We describe a seronegative myasthenia gravis patient with rapidly reversible tongue atrophy after treatment.

 

 

 

 

Tongue atrophy in MuSK+ and ACHR+ myasthenia gravis is known (photos). However, rapid resolution has not been reported and is documented in this patient after 5 weeks of therapy.

CASE HISTORY:   A 61 year old male developed a subacute progressive respiratory difficulty leading to hypercapneic respiratory failure requiring intubation.  By history at presentation he had experienced gradual loss of stamina, difficulty chewing, dysarthria, episodes of dysphagia and progressive weakness in all extremities over the previous year.  He remained ambulatory.  Presumptive diagnosis at presentation was amyotrophic lateral sclerosis.

   On examination after extubation, he was diffusely weak, normoreflexic with normal tone and sensory exam was intact. There was mild bilateral ptosis and extraocular muscle weakness. He had marked dysarthria and severe tongue atrophy.  (Photo).  Electromyography demonstrated widespread fibrillations but normal motor unit potential morphology including the tongue. SFEMG of his tongue demonstrated increased jitter with blocking.  AChR antibodies and MuSK antibodies were negative.

He underwent treatment with plasmapheresis (PLEX) and high dose daily prednisone with improvement in his weakness, dysarthria and dysphagia. At 5 weeks following PLEX along with prednisone daily, his tongue was markedly improved in bulk, strength and function.  (Photo)

Tongue atrophy often suggests motor neuron disease.  In this case, clinical profile suggested myasthenia gravis confirmed by electrodiagnostic testing. Rapid reversal of tongue atrophy with treatment in Myasthenia Gravis is unique and promising for selected individuals.