Behavioral variant frontotemporal dementia

Case contributed by Dr Thomas Rego

Presentation

Past history of schizoaffective disorder, admitted to the psychiatric ward with suspicion of relapse of psychosis. Apathy, amotivation, poor self-care and changed eating habits noted as well as frontal release signs on neurological examination.

Patient Data

Age: 60 years
Gender: Male

Background of mild small vessel disease and there is a moderate degree of generalized atrophy, with prominence of CSF in subarachnoid space noted in the left fronto-parietal and temporal lobe.

Nuclear medicine

SPECT

SPECT studies of the brain show severe hypoperfusion of the mesial cortex of both frontal lobes as well as left lateral frontal lobe cortex. Perfusion elsewhere in the cortex appears normal, in particular perfusion of the precuneus is normal. Perfusion of the basal ganglia, brainstem and cerebellum is normal. The findings are highly suspicious of the frontal ( behavioral ) variant or frontotemporal dementia.
Nuclear medicine

FDG-PET

There is moderate to severe hypometabolism affecting large regions of bilateral frontal lobes, worse on the left, especially along its mesial aspects and along the left lateral sulcus. There is also moderate left parietotemporal hypometabolism. No significant hypometabolism of the posterior cingulate gyrus, precuneus, occipital lobes, basal ganglia or thalamus.

In summary, moderate to severe bilateral frontal lobe hypometabolism is compatible with frontotemporal dementia. Features are not those of Lewy body dementia or Alzheimer disease.

Case Discussion

This 60-year-old single male from home alone presented to psychiatric ward with presumed relapse of chronic psychotic illness. Pronounced apathy, amotivation, decreased self-care and changed eating habits. Absence of positive psychotic symptoms or thought disorder other than poverty of thought. Similar past presentation ten years prior which had rapidly developed to mutism and no oral intake; treated with ECT. Detailed history revealed that the recent presentation was different with altered eating habits (eating inappropriate foods such as large quantities of sweet foods as a meal) rather than reduced oral intake. Neurological examination revealed extra-pyramidal rigidity in keeping with antipsychotic medication and frontal release signs (positive glabellar tap, palmomental and grasp reflexes).

MRI brain scan completed which showed marked atrophy of frontal and parietal lobes, particularly on the left. Subsequent SPECT and FDG-PET revealed marked hypoperfusion of frontal and temporal lobes, consistent with bvFTD.

This patient met criteria for "probable bvFTD" as per the international consensus criteria on behavioral variant fronto-temporal dementia.

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Case information

rID: 62431
Published: 17th Aug 2018
Last edited: 14th Aug 2019
Inclusion in quiz mode: Included

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