Loss of psychic self-activation after paramedian bithalamic infarction.
OBJECTIVE
Loss of psychic self-activation has been described after bilateral lesions to the globus pallidus, striatum, and white matter of the frontal lobes, but it is a very rare sign of bithalamic lesions. The exact functional-anatomic mechanism underlying loss of psychic self-activation following bithalamic lesions remains to be elucidated.


METHODS
We present clinical, neuropsychological, structural, and functional neuroimaging data of an 18-month follow-up period of a man with prominent loss of psychic self-activation after coronary arteriography. Except for memory decline, accompanying symptoms remained restricted to the acute phase. The neurobehavioral syndrome consisted mainly of apathy, indifference, poor motivation, and flattened affect, and this remained unchanged during the entire follow-up period. MRI showed a bithalamic infarction involving the nucleus medialis thalami bilaterally. Single-photon emission CT revealed a severe relative hypoperfusion of both thalami, a relative hypoperfusion of both nuclei caudati, and a relative hypoperfusion mesiofrontally.


CONCLUSIONS
Single-photon emission CT data support the hypothesis that the neurobehavioral manifestations after bithalamic paramedian infarction are caused by disruption of the striatal-ventral pallidal-thalamic-frontomesial limbic loop. Probably, bilateral disruption at different levels of the striatal-ventral pallidal-thalamic-frontomesial loop may lead to a similar clinical picture consisting of loss of psychic self-activation.
Engelborghs
S
S
Department of Neurology and Memory Clinic , Middelheim General Hospital, Antwerp, Belgium.
Marien
P
P
Pickut
B A
BA
Verstraeten
S
S
De Deyn
P P
PP
D000339:Affect; D000647:Amnesia / Q000000981:diagnostic imaging / Q000473:pathology; D001143:Arousal; D001364:Awareness; D002544:Cerebral Infarction / Q000000981:diagnostic imaging / Q000473:pathology* / Q000523:psychology; D007839:Functional Laterality; D006801:Humans; D007361:Intelligence Tests; D008297:Male; D008875:Middle Aged; D009042:Motivation; D019275:Radiopharmaceuticals; D012649:Self Concept; D020521:Stroke / Q000000981:diagnostic imaging / Q000473:pathology*; D019690:Technetium Tc 99m Exametazime; D013788:Thalamus / Q000098:blood supply / Q000473:pathology*; D015899:Tomography, Emission-Computed, Single-Photon
D019275:Radiopharmaceuticals; D019690:Technetium Tc 99m Exametazime