Dachshund with Cervical Spasms and Painful Episodes

Patient History: A 4 year old, f/s, Dachshund was presented to the Veterinary Neurological Center with a 6-week history of episodic neck muscle spasms and pain. Her signs temporarily improved with administration of prednisone and analgesics (tramadol, methocarbamol, gabapentin).

NOTE: Other than subtle muscle spasms, this patient's neurological exam was normal. View the video below and watch for subtle cervical spasms.

Question: Based on the patient's history and the accompanying video, what are reasonable differential diagnoses for this patient?