Can a corticosteroid shot to treat arthritis have side effects?

My father-in-law had a stroke nearly 2 years ago and has not been able to walk without a walker since. This week he had a corticosteroid shot to treat arthritis in his shoulder. Since then he is walking unassisted. He is agitated and anxious. He is now complaining of not being able to sleep. Could these be “side effects” of the steroid shot? How long should we expect that to last? Are these effects serious or dangerous?

Age: 80
Male
Medications: Aricept, Pravastatin, Lisinopril, Terazosin, Depakote, Metformin, Glipizide, Plavix