Case (34)

[Doctoor]

An 82-year-old man presents to the clinic with progressive difficulty swallowing and dysphagia over the last several weeks. He has been unable to eat food or drink water for the last 6 days and is thirsty. He denies odynophagia but reports that his speech has become slurred concurrently with his other difficulties. He denies having motor or sensory deficits, headache, fevers, urinary symptoms, malaise, or fatigue. On physical examination, the patient's vital signs are normal with a heart rate of 78 beats per minute and a blood pressure of 132/67 mm Hg. Pulse oximetry is 98% on room air. He has slurred speech. Examination of the head and neck reveals a normal oropharynx with intact tongue movements and a preserved gag reflex. However, the patient has bilateral, symmetric palpebral ptosis with a masklike face. In addition, he has to tilt his head back to look straight ahead. Because of an inability to lift his eyelids, he seems to be furrowing his eyebrows to compensate. The patient has normal motor strength, including strength in the extensors of his wrist and deltoids. He has intact sensation in his extremities and symmetric and normal deep tendon reflexes, and he can walk with no pronator drift. The patient has no difficulty breathing.

• What is your diagnosis?
• Mention one bedside test to confirm your diagnosis?
• What are the complications of this condition?
• How are you going to treat this patient?

Doctoor

[Mustafa]

Salam doctoor,

1. Myasthenia Gravis. MG is an acquired autoimmune disorder characterized clinically by weakness of skeletal muscles and fatigability on exertion. Thomas Willis reported the first clinical description in 1672.
2. The Tensilon test. It is often used to diagnose MG. The enzyme acetylcholinesterase breaks down acetylcholine (ACh) after the muscle is stimulated, preventing prolonged muscle response to a single nerve impulse. Edrophonium chloride (Tensilon) is a drug that temporarily blocks the action of acetylcholinesterase.
3. If left untreated, myasthenia gravis may affect muscles that control breathing, causing acute respiratory failure. Other considerable coplications are:
a.  dysphagia due to pharyngeal muscle weakness may occur and may lead to aspiration pneumonia.
b. Complications secondary to drug treatment: Long-term immunomodulating therapies may predispose patients with MG to various complications.
c. Long-term steroid use may cause or aggravate osteoporosis, cataracts, hyperglycemia, weight gain, avascular necrosis of hip, hypertension, and other complications.
d. Long-term steroid use increases the risk of gastritis or peptic ulcer disease. Patients on such therapy also should take an H2 blocker or antacid.
e. Some complications are common to any immunomodulating therapy, especially if the patient is on more than 1 agent. These would include infections such as tuberculosis, systemic fungal infections, and Pneumocystis carinii pneumonia.
f. Risk of lymphoproliferative malignancies may be increased with chronic immunosuppression.
Immunosuppressive drugs may have teratogenic effects.
4. AChE inhibitors (eg, pyridostigmine, neostigmine) and immunomodulators (eg, steroids, azathioprine, cyclosporine A) are the mainstays of treatment and used in most patients. Most patients with generalized MG require additional immunomodulating therapy.
Other therapeutic options are plasmapheresis, intravenous immunoglobulin and thymectomy especially if a thymoma is present.

[Doctoor]

Thanks Mustafa, it's the correct answer