Medial temporal lobe metabolic impairment in dementia associated with motor neuron disease

J Neurol Sci. 1999 Oct 15;168(2):145-50. doi: 10.1016/s0022-510x(99)00188-4.


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.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Amygdala / diagnostic imaging
  • Amygdala / metabolism
  • Dementia / complications*
  • Dementia / diagnostic imaging
  • Dementia / metabolism*
  • Entorhinal Cortex / diagnostic imaging
  • Entorhinal Cortex / metabolism
  • Female
  • Fluorodeoxyglucose F18
  • Frontal Lobe / diagnostic imaging
  • Frontal Lobe / metabolism
  • Glucose / metabolism
  • Glucose / pharmacokinetics
  • Hippocampus / diagnostic imaging
  • Hippocampus / metabolism
  • Humans
  • Male
  • Middle Aged
  • Motor Neuron Disease / complications*
  • Motor Neuron Disease / diagnostic imaging
  • Motor Neuron Disease / metabolism*
  • Parahippocampal Gyrus / diagnostic imaging
  • Parahippocampal Gyrus / metabolism
  • Radiopharmaceuticals
  • Temporal Lobe / diagnostic imaging
  • Temporal Lobe / metabolism
  • Tomography, Emission-Computed


  • Radiopharmaceuticals
  • Fluorodeoxyglucose F18
  • Glucose