title: Neuropsychological profile of bilateral paramedian infarctions: three cases.
abstract: BACKGROUND
  The thalamus is one of the strategic diencephalic structures of the human brain. The artery of Percheron, an asymmetrical common trunk arising from a P1 segment of the posterior cerebral artery, is a peculiar presentation of the three variants involved in the irrigation of the paramedian thalamic territory. Occlusion of this artery results in bilateral median thalamic infarction. The paramedian syndrome includes an acute loss or reduction of consciousness, often associated with oculomotor and neuropsychological disturbances.
  
  
  METHODS
  We present three cases of bilateral paramedian thalamic infarction with onset of acute coma, followed by fluctuations in the level of consciousness, memory, and behavioural alterations. A neuroradiological study with MRI identified individual thalamic nuclei, and a complete neuropsychological study was performed one month after onset of ictus.
  
  
  RESULTS
  One of the patients showed severe memory and executive function impairments without improvement of vertical gaze palsy. The other two patients presented with mild executive dysfunction with complete resolution of neurological symptoms. Neuroimaging results showed a bilateral lesion of the dorsomedial nuclei in the three patients.
  
  
  CONCLUSIONS
  Severe amnesia has been associated with an affection of the structures of the paramedian thalamic territory. Presently, the role of the dorsomedial nucleus remains controversial, with the suggestion that memory deficits observed in this type of lesion could be secondary to executive function deficits. In our case, the patient with the most severe dysexecutive deficit presented the most severe memory impairments.
authors.affiliation: Universitat Autònoma de Barcelona, Barcelona, Spain. merce.jodar@uab.cat
authors.forename: M
authors.initials: M
authors.lastname: Jodar
authors.forename: P
authors.initials: P
authors.lastname: Martos
authors.forename: S
authors.initials: S
authors.lastname: Fernández
authors.forename: D
authors.initials: D
authors.lastname: Canovas
authors.forename: A
authors.initials: A
authors.lastname: Rovira
mesh_terms: D000368:Aged; D002544:Cerebral Infarction / Q000150:complications / Q000473:pathology* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008569:Memory Disorders / Q000209:etiology / Q000503:physiopathology; D008875:Middle Aged; D009483:Neuropsychological Tests; D013787:Thalamic Nuclei / Q000473:pathology / Q000503:physiopathology; D013788:Thalamus / Q000098:blood supply* / Q000473:pathology*