title: Cognitive decline and hypersomnolence: thalamic manifestations of a tentorial dural arteriovenous fistula (dAVF).
abstract: BACKGROUND
  Intracranial dural arteriovenous fistulas (dAVFs) often present with pulsatile tinnitus, orbital congestion, and headache. Occasionally, they present with focal neurologic deficits, a dementia-like syndrome, hemorrhage, or ischemic infarction.
  
  
  METHODS
  This study is based on the case of a 71-year-old gentleman who presented with 6 months of progressive forgetfulness, inattention, and hypersomnolence. Four weeks prior to presentation, he developed symptoms of left-sided pain, numbness, and worsening weakness. Neurologic examination demonstrated hypersomnolence, a score of 30/38 on the Kokmen Short Test of Mental Status, and left hemiparesis. MRI brain revealed bilateral thalamic T2 hyperintensities with associated enhancement. MR venogram (MRV) showed a vascular malformation in the posterior fossa and occlusion of the straight sinus. Conventional cerebral angiogram confirmed a tentorial dAVF. The dAVF was definitively treated with transarterial embolization, followed by clip ligation of the arterialized draining vein. Twelve weeks later, there was clinical resolution of left hemiparesis and improvement in cognitive status. MRI revealed complete resolution of the thalamic hyperintensities. MRV demonstrated recanalization of the straight sinus.
  
  
  RESULTS
  Intracranial dAVFs are uncommon but potentially life-threatening acquired vascular malformations. The initiating factor is venous hypertension, causing retrograde flow, venous congestion, ischemia, and sometimes infarction. The spectrum of clinical manifestations in dAVFs reflects the degree of venous congestion present. If retrograde venous flow is surgically obliterated, then venous hypertension may be reversible. Bilateral thalamic venous congestion can present as a thalamic dementia.
  
  
  CONCLUSIONS
  We conclude that intracranial dAVFs with thalamic venous congestion should be considered in the diagnostic differential for patients who present with subacute cognitive decline and T2 hyperintense thalamic signal change.
authors: Department of Neurology, Mayo Clinic, Rochester, MN, USA. morparia.neha@mayo.edu
authors: Neha
authors: N
authors: Morparia
authors: Gary
authors: G
authors: Miller
authors: Alejandro
authors: A
authors: Rabinstein
authors: Giuseppe
authors: G
authors: Lanzino
authors: Neeraj
authors: N
authors: Kumar
mesh_terms: D000368:Aged; D020785:Central Nervous System Vascular Malformations / Q000150:complications* / Q000473:pathology; D003072:Cognition Disorders / Q000209:etiology* / Q000473:pathology; D003937:Diagnosis, Differential; D006970:Disorders of Excessive Somnolence / Q000209:etiology* / Q000473:pathology; D006801:Humans; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D013786:Thalamic Diseases / Q000209:etiology* / Q000473:pathology; D013788:Thalamus / Q000473:pathology