There are 3 main histological subtypes found at post-mortem: * FTLD-tau is characterised by tau positive inclusion bodies often referred to as Pick-bodies. Examples of FTLD-tau include; Pick's disease, corticobasal degeneration, progressive supranuclear palsy. * FTLD-TDP (or FTLD-U ) is characterised by ubiquitin and TDP-43 positive, tau negative, FUS negative inclusion bodies. The pathological histology of this subtype is so diverse it is subdivided into four subtypes based on the detailed histological findings: :*Type A presents with many small neurites and neuronal cytoplasmic inclusion bodies in the upper (superficial) cortical layers. Bar-like neuronal intranuclear inclusions can also be seen they are fewer in number. :*Type B presents with many neuronal and glial cytoplasmic inclusions in both the upper (superficial) and lower (deep) cortical layers, and lower motor neurons. However neuronal intranuclear inclusions are rare or absent. This is often associated with ALS and C9ORF72 mutations (see next section). :*Type C presents many long neuritic profiles found in the superficial cortical laminae, very few or no neuronal cytoplasmic inclusions, neuronal intranuclear inclusions or glial cytoplasmic inclusions. This is often associated with semantic<unk> . :*Type D presents with many neuronal intranuclear inclusions and dystrophic neurites, and an unusual absence of inclusions in the granule cell layer of the hippocampus. Type D is associated with VCP mutations. :*Type E presents with neuronal granulofilamentous inclusions and abundant fine grains involving upper (superficial) and lower (deep) cortical layers. This has been associated with behavioral variant of frontotemporal<unk>  with a rapid clinical course. Two groups independently categorized the various forms of TDP-43 associated disorders. Both classifications were considered equally valid by the medical community, but the physicians and researchers in question have jointly proposed a compromise classification to avoid confusion. * FTLD-FUS; which is characterised by FUS positive cytoplasmic inclusions, intra nuclear inclusions, and neuritic threads. All of which are present in the cortex, medulla, hippocampus, and motor cells of the spinal cord and XIIth cranial nerve. In December 2021 the structure of TDP-43 was resolved with cryo-EM but shortly after it was argued that in the context of FTLD-TDP the protein involved could be TMEM106B (which has been also resolved with cryo-EM), rather than of TDP-43.
medical cause of Frontotemporal dementia
medical cause of Dementia
medical cause of Parkinsonism
complications of Frontotemporal lobar degeneration
symptom of Alzheimer's disease
symptom of Pantothenate kinase-associated neurodegeneration
medical cause of Metachromatic leukodystrophy
symptom of Bannayan–Riley–Ruvalcaba syndrome