Introduction
Grisel's syndrome, also known as non-traumatic atlanto-axial rotatory subluxation, is a rare complication of head and neck surgery seen most commonly in the paediatric population. It was named after Dr P Grisel, who in 1930 first described the condition in a child with pharyngeal ulcer.Reference Grisel1
The pathophysiology of this rare complication is of interest. A two-part hypothesis has been proposed by Battiata and Pazos: a pre-existing cervical ligamentous laxity with superimposed soft tissue inflammation weakens the transverse and alar ligaments of the atlanto-axial joint.Reference Battiata and Pazos2 The neck manipulation involved in head and neck surgery is believed to be a contributory factor, especially in syndromic children who have ligamentous laxity.
Here, we report a case of Grisel's syndrome in a seven-year-old boy who presented with post-tonsillectomy torticollis.
Case report
A seven-year-old boy was admitted for tonsillectomy due to recurrent tonsillitis. He was otherwise healthy, with no other medical illness. Pre-operative assessment was unremarkable.
An uneventful tonsillectomy was performed. The boy was placed in the Rose position during the operation. His neck was extended and his head supported by a head ring. Modest bipolar electrocautery was used.
The patient was discharged well on the day after surgery.
One week later, the boy presented to our clinic with torticollis, with his chin tilted to the left. On the third day after surgery, he had complained of neck pain and limited neck movement, which had become progressively more disabling. He had no fever or limb weakness.
On examination, the tonsillar fossae were fairly clean with no signs of infection. Marked torticollis was seen, with tenderness on palpation.
Tonsil tissue culture showed no growth of micro-organisms.
A cervical plain radiograph (Figure 1) taken in the open-mouth view showed an obvious odonto-lateral mass interval asymmetry, with the odontoid process tilted to the left.
Fig. 1 Plain radiograph, open mouth odontoid view, showing asymmetry of the odonto-lateral mass intervals and tilting of the odontoid process to the left.
Urgent computed tomography of the cervical spine was performed. This showed Fielding class one atlanto-axial rotatory subluxation (with no anterior or posterior displacement of the atlas).Reference Fielding and Hawkins3 The atlas was rotated to the left (Figure 2). The anterior atlanto-dental interval was 3.0 mm, which was normal. The lateral atlanto-dental interval was asymmetrical, measuring 5.4 mm on the right side and 3.5 mm on the left. The coronal view revealed an upward tilt of the left lateral mass of the atlas (Figure 3). There was no displacement of other cervical vertebrae, and no fracture was noted.
Fig. 2 Axial computed tomography scan showing that the anterior atlanto-dental interval measures 3.0 mm (i.e. within the normal range). The atlas is rotated to the left. There is asymmetry of the lateral atlanto-dental intervals, which measure 5.4 mm on the right and 3.5 mm on the left.
Fig. 3 Coronal computed tomography scan showing marked deviation of the odontoid process to the left, with upward tilt of the left lateral mass of the atlas.
The patient was diagnosed with post-tonsillectomy Grisel's syndrome.
He was treated with a soft cervical collar, analgesics, antibiotics and a muscle relaxant. After two weeks, there was no improvement so he was hospitalised and received cervical traction for one week, followed by further six weeks with a soft cervical collar. The torticollis gradually reduced, and the patient regained full neck movement after two months.
Repeated computed tomography after this treatment showed significant joint reduction, which correlated with the patient's marked clinical improvement.
After a year of follow up the patient had fully recovered and was discharged from care.
Discussion
Post-tonsillectomy non-traumatic atlanto-axial subluxation, also known as Grisel's syndrome, has been documented in several case reports. Grisel's syndrome is a rare clinical entity which primarily affects the paediatric population.Reference Wilson, Jarvis and Haydon4
The aetiology of this potentially catastrophic condition mainly comprises upper respiratory infections and complications of head and neck procedures.Reference Karkos, Benton, Leong, Mushi, Sivaji and Assimakopoulos5, Reference Parke, Rothman and Brown6 A historical, 1830 case report by Bell described the autopsy of a patient who suffered from atlanto-axial subluxation as a result of syphilitic pharyngeal ulcer; the autopsy revealed erosion of the transverse ligament of the axis.Reference Bell7 Other infectious processes reported in Grisel's syndrome cases include pharyngitis, tonsillitis or adenoiditis, retropharyngeal or tonsillar abscess, mastoiditis, otitis media, and cervical adenitis.Reference Wilson, Jarvis and Haydon4
The pathophysiology of Grisel's syndrome has been postulated in two hypotheses.
The first proposes that pre-existing ligamentous laxity and instability of the atlanto-axial joint predispose the patient to cervical vertebral ligamentous injury during head and neck surgery which requires prolonged neck manipulation.Reference Wilson, Jarvis and Haydon4 Trisomy 21 is a classic example of a syndrome involving ligamentous laxity which confers a high risk of atlanto-axial subluxation. In some children, the atlanto-dental interval may reach 4.0 mm, compared with 2.5–3.0 mm in adults.Reference Jackson8 This condition results in hypermobility and instability of the atlanto-axial joint.
Neck extension in the Rose position during tonsillectomy is thought to carry a risk of ligamentous injury. However, our patient's head and shoulders were supported during this procedure, sparing the neck from weight-bearing. Furthermore, the operation was brief and uncomplicated. At present, there is debate over whether neck manipulation in head and neck surgery can constitute the main cause of atlanto-axial subluxation.
The second hypothesis holds that peripharyngeal infection, in the form of a septic exudate from the operative field or other sources in the upper respiratory tract, travels via the pharyngo-vertebral veins to the periodontoidal venous plexus.Reference Parke, Rothman and Brown6 Haematogenous spread to the upper cervical spine causes hyperaemic decalcification of the first and second cervical vertebrae and weakening of ligaments, leading to pathological rotation of the atlanto-axial joint. Inflammatory mediators are carried to the cervical muscle, where they induce spasm and subsequent joint subluxation.
Our patient did not show any signs of a septic condition post-operatively. Neither his clinical condition nor his tonsillar microbial cultures showed any sign of infection. However, subtle pharyngeal infection can have a subclinical presentation which is unnoticeable.
• Post-operative infection and pre-existing cervical ligamentous laxity predispose to atlanto-axial subluxation after tonsillectomy
• Vigilance is needed in cases of post-tonsillectomy torticollis
• Computed tomography is needed for early diagnosis, evaluation and treatment
• Early treatment helps to improve outcomes
The use of bipolar diathermy is believed sometimes to cause local thermal injury and to contribute to local wound infection.Reference Lakeisha, Thomas and Eric9 We advocate post-operative prophylactic oral antibiotics for patients who have undergone tonsillectomy with extensive electrocautery. However, the rationale of routine post-operative use of antibiotics is still debatable.
Battiata and Pazos had proposed a ‘two-hit’ hypothesis for Grisel's syndrome.Reference Battiata and Pazos2 Pre-existing cervical ligamentous laxity in the paediatric population acts as the first ‘hit’. A subsequent local infectious process acts as the second hit, leading to muscular spasm, weakening of the transverse and alar ligaments, and eventually to atlanto-axial subluxation as described earlier.
Patients receiving early diagnosis and treatment have been shown to have a better prognosis than those with delayed management.Reference Harma and Firat10–Reference Martinez-Lage, Morales and Fernandez Cornejo12 An initial two-week trial of cervical immobilisation with a soft cervical collar, together with anti-inflammatory drugs and muscle relaxants, can be attempted. However, if there is no clinical improvement after conservative management, cervical traction and physiotherapy should be initiated.Reference Deichmueller and Welkoborsky13 Surgery and closed reduction are recommended if these measures fail.Reference Karkos, Benton, Leong, Mushi, Sivaji and Assimakopoulos5
Conclusion
Grisel's syndrome is a rare condition which should be suspected in a patient with signs of post-operative infection (e.g. fever and tonsillar fossa bleeding) and prolonged neck pain. Patients should be warned before discharge that torticollis (‘wryneck’) is a warning sign which should prompt them to seek medical help. In cases of torticollis, early investigation for atlanto-axial rotatory subluxation should not be delayed. An early computed tomography scan is crucial to establish the diagnosis and to determine the best treatment modality, before the complication worsens. Although Grisel's syndrome is not common, clinicians must be aware of this potentially catastrophic complication of routine head and neck surgery.
