He mentioned his friend died fairly suddenly. Puzzling, I thought. Why suddenly?
Turns out that's common in FTD:
[Initial symptoms, survival and causes of death in...[Fortschr Neurol Psychiatr. 2007] - PubMed Result: "Causes of death were varied, but pneumonia and sudden unexplained deaths were particularly frequent."Hmm. Sudden death. Brain disease. Could there be a clue in FTD to the causes of Sudden Infant Death Syndrome?
Well, there are lots of Google hits on the paired terms, though the associations seem coincidental. On the other hand, a Pubmed search combining both terms had no hits (today). So maybe this research is yet to be published ...