Abstract

Background: We describe the phenomenon of crossed cerebellar diaschisis (CCD) in four subjects diagnosed with Alzheimer's disease (AD) according to the National Institute on Aging Alzheimer Association (NIA-AA) criteria, in combination with 18F-FDG PET and 11C-PiB PET imaging.

Methods: 18F-FDG PET showed a pattern of cerebral metabolism with relative decrease most prominent in the frontal-parietal cortex of the left hemisphere and crossed hypometabolism of the right cerebellum. 11C-PiB PET showed symmetrical amyloid accumulation, but a lower relative tracer delivery (a surrogate of relative cerebral blood flow) in the left hemisphere. CCD is the phenomenon of unilateral cerebellar hypometabolism as a remote effect of supratentorial dysfunction of the brain in the contralateral hemisphere. The mechanism implies the involvement of the cortico-ponto-cerebellar fibers. The pathophysiology is thought to have a functional or reversible basis but can also reflect in secondary morphologic change. CCD is a well-recognized phenomenon, since the development of new imaging techniques, although scarcely described in neurodegenerative dementias.

Results: To our knowledge this is the first report describing CCD in AD subjects with documentation of both 18F-FDG PET and 11C-PiB PET imaging. CCD in our subjects was explained on a functional basis due to neurodegenerative pathology in the left hemisphere. There was no structural lesion and the symmetric amyloid accumulation did not correspond with the unilateral metabolic impairment.

Conclusion: This suggests that CCD might be caused by non-amyloid neurodegeneration. The pathophysiological mechanism, clinical relevance and therapeutic implications of CCD and the role of the cerebellum in AD need further investigation.

Original languageEnglish
Pages (from-to)1267-1275
Number of pages9
JournalCurrent alzheimer research
Volume15
Issue number13
DOIs
Publication statusPublished - 2018

Keywords

  • Cerebellar diaschisis (CCD)
  • hypometabolism
  • supratentorial lesions
  • contralateral
  • dementia
  • Alzheimer's disease
  • POSITRON-EMISSION-TOMOGRAPHY
  • REFERENCE REGION
  • BASAL GANGLIA
  • MOTOR CORTEX
  • F-18-FDG PET
  • HUMAN BRAIN
  • DEMENTIA
  • METABOLISM
  • ORGANIZATION
  • DYSFUNCTION

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