title: Isolated hippocampal infarcts: Vascular and neuropsychological findings.
abstract: OBJECTIVE
  The hippocampus plays a role in the verbal and spatial memory processing, learning, and emotions. The purpose of this study was to determine clinical, etiological, and radiological features of isolated hippocampal infarcts.
  
  
  METHODS
  We reviewed, 6800 patients with first-ever ischaemic stroke included in our Stroke Registry between 2004 and 2014. Among them we studied 19 patients with an acute isolated hippocampal infarct confirmed by MRI.
  
  
  RESULTS
  Among 6800 patients, 19 patients (0.03%) showed ischaemic lesions in the hippocampal artery territory, allowing us to delineate 5 variant distributions; (1) anterior hippocampal infarcts (4 patients [21%]) were present with altered consciousness, transient visual vivid hallucinations, and transient global amnesia with episodic and verbal memory deficits. (2) Posterior hippocampal infarcts (3 patients [16%]) developed dizziness and dullness at stroke onset, confusion, episodic and procedural memory deficit and verbal learning deficit. (3) Unilateral complete hippocampal infarcts were present (4 patients [21%]) with confusion, object specific hallucinations, intense mood states changes as well as impulsivity or depressive behaviour. Memory dysfunctions were found in all patients. (4) Bilateral hippocampal infarcts (3 patients [16%]) had cognitive deficits and memory deficits in all patients. All patients had difficulties retrieving specific autobiographical events and retrieving recent memory, and disturbances of learning in verbal and visual task. Hippocampal dementia was observed in 2 patients with severe immediate, delayed verbal and visual memory deficits, dysexecutive syndrome, deficits in responding to feedback and error correction with dull and aimless appearance lasting several months. (5) Small circumscribed (punctiform) hippocampal infarcts (5 patients [26%]) showed dizziness or dullness sensation and difficulties finding words or objects that they use everyday. Cardioembolism (10; 53%) and large-artery disease of the vertebrobasilar system (6; 32%) were the main stroke mechanisms.
  
  
  CONCLUSIONS
  We described topographic patterns of hippocampal infarction with distinct manifestations and etiologies. We thought that different patterns of hippocampal infarcts are the result of variation in hippocampal arterial supply or reflect a source of embolism.
authors.affiliation: Stroke Unit, Neurology Department, Ege University, School of Medicine, İzmir 35100, Turkey. Electronic address: emre.kumral@ege.edu.tr.
authors.forename: Emre
authors.initials: E
authors.lastname: Kumral
authors.affiliation: Stroke Unit, Neurology Department, Ege University, School of Medicine, İzmir 35100, Turkey.
authors.forename: Emrah Emre
authors.initials: EE
authors.lastname: Deveci
authors.affiliation: Stroke Unit, Neurology Department, Ege University, School of Medicine, İzmir 35100, Turkey.
authors.forename: CanEmre
authors.initials: C
authors.lastname: Erdoğan
authors.affiliation: Stroke Unit, Neurology Department, Ege University, School of Medicine, İzmir 35100, Turkey.
authors.forename: Ceren
authors.initials: C
authors.lastname: Enüstün
mesh_terms: D000368:Aged; D020520:Brain Infarction / Q000209:etiology* / Q000473:pathology*; D002545:Brain Ischemia / Q000150:complications; D003072:Cognition Disorders / Q000209:etiology*; D005260:Female; D007839:Functional Laterality; D006624:Hippocampus / Q000473:pathology*; D006801:Humans; D008137:Longitudinal Studies; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D025341:Principal Component Analysis; D020521:Stroke / Q000150:complications* / Q000209:etiology / Q000473:pathology*
keywords: Cardioembolism; Hippocampal infarct; Large-artery disease; MRI; Memory deficits