This document contains a case study of a 23-year-old female student experiencing progressive weakness and vision problems. Her symptoms include ptosis, double vision, difficulty chewing and using utensils, and worsening weakness throughout the day. Examination found ptosis that worsened with upward gaze and improved with eye closing. The most likely diagnosis is myasthenia gravis due to the presentation of progressive fatigability, ptosis, bulbar involvement, and reflex-sparing symptoms. Myasthenia gravis is caused by antibodies targeting nicotinic acetylcholine receptors.

1. NSB Review
Ask Ethan about the Wu Tang/muscular dystrophy connection

2. • A 23-year old female student notices double vision while studying for
her examinations. She goes to see an ophthalmologist, who said she
had a "Iazy eye." These symptoms come and go for the next 2 years
without becoming significant. Then, she starts to have difficulties with
chewing food, and has troubles with getting in and out of the car.
SIowly, problems with using her arms and legs develop. She thinks she
is out of shape and needs more exercise. She begins spilling drinks and
missing her mouth when using utensils. Her vision is double by
afternoon each day, and by the evening, one eye is closed. The next
morning, her situation is improved, but again worsens by the evening.
Finally, she goes to see a neurologist. On examination, ptosis is noted.
The ptosis worsens when she is asked to sustain an upward gaze, and
closing her eyes for a short period improves it. Her voice has a nasal
quality. Sensory examination and deep tendon reflexes are normaI.
Which is the most likely diagnosis?
A) Botulism
B) Guillain-Barré syndrome
C) Lambert-Eaton syndrome
D) Myasthenia gravis
E) Wernicke syndrome

3. • A 23-year old female student notices double vision while studying for
her examinations. She goes to see an ophthalmologist, who said she
had a "Iazy eye." These symptoms come and go for the next 2 years
without becoming significant. Then, she starts to have difficulties with
chewing food, and has troubles with getting in and out of the car.
SIowly, problems with using her arms and legs develop. She thinks she
is out of shape and needs more exercise. She begins spilling drinks and
missing her mouth when using utensils. Her vision is double by
afternoon each day, and by the evening, one eye is closed. The next
morning, her situation is improved, but again worsens by the evening.
Finally, she goes to see a neurologist. On examination, ptosis is noted.
The ptosis worsens when she is asked to sustain an upward gaze, and
closing her eyes for a short period improves it. Her voice has a nasal
quality. Sensory examination and deep tendon reflexes are normaI.
Which is the most likely diagnosis?
A) Botulism
B) Guillain-Barré syndrome
C) Lambert-Eaton syndrome
D) Myasthenia gravis
E) Wernicke syndrome

4. • Progressive fatigability, ptosis, bulbar
involvement, reflex-sparing
• GBS often presents with somatosensory
involvement
• LEMS rarely has bulbar involvement

6. • The underlying pathophysiology in this disease
involves which of the following mechanisms?
A) Antibodies to nicotinic acetylcholine
receptors
B) Antibodies to voltage-gated calcium channels
C) Bacterial toxin
D) Infection-induced autoimmune response
E) Thiamine deficiency

7. • The underlying pathophysiology in this disease
involves which of the following mechanisms?
A) Antibodies to nicotinic acetylcholine
receptors
B) Antibodies to voltage-gated calcium channels
C) Bacterial toxin
D) Infection-induced autoimmune response
E) Thiamine deficiency

8. • MG is progressive, autoimmune disease
targeting nAChR
• LEMS is VGCC
• Botulinum toxin attacks SNARE
• GBS is post-infection
• Wernicke encephalopathy is associated with
thiamine deficiency

9. Questions?