thalamic infarct

Artery of
Percheron infarction presenting as nuclear third nerve palsy and transient loss of consciousness: a case report. Neurovascular anatomical variants supplying paramedian thalamus and mid brain as was described by Percheron [10]. (Adapted from, Artery of Percheron infarction: review of literature with a case report. Radiology and oncology. 2015 Jun 1;49 (2):141–6.Written permission was obtained from the author and the journal to use as an open access figure). a Variant I - each side perforating arteries arising from each PCA. b Variant IIa - asymmetrically arising two perforating arteries from one sided PCA. c Variant IIb - bilateral thalamic perforating arteries arising from a single common trunk (AOP). d Variant III - an arc bridging P1 segments of bilateral PCA giving rise to several perforating arteries. Vessels marked by initials: AICA - anterior inferior cerebellar artery, AOP - artery of Percheron, BA - basilar artery, MP - midbrain perforators, PCA – posterior cerebral artery, SCA - superior cerebellar artery, TP - thalamic perforators
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Bitalamic
infarction related to occlusion of Percheron artery in patient with patent foramen-ovale. Axial T2 FLAIR showing greater hyperintensity of the left thalamic infarction due to vasogenic oedema.
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Bitalamic
infarction related to occlusion of Percheron artery in patient with patent foramen-ovale. C.E. Axial GE T1 3D: damage of the blood brain barrier at this time is remarked by the enhancement of the lesion following contrast media administration.
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Bithalamic
venous infarction due to straight sinus thrombosis. Axial FLAIR acquisition. Bithalamic hyperintensity.
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Artery of
Percheron infarction presenting as nuclear third nerve palsy and transient loss of consciousness: a case report. MRI images showing AOP territory infarction. a DWI image showing paramedian thalamic infarctions. b DWI image showing right rostral midbrain infarction (Note the assymetry in rostral mid brain involvement). c ADC image showing paramedian thalamic infarctions. d ADC image showing assymetrical right rostral midbrain infarction
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Radiopaedia • CC-by-nc-sa 3.0 • de

Thalamic infarcts refer to ischemic strokes which affect the subcortical grey matter complex of nuclei known as the thalamus.

Epidemiology

Pure thalamic infarcts are reported to make up 3-4% of cerebral ischemic events .

Risk factors

Most of the risk factors are common to all types of ischemic infarcts and include:

Clinical presentation

Presentation is dependent on the region infarcted :

  • tuberothalamic (anterior) artery territory
    • cognitive and behavioral disturbances
    • left hemisphere lesions: memory, language deficit and acalculia
    • right hemisphere lesions: hemineglect
    • chronotaraxis (loss of time sense)
  • paramedian artery territory
    • decreased levels of consciousness
    • left hemisphere lesions: aphasia
    • right hemisphere lesions: hemineglect
    • vertical gaze abnormalities and other complex ophthalmoplegias
  • inferolateral artery territory
  • posterior choroidal artery territory
    • sensorimotor deficits
    • visual field defects

Pathology

The main cause of infarction is thrombotic occlusion secondary to atherosclerosis, the most common sites being the carotid bifurcation, the origin of the middle cerebral artery and the basilar tip .

Classic thalamic territories include :

Radiographic features

CT

Non-contrast CT may show ill-defined hypodensities of the thalamus or obscuration of the grey-white matter border between the adjacent internal capsule .

MRI

In the acute phase (within 72 hours) :

  • T2/FLAIR: normal to slightly hyperintense grey-matter (as infarct progresses)
  • DWI: hyperintense
  • ADC: hypointense

Treatment and prognosis

Thalamic strokes are typically medically managed and have a wide variety of prognoses depending on the location, size and nature of the infarct.

Cases have reported good outcomes regarding return to normal neurological function. The exception is with bilateral paramedian territory infarctions where cognitive deficits tend to persist in follow-up .

Siehe auch:
und weiter:
Assoziationen und Differentialdiagnosen zu Thalamusinfarkt:
bilateraler
Thalamusinfarkt
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percheron
artery infarct
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