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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.
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