentation. Audiometry showed flatright sensorineural hearing loss of 60 dB hearing level (HL)with a speech discrimination score of 30 percent. The pa-tient was treated with complete bed rest and 1 mg/kg oralprednisone for one week. As no improvement took place,she received two daily successive hyperbaric oxygen ses-sionsfollowedbyfivetreatmentsofintratympanicperfusionof 0.7 mL dexamethazone 10 mg/mL every three days.Weekly repeated audiograms did not show any significantchanges during the first five weeks after presentation. A fol-lowingstudydemonstratedpartialresolutionofpuretonehear-ing to 35 dB HL while the discrimination score remained low.Laboratory evaluation showed homozygosity for theC677T mutation of MTHFR, with normal blood count,prothrombin time, partial thromboplastine time, homocys-teine, folic acid, and vitamin B12 levels. Tests for factor VLeydan, prothrombin G20210A, anticardiolipin antibody,and lupus anticoagulants were negative. Auditory brainstem evoked response revealed normal morphology of allwaves and normal central conduction times.MRI of the temporal bones was performed seven daysfrom presentation, both before and after the intravenousadministration of a gadolinium-based contrast agent. Pre-contrast T1-weighted axial image (Fig 1) showed high sig-nal in the right cochlea, vestibule, and semicircular canals,with no further enhancement in the postcontrast image. Theleft inner ear structures appeared isointense to cerebrospinalfluid (CSF) in the T2-weighted axial image while the rightotic capsule structures were of low signal (Fig 2). Based onthe MRI studies, the patient was diagnosed with right sub-acute intralabyrinthine hemorrhage.Treatment with folic acid 1 mg/day, vitamin B12 400mg/day, and vitamin B6 10 mg/day was started.