title: Pattern of startle reflex to somatosensory stimuli changes after spinal cord injury.
abstract: Spinal cord injury (SCI) may cause functional changes at various levels in central and peripheral nervous systems. One of these changes is increased excitability above the lesion such as enhanced auditory startle responses (ASR). Startle response may also be obtained after somatosensory stimulus (startle reflex to somatosensory stimuli, SSS). In this study, we investigated changes of both ASR and SSS in SCI.
  
  
  
  We examined ASR and SSS in 14 patients with SCI and 18 age-matched healthy volunteers. SSS responses were recorded from orbicularis oculi (O.oc), sternocleidomastoid (SCM) and biceps brachii (BB) muscles by electrical stimulation of median nerve at the wrist. ASR was evoked by binaural auditory stimuli and recorded from O.oc, masseter, SCM and BB muscles. Probability, latency, amplitude and duration of responses were compared between two groups for each muscle.
  
  
  
  Presence of response over O.oc after somatosensory stimuli was decreased in patients compared to controls (P = 0.004). There were no differences in SSS responses of other muscles. ASR latency was shorter in masseter, SCM and BB in patients with SCI, but only BB had significantly reduced latency (P = 0.033). The duration of O.oc response was longer and the amplitude of SCM was larger in patients with SCI (P = 0.037 and P = 0.015, respectively).
  
  
  
  ASR is enhanced after SCI whereas SSS of eye muscles is hypoactive and pattern of SSS after median stimulation changes in SCI.
authors: a Department of Neurology, Cerrahpaşa School of Medicine , Istanbul University , Istanbul , Turkey.
authors: Yasin
authors: Y
authors: Abanoz
authors: a Department of Neurology, Cerrahpaşa School of Medicine , Istanbul University , Istanbul , Turkey.
authors: Yeşim
authors: Y
authors: Abanoz
authors: a Department of Neurology, Cerrahpaşa School of Medicine , Istanbul University , Istanbul , Turkey.
authors: Ayşegül
authors: A
authors: Gündüz
authors: b Department of Physical Medicine and Rehabilitation, Cerrahpaşa School of Medicine , Istanbul University , Istanbul , Turkey.
authors: Murat
authors: M
authors: Uludağ
authors: b Department of Physical Medicine and Rehabilitation, Cerrahpaşa School of Medicine , Istanbul University , Istanbul , Turkey.
authors: Nurettin İrem
authors: Nİ
authors: Örnek
authors: a Department of Neurology, Cerrahpaşa School of Medicine , Istanbul University , Istanbul , Turkey.
authors: Nurten
authors: N
authors: Uzun
authors: b Department of Physical Medicine and Rehabilitation, Cerrahpaşa School of Medicine , Istanbul University , Istanbul , Turkey.
authors: Halil
authors: H
authors: Ünalan
authors: a Department of Neurology, Cerrahpaşa School of Medicine , Istanbul University , Istanbul , Turkey.
authors: Meral
authors: M
authors: Kızıltan
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D019054:Evoked Potentials, Motor; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000503:physiopathology; D013216:Reflex, Startle; D013119:Spinal Cord Injuries / Q000503:physiopathology*
keywords: Auditory startle responses; Spinal cord injury; Startle reflex to somatosensory stimuli