Abstract
BackgroundPolymyositis is an immune-mediated myopathy with clinical features of proximal muscle weakness. Dysphagia and neck flexor weakness can develop along with respiratory muscle weakness as the disease progresses. Kennedy disease or X-linked spinobulbar muscular atrophy is a rare X-linked recessive disorder with clinical features of slowly progressive atrophy and weakness of limb and bulbar muscles. These two disorders may have overlapping clinical manifestations.Case presentationWe present the case of a 52-year-old Filipino man with chronic weakness involving his proximal muscle groups who carried the diagnosis of polymyositis and was refractory to multiple immunomodulatory therapies. Further neurologic examination and history taking along with selective serologic and electrodiagnostic studies instead confirmed the diagnosis of Kennedy disease.ConclusionsDistinction between polymyositis and Kennedy disease may be difficult given the potential overlapping clinical manifestations. However, with careful neurological history taking, examination, and selective serologic plus electrodiagnostic investigations the correct diagnosis may be made, thus sparing the patient ineffective therapy. One must always be sure of the diagnosis of polymyositis before it’s classified as refractory.
Highlights
Polymyositis is an immune-mediated myopathy with clinical features of proximal muscle weakness
At that time investigations included an elevated creatine kinase (CK) of 1522 IU/L, a magnetic resonance imaging (MRI) of the leg showing atrophy and increased signal on short TI inversion recovery (STIR) images, but no electromyogram, nerve conduction studies, or muscle biopsy. Given these findings along with his clinical picture, he was diagnosed with polymyositis and treated with a trial of highdose prednisone, which did not improve his clinical symptoms but did improve his CK levels according to his wife
In our patient’s case, an EMG/nerve conduction study and muscle biopsy were not performed until at least 7 years after the onset of his symptoms. If these studies had been performed earlier in the course of the patient’s investigations, this information along with the fact that there was no clinical response to therapy should have called into question the initial diagnosis of PM much sooner thereby sparing the patient ineffective treatment
Summary
Distinguishing between PM and Kennedy disease can be difficult. A thorough evaluation of the clinical history including family history along with a careful detailed neurological and electrophysiological examination plus genetic testing usually helps direct the physician towards the correct diagnosis and may spare the patient ineffective treatment. One must always be sure of the diagnosis of polymyositis before it’s classified as refractory. Consent Written informed consent was obtained from the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the Editor-in-Chief of this journal
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
