VIEWS: 38 PAGES: 20 POSTED ON: 4/28/2014
Unusual Brain Lesion with a Usual Cause Ryan Frederiksen MD, Sean Snodgress MD, Benjamin Kianmahd MSIV Department of Radiology Santa Barbara Cottage Hospital Clinical History: Patient A n 36 year old right handed male with no prior medical history n Found unresponsive at gas station n No history of drug abuse, trauma, hypertension, hypercoaguable state or significant family history n Physical Exam: GCS 8 n Labs: within normal limits except for BS > 500 Imaging: Patient A Initial Head CT Day 1: Normal. Imaging: Patient A MRI DWI MRI ADC MRI Day 2: Bilateral thalamic infarcts. Imaging: Patient A Head CTA Day 2: Bilateral thalamic infarcts; CTA portion was normal. Imaging: Patient A Head CT Day 3: Hemorrhagic thalamic infarcts. Clinical History: Patient B n 85 year old male with history of hypertension and GERD n Presented to PMD with 5 day history of ataxia and double vision n Physical Exam: leftward ataxic gait, bilateral horizontal nystagmus, no focal sensory or motor deficits n Labs: LDL 151 Imaging: Patient B MRI DWI MRI FLAIR MRI Day 5 of Symptoms: Bilateral thalamic infarcts. What’s the diagnosis? Bilateral Thalamic Infarcts n Broad differential diagnosis n Venous occlusion: vein of Galen, straight sinus, bilateral internal cerebral veins n Diffuse astrocytoma n ADEM n Arterial ischemia: artery of Percheron Discussion: Background n These two cases demonstrate an anatomic variant n Occlusion of the artery of Percheron results in a characteristic pattern of infarct n Infarct of the bilateral paramedian thalamus with or without midbrain involvement Discussion: Background n The thalamus’ blood supply is usually supplied by: n multiple perforator vessesls originating from the posterior communicating artery n the P1 and P2 segments of the posterior cerebral arteries Discussion: Background n The anterior region is supplied by n the polar (thalamotuberal) arteries, arising from the posterior communicating artery n The paramedian region is supplied by n the paramedian (thalamoperforating) arteries which originate from the P1 segment of the posterior cerebral artery n The inferolateral region is supplied by n the thalamogeniculate arteries which arise from the P2 segment of the posterior cerebral artery n The posterior region is supplied by n the posterior choroidal arteries, which originate from the P2 segment of the posterior cerebral artery. Discussion: Background n The paramedian arteries supplying the thalamus and midbrain exhibit the greatest amount of variability n According to Percheron, there are three variations n This exhibit focuses on a specific anatomic variant of the paramedian arteries, known as the Artery of Percheron Discussion: Paramedian Thalamic Blood Supply Variations 2 A. Many perforating arteries from the P1 segment of the PCA; the most common B. A single artery from the P1 segment; the artery of Perheron C. An arcade of perforating arteries from both PCAs Discussion: Artery of Percheron 3 A single dominant thalamoperforating artery supplying the bilateral medial thalami with variable contribution to the rostral midbrain Discussion n Common physical exam findings n Oculomotor palsy (76% of patients) n Mild gait ataxia (67%) n Deficits of attention (63%) n Fluency and error control (59%) n Learning and memory (67%) n Behavior (67%) Discussion n One retrospective study identified four patterns of artery of Percheron infarcts n Bilateral paramedian thalamic with midbrain (43%) n Bilateral paramedian thalamic without midbrain (38%) n Bilateral paramedian thalamic with anterior thalamus and midbrain (14%) n Bilateral paramedian thalamic with anterior thalamus without midbrain (5%) Conclusion The artery of Percheron is one of the few examples where a cerebral blood vessel supplies structures on both sides of the midline! References n Lazzaro NA, et al. Artery of Percheron infarction: imaging patterns and clinical spectrum. AJNR Am J Neuroradiol. 2010 Aug;31(7):1283-9. Epub 2010 Mar 18. n Matheus MG, et al. Imaging of acute bilateral paramedian thalamic and mesencephalic infarcts. AJNR Am J Neuroradiol. 2003 Nov- Dec;24(10):2005-8. n Mujeeb, S, et al. Symmetric bilateral thalamic infarcts: a rare complication of cardiac catheterization. The Internet Journal of Cardiology. 2009 Vol 7; No 1.
Pages to are hidden for
"Artery of Percheron Infarct_ Clinical and Radiological Manifestations"Please download to view full document