Thalamic hemorrhages or thalamic hemorrhagic 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 fibers and has a role in memory thus the clinical presentation reflects this .
Depending on the thalamic nuclei involved, thalamic strokes can present with :
- 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 behavioral patterns depending on the four main arterial thalamic territories:
- anterior: preservation, 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 behavioral pattern, however, can include cognitive dysfunction, neglect, aphasia
Thalamic hemorrhage 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 hemorrhage progression .