Neurology India Medknow Publications on behalf of the Neurological Society of India ISSN: 0028-3886 EISSN: 1998-4022 Vol. 51, Num. 1, 2003, pp. 130-131

Neurology India, Vol. 51, No. 1, Jan-Mar, 2003, pp. 130-131

Letter to Editor

Congenital exostoses of the cervical vertebrae

N. Chitkara, N. K. Sharma, U. Dhall,* N. Bakshi, H. Kamal

Department of Neurosurgery and *Anatomy, Pt. B.D.S. PGIMS, Rohtak, India.

Accepted on 10.07.2001.

Code Number: ni03047

Sir,

Any osseous disease may involve the spinous processes. Since the tips of the spinal processes are palpable, their examination is sometimes of great diagnostic value. This applies not only to percussion pain, but also to other disorders of bone tissue which can be demonstrated by pressure and percussion. The superficial position of the tips readily permits a biopsy and has significance in the localization of vertebral levels. Congenital anomalies of the spinous processes might cause a problem in identification on the roentgenogram and preoperative localization.

A 5-year-old female patient presented with two bony swellings at the back of the neck. The problem was only cosmetic to her. On examination, there was no neurological deficit. There was a bony stump palpable in the region of the upper cervical spine to the left of the spinous process. The second "rib"-like swelling was present beneath this, approximately 7 cm in length and running inferiorly to the left of the spinous processes of the lower cervical spine. X-ray cervical spine (Figure 1) confirmed these findings with no additional bony abnormality. MRI of the cervical spine showed normal spinal cord. Peroperatively, (Figure 2) "stump"-like bony growth was seen to be an enlarged left-sided spinous process of C₃ vertebra. The inferior "rib"-like outgrowth had its origin from the lamina of C₄ vertebra and was extending inferiorly up to D₂ level. C₄-C₇ spinous processes were fused with normal muscle attachment on either side and the bony outgrowth was superficial to the muscle attachment. Both these outgrowths were excised from their base and on histopathological examination these had normal osseous structure.

During 3-6 weeks of gestation, cellular differentiation, migration and segmentation of the axial skeleton takes place to form the mesenchymal analage of the vertebral column.¹ Chondrification centers in this analage are established within 7 weeks of gestation² and ossification centers appear from the second embryonic month onwards. The spinous process does not have its own ossification center (except for its tip), and is formed during the first year of life by fusion of the endochondral growing osseous extensions from both vertebral arches. The tip of the spinous process develops from a secondary ossification center at puberty. Hypoplasia of vertebral arches leading to spina bifida is well known. Hypoplasia of one arch and overgrowth of the other arch resulting in deviated spine is also known.³ Abnormal extension of chondrification and ossification of one vertebral arch with normal development of the other arch can only explain the present anomaly. Overgrowth of secondary ossification center for spinous process is ruled out, keeping in view the age of the patient.

N. Chitkara, N. K. Sharma, U. Dhall,* N. Bakshi, H. Kamal

Department of Neurosurgery and *Anatomy, Pt. B.D.S. PGIMS, Rohtak, India.

References

1. Lonstein JE. Spine embryology. In: Winter RB, editor. Congenital deformities of the spine. New York: Thieme-Stratton Inc; 1983. pp. 1-11.
2. Congenital and developmental abnormalities of spine. In: Sharrad WJM, editor. Oxford: Blackwell Scientific Publication; 1971. pp. 311-83.
3. Development, growth, anatomy and function of the spine. In: Schmoral G, Junghanns H. eds. The Human Spine in Health and Disease. New York: Grune and Stratton; 1971. pp. 2-41.
4. Willis TH. The separate neural arch. J Bone Surg 1931;13:709.
5. Ledda G. Processus styloides der Lendenwirbelsaule. Zentr Org Ges Chir 1935;71:268.
6. Variation and malformation of the spine. In: Schmoral G, Junghanns H. eds. The Human Spine in Health and Disease. New York: Grune and Stratton, 1971:55-96.

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