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The Auditory Nervous System. SPA 4302 Summer 2007. The Neuron. Generally: Dendrites receive stim. Creates ______________ Transmitted along axon Causes ____________ ____________ Stimulates new neuron. The Ascending Auditory Pathway. Primary Auditory Cortex. Medial Geniculate Body.
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The Auditory Nervous System SPA 4302 Summer 2007
The Neuron Generally: • Dendrites receive stim. • Creates ______________ • Transmitted along axon • Causes ____________ ____________ • Stimulates new neuron
The Ascending Auditory Pathway Primary Auditory Cortex Medial Geniculate Body Inferior Colliculus Lateral Lemniscus Superior Olivary Complex Cochlear Nucleus VIIIth Nerve
The Descending Auditory Pathways • ________________ Neurons • ______________ Neurons • Innervation of Middle Ear _____________
Development: VIIIth N. and Central Auditory Nervous System • VIIIth nerve initially: days 25 to 45 • Spiral Ganglion, Vestibular Ganglia identifiable by day 35 • Little else known about dev. of CANS
Hearing Loss and the CANS • VIIIth N: some SNHL, some normal • ___________! • ___________ SNHL, Initially high frequency • Possibly poor Word Recognition • ___________ Nerve Symptoms • Disorders of the Auditory Nerve • Vestibular Schwannoma • _____________ • Multiple Sclerosis • Auditory Neuropathy: a new dx category • Normal ________, Abnormal _______
Disorders of the Cochlear Nuclei • Kernicterus: • Result of Rh incompatibility • Hyperbilirubinemia • Cerebrovascular Accident: A brainstem stroke • Congenital trauma, malformation • Pressure (trauma, increased CSF pressure) • Syphilis • Aging
Disorders of the Higher Auditory Pathways • Brainstem Tumors: • Intra-axial: contralateral or __________ deficits • Extra-axial: ____________ deficits • Higher level lesions • CVA/Stroke/Aneurysm • produce _____________ deficits
Tests for Auditory Processing Disorder • ______________ • Filtered Speech • Speech with Competition • _____________ • Competing Sentence Tests • Dichotic Digits Test • Staggered _________ Word Test • Masking Level Difference Test
Therapeutic Management • _____________ Modifications • Improve Signal To Noise Ratios • Pre-Teaching • ______________ Activities • Listening “Games” • Computer Based Auditory Training • ______________ Strategies • Homework Buddy