Diaschisis after thalamic stroke: a comparison of metabolic and structural changes in a patient with amnesic syndrome.
BACKGROUND
We present a patient with a left anteromedial thalamic lesion with an amnesic syndrome. The patient underwent neuropsychological testing, cerebrospinal fluid (CSF) analyses, magnetic resonance imaging (MRI) [T2, flair, and diffusion tensor imaging (DTI)] and [18F]-2-fluoro-deoxy-d-glucose positron emission tomography (FDG-PET) to assess indirect effects of thalamic lesions on cortical function.


METHODS
A 67-year-old right-handed woman was admitted to a university-based memory unit because of memory and concentration problems. Neuropsychological testing revealed dysfunction of episodic memory, semantic memory and working memory. General intellectual function and attention capacity were preserved. MRI revealed an anteromedial thalamic lesion in the left hemisphere. FDG-PET showed decreased uptake in the frontal, parietal and temporal lobes of the left hemisphere. Regions of interest (ROI) in white matter were selected and left and right hemispheres were compared. Fractional anisotropy (FA) in ROI representing thalamo-cortical connections were decreased in the left hemisphere when compared with the right.


CONCLUSIONS
The results show the importance of a network that include the anterior and dorsomedian nuclei, which influence the activity in areas of the cortex responsible for memory processes. The imaging findings suggest that areas of cortical diaschisis after thalamic infarction correspond to areas affected by thalamo-cortical fibre loss as measured with FA.
Stenset
V
V
Department of Neurology, Akershus University Hospital, Lørenskog, Norway. vidar.stenset@medisin.uio.no
Grambaite
R
R
Reinvang
I
I
Hessen
E
E
Cappelen
T
T
Bjørnerud
A
A
Gjerstad
L
L
Fladby
T
T
D000368:Aged; D000647:Amnesia / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology*; D020643:Anterior Thalamic Nuclei / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D002540:Cerebral Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology; D004525:Efferent Pathways / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D005260:Female; D019788:Fluorodeoxyglucose F18; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D020645:Mediodorsal Thalamic Nucleus / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology; D008568:Memory / Q000502:physiology; D008569:Memory Disorders / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology*; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography; D011859:Radiography; D020521:Stroke / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013786:Thalamic Diseases / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology*; D013788:Thalamus / Q000000981:diagnostic imaging / Q000473:pathology / Q000503:physiopathology*
D019788:Fluorodeoxyglucose F18