Bilateral Vestibular Hypofunction in Quantitative Head Impulse Test : Clinical Characteristics in 23 Patients

OBJECTIVE: To explore clinical features of patients with bilateral vestibular hypofunction (BVH) verified in motorized head impulse test (MHIT). MATERIALS and METHODS: We examined clinical records of 23 adult patients (10 males and 13 females), whose gain of the vestibulo-ocular reflex in the MHIT was bilaterally lowered. Fifteen of 62 unilateral cochlear implant (CI) recipients routinely tested both pre-and postoperatively with the MHIT had BVH. Eight of 198 vestibular outpatients selected to the MHIT due to clinical causes had BVH. Clinical characteristics and a questionnaire regarding current sensations were analyzed. RESULTS: The mean gain +/- SD in the MHIT was 0.26 +/- 0.17 on the right and 0.26 +/- 0.14 on the left side. The mean gain in the CI recipients did not differ from that of vestibular outpatients (p>0.05). All outpatients with BVH suffered from oscillopsia, whereas only 46% of CI recipients experienced oscillopsia (p=0.048). Instability was more prominent (p=0.004) and quality of life further decreased (p=0.012) among vestibular outpatients compared with CI patients. Most common etiology for the BVH was meningitis. Other causes were either sudden or progressive loss of labyrinthine function, bilateral Meniere's disease, and ototoxicity. CONCLUSION: BVH is rare even in a specialized clinic. Vestibular outpatients were more disabled than CI recipients with the BVH.Peer reviewe

Simultaneous bilateral stapes surgery after follow-up of 13 years

Background Eighteen patients underwent simultaneous bilateral stapes surgery in 2003-2006. Objectives We evaluated the long-term outcomes in this patient group, and assessed their hearing in noise and binaural hearing. Material and Methods Fifteen patients returned questionnaires concerning their hearing, taste function, and balance. Thirteen patients underwent pure-tone and speech audiogram, Finnish matrix sentence test, video head impulse test, and clinical examination on average 13 years after surgery. Results We found no significant difference in air- and bone conduction pure-tone average, speech audiometry, and the air-bone gap between the 1-year and the late postoperative visits. One patient had bilaterally a partial loss of the vestibulo-ocular reflex of unknown cause. Conclusions and Significance The hearing results 13 years after simultaneous bilateral stapes surgery remained good without any significant delayed complications. Simultaneous bilateral stapes surgery is a viable treatment option in selected patients with otosclerosis.Peer reviewe

On classification in the case of a medical data set with a complicated distribution

Abstract In one of our earlier studies we noticed how straightforward cleaning of our medical data set impaired its classification results considerably with some machine learning methods, but not all of them, unexpectedly and against intuition compared to the original situation without any data cleaning. After a more precise exploration of the data, we found that the reason was the complicated variable distribution of the data although there were only two classes in it. In addition to a straightforward data cleaning method, we used an efficient way called neighbourhood cleaning that solved the problem and improved our classification accuracies 5–10%, at their best, up to 95% of all test cases. This shows how important it is first very carefully to study distributions of data sets to be classified and use different cleaning techniques in order to obtain best classification results.Peer reviewe

The Classification of Valid and Invalid Beats of Three-Dimensional Nystagmus Eye Movement Signals Using Machine Learning Methods

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Structural Brain Connectivity Correlates with Outcome in Mild Traumatic Brain Injury

PMID: 35018829We investigated the topology of structural brain connectivity networks and its association with outcome after mild traumatic brain injury, a major cause of permanent disability. Eighty-five patients with mild traumatic brain injury underwent magnetic resonance imaging (MRI) twice, about three weeks and eight months after injury, and 30 age-matched orthopedic trauma control subjects were scanned. Outcome was assessed with Extended Glasgow Outcome Scale on average eight months after injury. We performed constrained spherical deconvolution-based probabilistic streamlines tractography on diffusion MRI data and parcellated cortical and subcortical gray matter into 84 regions based on T1-weighted data to reconstruct structural brain connectivity networks weighted by the number of streamlines. Graph theoretical methods were employed to measure network properties in both patients and controls, and correlations between these properties and outcome were calculated. We found no global differences in the network properties between patients with mild traumatic brain injury and orthopedic control subjects at either stage. We found significantly increased betweenness centrality of the right pars opercularis in the chronic stage compared with control subjects, however. Further, both global and local network properties correlated significantly with outcome. Higher normalized global efficiency, degree, and strength as well as lower small-worldness were associated with better outcome. Correlations between the outcome and the local network properties were the most prominent in the left putamen and the left postcentral gyrus. Our results indicate that both global and local network properties provide valuable information about the outcome already in the acute/subacute stage and, therefore, are promising biomarkers for prognostic purposes in mild traumatic brain injury.Peer reviewe

Herpesviruses, polyomaviruses, parvoviruses, papillomaviruses, and anelloviruses in vestibular schwannoma

Etiology of vestibular schwannoma (VS) is unknown. Viruses can infect and reside in neural tissues for decades, and new viruses with unknown tumorigenic potential have been discovered. The presence of herpesvirus, polyomavirus, parvovirus, and anellovirus DNA was analyzed by quantitative PCR in 46 formalin-fixed paraffin-embedded VS samples. Five samples were analyzed by targeted next-generation sequencing. Viral DNA was detected altogether in 24/46 (52%) tumor samples, mostly representing anelloviruses (46%). Our findings show frequent persistence of anelloviruses, considered normal virome, in VS. None of the other viruses showed an extensive presence, thereby suggesting insignificant role in VS.Peer reviewe

Alterations in Microstructure and Local Fiber Orientation of White Matter Are Associated with Outcome after Mild Traumatic Brain Injury

Mild traumatic brain injury (mTBI) can have long-lasting consequences. We investigated white matter (WM) alterations at 6-12 months following mTBI using diffusion tensor imaging (DTI) and assessed if the alterations associate with outcome. Eighty-five patients with mTBI underwent diffusion-weighted magnetic resonance imaging (MRI) on average 8 months post-injury and patients' outcome was assessed at the time of imaging using the Glasgow Outcome Scale-Extended (GOS-E). Additionally, 30 age-matched patients with extracranial orthopedic injuries were used as control subjects. Voxel-wise analysis of the data was performed using a tract-based spatial statistics (TBSS) approach and differences in microstructural metrics between groups were investigated. Further, the susceptibility of the abnormalities to specific fiber orientations was investigated by analyzing the first eigenvector of the diffusion tensor in the voxels with significant differences. We found significantly lower fractional anisotropy (FA) and highermean diffusivity (MD) and radial diffusivity (RD) in patients with mTBI compared with control subjects, whereas no significant differences were observed in axial diffusivity (AD) between the groups. The differences were present bilaterally in several WM regions and correlated with outcome. Moreover, multiple clusters were found in the principal fiber orientations of the significant voxels in anisotropy, and similar orientation patterns were found for the diffusivity metrics. These directional clusters correlated with patients' functional outcome. Our study showed that mTBI is associated with WM changes at the chronic stage and these alterations occur in several WM regions. In addition, several significant clusters of WM alterations in specific fiber orientations were found and these clusters were associated with outcome.Peer reviewe