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The Auditory Nervous System. SPA 4302 Spring 2007. 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. Olivo-cochlear Neurons
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The Auditory Nervous System SPA 4302 Spring 2007
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 • Olivo-cochlear Neurons • Cortical Neurons • Innervation of Middle Ear Musculature
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 • Tinnitus! • Unilateral SNHL, Initially high frequency • Possibly poor Word Recognition • Facial Nerve Symptoms • Disorders of the Auditory Nerve • Vestibular Schwannoma • Neuritis • Multiple Sclerosis • Auditory Neuropathy: a new dx category • Normal OAEs, Abnormal ABR
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 bilateral deficits • Extra-axial: ipsilateral deficits • Higher level lesions • CVA/Stroke/Aneurysm • produce contralateral deficits
Tests for Auditory Processing Disorder • PI-PB • Filtered Speech • Speech with Competition • SSI • Competing Sentence Tests • Dichotic Digits Test • Staggered Spondaic Word Test • Masking Level Difference Test
Therapeutic Management • Classroom Modifications • Improve Signal To Noise Ratios • Pre-Teaching • Remediation Activities • Listening “Games” • Computer Based Auditory Training • Compensatory Strategies • Homework Buddy