Annals of Indian Academy of Neurology
: 2014  |  Volume : 17  |  Issue : 2  |  Page : 202--203

Atlantoaxial instability as the presenting feature of Morquio syndrome

Deepak S. Amalnath, S. Kalaimani, Tarun Kumar Dutta 
 Department of Medicine, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry, India

Correspondence Address:
Deepak S. Amalnath
Department of Medicine, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry - 605 011

How to cite this article:
Amalnath DS, Kalaimani S, Dutta TK. Atlantoaxial instability as the presenting feature of Morquio syndrome.Ann Indian Acad Neurol 2014;17:202-203

How to cite this URL:
Amalnath DS, Kalaimani S, Dutta TK. Atlantoaxial instability as the presenting feature of Morquio syndrome. Ann Indian Acad Neurol [serial online] 2014 [cited 2022 Jun 30 ];17:202-203
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Full Text


Atlantoaxial instability with high cord compression is an important type of craniovertebral junction anomaly. Here, we report a boy who presented with new onset episodes of transient quadriparesis on neck flexion. Computed tomography (CT) and magnetic resonance imaging (MRI) showed hypoplastic dens with anterior beaking of vertebrae. X-ray pelvis showed femoral head hypoplasia. These radiological features were characteristic of (mucopolysaccharidosis (MPS; Morquio syndrome).

 Case Repor

An adolescent presented with complaints of recurrent episodes of sudden loss of power of all the limbs for the past 4 months. These episodes lasted for a few seconds after which his power improved. He also noticed progressive difficulty in cycling. He did not have any sensory loss or bladder disturbance.

On examination, he had wasting of the intrinsic muscles of his hands and mild proximal weakness of the shoulders and hips with brisk tendon reflexes. There were no sensory or cerebellar signs. He also had kyphosis, broad fingers, and flatfoot. In view of the skeletal features, MPS was suspected.

X-ray of the spine showed flat vertebrae with anterior beaking [Figure 1]. MRI [Figure 2] and CT of the cervical spine [Figure 3] showed atlantoaxial dislocation due to hypoplastic odontoid process, which was causing compression of the cervical cord at the foramen magnum [Figure 4]. X-ray of the pelvis [Figure 5] showed bilateral hypoplastic femoral heads which are classically seen in MPS.{Figure 1}{Figure 2}{Figure 3}{Figure 4}{Figure 5}

In view of the typical radiological features, a diagnosis of Morquio syndrome with compressive myelopathy due to atlantoaxial instability was made. The patient is planned for spine stabilization surgery.


MPS-IVA, also known as Morquio-Brailsford or Morquio A syndrome, is a rare lysosomal storage disorder caused by a deficiency of N-acetylgalactosamine-6-sulfate sulfatase.

Patients with Morquio syndrome have severe bone deformities, but with preserved intelligence as compared to other types of MPS.

Hypoplasia of the odontoid process is seen in almost all patients. [1] This causes cervical instability and high cord compression. This can present with chronic compressive myelopathy as well as sudden cord compression. [2] Other neurological manifestations can be due to spinal canal stenosis (focal or diffuse). The mainstay of treatment is cervical fixation by fusing the vertebrae to stabilize the atlantoaxial joint.


Patients with Morquio syndrome have to be screened for the potentially lethal condition of atlantoaxial dislocation.


1Solanki GA, Martin KW, Theroux MC, Lampe C, White KK, Shediac R, et al. Spinal involvement in mucopolysaccharidosis IVA (Morquio-Brailsford or Morquio A syndrome): Presentation, diagnosis and management. J Inherit Metab Dis 2013;36:339-55.
2Li MF, Chiu PC, Weng MJ, Lai PH. Atlantoaxial instability and cervical cord compression in Morquio syndrome. Arch Neurol 2010;67:1530.