Metabolic correlates of behavioral and affective disturbances in frontal lobe pathologies.
OBJECTIVE
Although previous studies have shown that the human frontal cortex is involved in the experience of emotions as well as in social behavior, data regarding the exact anatomical substrates of behavioral and affective deficits in frontal lobe pathologies are still scarce. The aim of this study was to investigate the metabolic correlates of these deficits in a group of non-selected consecutive patients with frontal lobe lesions.


METHODS
Clinicometabolic correlations between several emotional and social parameters and metabolic patterns in the frontal cortex and amygdala were investigated in 32 patients with frontal lobe pathologies. The behavioral disturbances were evaluated using the Lhermitte's informant questionnaire. Regional cerebral glucose metabolism was measured with [(18)F] fluorodeoxyglucose and high-resolution positron emission tomography. Statistical analysis was performed using both single variable correlation and multiple regression analyses.


RESULTS
Both single variable and multivariate analyses demonstrate that decreased regional glucose metabolism in the right medial area 10 was associated with apathy. There were also significant negative relationships between metabolism in the right orbitofrontal cortex and stereotypy and indifference to rules. Impulsiveness, personality disturbances and loss of emotional control were associated with decreased metabolism in the left amygdala.


CONCLUSIONS
In terms of clinicometabolic correlations, the present data support the implication of different functional anatomic systems in frontal lobe-related behavioral and affective disturbances. In particular, they imply that the classically described symptoms of impaired behavioral control may be related to right orbitofrontal cortex hypometabolism whereas impaired regulation of emotions may result from a functional damage of the left amygdala.
Sarazin
Marie
M
Inserm E 007 and Federation of Neurology, Salpêtrière Hospital, Paris, France.
Michon
Agnès
A
Pillon
Bernard
B
Samson
Yves
Y
Canuto
Alessandra
A
Gold
Gabriel
G
Bouras
Constantin
C
Dubois
Bruno
B
Giannakopoulos
Panteleimon
P
D000328:Adult; D000368:Aged; D005260:Female; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology*; D006801:Humans; D016015:Logistic Models; D008297:Male; D001523:Mental Disorders / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D008875:Middle Aged; D019964:Mood Disorders / Q000000981:diagnostic imaging / Q000378:metabolism* / Q000473:pathology; D015999:Multivariate Analysis; D012044:Regression Analysis; D018709:Statistics, Nonparametric; D014055:Tomography, Emission-Computed / Q000379:methods