Abstract
Introduction We report a case of Lambert Eaton Myaesthenic Syndrome (LEMS) in an 85-year-old gentleman with no active malignancy.
Case An 85-year-old gentleman presented with a 3-month history of proximal weakness, confusion, nausea and vomiting. His medical history included gastric adenocarcinoma with curative resection 21-years ago and a 2-year history of a stable sensorimotor peripheral neuropathy. During his admission he experienced an episode of new onset fluctuating diplopia. Neurological examination demonstrated mild upper and lower limb non-fatiguable weakness. There was no detectable cranial nerve palsy.
A myasthenia antibody panel was ordered. Voltage-gated-calcium-channel-antibodies were positive (47pM) (normal range < 30pM). Repetitive nerve stimulation demonstrated an increment in compound muscle action potential of the right nasalis and right abductor digiti minimi following exercise and high-rate stimulation consistent with the clinical diagnosis of LEMS. Investigation for malignancy including tumour markers, CT chest, abdomen and pelvis, MRI-pancreas and whole body PET scan were unremarkable.
The patient underwent a 1-month period of inpatient rehabilitation and was discharged home. At 6 months, he remains well with no further episodes of diplopia or weakness. To date, no malignancy has been identified.
Conclusion LEMS in absence of an identified malignancy is an uncommon diagnosis. Those cases that have been documented are also more likely to occur in younger patients. The case we present here highlights a constellation of vague seemingly discordant symptoms with a unifying diagnosis and offers the patient a chance to be actively monitored for the development of malignancy in the future.