title: Somatosensory evoked potential findings in ankylosing spondylitis.
abstract: OBJECTIVE
  Somatosensory evoked potential (SSEP) abnormalities were reported in patients with ankylosing spondylitis (AS). This study aimed to investigate SSEP abnormalities and its relation with clinical findings in AS patients.
  
  
  METHODS
  The study included 26 patients with AS and 17 age-matched health volunteers (Control for SSEP). Median nerve SSEP findings were normal in all AS cases.
  
  
  RESULTS
  However, delayed latency and/or very low amplitude of tibial nerve SSEP was found in 20 (76.9%) AS patients. There were significant correlations between tibial SSEP latency and disease duration (R=0.433 to 0.635). There was also an inverse correlation between tibial SSEP amplitude and disease duration (R=-0.429, p=0.047). Serum estradiol level, hip total bone mineral density, The Bath Ankylosing Spondylitis Functional Index (BASFI) score and Beck depression score were significantly lower in AS patients with SSEP abnormalities (37.3±10.8 pg/mL, 0.916±0.123 g/cm(2), 35.0±27.9, 12.8±8.4, respectively) than in AS patients without SSEP abnormalities (53.7±12.3 pg/mL, 1.103±0.197 g/cm(2), 64.8±15.5, 24.8±10.1, respectively).
  
  
  CONCLUSIONS
  Significant inverse correlations between SSEP latencies and dehydroepiandrosterone sulphate (DHEAS) levels were found (R=-0.400 to -0.713). There were also significant inverse correlation between SSEP latencies and DHEAS/oestrogen index (R=-0.596 to -0.868), and between SSEP latencies and DHEAS/Progesterone index (R=-0.467 to -0.685). As a conclusion, this study indicates that tibial nerve SSEP abnormalities are common in patients with AS and there are significant correlations between clinical findings of AS and SSEP abnormalities.
authors.affiliation: Department of Physical Therapy and Rehabilitation, Bagcilar Education and Research Hospital, Istanbul, Turkey.
authors.forename: Muharrem
authors.initials: M
authors.lastname: Cidem
authors.affiliation: Department of Physical Therapy and Rehabilitation, Haydarpasa Numune Education and Research Hospital, Istanbul, Turkey.
authors.forename: Zerrin
authors.initials: Z
authors.lastname: Sahin
authors.affiliation: Department of Physical Therapy and Rehabilitation, Faculty of Medicine, Bezm-i Alem University, Istanbul, Turkey.
authors.forename: Teoman
authors.initials: T
authors.lastname: Aydin
authors.affiliation: Department of Neurology, Bakirkoy Mental and Nervous Diseases Education and Research Hospital, Istanbul, Turkey.
authors.forename: Fikret
authors.initials: F
authors.lastname: Aysal
keywords: Ankylosing spondylitis; clinical findings; neurologic involvement; somatosensory evoked potentials