Neck-tongue syndrome secondary to atlantoaxial dislocation.

Background: Neck-tongue syndrome is a rare paroxysmal disorder characterised by occipito-cervical pain with ipsilateral hemilingual numbness or dysaesthesia, typically triggered by head rotation or prolonged speaking. Although abnormal mechanical stimulation of the C2 spinal nerve/ root ventral ramus near the lateral atlantoaxial joint is widely implicated, neck-tongue syndrome occurring in patients with atlantoaxial dislocation has been seldom described. Methods: We retrospectively reviewed 176 consecutive patients with atlantoaxial dislocation who underwent posterior reduction and instrumented fusion between September 2018 and October 2025. Patients fulfilling prespecified diagnostic criteria for neck-tongue syndrome were identified. Demographics, aetiology, symptom duration, pain severity assessed using the visual analogue scale, neurological status assessed using the Frankel grade, imaging findings, operative details, and postoperative outcomes were analysed. Results: Six patients met criteria for NTS, yielding a prevalence of 3.4% (6/176). Symptom duration was 3-17 months with a median of 9 months. Preoperative visual analogue scale scores ranged from 4 to 8with a mean of 5.67 ± 1.37. All patients reported reproducible tongue symptoms including pain, numbness, or dysaesthesia, provoked by head turning or sustained speaking; symptoms were alleviated by cervical immobilisation or complete neck muscle relaxation in the supine position. Two patients showed mild hemilingual atrophy with dysarthria. Four patients had limb sensory symptoms; preoperative Frankel grades were B in one patient, C in one patient, and E in four patients. All six underwent. All six underwent posterior atlantoaxial reduction and fusion; C2 root sacrifice was performed in two cases to facilitate joint release and implant placement. During follow-upof 3-63 months, with a median of 30 months, neck-tongue syndrome-related symptoms improved in all patients, with visual analogue scale scores decreasing to 0-3 at the last follow-up with a mean of 1.16 ± 1.47. Radiographs confirmed satisfactory reductiondefined as an atlantodental interval of less than 3 mm, and solid fusion. Two patients who underwent C2 root sacrifice had persistent focal occipital or scalp hypoesthesia without neurogenic ulceration or pressure sores. Conclusion: In atlantoaxial dislocation, pathological hypermobility of the lateral atlantoaxial joint may cause repeated dynamic impingement and traction on the C2 root ventral ramus, triggering tongue- related afferent disturbances and the clinical phenotype of neck-tongue syndrome. Posterior reduction and instrumented fusion can interrupt this dynamic irritation and are associated with substantial symptom relief.