General description

Frontotemporal lobar degeneration (FTLD) is a neurodegenerative disorder characterized by a constellation of clinical manifestations, including behavioral abnormalities, executive dysfunction, and language impairments, primarily affecting the frontal and temporal lobes.

FTLD can be further subdivided into three distinct subtypes:

1. Behavioral variant frontotemporal dementia (bvFTD): This subtype primarily involves the frontal lobes, with the predominant clinical manifestation being behavioral abnormalities.
2. Semantic dementia (SD): Characterized by impairments in semantic memory, this subtype primarily affects the temporal pole, middle temporal gyrus, and inferior temporal gyrus.
3. Progressive non-fluent aphasia (PNFA): This subtype exhibits focal atrophy in the regions surrounding the Sylvian fissure, resulting in non-fluent aphasia as a prominent feature.

In cases diagnosed with FTLD, it is recognized that Amyotrophic lateral sclerosis (ALS) can coexist as an associated complication. FTLD and ALS are considered part of a disease spectrum, with their underlying pathologies exhibiting positive immunoreactivity for the TDP-43 protein.