Neuroscience Analysis of Occupational Performance (OCTH 455)
and
Neuroscience (PTRS 850)
Example case study
Green #35
Hanna Charoset spent a weekend skiing in Colorado, in very cold weather. She awakens on the following Monday to find that theskin on the right side of her face feels "tight", as if it is "pulled to the right". While washing her face, she repeatedly got soap into the outside corner of her right eye. She notices that sounds are much louder in her right ear than her left ear, and that her food tastes differently than normal. Clinical tests reveal that there is moderate muscle weakness of all facial muscles on the right side of the face, and a loss of taste sensation in the anterior portion of the right side of her tongue. After treatment with steroids, her situation improves slowly. On a return visit several months later, testing shows that the right (but not left) corner of her mouth raises when she squeezes her eyes shut. She reports that strongly-flavored foods cause her right eye to produce tears.
Here's an example answer to the same case study, illustrating the deductive process:
Green #35
Answer: Structure = Cranial Nerve VII (Facial)
Your reasoning may look something like this:
- Motor involvement of facial region; unilateral muscular weakness of facial muscles (entire right side)
- therefore cortex not involved (not localized to lower right quadrant)
- Blink response reduced on right side; soap enters eye due to reduced muscle responses
- Diminished taste; unilateral & anterior tongue (right reduced); CN VII has sensory input from anterior tongue
- Unilateral change in sound intensity (right louder)
- CN VII innervates stapedius muscle of ear; this motor output limits ossicle movements to sounds
Long-term changes:
- Abnormal muscle movements & abnormal autonomic responses perhaps due to re-growth of damaged CN VII fibers, which innervate inappropriate targets after collateral growth of axon branches from intact neighboring nerves.
- Tears due to re-growth of damaged autonomic axons which should normally innervate salivary glands, but instead are misrouted and innervate the lacrimal glands
In developing an answer, remember to discuss therapeutic considerations.
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