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Hyper Smash
Showing posts with label base of the brain. Show all posts
Showing posts with label base of the brain. Show all posts

Sunday, January 13, 2008

Hearing Loss, what is Trigeminal Nerve doing instead of VIII Nerve?

Dorsal cochlear nucleus responses to somatosensory stimulation are enhanced after noise-induced hearing loss
S. E. Shore1,2,3
1Department of Otolaryngology, Kresge Hearing Research Institute
2Department of Molecular and Integrative Physiology and
3Department of Biomedical Engineering, University of Michigan Medical School, Ann Arbor, MI 48109, USA,
S. Koehler1,3
1Department of Otolaryngology, Kresge Hearing Research Institute
3Department of Biomedical Engineering, University of Michigan Medical School, Ann Arbor, MI 48109, USA,
M. Oldakowski1
1Department of Otolaryngology, Kresge Hearing Research Institute,
L. F. Hughes4
4Southern Illinois University School of Medicine, Department of Surgery/Otolaryngology, Springfield, IL, USA and
S. Syed1
1Department of Otolaryngology, Kresge Hearing Research Institute

The above article published in the latest issue of "European Journal of Neuroscience, discusses issues on hearing loss and possible involvement of trigeminal nerve?

Abstract:
Hearing loss due to VIII nerve damage or loss of synaptic connectivity of VIII nerve in the cochlear nucleus is a common degenerative changes observed in models of noise damage, similar degeneration of terminals also reported in cases of hearing loss in humans. However, the above article discusses the possiblity of the involement of "Trigeminal Nerve" as a compensatory response to the loss of VIII nerve connections following noise induced hearing loss in animal models. How much of this compensatory response is due to hearing loss or changes in VIII nerve connectivity is not clear, however, it is interesting to note how the neighbouring cranial nerve respond.

The authors observe the following changes in responses to trigeminal stimulation: The guinea pigs with noise-induced hearing loss had significantly lower thresholds, shorter latencies and durations, and increased amplitudes of response to trigeminal stimulation than normal animals. Noise-damaged animals also showed a greater proportion of inhibitory and a smaller proportion of excitatory responses compared with normal. Authors also argue that there is increased inhibitory responses and increased activity of somatosensory response, prompting them to conclude a role of somatosensory inputs in noise induced hearing loss? is yet to be clarified by extensive studies!.

Here is a Science Daily which is jumbing into conclusions of the following kind?.
'Ringing In The Ears' May Be Caused By Overactive Nerves, Acupuncture May Help, Study Suggests
ScienceDaily (Jan. 10, 2008) — Do your ears ring after a loud concert? Nerves that sense touch in your face and neck may be behind the racket in your brain, University of Michigan researchers say.
Note: the above image is from Science Daily.

Monday, September 10, 2007

American Society of Anesthesiologissts: Upcoming Conference & Abstracts on Neuromonitoring



Tha annual meeting of American Association of Anesthesiologist will be held during
October 13-17, 2007 San Francisco, CA. There are several interesting research and clinical studies on using neuromonitoring, how different anesthesia affects the intraoperative recording. You can click this highligted assn "Amer Assoc Anesthesiologist Meeting" and read all the important abstracts.
Here is a sample abstrat:
A1 October 13, 2007 9:00 AM - 10:30 PM

Room 301
Somatosensory and Motor Evoked Potentials during Sevoflurane and Propofol Anesthesia

Michael S. Kincaid, M.D., Michael J. Souter, M.D., Patrick D. Bryan, Mark Klein, Arthur M. Lam, M.D.Anesthesiology, University of Washington, Seattle, Washington

Background and Purpose: Transcranial electrical motor evoked potentials (MEP) have joined somatosensory evoked potentials (SSEP) as an important aspect of neurophysiologic monitoring during both intracranial and spine surgery. General anesthesia is known to diminish the quality of signals with SSEP, decreasing amplitude and increasing latency, with volatile anesthesia having a greater effect than intravenous anesthesia. There is little quantitative information on the comparative effect of volatile and intravenous anesthetics on MEP signal quality, however. The purpose of this study is to describe the effects of propofol and sevoflurane on SSEP and MEP in patients undergoing both spine and neurosurgical procedures.