Boden SD, McCowin PR, Davis DO, Dina TS, Mark AS, Wiesel S.
Abnormal magnetic-resonance scans of the cervical spine in asymptomatic subjects. A prospective investigation.
J Bone Joint Surg Am. 1990 Sep;72(8):1178-84.
Abstract/Text
Previous investigations with plain radiography, myelography, and computed tomography have shown that degenerative disease of the cervical spine frequently occurs in the absence of clinical symptoms. We studied the magnetic resonance-imaging scans of sixty-three volunteers who had no history of symptoms indicative of cervical disease. The scans were mixed randomly with thirty-seven scans of patients who had a symptomatic lesion of the cervical spine, and all of the scans were interpreted independently by three neuroradiologists. The scans were interpreted as demonstrating an abnormality in 19 per cent of the asymptomatic subjects: 14 per cent of those who were less than forty years old and 28 per cent of those who were older than forty. Of the subjects who were less than forty, 10 per cent had a herniated nucleus pulposus and 4 per cent had foraminal stenosis. Of the subjects who were older than forty, 5 per cent had a herniated nucleus pulposus; 3 per cent, bulging of the disc; and 20 per cent, foraminal stenosis. Narrowing of a disc space, degeneration of a disc, spurs, or compression of the cord were also recorded. The disc was degenerated or narrowed at one level or more in 25 per cent of the subjects who were less than forty years old and in almost 60 per cent of those who were older than forty. The prevalence of abnormal magnetic-resonance images of the cervical spine as related to age in asymptomatic individuals emphasizes the dangers of predicating operative decisions on diagnostic tests without precisely matching those findings with clinical signs and symptoms.
Teresi LM, Lufkin RB, Reicher MA, Moffit BJ, Vinuela FV, Wilson GM, Bentson JR, Hanafee WN.
Asymptomatic degenerative disk disease and spondylosis of the cervical spine: MR imaging.
Radiology. 1987 Jul;164(1):83-8. doi: 10.1148/radiology.164.1.3588931.
Abstract/Text
Evidence on magnetic resonance (MR) images of disk degeneration and herniation, as well as of cord and root impingement, may be regarded either as normal, age-related changes or as causative of symptoms. Individuals referred for MR examinations of the larynx without symptoms referable to the cervical spine were studied retrospectively (35 patients) or prospectively (65 patients) over a 2-year period. With a solenoid surface coil, 5-mm-thick sections were acquired in sagittal, axial, and coronal planes with T1-weighted spin-echo pulsing sequences. Disk protrusion (herniation/bulge) was seen in five of 25 (20%) patients aged 45-54 and 24 of 42 (57%) patients older than 64 years of age. Posterolateral protrusions were seen in only nine of 100 patients and occurred with greatest frequency in patients over 64 years of age. In no patient was obliteration of the intraforaminal fat seen. Spinal cord impingement was observed in nine of 58 (16%) patients under 64 years of age, and in 11 of 42 (26%) patients over 64 years of age. Cord compression was observed in seven of 100 patients and occurred solely secondary to disk protrusion in all cases. The percentage of cord area reduction never exceeded 16% and averaged approximately 7%.
Chen IH, Liao KK, Shen WY.
Measurement of cervical canal sagittal diameter in Chinese males with cervical spondylotic myelopathy.
Zhonghua Yi Xue Za Zhi (Taipei). 1994 Aug;54(2):105-10.
Abstract/Text
BACKGROUND: Cervical canal encroachment can be properly assessed from lateral cervical radiographs either by defining its magnification rate or by a ratio-method. Data of the latter obtained from Chinese males with cervical myelopathy were compared with the data of general population in different age groups.
METHODS: A total of 200 Chinese males were included in this study. Half of them had undergone decompressive procedures for cervical myelopathy, while the remaining 100 cases were volunteers. Sagittal diameters of cervical canal and vertebra were measured from C3 to C6 on lateral cervical radiographs, while ratios (Torg-Pavlov's ratios) of the two reflected the extent of sagittal canal encroachment. Cut-off values and discriminant rates of these parameters in different age groups were obtained by discriminant analysis. The tube-to-film distance was set as 40 inches.
RESULTS: In myelopathic group (age < 55 y/o), Torg-Pavlov's ratios, as expressed by mean +/- standard deviation, were 0.77 +/- 0.12 for C3, 0.75 +/- 0.14 for C4, 0.80 +/- 0.14 for C5, and 0.81 +/- 0.15 for C6. In control group (age < 55 y/o) the ratios were 0.94 +/- 0.12, 0.95 +/- 0.13, 0.97 +/- 0.13, and 0.97 +/- 0.13 respectively. In myelopathic group (age > or = 55 y/o), the ratios were 0.76 +/- 0.09, 0.71 +/- 0.10, 0.73 +/- 0.11, and 0.76 +/- 0.11; while in control group (age > or = 55 y/o), the ratios were 0.93 +/- 0.10, 0.89 +/- 0.09, 0.88 +/- 0.11, and 0.91 +/- 0.12 respectively. The cutoff values and their discriminant rates are also presented.
CONCLUSIONS: The differences of canal sagittal diameter as well as Torg-Pavlov ratio between myelopathic and control group of Chinese males in individual age group were statistically significant. It is concluded that congenitally narrow cervical canal is a major predisposing factor to cervical spondylotic myelopathy.
Yue WM, Tan SB, Tan MH, Koh DC, Tan CT.
The Torg--Pavlov ratio in cervical spondylotic myelopathy: a comparative study between patients with cervical spondylotic myelopathy and a nonspondylotic, nonmyelopathic population.
Spine (Phila Pa 1976). 2001 Aug 15;26(16):1760-4. doi: 10.1097/00007632-200108150-00006.
Abstract/Text
STUDY DESIGN: A radiologic study to compare the Torg--Pavlov ratios between patients with cervical spondylotic myelopathy and a nonspondylotic, nonmyelopathic population.
OBJECTIVES: To determine and compare the Torg--Pavlov ratios between the two groups of patients.
SUMMARY OF BACKGROUND DATA: Patients with congenital cervical spinal canal stenosis are more likely to develop cervical spondylotic myelopathy. The Torg--Pavlov ratio eliminates errors related to magnification, a problem with determination of spinal canal stenosis from direct measurements of plain cervical spine radiographs. There has only been one other study that directly compares the Torg--Pavlov ratio between patients with cervical spondylotic myelopathy and a normal control population.
METHODS: The preoperative plain lateral cervical spine radiographs of 28 patients with cervical spondylotic myelopathy requiring surgical decompression were compared with radiographs of 88 nonspondylotic, nonmyelopathic patients. The Torg--Pavlov ratio was computed for each level from C3 to C7.
RESULTS: The study showed that the Torg--Pavlov ratio is significantly smaller (P < 0.001) in myelopathic patients (mean 0.72 +/- 0.08) compared with the control patients (mean 0.95 +/- 0.14). This was so when individual levels and the mean values were compared. Age was also found to be a significant factor (P = 0.002), although lesser in magnitude when compared with the Torg--Pavlov ratio (P = 0.0001).
CONCLUSIONS: The Torg--Pavlov ratio is significantly lower in patients with cervical spondylotic myelopathy compared with a nonspondylotic, nonmyelopathic population. It could possibly be used to predict the likelihood of developing cervical spondylotic myelopathy.
Harsh GR 4th, Sypert GW, Weinstein PR, Ross DA, Wilson CB.
Cervical spine stenosis secondary to ossification of the posterior longitudinal ligament.
J Neurosurg. 1987 Sep;67(3):349-57. doi: 10.3171/jns.1987.67.3.0349.
Abstract/Text
Ossification of the posterior longitudinal ligament (OPLL) is a well-documented cause of cervical spine stenosis and myelopathy among Japanese patients. Reports of OPLL in North Americans are rare. Choices of diagnostic method and treatment for this entity remain controversial. The authors report the results of management of 20 patients in the United States with symptomatic OPLL of the cervical spine. These represented 10% to 20% of patients operated on over the last 3 years for myelopathy secondary to structural spinal compression. Most of these OPLL patients were Caucasian (60%), male (male:female 4:1), and middle-aged (median age 47.5 years). Six had previously undergone laminectomy or discectomy. Cervical roentgenograms and standard myelography occasionally suggested the diagnosis. Axial computerized tomography (CT) metrizamide myelography with small interslice intervals proved invaluable for diagnosis and operative planning. Magnetic resonance imaging was not necessary for diagnosis. Retrovertebral calcification extended over one to five bodies (mean 2.75). The mass ranged in size from 5 to 16 mm in anteroposterior diameter and reduced the residual canal diameter to a mean (+/- standard deviation) caliber of 9.42 +/- 2.41 mm (mean narrowing ratio 0.44 +/- 0.12). Anterior cervical decompression by medial corpectomy and discectomy with fusion uniformly reduced preoperative myelopathy. Complications were limited to transient neurological deterioration in two patients, recurrent laryngeal nerve palsy in one, and halo device pin site infections in two. At a mean postoperative interval of 15 months, improvement was seen in each category of deficit: extremity weakness, hypesthesia, hypertonia, and urinary dysfunction. All fusions produced solid unions. It is concluded that OPLL of the cervical spine is an unexpectedly prevalent cause of myelopathy among patients treated in the United States. Thin-section axial CT metrizamide myelography with small interslice intervals is essential for the investigation of patients who may have OPLL. Anterior decompression and stabilization by medial corpectomy, discectomy, removal of the calcified mass, and fusion is a safe and effective method of treatment.
Matsunaga S, Kukita M, Hayashi K, Shinkura R, Koriyama C, Sakou T, Komiya S.
Pathogenesis of myelopathy in patients with ossification of the posterior longitudinal ligament.
J Neurosurg. 2002 Mar;96(2 Suppl):168-72. doi: 10.3171/spi.2002.96.2.0168.
Abstract/Text
OBJECT: The goal of this study was to clarify the pathogenesis of myelopathy in patients with ossification of the posterior longitudinal ligament (OPLL) based on the relationship between static compression factors and dynamic factors.
METHODS: There was a total of 247 patients, including 167 patients who were conservatively followed for a mean of 11 years and 2 months and 80 patients who had myelopathy at initial consultation and underwent surgery. The changes in clinical symptoms associated with OPLL in the cervical spine were examined periodically. During the natural course of OPLL in the cervical spine, 37 (22%) of 167 patients developed or suffered aggravated spinal symptoms. All of the patients with a space available for the spinal cord (SAC) less than 6 mm suffered myelopathy, whereas the patients with an SAC diameter of 14 mm or greater did not. No correlation was found between the presence or absence of myelopathy in patients whose SAC diameter ranged from 6 mm to less than 14 mm. In patients with myelopathy whose minimal SAC diameter ranged from 6 mm to less than 14 mm, the range of motion of the cervical spine was significantly greater.
CONCLUSIONS: These results indicate that pathological compression by the ossified ligament above a certain critical point may be the most significant factor in inducing myelopathy, whereas below that point dynamic factors may be largely involved in inducing myelopathy.
Kadanka Z, Kerkovsky M, Bednarik J, Jarkovsky J.
Cross-sectional transverse area and hyperintensities on magnetic resonance imaging in relation to the clinical picture in cervical spondylotic myelopathy.
Spine (Phila Pa 1976). 2007 Nov 1;32(23):2573-7. doi: 10.1097/BRS.0b013e318158cda0.
Abstract/Text
STUDY DESIGN: Prospective observational cohort study.
OBJECTIVE: To ascertain the threshold of critical spondylotic cervical cord compression and its relation to MRI-increased signal intensities.
SUMMARY OF BACKGROUND DATA: The critical degree of spinal cord compression required to induce significant clinical signs remains unknown.
METHODS: The study group consisted of 243 patients (mean age, 53.9 +/- 9.8 years), with spondylotic cervical spine compression. The transverse cross-sectional area of the spinal cord at the level of maximum compression was measured, while MRI hyperintensities were recorded and related to clinical status and quantified by modified JOA score (mJOA).
RESULTS: A statistically significant difference in mJOA was shown between patients with a spinal cord sectional area of under 50 mm2 and a group of patients with a spinal cord sectional area of over 60 mm2. This difference was highly significant (P = 0.001) in a subgroup with MRI hyperintensities (187 patients, P = 0.001), whereas within the group of patients without hyperintensities this difference was not observed (P = 0.63).
CONCLUSION: The critical degree of spinal cord compression needed to induce clinically significant signs was found between 50 and 60 mm2 of cross-sectional transverse area at the level of maximal compression in association with MRI hyperintensities.
Penning L, Wilmink JT, van Woerden HH, Knol E.
CT myelographic findings in degenerative disorders of the cervical spine: clinical significance.
AJR Am J Roentgenol. 1986 Apr;146(4):793-801. doi: 10.2214/ajr.146.4.793.
Abstract/Text
CT myelographic data in 80 patients with clinical evidence of nerve-root involvement or long tract signs attributed to degenerative disorders of the cervical spine were classed into five diagnostic groups, and their clinical significance was assessed. Unilateral flattening of the cord by a spondylotic mass or bulging disk in a normally wide canal (group 1) was considered nonspecific because nerve-root signs were nearly as often contralateral as unilateral to the radiologic findings, and none of the patients had long tract signs. As a rule, conventional myelography showed only minor root-sleeve deformity. Concentric compression of the cord in a narrow (stenotic) canal (group 2) proved to produce long tract signs only after the cross-sectional area of the cord had been reduced by about 30% to a value of about 60 mm2 or less. In most cases, nerve-root swelling (group 3) coincided with the side of nerve-root symptoms. A 100% correlation was found between the side of disk herniation with occlusion of the corresponding foramen (group 4) and the side of nerve-root symptoms. In 24 patients, cord and nerve roots showed no abnormalities (group 5). If stenosis of the spinal canal, nerve root swelling, and disk herniation are considered specific CT myelographic signs in nerve-root symptomatology, a specific diagnosis could be made in about 40% of the cases.
Glaser JA, Curé JK, Bailey KL, Morrow DL.
Cervical spinal cord compression and the Hoffmann sign.
Iowa Orthop J. 2001;21:49-52.
Abstract/Text
Little information exists about the ability of the Hoffmann sign to predict cervical spinal cord compression. The objective of this study was to determine the correlation between the Hoffmann sign and cervical spinal cord compression in a consecutive series of patients seen by a single spine surgeon. All new patients with complaints related to their cervical spine were included. Hoffmann sign was elicited by flicking the nail of the middle finger. Any flexion of the ipsilateral thumb and/or index finger was considered positive. All imaging studies were reviewed for spinal cord compression. Cord compression was defined as flattening of the AP diameter of the spinal cord coexisting with obliteration of CSF around the cord compared to normal levels. Of 165 patients, 124 patients had imaging of their spinal canal. Review by the spine surgeon found sensitivity of the Hoffmann sign relative to cord compression was 58%, specificity 78%, positive predictive value 62%, negative predictive value 75%. 49 studies were also read by a "blinded" neuroradiologist, the sensitivity was 33%, specificity 59%, positive predictive value, 26%, negative predictive value 67%. Although attractive as a simple method of screening for cervical spinal cord compression, the Hoffmann sign, in the absence of other clinical findings, is not in our experience a reliable test.
Sung RD, Wang JC.
Correlation between a positive Hoffmann's reflex and cervical pathology in asymptomatic individuals.
Spine (Phila Pa 1976). 2001 Jan 1;26(1):67-70. doi: 10.1097/00007632-200101010-00013.
Abstract/Text
STUDY DESIGN: Asymptomatic patients with a positive Hoffmann's reflex were prospectively studied with cervical radiographs and magnetic resonance imaging.
OBJECTIVES: To determine a relationship between a positive Hoffmann's reflex and cervical pathology in asymptomatic patients and to evaluate if further work-up was necessary in this patient population.
SUMMARY OF BACKGROUND DATA: A positive Hoffmann's reflex usually implies an upper motor neuron lesion from spinal cord compression. Although this reflex is commonly tested, the significance of this reflex in asymptomatic patients is not known.
METHODS: Sixteen patients without cervical pain or radiculopathy and a positive Hoffmann's reflex were prospectively studied with cervical radiographs and magnetic resonance imaging. Positive findings were correlated with a detailed neurologic examination.
RESULTS: All 16 patients were asymptomatic. Fourteen patients (87.5%) demonstrated spondylosis on cervical radiographs. The magnetic resonance imaging studies showed pathologic findings in all 16 patients. Fifteen patients (94%) had cervical involvement with cord compression from a herniated nucleus pulposus. The remaining patient had a T5-T6 thoracic disc with resultant compression. No treatment was instituted, and the clinical course of each patient was not affected.
CONCLUSIONS: Although the presence of cervical cord impingement is extremely high in these patients, no treatment was rendered specifically to address the cervical pathology. Therefore, the presence of a positive Hoffmann's reflex in asymptomatic patients strongly suggests underlying cervical pathology, but it does not warrant further evaluation with either cervical radiographs or magnetic resonance imaging since the management and clinical course are not affected by positive studies.
Houten JK, Noce LA.
Clinical correlations of cervical myelopathy and the Hoffmann sign.
J Neurosurg Spine. 2008 Sep;9(3):237-42. doi: 10.3171/SPI/2008/9/9/237.
Abstract/Text
OBJECT: The Hoffmann sign is commonly used in clinical practice to assess cervical spine disease. It is unknown whether the sign correlates with the severity of myelopathy, and no consensus exists regarding the significance of a positive sign in asymptomatic individuals.
METHODS: In a retrospective review of cervical spine surgeries for myelopathy due to cervical spondylosis, ossification of the posterior longitudinal ligament, or disc herniation performed at a tertiary center, the authors compiled data on the presence of hyperreflexia, the Hoffmann and Babinski signs, and modified Japanese Orthopaedic Association (mJOA) scale scores. Then, in a prospective evaluation, new patients with lumbar spine complaints were examined for the presence of a Hoffmann sign, and, if present, a cervical MR imaging study was assessed for cord compression.
RESULTS: Of the 225 surgically treated patients, a Hoffmann sign occurred in 68%, hyperreflexia in 60%, and a Babinski sign in 33%. In patients with milder disability (mJOA Scores 14-16), the Hoffmann sign was present in 46%, whereas a Babinski sign occurred in 10%; in those with severe myelopathy and mJOA scores of < or =10, the Hoffmann sign was present in 81% and the Babinski sign in 83%. Of 290 patients presenting exclusively with lumbar spine-related complaints, 36 (12%) had a positive Hoffmann sign. Magnetic resonance imaging demonstrated spinal cord compression in 91% when the sign was present bilaterally and 50% when positive unilaterally.
CONCLUSIONS: In patients surgically treated for cervical myelopathy, the Hoffmann sign is more prevalent and more likely to be seen in individuals with less severe neurological deficits than the Babinski sign. In patients with lumbar symptoms, a bilateral Hoffmann sign was a highly sensitive marker for occult cervical cord compression, whereas a unilateral Hoffmann sign correlated with similar disease in about one-half of patients.
Fouyas IP, Statham PF, Sandercock PA.
Cochrane review on the role of surgery in cervical spondylotic radiculomyelopathy.
Spine (Phila Pa 1976). 2002 Apr 1;27(7):736-47. doi: 10.1097/00007632-200204010-00011.
Abstract/Text
STUDY DESIGN: This study involved a search of MEDLINE (1966 to 2000), EMBASE (1980 to 2000), and the Cochrane Controlled Trials Register. The authors of the identified randomized controlled trials were contacted to detect any additional published or unpublished data. The trials selected for this study included all the truly unconfounded or quasi-randomized controlled investigations allocating patients with cervical radiculopathy or myelopathy to 1) "best medical management" or "decompressive surgery (with or without some form of fusion) plus best medical management," or 2) "early decompressive surgery" or "delayed decompressive surgery." Two reviewers independently selected trials for inclusion, assessed trial quality, and extracted the data.
OBJECTIVES: To determine whether surgical treatment of cervical radiculopathy or myelopathy is associated with improved outcome, as compared with conservative management, and whether the timing of surgery (immediate or delayed because of persistence or progression of relevant symptoms and signs) has an impact on outcome.
SUMMARY OF BACKGROUND DATA: Cervical spondylosis causes pain and disability by compressing the spinal cord or roots. Surgery to relieve the compression may reduce the pain and disability. However, it is associated with a small but definite risk. This study sought to assess the balance of risk and benefit from surgery.
METHODS: Two trials involving a total of 130 patients were included. One trial with 81 patients compared surgical decompression with either physiotherapy or cervical collar immobilization in patients with cervical radiculopathy.
RESULTS: The short-term effects of surgery, in terms of pain, weakness, or sensory loss were superior. However, at 1 year no significant differences between the groups were observed. Another trial with 49 patients compared the effects of surgery with those of conservative treatment in patients who had a mild functional deficit associated with cervical myelopathy. No significant differences were observed between the groups up to 2 years after treatment.
CONCLUSIONS: The data from the reviewed trials were inadequate to provide reliable conclusions on the balance of risk and benefit from cervical spine surgery for spondylotic radiculopathy or myelopathy.
Kadanka Z, Bednarík J, Vohánka S, Vlach O, Stejskal L, Chaloupka R, Filipovicová D, Surelová D, Adamová B, Novotný O, Nemec M, Smrcka V, Urbánek I.
Conservative treatment versus surgery in spondylotic cervical myelopathy: a prospective randomised study.
Eur Spine J. 2000 Dec;9(6):538-44. doi: 10.1007/s005860000132.
Abstract/Text
A prospective randomised 2-year study was performed to compare the conservative and operative treatment of mild and moderate forms of spondylotic cervical myelopathy (SCM). Forty-eight patients presenting with the clinical syndrome of SCM, with a modified Japanese Orthopaedic Association (mJOA) score of 12 points or more, were randomised into two groups. Group A, treated conservatively, consisted of 27 patients, mean age 55.6 +/- 8.6 years, while group B was treated surgically (21 patients, mean age 52.7 +/- 8.1 years). The clinical outcome was measured by the mJOA score, recovery rate (RR), timed 10 m walk, score of daily activities (recorded by video and evaluated by two observers blinded to the therapy), and by the subjective assessment of the patients at 6, 12, and 24 months of the follow-up. There was, on average, no significant deterioration in mJOA score, recovery ratio, or timed 10 m walk within either group during the 2 years of follow-up. In the surgery group there was a slight decline in the scores for daily activities and subjective evaluation. A comparison of the two groups showed no significant differences in changes over time in mJOA score or quantified gait, but there were significant differences in the score of daily activities recorded by video at 24 months, which was a little lower in the surgical group, and also in RR and subjective evaluation, which were both worse in the surgical group at months 12 and 24. However, at month 6, this last parameter was significantly better in the surgical than in conservative group. Surgical treatment of mild and moderate forms of SCM in the present study design, comprising the patients with no or very slow, insidious progression and a relatively long duration of symptoms, did not show better results than conservative treatment over the 2-year follow-up.
