Ocular myasthenia gravis in a person with tetraplegia presenting challenges in diagnosis and management

Abstract

We report the first case of ocular myasthenia gravis (OMG) in a patient with complete tetraplegia, highlighting diagnostic and management challenges. Spinal multidisciplinary rural clinic and specialised inpatient Spinal Cord Injury Unit, NSW, Australia. A 61-year-old man with established C5 AIS A tetraplegia, presented with sudden onset of diplopia and bilateral ptosis, later diagnosed as OMG, in context of other complex co-morbidities, including a cervical cord syrinx, obstructive sleep apnoea and labile blood pressure. Clinical findings were consistent with fluctuating bilateral partial third and sixth nerve palsies. Acetylcholine receptor antibodies were negative, but electromyography demonstrated muscle fatigue. The ocular signs responded well to pyridostigmine. Medications taken before diagnosis, including solifenacin for neurogenic bladder overactivity, were ceased to avoid attenuating the anti-cholinesterase effect. However, the unopposed anti-cholinesterase activity led to frequent and painful abdominal spasms, associated with uncontrolled detrusor hyperreflexia and worsening autonomic dysreflexia (AD). A trans-vesical phenol block to treat this provided only short-lasting benefit. Pyridostigmine was ceased to avoid provoking his abdominal spasms and his regular medications were recommenced. It was decided that the most appropriate treatment for his distressing diplopia was an eye patch. After discharge home, he continued to experience problems with recurrent urinary tract infections, abdominal spasms, episodic postural hypotension and AD. After 5 months, the patient died from an acute myocardial infarction. This case report contributes new knowledge about the rare presentation of OMG in a person with chronic tetraplegia.

Keywords: Neurological disorders; Spinal cord diseases.