Cervical Paraspinal Muscle Twitching and Cervical Facet Radiofrequency Ablation Outcomes

The investigators aim to determine whether cervical paravertebral muscle twitching during motor testing as part of performing cervical RFAs is associated with a greater likelihood of treatment success, and greater magnitude or duration of analgesia. The investigators propose a straightforward grading scale based on visual and tactile information readily available during RFA procedures as part of routine practice (per radiofrequency electrode: 0 = no twitches palpated or observed; 1 = twitches palpated but not observed; 2 = twitches palpated and observed at 1-2 levels; 3= twitches palpated and observed at \>2 levels). If a higher weighted score (total score divided by number of radiofrequency lesion sites) correlates with a greater likelihood of treatment success, or magnitude or duration of analgesia following cervical RFA, cervical paraspinal muscle twitching may serve as a readily obtainable prognostic factor (marker) for effectiveness.

Approximately 60 patients with cervical facet arthropathy who are undergoing cervical radiofrequency ablation (RFA) will be recruited for this study. Only patients who have already been deemed candidates by their primary pain physician for cervical RFA (e.g. \> 50% relief from a diagnostic cervical medial branch block) will be recruited. During the cervical RFA procedure, all patients will undergo sensory and motor stimulation testing prior to receiving radiofrequency lesioning, which is a standard and recommended practice. The investigators will align the electrodes to optimize sensory testing.

During the motor stimulation testing step, the pain physicians performing the procedure (e.g. attending, fellows, residents, etc.) will assess the presence or absence of cervical paraspinal muscle twitching by using a standardized grading scale (per radiofrequency electrode: 0 = no twitches observed or palpated; 1 = twitches palpated but not observed; 2 = twitches observed and palpated at 1-2 levels; 3 = twitches observed at \> 2 levels). A total score and a weighted score (total score divided by the number of radiofrequency lesion sites), will be recorded for each patient, and the RFA procedure will be completed per usual practice.

The interventional procedure used in this study (radiofrequency ablation) will be performed in the usual manner and as per "standard of care." The use of the grading scale described above to assess the presence/absence and magnitude of cervical paraspinal muscle twitching will be unique to this research study.

The investigators will also obtain the following data immediately pre-procedurally, from electronic health record review and also a standardized set of questionnaires provided to study participants:

* Information routinely obtained as standard practice: age, sex, average and worst neck pain score over the past week on numeric rating scale (NRS), percent pain relief from diagnostic block, duration of pain, inciting event, MRI findings if available, obesity (defined as BMI \> 30), smoking, co-existing pain conditions, co-existing psychiatric conditions, and potential sources of secondary gain (e.g. worker's compensation claim, ongoing litigation, etc.)
* Information obtained as part of the research study: Neck Disability Index (NDI) score, Athens Insomnia Scale (AIS) score, Hospital Anxiety and Depression Scale (HADS) scores.

At a 1-month post-procedural follow-up timepoint, the investigators will obtain the following data, from electronic health record review and also a standardized set of questionnaires provided to study participants:

* Information routinely obtained as standard practice: categorical binary outcome (positive outcome defined as \>/= 2-point decrease in average neck pain score coupled with PGIC score \>/= 5/7) analgesic medications and doses; status of medication reduction (yes or no); average and worst NRS pain score over the past week; description of any procedural complications
* Information obtained as part of the research study: NDI, AIS, and HADS scores; Patient Global Impression of Change Scale (PGIC) score
* Exiting the trial: patients may choose to exit the study at any time for any reason. A patient will exit the study to receive alternative care if the patient reports a PGIC score \<5 or \< 2-point reduction in average NRS pain score. This would indicate that the RFA treatment was unsuccessful.

At a 3-month post-procedural follow-up timepoint, the investigators will obtain the following data, from electronic health record review and also a standardized set of questionnaires provided to study participants:

* Information routinely obtained as standard practice: categorical binary outcome, analgesic medications and doses; status of medication reduction (yes or no); average and worst NRS pain score over the past week; description of any procedural complications
* Information obtained as part of the research study: NDI, AIS, and HADS scores; Patient Global Impression of Change Scale (PGIC) score on 7-point Likert scale
* Exiting the trial: patients may choose to exit the study at any time for any reason. A patient will exit the study to receive alternative treatment if the patient reports a PGIC score \<5 or \< 2-point reduction in average NRS pain score. This would indicate that the analgesic and functional benefit of the RFA procedure has now been exhausted.

At a 6-month post-procedural follow-up timepoint, the investigators will obtain the following data, from electronic health record review and also a standardized set of questionnaires provided to study participants:

* Information routinely obtained as standard practice: binary categorical outcome, analgesic medications and doses; status of medication reduction (yes or no); average and worst NRS pain score over the past week; description of any procedural complications
* Information obtained as part of the research study: NDI, AIS, and HADS scores; Patient Global Impression of Change Scale (PGIC) score
* Exiting the trial: All patients who remain in the study will exit at 6 months.

Eligibility Criteria:
Inclusion Criteria:

* Age 18 years or older
* Cervical facet arthropathy based on history and physical exam (e.g. axial cervical neck pain, paraspinal tenderness, no pain referral below the ipsilateral shoulder)
* Radiologic evidence of cervical pathology consistent with symptoms if MRI is available
* Pain duration of greater than 3 months
* Obtained 50% or greater pain relief from at least 1 diagnostic cervical medial branch block of the identical medial branch nerves targeted for RFA

Exclusion Criteria:

* Untreated coagulopathy
* Signs or symptoms of cervical myelopathy
* Signs or symptoms of cervical radiculitis/radiculopathy
* Allergic reactions to local anesthetics
* Serious psychiatric disorder (e.g. uncontrolled or refractory depression) that might preclude optimal outcome
* Poorly controlled medical condition (e.g. pacemaker that cannot be switched off, unstable angina)
* Pregnancy