The Skin as a Window to the Central Nervous System in Frontotempolar Lombar Degeneration

Inclusion Criteria (patients): * Adressed or followed at memory clinic or ALS expert center at Nantes university hospital. * Aged 50-75 years * Fulfilling current diagnosis criteria for one of the disorder: vcfFTD, non-Alzheimer PPA (semantic or non fluent), DCB or PSP,ALS * MMSE ≥ 18 * Membership of social security scheme Inclusion Criteria (healthy volunteers): * No history of neurological disease, diabetes, or alteration/damage of peripheral nervous system * Aged 50-75 years Paired to at least one patient on age (less or more 5 years) * MOCA ≥ 26 * Membership of social security scheme Non inclusion Criteria (Patients and healthy volunteers): * Concomitting conditions affecting the peripheral nervous system such as but not limited to diabetes, renal failure, thyroid disorder, vitamin B12 deficiency, acute and chronic inflammatory diseases HIV, syphilis * Know allergy to local anesthetic * Known coagulopathy * Pregnant women or breastfeeding women * Person under court protection sous sauvegarde de justice * Person under guardianship * Inability to sign an informed consent Non inclusion criteria (Patients) • Patient with neurological disease other than FTLD Non inclusion criteria (Healthy volunteers) : • Evidence of neurological disorder at the inclusion including but not limted to FTLD, Parkinson disease, Alzheimer disease, lewy body dementia, Huntington disease, systemic lupus erythematosus multiple sclerosis; learning disabilities, mental retardation, severe hypoxic brain injuries, brain trauma with permanent cognitive impairments.