Janet, age 22, was preparing for her 6-week postpartum checkup.  Six weeks earlier, she had delivered her first son.  The day of her checkup, she became very dizzy.  The room was spinning, and she felt she had lost all equilibrium.  She mentioned the dizziness to her doctor, who suggested an iron supplement for postpartum anemia.  2 days later the dizziness subsided and she felt fine.

At 25, in the third trimester of her second pregnancy, Janet began to have migraine headaches, something she had not experienced before.  Her little finger went numb and tingly.  This sensation traveled up her arm and into her face.    The headaches and the numbness lasted a few days.  One year later, this episode repeated itself.  This time, Janet was not pregnant.

Nine years went by, symptom free.  Janet was now 31.  She had brushed off the previous episodes as a strange reaction to stress until  she woke up one morning extremely nauseated.  Not only was she nauseated but her eyes would not focus.  She put her contacts in; she could see fine out of the left eye but saw double out of the right.  The following day, her vision had not improved.   Her husband called the ophthalmologist who agreed to see her immediately.  The ophthalmologist performed a routine eye exam which included checking for changes in visual fields and checking visual acuity.  Janet's exam showed a decrease in her visual acuity and her visual field in her right eye was also decreased.  Her right eye showed nystagmus, involuntary rapid eye movement. The ophthalmologist referred Janet to a neurologist for further testing.

1.  What is a visual field?
2.  What conditions may affect the visual field of the eye?
3.  What is a visual acuity test?
4.  Why is a visual acuity test performed?

The neurologist told Janet that he suspected she was showing initial symptoms of multiple sclerosis (ms).  He ordered a  computerized tomography or CT scan of the brain to look for characteristic plaques.  No plaques were evident and the neurologist could not make a definitive diagnosis.  By this point, Janet was regaining her normal vision.  The attack had lasted four days. 

Instructor's Note:  At the time Janet had this testing done, a CT scan was the most sophisticated imaging technique available.  Magnetic Resonance Imaging (MRI scan), a more sophisticated imaging technique, did not yet exist! 

5.  What happens to the myelin sheath of the nerve in MS? 
6.  Why does this occur?
7.  How does this affect a patient with MS?
8.  What functions may be affected by MS?
9.  What happens to the nerve after an assault on the myelin sheath?
10.  What is the most common pattern of MS attacks?
11.  What is the difference between primary progressive and relapsing remitting MS?
12.  What symptoms are suggestive of MS?
13.  Describe what a CT scan is.