Pathological and genetic distribution in FTD and ALS. Visual representation of the continuum of clinical syndromes from FTD to ALS (bottom). The prevalence of pathological subtypes is depicted in pie charts with FTD on the left and ALS on the right. The most common genetic mutations are listed above the pie charts. ALS, amyotrophic lateral sclerosis; ALS-bi, ALS with behavioral impairment; ALS-cbi, ALS with combined cognitive and behavioral impairment; ALS-ci, ALS with cognitive impairment; FTD, frontotemporal dementia; MND, motor neuron disease.