J Neurosurg 76:296-297, 1992
Stenosis of the axis and cervical myelopathy Case report SHANKAR G. PRAKASH, M.CH.(NEUROSURG.), MATHEW J. CHANDY, M.S.(GEN. SUR6.), M.CH.(NEUROSURG.), AND JACOB ABRAHAM, M.S.(GEN. SURG.), M.S.(NEUROSURG.)
Department of Neurological Sciences, Christian Medical College Hospital Vellore, India ~" A rare case is described of marked segmental stenosis of the axis secondaryto developmentalhypertrophy of the posterior neural arch causing cervical myelopathy. The patient made a remarkable recovery following decompressivelaminectomy. KEY WORDS
9
stenosis
9 axis
EVELOPMENTALcervical canal stenosis with no radiological features of spondylosis is a recognized cause of cervical myelopathyY -7 However, localized spinal canal stenosis due to developmental hypertrophy of the posterior neural arch of C-2 has not been reported to date as a cause of myelopathy.
D
Case Report
This 40-year-old man presented with a 4-year history of burning paresthesia and progressive stiffness of all four extremities and urgency of micturition. The paresthesia attacks lasted 2 to 5 seconds and were precipitated by flexion and extension movements of the neck. During the year before admission, the paresthesia had become continuous, with exacerbation upon hyperextension of the neck. There was no history of trauma or loss of consciousness. Examination. There was a slight weakness of the right arm musculature, especially distally, and paresis of both limbs. Examination revealed no fasciculations and no evidence of atrophy. Muscle tone was increased markedly in all four limbs and there was diminution of all sensory modalifies, including joint position sense and vibratory appreciation. The deep-tendon reflexes were exaggerated in both upper and lower limbs, with absent cremasteric and abdominal reflexes. Hoffmann's signs were present bilaterally and the plantar reflex was extensor. Cervical mobility, especially flexion and extension, was restricted in part because of the aggravation 296
9 cervical myelopathy
9 neural arch
9 hypertrophy
of paresthesia. Although the patient was spastic, he could walk with assistance. Plain x-ray films of the cervical spine showed narrowing at the C-2 level; articulation was observed between the posterior arch of the atlas and the hypertrophied C-2 laminae. There was no evidence of atlantoaxial dislocation or cervical spondylosis. Computerized tomography of the cervical spine showed gross hypertrophy of the C-2 laminae causing constriction of the dural sac and cord at that level (Fig. 1 left). Magnetic resonance imaging showed gross focal constriction of the dural sac with compressed subarachnoid spaces and cord at the C-2 level due to hypertrophy of the C-2 laminae (Fig. 1 right). Operation. The patient was operated on in the seated position with the head restrained in the neutral position by three-pin fixation. The C-2 spinous process and laminae were found to be grossly hypertrophied. The dural sac was markedly pinched both anteroposteriorly and sideward. Bilateral laminectomy of C-2 with removal of the posterior arch of the atlas was performed. Postoperative Course. By 2 weeks following the operation, the patient was able to walk independently with a marked decrease in spasticity and improvement in sensation. Discussion
Boijsen I and Wolf, et al.,8 first investigated the significance of a shallow cervical canal in patients with J. Neurosurg. / Volume 76/February, I992
Stenosis of the axis and cervical myelopathy
FIG. 1. Left: Computerized tomography scan, axial view, showing hypertrophy of the C-2 laminae (arrows). Right: Magnetic resonance image, coronal projection, showing focal constriction of the dural sac and cord at the C-2 level.
cervical spondylosis. Developmental stenosis of the cervical canal as an isolated anomaly was recognized by Hinck, et alJ Later, Hinck and Sachdev, 6 who highlighted cervical stenosis as a neurologically significant anomaly, noted that individuals with developmental stenosis of the cervical spinal canal remain asymptomatic until the occurrence of complications such as spondylosis, vertebral subluxation, or injury due to hyperextension. Epstein, et at.,'- stated that symptomatic developmental stenosis in the cervical area occurred only rarely. However, cervical canal stenosis with no radiological features of spondylosis was recognized later as a cause of cervical myelopathy by several authors. 3'5-7Although hyperextension injuries were implicated in the causation of myelopathy, the spontaneous onset of myelopathy in cervical canal stenosis without trauma was also reported by Epstein, et al. 3 Normally, the canal is expected to be wider at the C-2 level, even in cases of developmental cervical canal stenosis. No data have hitherto been published with regard to localized canal stenosis at the level of the axis. In the case reported here, stenosis was caused by hypertrophied laminae; however, the remaining cervical canal had normal dimensions. The related change in bone with tight encasement of neural content in this patient could be due to premature fusion of the cartilaginous neurocentral synchondrosis. This would limit the growth of the neural arch with subsequent increased periosteal bone formation, resulting in thick laminae as suggested by Epstein and Epstein. 4
J. Neurosurg. / Volume 76 /February, 1992
Acknowledgments
We thank Mr. C. Ragupathi and Mr. Seethapathy for assistance in the preparation of this manuscript. References
1. Boijsen E: The cervical spinal canal in intraspinal expansive processes. Acta Radio142:101-115, 1954 2. Epstein JA, Carras R, Epstein BS, et al: Myelopathy in cervical spondylosis with the vertebral subluxation and hyperlordosis. J Neurosnrg 32:421-426, 1970 3. Epstein JA, Carras R, Hyman RA, et at: Cervical myelopathy caused by developmental stenosis of the spinal canal. J Neurosurg 51:362-367, 1979 4. Epstein JA, Epstein BS: Stenosis of the lumbar and cervical spinal canal, in Vinken PJ, Bruyn GW (eds): Handbook of Clinical Neurology, Vol 31. Congenital Malformations of the Spine and Spinal Cord. Amsterdam: North-Holland, 1978, pp 329-346 5. Hinck VC, Gordy PD, Storino HE: Developmental stenosis of the cervical spinal canal. Radiological considerations. Neurology 14:864-868, 1964 6. Hinck VC, Sachdev NS: Developmental stenosis of the cervical spinal canal. Brain 89:27-36, 1966 7. Moiel RH, Raso E, Waltz TA: Central cord syndrome resulting from congenital narrowness of the cervicalspinal canal. J Trauma 10:502-510, 1970 8. Wolf BS, Khilnani M, Malis L: The sagittal diameter of the bony cervical spinal canal and its significance in cervical spondylosis. J Mt Sinai Hosp 23:283-292, 1956 Manuscript received May 6, 1991. Address reprint requests to: Mathew J. Chandy, M.S., M.Ch., Department of Neurological Sciences, Christian Medical College Hospital, Vellore 632004, India.
297
Stenosis of the axis and cervical myelopathy Case report SHANKAR G. PRAKASH, M.CH.(NEUROSURG.), MATHEW J. CHANDY, M.S.(GEN. SUR6.), M.CH.(NEUROSURG.), AND JACOB ABRAHAM, M.S.(GEN. SURG.), M.S.(NEUROSURG.)
Department of Neurological Sciences, Christian Medical College Hospital Vellore, India ~" A rare case is described of marked segmental stenosis of the axis secondaryto developmentalhypertrophy of the posterior neural arch causing cervical myelopathy. The patient made a remarkable recovery following decompressivelaminectomy. KEY WORDS
9
stenosis
9 axis
EVELOPMENTALcervical canal stenosis with no radiological features of spondylosis is a recognized cause of cervical myelopathyY -7 However, localized spinal canal stenosis due to developmental hypertrophy of the posterior neural arch of C-2 has not been reported to date as a cause of myelopathy.
D
Case Report
This 40-year-old man presented with a 4-year history of burning paresthesia and progressive stiffness of all four extremities and urgency of micturition. The paresthesia attacks lasted 2 to 5 seconds and were precipitated by flexion and extension movements of the neck. During the year before admission, the paresthesia had become continuous, with exacerbation upon hyperextension of the neck. There was no history of trauma or loss of consciousness. Examination. There was a slight weakness of the right arm musculature, especially distally, and paresis of both limbs. Examination revealed no fasciculations and no evidence of atrophy. Muscle tone was increased markedly in all four limbs and there was diminution of all sensory modalifies, including joint position sense and vibratory appreciation. The deep-tendon reflexes were exaggerated in both upper and lower limbs, with absent cremasteric and abdominal reflexes. Hoffmann's signs were present bilaterally and the plantar reflex was extensor. Cervical mobility, especially flexion and extension, was restricted in part because of the aggravation 296
9 cervical myelopathy
9 neural arch
9 hypertrophy
of paresthesia. Although the patient was spastic, he could walk with assistance. Plain x-ray films of the cervical spine showed narrowing at the C-2 level; articulation was observed between the posterior arch of the atlas and the hypertrophied C-2 laminae. There was no evidence of atlantoaxial dislocation or cervical spondylosis. Computerized tomography of the cervical spine showed gross hypertrophy of the C-2 laminae causing constriction of the dural sac and cord at that level (Fig. 1 left). Magnetic resonance imaging showed gross focal constriction of the dural sac with compressed subarachnoid spaces and cord at the C-2 level due to hypertrophy of the C-2 laminae (Fig. 1 right). Operation. The patient was operated on in the seated position with the head restrained in the neutral position by three-pin fixation. The C-2 spinous process and laminae were found to be grossly hypertrophied. The dural sac was markedly pinched both anteroposteriorly and sideward. Bilateral laminectomy of C-2 with removal of the posterior arch of the atlas was performed. Postoperative Course. By 2 weeks following the operation, the patient was able to walk independently with a marked decrease in spasticity and improvement in sensation. Discussion
Boijsen I and Wolf, et al.,8 first investigated the significance of a shallow cervical canal in patients with J. Neurosurg. / Volume 76/February, I992
Stenosis of the axis and cervical myelopathy
FIG. 1. Left: Computerized tomography scan, axial view, showing hypertrophy of the C-2 laminae (arrows). Right: Magnetic resonance image, coronal projection, showing focal constriction of the dural sac and cord at the C-2 level.
cervical spondylosis. Developmental stenosis of the cervical canal as an isolated anomaly was recognized by Hinck, et alJ Later, Hinck and Sachdev, 6 who highlighted cervical stenosis as a neurologically significant anomaly, noted that individuals with developmental stenosis of the cervical spinal canal remain asymptomatic until the occurrence of complications such as spondylosis, vertebral subluxation, or injury due to hyperextension. Epstein, et at.,'- stated that symptomatic developmental stenosis in the cervical area occurred only rarely. However, cervical canal stenosis with no radiological features of spondylosis was recognized later as a cause of cervical myelopathy by several authors. 3'5-7Although hyperextension injuries were implicated in the causation of myelopathy, the spontaneous onset of myelopathy in cervical canal stenosis without trauma was also reported by Epstein, et al. 3 Normally, the canal is expected to be wider at the C-2 level, even in cases of developmental cervical canal stenosis. No data have hitherto been published with regard to localized canal stenosis at the level of the axis. In the case reported here, stenosis was caused by hypertrophied laminae; however, the remaining cervical canal had normal dimensions. The related change in bone with tight encasement of neural content in this patient could be due to premature fusion of the cartilaginous neurocentral synchondrosis. This would limit the growth of the neural arch with subsequent increased periosteal bone formation, resulting in thick laminae as suggested by Epstein and Epstein. 4
J. Neurosurg. / Volume 76 /February, 1992
Acknowledgments
We thank Mr. C. Ragupathi and Mr. Seethapathy for assistance in the preparation of this manuscript. References
1. Boijsen E: The cervical spinal canal in intraspinal expansive processes. Acta Radio142:101-115, 1954 2. Epstein JA, Carras R, Epstein BS, et al: Myelopathy in cervical spondylosis with the vertebral subluxation and hyperlordosis. J Neurosnrg 32:421-426, 1970 3. Epstein JA, Carras R, Hyman RA, et at: Cervical myelopathy caused by developmental stenosis of the spinal canal. J Neurosurg 51:362-367, 1979 4. Epstein JA, Epstein BS: Stenosis of the lumbar and cervical spinal canal, in Vinken PJ, Bruyn GW (eds): Handbook of Clinical Neurology, Vol 31. Congenital Malformations of the Spine and Spinal Cord. Amsterdam: North-Holland, 1978, pp 329-346 5. Hinck VC, Gordy PD, Storino HE: Developmental stenosis of the cervical spinal canal. Radiological considerations. Neurology 14:864-868, 1964 6. Hinck VC, Sachdev NS: Developmental stenosis of the cervical spinal canal. Brain 89:27-36, 1966 7. Moiel RH, Raso E, Waltz TA: Central cord syndrome resulting from congenital narrowness of the cervicalspinal canal. J Trauma 10:502-510, 1970 8. Wolf BS, Khilnani M, Malis L: The sagittal diameter of the bony cervical spinal canal and its significance in cervical spondylosis. J Mt Sinai Hosp 23:283-292, 1956 Manuscript received May 6, 1991. Address reprint requests to: Mathew J. Chandy, M.S., M.Ch., Department of Neurological Sciences, Christian Medical College Hospital, Vellore 632004, India.
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