Lambert-Eaton Myasthenic Syndrome

More Weakness

Step 1: View clinicals

A 32 year old woman presents with worsening lower back pain, difficulty in walking and weakness of both lower limbs for 6 months. The pain was severe, exacerbated by activity and poorly responsive to analgesics. The lower limb weakness was pronounced when climbing stairs and getting up from chairs. She also complains of a dry mouth, constipation and urinary frequency. Serum electrolyte levels are normal, while her ESR is 10 mm/1h.


Step 2: Order all relevant investigations

Electrodiagnostic studies

The initial compound muscle action potential amplitude in the deep peroneal nerve was low while repetitive stimulation of the nerve showed an initial decremental response followed by an incremental response of >100% after brief exercise.

VGCC & Ach antibodies

P/Q type VGCC antibodies : positive Ach receptor antibodies: negative

MRI brain & spine

No abnormalities are noted.

CT Chest

The CT scan of the chest appears normal.


Step 3: Select appropriate management

3,4-DAP
Steroids
Chemotherapy
Neostigmine


Score: ★★☆