Abstract
Answer A. Acute spasmodic torticollis
Acute spasmodic torticollis is common and is caused by spasm of the muscles in the neck. It typically presents with unilateral neck pain and stiffness. It is normally self-limiting. Cervical spondylosis will usually present with progressive ongoing neck pain (or may be found incidentally on imaging). Dislocation of the atlantoaxial joint would usually present with reduced neck mobility. A whiplash associated disorder is typically brought on by trauma and a prolapsed intervertebral disc would usually cause neuropathic pain radiating into the arm.
InnovAiT article: Neck pain. DOI: 10.1177/17557380211016506.