The mechanism involved in the development of tinnitus may depend on its laterality. Bilateral tinnitus may be associated with hyperactivity at the level of the cochlear nucleus whereas a higher-order cortical area may be involved in unilateral tinnitus.
Background and ObjectivesWe aimed to assess the clinical significance of dizziness associated with acute peripheral facial palsy (APFP).Subjects and MethodsMedical records of patients who visited an otorhinolaryngology clinic at a university hospital and were admitted for treatment of APFP between 2014 and 2016 were thoroughly reviewed.ResultsIn total, 15.3% (n=15) of patients had dizziness. Continuous, rotatory dizziness without exacerbating factors was most common and frequently accompanied by nausea/vomiting. Dizziness disappeared within 1 week during the hospitalization period. Patients with Ramsay Hunt syndrome (31.0%) had dizziness more frequently than those with Bell’s palsy (8.7%). In addition, higher hearing thresholds and pain around the ear was reported more often in dizzy patients (p<0.05). Logistic regression analysis revealed that the initial House-Brackmann grade of facial paralysis was solely associated with final recovery, but dizziness was not associated with prognosis.ConclusionsPatients with APFP may have transient dizziness in the early stage, which may be more frequently accompanied by worse hearing thresholds and/or pain around the ear. However, these symptoms including dizziness seem to be unrelated to final prognosis.
Infection caused by Varicella zoster virus (VZV) is a common etiology of acute peripheral facial palsy (APFP). We aimed to assess the clinical significance of detecting VZV DNA from the saliva of patients with APFP. Saliva collected from 36 patients with unilateral APFP at initial visit was analyzed to detect VZV DNA by polymerase chain reaction. The House-Brackmann (HB) scale was used to evaluate FP severity on admission day, at week 2, and at weeks 10-12 after start of treatment. Among the 28 patients without rash, VZV DNA was detected in 3 patients (10.7%); 6 of 8 patients (75.0%) with rash showed VZV DNA (P = 0.001). VZV DNA-positive patients had worse hearing than VZV DNA-negative patients (P < 0.05). A significantly higher proportion of VZV DNA-negative patients (96.3%) showed complete recovery than VZV DNA-positive patients (55.6%) (P = 0.006). In conclusion, VZV DNA-positive patients had worse hearing and incomplete recovery compared to VZV DNA-negative patients, irrespective of the presence of rash. Tests for the detection of VZV DNA in saliva may be helpful for early differential diagnosis and choosing an appropriate medical treatment of APFP.
PurposeBlind individuals who have photoreceptor loss are known to perceive phosphenes with electrical stimulation of their remaining retinal ganglion cells. We proposed that implantable lateral geniculate body (LGB) stimulus electrode arrays could be used to generate phosphene vision. We attempted to refine the basic reference of the electrical evoked potentials (EEPs) elicited by microelectrical stimulations of the optic nerve, optic tract and LGB of a domestic pig, and then compared it to visual evoked potentials (VEPs) elicited by short-flash stimuli.MethodsFor visual function measurement, VEPs in response to short-flash stimuli on the left eye of the domestic pig were assessed over the visual cortex at position Oz with the reference electrode at Fz. After anesthesia, linearly configured platinum wire electrodes were inserted into the optic nerve, optic track and LGB. To determine the optimal stimulus current, EEPs were recorded repeatedly with controlling the pulse and power. The threshold of current and charge density to elicit EEPs at 0.3 ms pulse duration was about ±10 µA.ResultsOur experimental results showed that visual cortex activity can be effectively evoked by stimulation of the optic nerve, optic tract and LGB using penetrating electrodes. The latency of P1 was more shortened as the electrical stimulation was closer to LGB. The EEPs of two-channel in the visual cortex demonstrated a similar pattern with stimulation of different spots of the stimulating electrodes. We found that the LGB-stimulated EEP pattern was very similar to the simultaneously generated VEP on the control side, although implicit time deferred.ConclusionsEEPs and VEPs derived from visual-system stimulation were compared. The LGB-stimulated EEP wave demonstrated a similar pattern to the VEP waveform except implicit time, indicating prosthetic-based electrical stimulation of the LGB could be utilized for the blind to perceive vision of phosphenes.
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