title: Stiff person syndrome in South Asia.
abstract: BACKGROUND
  Stiff person syndrome is a highly disabling, progressive autoimmune disorder of the central nervous system characterized by muscle rigidity and spasms. Stiff person syndrome is rare, but is believed to be under diagnosed with only 14 cases been reported among a 1.7 billion population in South Asia. We report the first authenticated case from Sri Lanka.
  
  
  METHODS
  A 55-year-old Sri Lankan female presented with difficulty in walking and recurrent falls due to progressive muscular rigidity in her lower limbs and trunk with superimposed muscle spasms that occurred in response to unexpected noise, startle or emotional upset. She had anxiety and specific phobias to open spaces, walking unaided and being among crowds of people. She had insulin-dependent diabetes mellitus and was on thyroxine replacement. On examination, she had hyperlordosis combined with board-like rigidity of her anterior abdomen and rigidity of her lower limbs bilaterally. Upper limbs were normal. Magnetic resonance imaging of her neuraxis was normal. Electromyography showed continuous motor unit activity at rest. Glutamic acid decarboxylase antibodies were detected in her serum at a titre of 15,500 IU/ml (normal <5). She showed a remarkable and sustained improvement to treatment with intravenous immunoglobulins, immunosuppressive and muscle relaxant medications, regaining independent ambulation.
  
  
  CONCLUSIONS
  Diagnosis of stiff person syndrome remains clinical, supported by electromyography and serology for glutamic acid decarboxylase antibodies, facilitated by a high index of clinical suspicion. An autoimmune basis lends stiff person syndrome amenable to treatment highlighting the importance of diagnosis. This case adds to map the worldwide distribution of stiff person syndrome.
authors.affiliation: Department of Clinical Medicine, Faculty of Medicine, University of Colombo, 25, Kynsey Road, Colombo, 00800, Sri Lanka. thashichang@gmail.com.
authors.forename: Thashi
authors.initials: T
authors.lastname: Chang
authors.affiliation: Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5/6 West Wing, Oxford, OX3 9DU, UK.
authors.forename: Bethan
authors.initials: B
authors.lastname: Lang
authors.affiliation: Nuffield Department of Clinical Neurosciences, John Radcliffe Hospital, Level 5/6 West Wing, Oxford, OX3 9DU, UK.
authors.forename: Angela
authors.initials: A
authors.lastname: Vincent
mesh_terms: D004576:Electromyography; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D013188:Sri Lanka; D016750:Stiff-Person Syndrome / Q000175:diagnosis* / Q000503:physiopathology
keywords: Autoimmune; CNS; Case report; GAD antibodies; Sri Lanka; Stiff person syndrome