title: The effect of penicillin therapy on cognitive outcomes in neurosyphilis: a systematic review of the literature.
abstract: OBJECTIVE
  Neurosyphilis commonly presents with cognitive impairment, and penicillin remains the treatment of choice. However, despite a rapid increase in syphilis incidence, the effect of penicillin on long-term cognitive outcomes has not previously been evaluated. We therefore aimed to assess the effect of penicillin on cognitive function in neurosyphilis.
  
  
  METHODS
  We performed a systematic review of all studies of neurosyphilis, where cognitive function was assessed objectively both before and after penicillin therapy for at least one patient. Where Mini-Mental State Examination (MMSE) scores were taken, we performed a paired-samples t test to assess the change in cognitive function and aimed to correlate this with change in serological titers.
  
  
  RESULTS
  Nine studies met inclusion criteria. The one cohort study reported a nonsignificant overall improvement in MMSE, while amalgamation of case reports produced a significant improvement (P=.02) in MMSE after treatment. However, follow-up duration was inadequate, and data were insufficient to correlate changes in cognitive function with serological markers.
  
  
  CONCLUSIONS
  Despite evidence of short-term improvement, there are insufficient data to support the long-term benefit of penicillin therapy on cognitive function in neurosyphilis.
authors.affiliation: Department of Psychological Medicine, Institute of Psychiatry, King's College London. Electronic address: calum.moulton@kcl.ac.uk.
authors.forename: Calum D
authors.initials: CD
authors.lastname: Moulton
authors.affiliation: Department of Psychosis Studies, Institute of Psychiatry, King's College London.
authors.forename: Ivan
authors.initials: I
authors.lastname: Koychev
mesh_terms: D003072:Cognition Disorders / Q000188:drug therapy* / Q000209:etiology; D006801:Humans; D009494:Neurosyphilis / Q000150:complications / Q000188:drug therapy*; D010406:Penicillins / Q000494:pharmacology*
chemical_list: D010406:Penicillins
keywords: Cognition; Mini-Mental State Examination; Neurosyphilis; Penicillin