Behavioral variant of frontotemporal dementia (bv-FTD) is a form of frontotemporal dementia (FTD; see this term), characterized by progressive behavioral impairment and a decline in executive function with frontal lobe-predominant atrophy.

A thickening of the skin thickness in the posterior aspect of the fetal neck. A nuchal fold measurement is obtained in a transverse section of the fetal head at the level of the cavum septum pellucidum and thalami, angled posteriorly to include the cerebellum. The measurement is taken from the outer edge of the occiput bone to the outer skin limit directly in the midline. A measurement 6 mm or more is considered significant between 18 and 24 weeks and a measurement of 5 mm or more is considered significant at 16 to 18 weeks (pmid:16100637).