Table I.

Diagnostic categories of the FTLD-ALS disease spectrum.

		Main clinical characteristics
FTLD	bvFTD	Disinhibition, apathy, lack of emotional concern, hyperorality, stereotypic behavior and executive dysfunction
	PNFA	Labored speech, agrammatism with relatively spared comprehension
	SD	Comprehension deficits, naming errors with fluent speech
FTLD-MND-like		FTLD with minor motor system dysfunction
FTLD-ALS		Meeting the diagnostic criteria of both FTLD and ALS
ALSci		ALS with minor cognitive impairment
ALSbi		ALS with minor behavioral impairment
ALS		Muscle weakness, hyperreflexia, spasticity, atrophy and fasciculations

ALSbi = ALS with a mild behavioral impairment; ALSci = ALS with a mild cognitive impairment; bvFTD = behavioral variant FTLD; LMN = lower motor neuron; PNFA = progressive non-fluent aphasia; SD = semantic dementia; UMN = upper motor neuron; MND = motor neuron disease.