Topographical relationships between the brainstem auditory and somatosensory evoked potentials and the location of lesions in posterior fossa stroke

Evaluation of central vestibular syndrome in dogs using brainstem auditory evoked responses recorded with surface electrodes

ABSTRACT The present study aimed to analyse the wave morphology, amplitude, latency, and intervals of the brainstem auditory evoked responses (BAERs) in dogs with central vestibular syndrome (CVS) recorded with surface electrodes. Ten dogs with CVS were examined by mono- and binaural stimulation, using the Neuropack electrodiagnostic system, with stimulus intensities of 90 dBSPL. BAERs examinations revealed morphological changes of waves I, II, III, and V and decreased amplitudes of all waves in 7/10 dogs. P values obtained were = 0.014 for wave I amplitude, 0.031 for II, and III and 0.032 for V. Comparing the latencies of waves I, II, III, and V generated by right and left monoaural stimulation in dogs with CVS, we did not observe significant differences (P>0.05). No statistical differences were observed for BAERs latencies of the waves recorded after binaural and monaural stimulation (left or right). As far as we know, this is the first study of BAERs using surface electrodes, obtained from dogs with CVS.

[The modern approaches to the prognostication of rehabilitation of the patients after stroke on an individual basis: a review of the literature and the results of original investigations]

This article was designed to analyze the results of the investigations with the purpose of elucidation of the prognostic factors relevant to the rehabilitation of the patients who survived after stroke. Special attention is given to the role of demographic (age and sex) factors and the data of the clinical, neurological, psychological, cognitive, and instrumental examination of the patients. The results of the original studies based on the treatment of 203 stroke patients are discussed in the context of modern concepts of the significance of the factors contributing to the recovery of the patients in the course of the post-stroke rehabilitation. The prognostic value of the selected factors, such as leukoareosis (for the patients presenting with hemorrhagic stroke), has been demonstrated for the first time. The new data on the duration of the rehabilitation period are presented with reference to its dependence on the type of stroke and localization of the lesions. Specifically, it is estimated to be 2 years for the patients who suffered from ischemic stroke in the brain stem, 31 months for those with ischemic stroke of the hemispherical localization, and 38 months for the patients presenting with hemorrhagic stroke (hemispherical hematoma). In addition, the data on the magnitude of the post-ischemic atrophic changes of prognostic values are presented.

Evaluation of wavelet techniques in rapid extraction of ABR variations from underlying EEG

The aim of this study is to analyse an effective wavelet method for denoising and tracking temporal variations of the auditory brainstem response (ABR). The rapid and accurate extraction of ABRs in clinical practice has numerous benefits, including reductions in clinical test times and potential long-term patient monitoring applications. One method of achieving rapid extraction is through the application of wavelet filtering which, according to earlier research, has shown potential in denoising signals with low signal-to-noise ratios. The research documented in this paper evaluates the application of three such wavelet approaches on a common set of ABR data collected from eight participants. We introduced the use of the latency-intensity curve of ABR wave V for performance evaluation of tracking temporal variations. The application of these methods to the ABR required establishing threshold functions and time windows as an integral part of the research. Results revealed that the cyclic-shift-tree-denoising performed superior compared to other tested approaches. This required an ensemble of only 32 epochs to extract a fully featured ABR compared to the 1024 epochs with conventional ABR extraction based on linear moving time averaging.