[A study using positron emission tomography of a case of vascular dementia due to left thalamic haematoma, an example of the diaschisis phenomenon].

INTRODUCTION: Thalamic vascular lesions as strategic strokes can cause amnesia, executive dysfunctions or dysphasia and behavioral or psychological symptoms causing vascular dementia.

CASE REPORT: A 58 years-old woman with hypertension and dyslipemia, who after a left thalamic hemorrhage with good radiological evolution, presents a severe amnesic syndrome as well as other subtle changes in orientation and in language, difficulties in managing money and depressive symptoms requiring anxiolytic and antidepressive treatment. All this joined to limitations in the normal course of her work. Followed by neurology service, a positron emission tomography with 18F-2-fluoro-2-deoxy-D-glucose integrated with computed tomography was performed, which showed a hypometabolism in left thalamic area and also in ipsilateral inferior frontal region, explained by the diaschisis phenomenon.

CONCLUSIONS: Diaschisis phenomenon is a neuroimaging and pathophysiological finding whereby thalamic or basal ganglia strokes cause hypoperfusion/hypometabolism in the ipsilateral or contralateral cortex and could explain cortical distal symptoms. This case report demonstrates the presence of thalamocortical connections, which helps to understand the circuitry of memory and help to explain the association of other cortical symptoms as dysphasia or executive dysfunction.