Thalamic haemorrhages or thalamic haemorrhagic strokes are often the result of chronic hypertension. The thalamus transmits or prevents transmission of sensory signals from sensory areas of the cerebral cortex through internal capsule fibres and has a role in memory thus the clinical presentation reflects this 1.
Depending on the thalamic nuclei involved, thalamic strokes can present with 2:
- downward gaze (paralysis of upward gaze)
- small pupils (lack of light pupillary response)
- depressed consciousness
- visual hallucinations
- impairment of verbal memory
- visuospatial dysfunction
- pain and sensory anomalies (including Déjerine-Roussy syndrome)
Thalamic strokes can also present with behavioural patterns depending on the four main arterial thalamic territories:
anterior: perservations, apathy and amnesia
- paramedian infarction: disinhibition, personality change and amnesia (severe retrograde and anterograde amnesia)
- extensive lesions: "thalamic dementia"
- inferolateral: executive dysfunction and occasionally severe long-term disability
- posterior: no specific behavioural pattern, however, can include cognitive dysfunction, neglect, aphasia
Thalamic haemorrhage is easily recognisable on CT as hyperdensity within the thalamus.
Treatment and prognosis
The treatment is no different for other hypertensive strokes. Generally supportive measures are required but control of hypertension and reversal of any anticoagulation is vital. Current studies are looking at the use of tranexamic acid to stop haemorrhage progression 3.
- 1. Kandel, Eric R, (editor.), Schwartz, James H. (James Harris), 1932-2006, (editor.), Jessell, Thomas M, (editor.), Siegelbaum, Steven, (editor.) and Hudspeth, A. James, (editor.) Principles of neural science (Fifth edition). New York McGraw Hill Medical, 2013.
- 2. Donaghy M. Brain's Diseases of the Nervous System. Oxford University Press. ISBN:0198569386. Read it at Google Books - Find it at Amazon
- 3. Sprigg N, Renton CJ, Dineen RA et-al. Tranexamic acid for spontaneous intracerebral hemorrhage: a randomized controlled pilot trial (ISRCTN50867461). J Stroke Cerebrovasc Dis. 2014;23 (6): 1312-8. doi:10.1016/j.jstrokecerebrovasdis.2013.11.007 - Pubmed citation