spasmodic vs spastic

spasmodic is not a noun while spastic is a noun.

Word	Noun	Adjective	Verb	Adverb
spasmodic	No	Yes	No	No
spastic	Yes	Yes	No	No

As adjectives, spasmodic and spastic are synonyms defined as:

spasmodic and spastic: affected by involuntary jerky muscular contractions; resembling a spasm

Other synonyms of spasmodic include convulsive.

spasmodic (noun)	spastic (noun)
	a person suffering from spastic paralysis

spasmodic (adjective)	spastic (adjective)
occurring in spells and often abruptly	relating to or characterized by spasm
affected by involuntary jerky muscular contractions; resembling a spasm	suffering from spastic paralysis
	affected by involuntary jerky muscular contractions; resembling a spasm