Medial temporal lobe metabolic impairment in dementia associated with motor neuron disease.
In the course of their disease certain patients with frontotemporal dementia (FTD) develop clinical features compatible with a motor neuron disease (FTD-MND). Previous reports have suggested that the functional pattern is similar in FTD and FTD-MND. However, some neuropathological studies suggest greater involvement of medial temporal regions in FTD-MND than in FTD. Using statistical parametric mapping (SPM96), we compared the metabolic patterns obtained at rest with positron emission tomography in 10 FTD patients and three FTD-MND patients with those obtained from 46 healthy subjects (HS). Mean age, duration of illness and dementia stage did not differ statistically between the FTD and FTD-MND groups. In comparison with HS, both groups showed frontal and anterior temporal hypometabolism at P<0.001. When the FTD-MND group was compared to the FTD group, significant hypometabolism was only observed in bilateral amygdala, bilateral hippocampus, and bilateral enthorinal and parahippocampal regions (Brodmann's areas, BA 28/36) at P<0.005. We found no significant differences in regional glucose uptake when FTD patients were contrasted to FTD-MND patients. Our results suggest statistically comparable frontal and lateral temporal hypometabolism in both conditions but greater impairment of medial temporal lobe activity in FTD-MND. Our results and a review of the literature support the hypothesis that there is a functional continuum between classical motor neuron disease (cMND), FTD-MND, and FTD.
Garraux
G
G
Cyclotron Research Center, Sart Tilman B30, B-4000, Liège, Belgium. garraux@pet.crc.ulg.ac.be
Salmon
E
E
Degueldre
C
C
Lemaire
C
C
Franck
G
G
D000368:Aged; D000679:Amygdala / Q000000981:diagnostic imaging / Q000378:metabolism; D003704:Dementia / Q000150:complications* / Q000000981:diagnostic imaging / Q000378:metabolism*; D018728:Entorhinal Cortex / Q000000981:diagnostic imaging / Q000378:metabolism; D005260:Female; D019788:Fluorodeoxyglucose F18; D005625:Frontal Lobe / Q000000981:diagnostic imaging / Q000378:metabolism; D005947:Glucose / Q000378:metabolism / Q000493:pharmacokinetics; D006624:Hippocampus / Q000000981:diagnostic imaging / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D016472:Motor Neuron Disease / Q000150:complications* / Q000000981:diagnostic imaging / Q000378:metabolism*; D020534:Parahippocampal Gyrus / Q000000981:diagnostic imaging / Q000378:metabolism; D019275:Radiopharmaceuticals; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000378:metabolism; D014055:Tomography, Emission-Computed
D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D005947:Glucose