title: Phonological short-term memory networks following recovery from Landau and Kleffner syndrome.
abstract: Landau-Kleffner syndrome (LKS) is a rare acquired aphasia occurring in otherwise healthy children, together with spike-wave discharges predominating over superior temporal regions and activated by sleep. Although the outcome of language abilities is variable, a residual impairment in verbal short-term memory (STM) is frequent. This STM deficit might be related to the persistent dysfunction of those temporal lobe regions where epileptic discharges were observed during the active phase of the disorder. We tested this hypothesis by measuring brain activation during immediate serial recall of lists of 4 words, compared to single word repetition, using H(2) (15)O positron emission tomography (PET), in 3 LKS patients after recovery and in 14 healthy controls. The patients (TG, JPH, and DC) had shown abnormally increased or decreased glucose metabolism in left or right superior temporal gyrus (STG) at different stages during the active phase of their disease. At the time of this study, the patients were 6-10 years from the active phase of LKS. Results showed that Patients JPH and DC had impaired performance in the STM condition, whereas TG showed near normal performance. PET data showed that JPH and DC activated significantly less than controls left and right posterior STG. TG, having near normal STM performance, showed increased activity in the posterior part of the right STG. These data suggest that impaired verbal STM at late outcome of LKS might indeed be related to a persistent decrease of activity in those posterior superior temporal gyri that were involved in the epileptic focus during the active phase.
authors.affiliation: Department of Cognitive Sciences, University of Liège, Liège, Belgium. smajerus@ulg.ac.be
authors.forename: Steve
authors.initials: S
authors.lastname: Majerus
authors.forename: Steven
authors.initials: S
authors.lastname: Laureys
authors.forename: Fabienne
authors.initials: F
authors.lastname: Collette
authors.forename: Guy
authors.initials: G
authors.lastname: Del Fiore
authors.forename: Christian
authors.initials: C
authors.lastname: Degueldre
authors.forename: André
authors.initials: A
authors.lastname: Luxen
authors.forename: Martial
authors.initials: M
authors.lastname: Van der Linden
authors.forename: Pierre
authors.initials: P
authors.lastname: Maquet
authors.forename: Marie-Noëlle
authors.initials: MN
authors.lastname: Metz-Lutz
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D001184:Articulation Disorders / Q000000981:diagnostic imaging / Q000209:etiology*; D001931:Brain Mapping; D005260:Female; D005947:Glucose / Q000378:metabolism; D006801:Humans; D018887:Landau-Kleffner Syndrome / Q000150:complications / Q000000981:diagnostic imaging / Q000503:physiopathology*; D008297:Male; D008570:Memory, Short-Term / Q000502:physiology*; D011939:Mental Recall / Q000502:physiology; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000503:physiopathology; D014055:Tomography, Emission-Computed
chemical_list: D005947:Glucose