title: Cognitive impairment as a central cholinergic deficit in patients with Myasthenia Gravis.
abstract: BACKGROUND
  The purpose of this study was to investigate with neurophysiological and neuropsychological methods such as pupillometry, cognitive test and Hamilton Depression Rating Scale (HAM-D) the hypothesis of Central Nervous System (CNS) cholinergic involvement in patients with Myasthenia Gravis (MG).
  
  
  METHODS
  Thirty-two patients (32) with MG and a mean age of 51.1 ± 17.2 volunteered to participate in this investigation, while thirty-three (33) healthy subjects with a mean age of 50.2 ± 14.8 served as controls. All subjects underwent pupillometric measurements and performed the Wechsler Memory Scale (WMS) and HAM-D. The pupillometric indices studied were: 1) latency for the onset of constriction (T1), 2) maximum constriction velocity (VCmax) and 3) maximum constriction acceleration (ACmax).
  
  
  RESULTS
  T1 was found significantly increased by 21.7% (p < 0.05) in MG patients as compared to healthy subjects. Conversely, VCmax and ACmax were significantly decreased in MG patients by 33.3% (p < 0.05) and 43.5% (p < 0.05) respectively, as opposed to healthy subjects. Additionally, MG patients showed significantly decreased score in WMS by 41.6% (p < 0.05) as compared to healthy controls. No significant difference was found for HAM-D between the two groups.
  
  
  CONCLUSIONS
  VCmax and ACmax are governed mainly by the action of the Parasympathetic Nervous System, through acetylcholine. The results of this study demonstrate that the CNS may be affected in MG and support the hypothesis that MG has central cholinergic effects manifested by cognitive dysfunction.
authors.affiliation: Neurology Clinic of AHEPA Hospital, Neuroscience Division, Medicine School, Aristotle University of Thessaloniki, Greece.
authors.forename: Antonia
authors.initials: A
authors.lastname: Kaltsatou
authors.affiliation: Neurology Clinic of AHEPA Hospital, Neuroscience Division, Medicine School, Aristotle University of Thessaloniki, Greece.
authors.forename: Dimitris
authors.initials: D
authors.lastname: Fotiou
authors.affiliation: Neurology Clinic of AHEPA Hospital, Neuroscience Division, Medicine School, Aristotle University of Thessaloniki, Greece.
authors.forename: Dimitris
authors.initials: D
authors.lastname: Tsiptsios
authors.affiliation: Neurology Clinic of AHEPA Hospital, Neuroscience Division, Medicine School, Aristotle University of Thessaloniki, Greece.
authors.forename: Anastasios
authors.initials: A
authors.lastname: Orologas
keywords: Autonomic nervous system; Cholinergic deficit; Cognitive dysfunction; Myasthenia Gravis; Pupillometry