spasmodic
     adj 1: affected by involuntary jerky muscular contractions;
            resembling a spasm; "convulsive motions"; "his body
            made a spasmodic jerk"; "spastic movements" [syn: {convulsive},
             {spastic}]
     2: occurring in spells and often abruptly; "fitful bursts of
        energy"; "spasmodic rifle fire" [syn: {fitful}]
Source: WordNet® 2.0