Headword and gloss differ, in the Greek, only in the prepositional prefix creating the compound verb.
The headword itself -- present indicative active, first person singular, of perikake/w -- is attested only here and in the writings of Epiphanius (e.g. Ancoratus 14.1, 106.7); other forms of the verb, however, are attested in Polybius (see LSJ s.v.) and in several Christian writers.