title: Ulnar nerve compression at the wrist: diagnostic role of palmar stimulation.
abstract: OBJECTIVE
  Electrophysiological diagnosis of ulnar nerve entrapment at the wrist is sometimes difficult. The aim was to evaluate the diagnostic role of ulnar nerve stimulation above and below the Guyon channel in ulnar nerve entrapment at the wrist.
  
  
  METHODS
  Supramaximal ulnar nerve stimulation at the wrist and palm, in addition to the standard nerve conduction studies, in 10 patients with ulnar nerve entrapment at the wrist and 40 controls.
  
  
  RESULTS
  Motor latencies to the first dorsal interosseous muscle with wrist stimulation were prolonged unilaterally in six and bilaterally in four patients. Palmar stimulation showed partial conduction blocks on the more symptomatic side in all. In two bilateral cases, there were 28.8% and 44.3% amplitude loss on the less symptomatic side. Motor responses elicited with palm stimulation were also found to have prolonged latencies and decreased amplitudes.
  
  
  CONCLUSIONS
  Stimulation of the deep branch of the ulnar nerve can expand the information about ulnar nerve entrapment at the wrist by providing evidence about its nature, prognosis, precise localization, and distal extent.
authors.affiliation: *Department of Neurology, Bakirkoy Research and Training Hospital for Psychiatry, Neurology and Neurosurgery, Istanbul, Turkey; and †Department of Neurology, Istanbul University, Istanbul, Turkey.
authors.forename: Fikret
authors.initials: F
authors.lastname: Aysal
authors.forename: Belgin
authors.initials: B
authors.lastname: Mutluay
authors.forename: Aysun
authors.initials: A
authors.lastname: Soysal
authors.forename: Ayhan
authors.initials: A
authors.lastname: Koksal
authors.forename: Sevim
authors.initials: S
authors.lastname: Baybas
authors.forename: Ali Emre
authors.initials: AE
authors.lastname: Oge
mesh_terms: D000328:Adult; D000368:Aged; D004576:Electromyography; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality; D006801:Humans; D008297:Male; D008875:Middle Aged; D009431:Neural Conduction / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D017769:Ulnar Nerve Compression Syndromes / Q000175:diagnosis* / Q000503:physiopathology; D014953:Wrist / Q000294:innervation*; D055815:Young Adult