Citation, DOI & article data
Pure thalamic infarcts are reported to make up 3-4% of cerebral ischemic events 1.
Most of the risk factors are common to all types of ischemic infarcts 2 and include:
Presentation is dependent on the region infarcted 2,5:
anterior territory and (postero)medial territory
decreased level of consciousness, impaired memory, personality change
left hemisphere lesions: aphasia
right hemisphere lesions: hemineglect
visual field defects
variable sensorimotor deficits
Thalamic infarction can be caused by small vessel disease (most common), large artery atherosclerosis, cardioembolism, or unknown factors (cryptogenic) 3.
Classic thalamic territories include the following groups based on vascular supply and corresponding thalamic nuclei 3,5:
supplied by tuberothalamic/polar artery from the posterior communicating artery, although this is absent in a third of patients so the territory is irrigated by the paramedian artery
includes reticular nucleus, intralaminar nucleus, ventral pole of medial dorsal nucleus, anterior nuclei, ventral anterior nucleus, and rostral ventral lateral nucleus
supplied by paramedian/thalamoperforating artery from the P1 segment of the posterior cerebral artery
includes medial dorsal nucleus and intralaminar nuclei
supplied by thalamogeniculate/inferolateral arteries from the P2 segment of the posterior cerebral artery
includes ventral lateral nucleus and ventral posterior nucleus (including ventral posterolateral and ventral posteromedial subnuclei)
supplied by posterior choroidal artery from the P2 segment of the posterior cerebral artery
includes lateral and medial geniculate nuclei
Different territory involvement has an association with some stroke etiologies 3. Large artery disease-related thalamic infarcts most often involve the posteromedial territory, while small vessel disease-related thalamic infarcts usually involve the ventrolateral territory.
The topography of thalamic strokes is associated with broader stroke syndrome 3. Both isolated thalamic (lacunar) strokes and posterior cerebral artery territorial strokes most commonly present involving the ventrolateral territory. In contrast, basilar and vertebrobasilar (extended posterior circulation) strokes most commonly involve the posteromedial territory of the thalamus.
Non-contrast CT may show ill-defined hypodensities of the thalamus or obscuration of the grey-white matter border between the adjacent internal capsule 4.
In the acute phase (within 72 hours) 4:
T2/FLAIR: normal to slightly hyperintense grey-matter (as infarct progresses)
Treatment and prognosis
Thalamic strokes are managed as other strokes are, with thrombectomy, thrombolysis, and/or antithrombotic therapy depending on the acuity, deficits, and etiology.
Thalamic strokes 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 1.
- 1. Kumral E, Evyapan D, Kutluhan S. Pure Thalamic Infarctions: Clinical Findings. J Stroke Cerebrovasc Dis. 2000;9(6):287-97. doi:10.1053/jscd.2000.18741
- 2. Amici S. Thalamic infarcts and hemorrhages. (2012) Frontiers of neurology and neuroscience. 30: 132-6. doi:10.1159/000333611 - Pubmed
- 3. Song Y. Topographic Patterns of Thalamic Infarcts in Association with Stroke Syndromes and Aetiologies. J Neurol Neurosurg Psychiatry. 2011;82(10):1083-6. doi:10.1136/jnnp.2010.239624 - Pubmed
- 4. Clinical Neuroradiology: The ESNR Textbook. (2019) ISBN: 9783319685366 - Google Books
- 5. Schmahmann JD. Vascular Syndromes of the Thalamus. (2003) Stroke. 34 (9): 2264-78. doi:10.1161/01.STR.0000087786.38997.9E - Pubmed