Neurol India Home 

Year : 2022  |  Volume : 70  |  Issue : 4  |  Page : 1736--1737

‘Fixed’ Hyperextension of Neck as a Major Presenting Symptom of Basilar Invagination

Atul Goel1, Sandeep More2, Abhidha Shah2, Survendra Rai2, Abhinandan Patil2,  
1 Department of Neurosurgery, K.E.M. Hospital and Seth G.S. Medical College, Parel; Consultant Neurosurgeon, Lilavati Hospital and Research Centre, Bandra (E), Mumbai, Maharashtra, India
2 Department of Neurosurgery, K.E.M. Hospital and Seth G.S. Medical College, Parel, India

Correspondence Address:
Atul Goel
Department of Neurosurgery, K.E.M. Hospital and Seth G.S. Medical College, Parel, Mumbai - 400 012, Maharashtra

How to cite this article:
Goel A, More S, Shah A, Rai S, Patil A. ‘Fixed’ Hyperextension of Neck as a Major Presenting Symptom of Basilar Invagination.Neurol India 2022;70:1736-1737

How to cite this URL:
Goel A, More S, Shah A, Rai S, Patil A. ‘Fixed’ Hyperextension of Neck as a Major Presenting Symptom of Basilar Invagination. Neurol India [serial online] 2022 [cited 2022 Dec 3 ];70:1736-1737
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Full Text


A number of musculoskeletal and neural abnormalities are associated with basilar invagination. Short neck and torticollis are frequent observations. Fixed hyperextension of the neck in neutral position as one of the major presenting symptoms has not been recorded.

A 10-year-old girl child had neck pain and weakness in all 4 limbs for 6 months. It all started with an episode of trivial trauma whilst playing. The parents noticed that she discontinued playing with her friends, as she was unable to run fast and keep up with them. The weakness gradually progressed and ultimately she needed help for all her daily activities and had to leave school. For about 4 months, the child also complained of neck pain and she started keeping her neck in a substantially extended position as it alleviated her neck pain. The disability progressed and she had difficulty in tying her hair and her shoelaces. She was unable to sleep supine because of this hyperextended posture [Figure 1]. At the time of hospital admission, she had spastic quadriparesis (Goel grade 4).[1] Her neck was in near-complete hyperextension [Figure 1]e and [Figure 1]f. Passive neck flexion, even with moderate pressure on the vertex was not possible and resulted in neck pain. Investigations revealed assimilation of the atlas with Group A basilar invagination with evidences of cord compression [Figure 1]. Surgery involved opening of the atlantoaxial joint, denuding of articular cartilage, stuffing of bone chips into the articular cavity and lateral mass plate and screw fixation with the techniques described by us in 1994 and 2004.[1] In the immediate postoperative period, the child was able to sleep comfortably in a supine position, a position that she had abandoned for a few weeks. She also improved in her neurological function. Her neck had now returned to normal position [Figure 2]. Investigations showed atlantoaxial fixation and craniovertebral realignment [Figure 2]. At a follow-up of 6 months, her neck movements – both neck flexion and extension, were significantly supple, free, and painless. She had joined her school again.{Figure 1}{Figure 2}

A number of musculoskeletal deformities are known and well described in cases with basilar invagination.[2] Short neck and torticollis are amongst the commoner forms of neck deformities. Assimilation of atlas, C2-3 fusion, and Klippel-Feil abnormalities are common forms of bone fusions that accompany short neck.[2] Recently, we identified that short neck is associated with short head.[3] Platybasia and shorter length of the clivus are the bone malformations associated with short head.

In the year 2004, we suggested that manifest or potential atlantoaxial instability is the primary abnormality and basilar invagination is a secondary or protective natural formation.[4] Essentially, we discussed that musculoskeletal deformities in general and neck deformities in particular are secondary to primary atlantoaxial dislocation. It was described that atlantoaxial fixation has the potential of immediate postoperative reversal of neck deformities. We discussed increase in neck size and reversal of torticollis in the immediate postoperative period.[2]

In general, in cases with basilar invagination, the neck deformities permit hyperextension of the head and neck flexion is restricted. Atlantoaxial instability is known to reduce on neck extension and worsen on neck flexion. Our earlier article on the subject identified exaggerated posterior cervical lordosis or hyperextension of the neck in >90% cases with basilar invagination.[2] We measured cervical lordosis with a modification of the Klaus omega angle and a modified omega angle.[2] Head fixed in a hyperextended position is extremely rare and has not been reported. No objective parameter to describe hyperextension, be it mild, moderate, or severe has been described in the literature. The head in the presented patient was in a near-complete hyperextended state. Exact reason of the fixed hyperextension of the neck can only be speculated. The neural structures at the craniovertebral junction were severely compromised. The facets of atlas and axis were not in direct contact and as per our earlier definition there was atlas over axis facetal spondyloptosis.[5] It is unclear if the severity of neural compromise or the facetal mal-alignment was a cause of hyperextension. Reversal of head extension in the immediate postoperative phase suggests that atlantoaxial instability formed the basis of the physical alteration.

Reversal of hyperextension and return of normal neck movements in the immediate postoperative phase after atlantoaxial fixation and craniovertebral realignment surgery suggests the cause-effect relationship.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

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Conflicts of interest

There are no conflicts of interest.


1Goel A, Laheri VK. Plate and screw fixation for atlanto-axial dislocation. (Technical report). Acta Neurochir (Wien) 1994;129:47-53.
2Goel A, Shah A. Reversal of longstanding musculoskeletal changes in basilar invagination after surgical decompression and stabilization. J Neurosurg Spine 2009;10:220-7.
3Goel A, Jain S, Shah A. Radiological Evaluation of 510 Cases of Basilar Invagination with Evidence of Atlantoaxial Instability (Group A Basilar Invagination). World Neurosurg 2018;110:533-43.
4Goel A. Treatment of basilar invagination by atlantoaxial joint distraction and direct lateral mass fixation. J Neurosurg Spine 2004;1:281-6.
5Goel A, Muzumdar D, Dange N. One stage reduction and fixation for atlantoaxial spondyloptosis: Report of four cases. Br J Neurosurg 2006;20:209-13.