Archives of Physical Medicine and Rehabilitation
Volume 83, Issue 3 , Pages 427-429, March 2002

Sudden onset of cervical spondylotic myelopathy during sleep: A case report☆

Presented in preliminary form at the American Spinal Injury Association's Millennium Meeting, April 14-16, 2000, Chicago, IL.

Department of Rehabilitation Medicine, University of Washington (Young, Burns, Little) and the Spinal Cord Injury Service, VA Puget Sound Health Care System (Burns, Little), Seattle, WA.

Received in revised form 10 April 2001; accepted 10 April 2001.

Correspondence to Stephen P. Burns, MD, SCI Service (128), VA Puget Sound, 1660 S Columbian Way, Seattle, WA 98108. Reprints are not available.

Article Outline

Abstract 

Young IA, Burns SP, Little JW. Sudden onset of cervical spondylotic myelopathy during sleep: a case report. Arch Phys Med Rehabil 2002;83:427-9. Cervical spondylotic myelopathy is a common cause of compressive spinal cord dysfunction. The typical course involves either a gradual or an episodic increase in symptoms and neurologic deficits, with impairment evolving over a period of months to years. Acute neurologic deterioration in conjunction with cervical spondylosis has been described almost exclusively in traumatic situations such as disk herniation. We report a case of an acute, nontraumatic onset of tetraplegia in association with cervical spondylosis. A 56-year-old man developed tetraplegia during a 1-hour nap, with loss of volitional control of his extremities, impaired sensation below the C3 dermatome, and increased muscle tone. Magnetic resonance imaging of the cervical spine revealed canal stenosis and increased T2 signal within the cord. This case report describes the rehabilitation course for this patient and reviews the clinical spectrum of onset and progression of cervical spondylotic myelopathy. © 2002 by the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation

Keywords:  Case report, Quadriplegia, Rehabilitation, Spinal cord injuries, Spinal osteophytosis, Spinal stenosis

 

Cervical spondylotic myelopathy is among the most common types of spinal cord dysfunction in patients age 50 years or older. Spinal cord dysfunction primarily results from progressive cord compression with advancing degenerative changes in the spinal column. The exact pathogenesis of cervical spondylotic myelopathy is still poorly understood but is felt to be multifactorial and related to a congenitally narrow spinal canal and progressive cervical spondylosis, resulting in direct spinal cord compression and possible ischemic injury to the spinal cord.1 This condition was first described in the 1950s by Brain2 and Clarke and Robinson.3 These investigators recognized that the pathogenesis of spondylotic myelopathy differed from cord compression secondary to acute disk herniation. Clarke and Robinson3 described the clinical onset of cervical myelopathy as the gradual progression of lower limb spasticity and weakness occurring around the age of 50 years. The disease was noted to be more prominent in men, especially those exposed to occupational trauma, and included myelopathic signs caused by cervical cord compression and/or radicular signs caused by cervical nerve root impingement.

We describe a rare presentation of sudden onset nontraumatic tetraplegia caused by cervical spondylotic myelopathy. The natural history of cervical spondylotic myelopathy is usually either episodic or shows a slow, steady increase in symptoms and neurologic deficits; rapid symptom onset is uncommon. Clarke and Robinson3 reported episodic worsening in 75% of cases, slow and steady progression in 20%, and a rapid onset in only 5% of cases. Lees and Turner4 reviewed the natural history of 95 patients with cervical spondylosis, including 44 with myelopathy on initial presentation. They found that the course after presentation was similar whether symptoms had existed for more or fewer than 10 years. There was initial worsening of symptoms followed by a static period or improvement, with only the exceptional case showing continuous decline over years. Lees and Turner4 concluded that the course of cervical spondylotic myelopathy is characterized by long periods of static disability, with continuous decline occurring only exceptionally. Some have concluded that the prognosis is good even without treatment,5 whereas other investigators argue that most patients will progress to severe disability if left untreated.6

Although the natural history of cervical spondylotic myelopathy is usually episodic or slow continuous decline in function, it can uncommonly present as rapid onset. In this report, we describe a patient with acute onset motor-complete tetraplegia (American Spinal Injury Association [ASIA] class B) caused by cervical spondylotic myelopathy.

Back to Article Outline

Case description 

A 56-year-old man was transferred to our center for spinal cord injury (SCI) rehabilitation. Four weeks earlier, he had developed acute onset of tetraplegia during a 1-hour nap. The patient had fallen asleep in a supine position on the floor at home after dinner. He was transported to the emergency department and found to have no volitional control of his upper or lower limbs, increased muscle tone in all limbs, and impaired sensation below the clavicles. He did not require mechanical ventilation acutely, and his vital capacity was not measured. Magnetic resonance imaging (MRI) of the cervical spine (fig 1) revealed spinal canal stenosis at the C2–3 and C3–4 intervertebral levels, with increased T2 signal of the spinal cord at C2–3, suggesting cord infarction caused by compression.

  • View full-size image.
  • Fig. 1. 

    T2-weighted MRI of the cervical spine shows moderate spinal canal stenosis at C2–3 and C3–4 intervertebral levels, with increased cord signal at the level of C2–3. The fusion between C6 and C7 is from a previous anterior cervical diskectomy. Additional bony abnormalities include congenital fusion of occiput and C1 and between T1 and T2, consistent with Klippel-Feil syndrome.

Degenerative changes of the cervical spine with ligamentum flavum hypertrophy, increased cervical lordosis, and bulging disks at C2–3 and C3–4 caused the cord compression. He received intravenous methylprednisolone and underwent C3 laminectomy with ligamentum flavum removal at C2–3 and C3–4.

Significant medical history included a C6–7 fusion 5 years earlier secondary to neck pain and right upper limb numbness with postoperative symptom resolution. He denied recent neurologic symptoms before the acute onset of tetraplegia. Premorbidly, he was physically active and had ridden a bicycle across the United States 6 months before the tetraplegia.

At the time of rehabilitation admission, he had no volitional movement of his upper or lower limbs. There was increased tone in all limbs with clonus noted at the ankles, and toes were upgoing bilaterally. Light touch was intact to C3 bilaterally, impaired from C3–T10, and absent below T10 except for some sacral light touch sensation. Pinprick sensation was intact through C3 and absent below. According to the International Standards for Neurological and Functional Classification of Spinal Cord Injury,7 he was classified as having C3 level (for sensory and motor bilaterally) ASIA class B tetraplegia. His vital capacity at time of rehabilitation admission was approximately 600mL, and an arterial blood gas showed hypercarbia with a carbon dioxide partial pressure of 68mmHg.

Six months post-onset, he recovered trace voluntary strength in bilateral extensor hallucis longus muscles, and by this time, he had regained normal sensation in the C4 dermatome bilaterally. He did not regain any functional use of upper or lower limbs, and his neurologic recovery was at a plateau at the time of discharge. Spasticity and muscle spasms were problematic throughout his stay, affecting both his comfort and range of motion.

Rehabilitation for this patient required the expertise of multiple therapeutic disciplines. Although his vital capacity increased to 1000mL by the time of discharge, he continued to have daytime hypercarbia and nocturnal desaturation without episodes of apnea. Respiratory therapy attempted to institute noninvasive positive pressure ventilation, but he was unable to tolerate it because of discomfort from the mask. He worked with speech therapy to learn glossopharyngeal breathing and was able to augment his vital capacity by 400mL. Physical therapy and occupational therapy provided proper fitting of an electric wheelchair with chin drive controls and a tilt-in-space system for pressure relief. He remained dependent for his activities of daily living and transfers. On discharge he was transferred to a rehabilitation unit closer to his home for community reintegration, continued respiratory rehabilitation, advanced care training for his spouse, and transition to an assisted living facility for persons with SCI.

Back to Article Outline

Discussion 

Cervical spondylotic myelopathy is defined as spinal cord compromise caused by degenerative changes in the cervical spine.8 Spondylotic changes that reduce spinal canal diameter and compress the spinal cord include posterior spinal ligament hypertrophy or ossification, osteophyte formation, disk bulging, and vertebral subluxation.9 Cervical spondylosis is common in older people, appearing in 85% of persons over age 60 years and in almost all persons older than 80 years.10 Some degree of narrowing from degenerative changes occurs not only in persons with spinal pain but also in more than 25% of asymptomatic persons who have never had neck or arm pain.10, 11 However, a minority of those with cervical spondylosis, particularly older persons, will develop compression of the spinal cord or spinal roots, producing myelopathy and/or radiculopathy. The clinical presentation may include weakness, sensory deficits, bladder and bowel dysfunction, and spasticity in upper or lower limbs. Because the presentation of the disease is frequently gradual, it is often overlooked or misdiagnosed. This oversight may contribute to falls, fractures, traumatic brain injuries, and traumatic SCIs in older patients.12

In most adults, the normal cervical spinal canal has sufficient room to accommodate spondylotic changes without cord compression. The sagittal diameter of the cervical spinal canal in cervical spondylosis correlates with development of myelopathy.13 A sagittal diameter of 12mm or less is a critical factor in the development of cervical spondylotic myelopathy. Normally, there is a “safety factor” for encroachment of the spinal cord because of spondylosis. The normal cervical spinal canal diameter from C3–7 in whites is 17 to 18mm, with slight variation between sexes.14 The cervical cord varies little in size from C1–7, measuring approximately 10mm in diameter (range, 8.5–11.5mm).15 Normally only one third of the canal cross-sectional area is occupied by the spinal cord from C1–3, compared with about 75% of the area from C3–7. If the canal is initially of normal size, narrowing caused by osteophyte formation, disk bulging, and ligamentum flavum hypertrophy can be accommodated without cord compression. Therefore, cervical spondylotic myelopathy is more likely to develop in a person with a congenitally narrowed cervical canal.16

Acute neurologic deterioration from cervical spondylosis is contrary to the typical episodic or slow steady progression of cervical spondylotic myelopathy. It has, however, been described perioperatively from intubation and surgical positioning under anesthesia.11, 17 In the literature, we identified 2 nontraumatic, nonsurgical cases with cervical spondylosis who developed rapidly progressive myelopathy, but in both cases, the tetraplegia developed over several days, unlike the present case, which evolved over 1 hour.18, 19

Vascular compromise likely plays a significant role in the pathophysiology of cervical spondylotic myelopathy. Histopathologic observations support the concept of ischemic injury to the gray and medial white matter tracts in patients with cervical spondylotic myelopathy.9 The vascular supply of the gray and medial white matter arises from transverse perforating vessels that arborize from the anterior sulcal arteries. These vessels are vulnerable to mechanical distortion from longitudinal traction on the cord with neck flexion and to compression from ligamentum flavum buckling with hyperextension.1, 9 Animal spinal cord compression models show intramedullary vessel (sulcal and transverse) pathology and hypotension-induced watershed zone central cord ischemia.9, 20 According to Bohlman and Emery,1 pathologic changes are often seen in the distribution of anterior spinal artery, but anterior spinal artery thrombosis has not been shown.

In this patient, the exact origin of the SCI is unclear, but it is likely related to his cervical spondylotic changes. This case is unusual in that the patient did not have any prior myelopathic symptoms, and he developed acute tetraplegia over a 1-hour period. He had experienced symptoms consistent with cervical radiculopathy 5 years earlier, which had resolved after diskectomy and fusion. However, he specifically denied even mild symptoms that could be attributable to myelopathy, including urinary urgency, limb stiffness, and gait changes such as tripping. Vascular compromise precipitated by cervical spondylosis, including ligamentum flavum hypertrophy, increased cervical lordosis, and bulging disks at C2–3 and C3–4, is the most plausible explanation for this acute presentation. While he was napping, it is possible that, secondary to neck positioning and severe spondylotic changes, he occluded a vessel to his spinal cord, resulting in infarction. MRI revealed increased signal at C2–3, suggesting cord infarction.21 We cannot absolutely exclude other origins such as transverse myelitis, fibrocartilage embolism to the cervical spinal cord, or multiple sclerosis, but the rapid onset over 1 hour and the associated spondylotic changes of the cervical cord suggest cervical spondylosis with cord infarction.22, 23, 24, 25

Back to Article Outline

Conclusion 

Cervical spondylotic myelopathy commonly leads to episodic or slow steady neurologic decline, but a small subset of patients can have acute deterioration, as in the case described previously. The possibility of acute onset of cervical myelopathy caused by spondylosis must be kept in mind, even if no precipitating event can be identified. Cervical spondylotic myelopathy should be included in the differential diagnosis for patients with acute neurologic deterioration. Although surgical decompression was recommended for this patient, there is no evidence whether immediate surgery is beneficial or harmful to patients with acute onset of cervical spondylotic myelopathy.

Back to Article Outline

References 

  1. Bohlman HH, Emery SE. The pathophysiology of cervical spondylosis and myelopathy. Spine. 1988;13:843–846
  2. Brain R. Cervical spondylosis. Ann Intern Med. 1954;41:439
  3. Clarke E, Robinson PK. Cervical myelopathy: a complication of cervical spondylosis. Brain. 1956;79:483–510
  4. Lees F, Turner JW. Natural history and prognosis of cervical spondylosis. Br Med J. 1963;2:1607–1610
  5. LaRocca H. Cervical spondylotic myelopathy: natural history. Spine. 1988;13:854–855
  6. Law MD, Bernhardt M, White AA. Evaluation and management of cervical spondylotic myelopathy. J Bone Joint Surg Am. 1995;76:1420–1433
  7. Maynard FM, Bracken MB, Creasey G, et al.  International Standards for Neurological and Functional Classification of Spinal Cord Injury. American Spinal Injury Association. Spinal Cord. 1997;35:266–274
  8. Orr RD, Zdeblick TA. Cervical spondylotic myelopathy. Approaches to surgical treatment. Clin Orthop. 1999;359:58–66
  9. Fehlings MG, Skaf G. A review of the pathophysiology of cervical spondylotic myelopathy with insights for potential novel mechanisms drawn from traumatic spinal cord injury. Spine. 1998;23:2730–2737
  10. Frymoyer JW. The adult spine: principles and practice. New York: : Raven Pr; 1991;
  11. Greene KA, Gorman WF, Sonntag VK. Gentle cervical hyperextension causing quadriplegia in an older man with symptomatic cervical spondylosis. J Am Geriatr Soc. 1998;46:208–209
  12. Bernhardt M, Hynes RA, Blume HW, White AA. Cervical spondylotic myelopathy. J Bone Joint Surg Am. 1993;75:119–128
  13. Arnold JG. The clinical manifestations of spondylochondrosis (spondylosis) of the cervical spine. Ann Surg. 1955;141:872–889
  14. Burrows EH. The sagittal diameter of the spinal canal in cervical spondylosis. Clin Radiol. 1963;14:77–86
  15. Payne EE, Spillane JD. The cervical spine, an anatomicopathologic study of 70 specimens (using a special technique) with particular reference to the problem of cervical spondylosis. Brain. 1957;80:571–596
  16. Veidlinger OF, Colwill JC, Smyth HS, Turner D. Cervical myelopathy and its relationship to cervical stenosis. Spine. 1981;6:550–552
  17. Deem S, Shapiro HM, Marshall LF. Quadriplegia in a patient with cervical spondylosis after thoracolumbar surgery in the prone position. Anesthesiology. 1991;75:527–528
  18. Wilberger JE, Chedid MK. Acute cervical spondylytic myelopathy. Neurosurgery. 1988;22:145–146
  19. Romano A, Marsella M, Swamy N, de Courten-Myers G, Zuccarello M. Cervical subarachnoid hematoma of unknown origin: case report. Acta Neurochir. 1999;141:1115–1117
  20. Hukuda S, Ogata M, Katsuura A. Experimental study on acute aggravating factors of cervical spondylotic myelopathy. Spine. 1988;13:15–20
  21. Nagashima C, Nagashima R, Morota N, Kobayashi S. Magnetic resonance imaging of human spinal cord infarction. Surg Neurol. 1991;35:368–373
  22. Dawson DM, Potts F. Acute nontraumatic myelopathies. Neurol Clin. 1991;9:585–603
  23. McLean JM, Palagallo GL, Henderson JP, Kimm JA. Myelopathy associated with fibrocartilaginous emboli (FE): review and two suspected cases. Surg Neurol. 1995;44:228–234
  24. Toro G, Roman GC, Navarro-Roman L, Cantillo J, Serrano B, Vergara I. Natural history of spinal cord infarction caused by nucleus pulposus embolism. Spine. 1994;19:360–366
  25. Silber MH. Idiopathic acute myelopathy. S Afr Med J. 1990;77:128–130

☆ No commercial party having a direct financial interest in the results of the research supporting this article has or will confer a benefit upon the authors(s) or upon any organization with which the author(s) is/are associated.

PII: S0003-9993(02)91943-X

doi:10.1053/apmr.2002.29621

Archives of Physical Medicine and Rehabilitation
Volume 83, Issue 3 , Pages 427-429, March 2002

Article Tools

* Image Usage & Resolution