Case Studies for Peripheral Nervous System for Undergraduate Students

Written By: Nancy Palmer-Shevlin, MD

DISCLAIMER: These hypothetical cases referencing selected structures of the PNS were developed and written by Nancy Palmer-Shevlin MD, (for use in undergraduate Human Biology courses), to assist students in applying concepts learned in lecture. They are intended for educational purposes only, not for personal or professional diagnoses or treatment of any person.No personal or confidential medical information of any real patient is included.

Transcript

1. • Case Studies for Peripheral Nervous System Unit for Undergraduate Human Biology Students • Written By:Nancy Palmer-Shevlin,MD • Use your Class Notes and Online Text to review structure and function of Human Nervous System. • DISCLAIMER: These hypothetical cases were developed and written by Nancy Palmer-Shevlin MD, (for use in undergraduate Human Biology courses), to assist students in applying concepts learned in lecture. They are intended for educational purposes only,not for personal or professional diagnoses or treatment of any person.No personal or confidential medical information of any real patient is included.
2. Person 1:Bob could not see the numerals in the Ishiara Plates below,and couldn’t match his socks. His Snellen test and pupillary responses to light are normal. 1.Review the anatomy of the eye. List the layers of the retina and their functions. 2. What is the reason he cant see the numerals? 3.What causes this disorder? 4.What is the genetic basis for this disorder? 5.Why is this so rare in females?
3. https://www.youtube. com/watch?v=AuLR0k zfwBU
4. Person #2 Mary has no afferent (direct) pupillary response to light shined in R eye.But when light was presented to L eye, afferent and consensual pupillary reactions were both intact. 1.Where is the lesion? (What Cranial Nerve is not working?) 2.Describe the path of light through a normally functioning eye.
5. Person 3 • 20 year old Beth has 20/40 vision OS and OD .This means she is______sighted ( ) her eyeballs are too________ and the image focuses ___________the retina. Her optometrist also remarked that she has an astigmatism that can be corrected with lenses. What causes astigmatism?
6. Person 3: Recall
7. PERSON # 4 • When light shines into Bobs L eye he has constriction of L pupil AND the Right pupil. But when light shines into R eye he has pupillary constriction on the R eye but NO pupillary constriction on the LEFT. What Cranial Nerve is damaged?
8. Person #5 Joseph A 19 yo college basketball player is complaining of hearing loss bilaterally.Examination of his ears with the otoscope shows no inflammation in either ear, and intact tympanic membranes bilaterally. No history of falling, tinnitus or dizziness. He has been using his IPOD daily and attends loud concerts on a regular basis. What do you suspect? View the structures of the inner and outer ears.Be sure to review the cochlea and its Organ of Corti. 1.What structure(s) in his auditory system might be damaged? 2.Describe the pathway of sound waves through the ear to the brain. 3.What Weber results would you expect? 4.What is the treatment for this if it does not resolve? 5. How many decibels are safe for the human ear? 6.How could this have been prevented? 7.Describe the potential role of RNA for the treatment of damage to these structures.
9. Person 6: Ada Ada is a two year old child who has been “cranky” and keeps tugging on her R ear.She has had a fever for three days. This has not been resolved with amoxicillin. 1.What would you expect to find when examining her ear with an otoscope? 2.What anatomical structure can you view with an otoscope? 3.If this condition persisted, what type of hearing loss could result from this? Why? 4.If she were older and a tuning fork test could be done, what results would you expect? 5.What antibiotic might have been more effective in treating this condition?
10. SOURCE: fairview.org No copyright infringement intended 1.List the path of sound waves through the outer ear and to the brain
11. PERSON 7: Alex is a 72 yo who man has lost 30 lbs in the last 3 months because he “cant taste his food”. He does not have any other symptom except food has no taste for him. His test for SARS-coV2 was negative.CT of his brain showed mild atrophic changes with no mass lesions and no areas of obvious degenerative changes.It was determined, through Neurological testing, that there may be damage to a cranial nerve. 1.What Cranial Nerves are responsible for the sense of taste? Neurological exam shows that CN VII,IX,X are intact. 2.What other Cranial Nerve should be tested?
12. 3.Which cranial nerve is affected? 4.Explain how this cranial nerve affects taste. Note: There are many potential causes of loss of olfaction in elderly people. For more information read:https://www.karger.com/Article/Fulltext/381619 5.What is the difference between a canine olfactory system and a humans?
13. Person 8: Sara • Sara is a 21 yo woman who woke up one morning feeling numbness and tingling in the L side of her face. When she attempted to drink her coffee it ran out of the side of her mouth. She even experienced some hyperacusis. She called 911, and suspecting a CVA, the EMT rushed her to the hospital. She also could not taste food on the anterior 2/3 of her tongue. CT w contrast was normal and an MRI showed normal brain. The ER physician asked her to close her eyes and noted that the L one remained open. She lost sensation in her L face, and could not smile or make any facial expression.She has no other neurologic deficits. 1.What is her problem? 2.Is this a problem in the PNS or CNS? 3.List the structures that are involved. 4.What are probable causes of this condition? 5.List the treatments available.
14. Person 9:Jim • Jim is a 21 yo Health Education major who presented to the Student Health Center with lower back pain which he described as “really bad”. He said the pain began yesterday morning, and he had been lifting heavy weights the evening before.He described the pain as aching and said it radiated down his leg to the dorsum of his left foot. He said it was not relieved with Motrin. The Nurse Practitioner suspected Jim was just seeking pain meds because he had just attended a seminar on the risks of addiction to prescription pain meds in young adults.He sent Jim back to his dorm and told him to get back to class after two hrs. and keep running track. 1.What questions should the Nurse Practitioner have asked? 2.What simple tests could he have performed in the office? 3.What other tests might be helpful?
15. On the advice of his parents, Jim returned to his home, and his Primary Care Physician ordered the studies shown in the Right Lower images. 4.List the anatomical structures depicted in the MRI images shown. What appears to be causing his symptoms? Describe the findings in anatomical terms. 5.Why might PT be helpful in his condition? 6.List other non-invasive interventions to help alleviate Jim’s symptoms? 6.What is GDF5 Gene Therapy? When is it used? Discuss some of the data on this. SOURCE: FOR UPPER R IMAGE:MAYO FOUNDATION FOR MEDICAL EDUCATION AND RESEARCH. NO COPYRIGHT INFRINGEMENT INTENDED. SOURCE:FOR LOWER R IMAGE: youtube.com.No COPYRIGHT INFRINGEMENT INTENDED.