title: Sensory Ganglionopathy and the Blink Reflex: Electrophysiological Features.
abstract: BACKGROUND
  Sensory ganglionopathy (SG) is characterised by asymmetrical sensory fibre degeneration, with the primary pathology occurring at the level of the dorsal root ganglion. It is seen in the context of autoimmune, paraneoplastic, and degenerative disorders. There is limited literature examining the electrophysiological correlate of the trigeminal ganglion and associated pathways, the blink reflex (BR), in cases of SG. Previous work has suggested that the BR is preserved in cases of SG associated with paraneoplasia.
  
  
  METHODS
  The local clinical neurophysiology database was searched for patients diagnosed with SG from peripheral nerve conduction studies in whom the BR was performed. Twenty-six patients were included in the final analysis.
  
  
  RESULTS
  Sjögren's syndrome constituted the most common SG aetiology (8/26), followed by idiopathic cases (7/26) and paraneoplasia (5/26). BR abnormalities were seen in 9 of the 26 patients (34.6%) across all aetiologies. No patients reported sensory disturbance in the distribution of the trigeminal nerve, indicating that the changes noted are subclinical. Three patients showed abnormality of the R1 response; in the remaining six patients, only R2 responses were affected.
  
  
  CONCLUSIONS
  Subclinical abnormalities of both R1 and R2 can be seen in the context of SG of varying aetiologies, including paraneoplasia. Performing the BR in patients with suspected of having SG may be helpful in providing additional evidence of patchy sensory fibre involvement that is characteristic of the disease.
authors.affiliation: 1Department of Clinical Neurophysiology,Royal Hallamshire Hospital,Sheffield,UK.
authors.forename: Taimour
authors.initials: T
authors.lastname: Alam
authors.affiliation: 1Department of Clinical Neurophysiology,Royal Hallamshire Hospital,Sheffield,UK.
authors.forename: Alexander StJ E
authors.initials: AS
authors.lastname: Barker
authors.affiliation: 1Department of Clinical Neurophysiology,Royal Hallamshire Hospital,Sheffield,UK.
authors.forename: James J P
authors.initials: JJ
authors.lastname: Alix
authors.affiliation: 2Department of Neurology,Royal Hallamshire Hospital,Sheffield,UK.
authors.forename: Marios
authors.initials: M
authors.lastname: Hadjivassiliou
authors.affiliation: 1Department of Clinical Neurophysiology,Royal Hallamshire Hospital,Sheffield,UK.
authors.forename: Dasappaiah G
authors.initials: DG
authors.lastname: Rao
mesh_terms: D000328:Adult; D000368:Aged; D001767:Blinking / Q000502:physiology*; D016208:Databases, Factual / Q000706:statistics & numerical data; D004576:Electromyography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D020364:Paraneoplastic Polyneuropathy / Q000503:physiopathology*; D012678:Sensation Disorders / Q000473:pathology* / Q000503:physiopathology*; D012668:Trigeminal Ganglion / Q000473:pathology*; D055815:Young Adult
keywords: electrodiagnostic studies; paraneoplastic conditions; sensory neurons