title: The GABAB receptor agonist, baclofen, contributes to three distinct varieties of amnesia in the human brain - A detailed case report.
abstract: We describe a patient in whom long-term, therapeutic infusion of the selective gamma-amino-butyric acid type B (GABAB) receptor agonist, baclofen, into the cerebrospinal fluid (CSF) gave rise to three distinct varieties of memory impairment: i) repeated, short periods of severe global amnesia, ii) accelerated long-term forgetting (ALF), evident over intervals of days and iii) a loss of established autobiographical memories. This pattern of impairment has been reported in patients with temporal lobe epilepsy (TLE), in particular the subtype of Transient Epileptic Amnesia (TEA). The amnesic episodes and accelerated forgetting remitted on withdrawal of baclofen, while the autobiographical amnesia (AbA) persisted. This exceptional case highlights the occurrence of 'non-standard' forms of human amnesia, reflecting the biological complexity of memory processes. It suggests a role for GABAB signalling in the modulation of human memory over multiple time-scales and hints at its involvement in 'epileptic amnesia'.
authors.affiliation: Cognitive Neurology Research Group, University of Exeter Medical, School, College House, St Luke's Campus, Exeter, UK. Electronic address: a.zeman@exeter.ac.uk.
authors.forename: Adam
authors.initials: A
authors.lastname: Zeman
authors.affiliation: Human Cognitive Neuroscience, University of Edinburgh, 7 George Square, UK. Electronic address: sergehoefeijzers@gmail.com.
authors.forename: Serge
authors.initials: S
authors.lastname: Hoefeijzers
authors.affiliation: Discipline of Psychology, University of Exeter, Washington Singer Laboratories, Exeter, UK. Electronic address: F.N.Milton@Exeter.ac.uk.
authors.forename: Fraser
authors.initials: F
authors.lastname: Milton
authors.affiliation: Human Cognitive Neuroscience, University of Edinburgh, 7 George Square, UK; Department of Psychology, Heriot-Watt University, Edinburgh, UK. Electronic address: m.dewar@hw.ac.uk.
authors.forename: Michaela
authors.initials: M
authors.lastname: Dewar
authors.affiliation: Cognitive Neurology Research Group, University of Exeter Medical, School, College House, St Luke's Campus, Exeter, UK.
authors.forename: Melanie
authors.initials: M
authors.lastname: Carr
authors.affiliation: Cognitive Neurology Research Group, University of Exeter Medical, School, College House, St Luke's Campus, Exeter, UK.
authors.forename: Claire
authors.initials: C
authors.lastname: Streatfield
mesh_terms: D000647:Amnesia / Q000139:chemically induced*; D000700:Analgesics / Q000009:adverse effects* / Q000494:pharmacology / Q000627:therapeutic use; D001418:Baclofen / Q000009:adverse effects* / Q000494:pharmacology / Q000627:therapeutic use; D005260:Female; D006801:Humans; D061212:Memory, Episodic; D008570:Memory, Short-Term / Q000187:drug effects*; D008875:Middle Aged; D010146:Pain / Q000188:drug therapy*; D012153:Retention, Psychology / Q000187:drug effects*
chemical_list: D000700:Analgesics; D001418:Baclofen
keywords: Accelerated long term forgetting; Autobiographical amnesia; Baclofen; Transient amnesia; Transient epileptic amnesia