Assessing hand dysfunction in cervical spondylotic myelopathy

Autoři: Zachary A. Smith aff001;  Alexander J. Barry aff002;  Monica Paliwal aff001;  Benjamin S. Hopkins aff001;  Donald Cantrell aff003;  Yasin Dhaher aff002
Působiště autorů: Department of Neurological Surgery, Northwestern University, Chicago, Illinois, United States of America aff001;  Shirley Ryan Ability Lab, Northwestern University, Chicago, Illinois, United States of America aff002;  Department of Radiology, Northwestern University, Chicago, Illinois, United States of America aff003
Vyšlo v časopise: PLoS ONE 14(10)
Kategorie: Research Article
doi: 10.1371/journal.pone.0223009


Cervical Spondylotic Myelopathy (CSM) is a common spinal condition that presents as hyperreflexia, loss of dexterity, and strength. Despite its prevalence, little is known about the specific neuromechanical deficits that constitute overall disability in CSM. Compression on MRI doesn’t exclusively relate to disability. Moreover, clinical assessment often relies on the subjective exams and self-reported questionnaires. Therefore, the purpose of this study was to assess hyperreflexia, proprioception, and loss of strength, and its association with common MRI scales.


Twenty patients with CSM and 17 controls were recruited. Clinical scores of modified Japanese Orthopedic Association (mJOA) and Nurick were collected. MRI based compression grades such as cord distortion were assessed. Hand dysfunction was tested using a custom motorized apparatus. Subject’s forearm was placed in a cast and positioned such that their metacarpophalangeal (MCP) joint was vertically aligned with the motor shaft. Surface electromyographic sensors were placed on flexor digitorum superficialis (FDS) and extensor digitorum communis muscles. Hyperreflexia was measured as the FDS muscle activation during reflex when the MCP joint was moved from flexion to extension at 300°/sec. Proprioception was quantified as the angle of detection in absence of visual or auditory cues (subjects were blindfolded and given noise-cancelling headphones). Strength was measured as the maximum isometric force at the MCP joint. 2-sample t-test (p<0.05) were performed to assess significant differences in reflexes, proprioception and strength among patients and controls (SPSS software version 24).


Patients reported higher Nurick (1.90±1.0 vs 0±0, p<0.001) and lower mJOA scores (14.3±1.9 vs 18.0±0, p<0.001) as compared to controls. Similarly, patients with CSM had increased reflexes (peak FDS EMG) (0.073±0.096 vs. 0.014±0.010, p = 0.019). Patient proprioception was significantly worse; mean angle of detection was greater than twice as high in patients (9.6± 9.43°) compared to controls (4.0± 2.3°), p = 0.022. MRI based compression ratio (CR) was a significant predictor of hyperreflexia, CR<0.44 resulted in steep increase in reflex activity. Fifteen of the 20 patients who completed follow up testing at 6 months after surgery show substantial clinical improvement in reflexes and proprioceptive angle, while repeated testing in controls were unchanged.


In conclusion, hyperreflexia and decline in proprioception are the main drivers of hand disability in patients with CSM. Of multiple scales, only a select few MRI scales (such as compression ratio) were predictive of increased reflexes. The study describes a pre-clinical testing apparatus to quantitatively and objectively assess primary presenting symptoms in CSM. This pilot apparatus has the potential to evaluate treatment efficacy through repeated testing. Objective testing of hand dysfunction can help inform the design of clinically feasible devices, guide MRI biomarker analysis, and improve our understanding of the progression of neurological injury in this patient population.

Klíčová slova:

Electromyography – Hands – Magnetic resonance imaging – Reflexes – Skeletal joints – Spinal cord – Surgical and invasive medical procedures – Proprioception


1. Benzel EC, Lancon J, Kesterson L, Hadden T. Cervical laminectomy and dentate ligament section for cervical spondylotic myelopathy. J Spinal Disord. 1991;4(3):286–95. 1802159

2. Crandall PH, Batzdorf U. Cervical spondylotic myelopathy. J Neurosurg. 1966;25(1):57–66. doi: 10.3171/jns.1966.25.1.0057 5947048

3. Bakhsheshian J, Mehta VA, Liu JC. Current Diagnosis and Management of Cervical Spondylotic Myelopathy. Global Spine J. 2017;7(6):572–86. doi: 10.1177/2192568217699208 28894688

4. Lebl DR, Hughes A, Cammisa FP Jr., O’Leary PF. Cervical spondylotic myelopathy: pathophysiology, clinical presentation, and treatment. HSS J. 2011;7(2):170–8. doi: 10.1007/s11420-011-9208-1 22754419

5. Fehlings MG, Tetreault LA, Riew KD, Middleton JW, Wang JC. A Clinical Practice Guideline for the Management of Degenerative Cervical Myelopathy: Introduction, Rationale, and Scope. Global Spine J. 2017;7(3 Suppl):21S–7S. doi: 10.1177/2192568217703088 29164027

6. Pavlov H, Torg JS. Redefining cervical spinal stenosis using MRI. Med Sci Sports Exerc. 1993;25(9):1082–4. 8231779

7. Engsberg JR, Lauryssen C, Ross SA, Hollman JH, Walker D, Wippold FJ 2nd. Spasticity, strength, and gait changes after surgery for cervical spondylotic myelopathy: a case report. Spine (Phila Pa 1976). 2003;28(7):E136–9.

8. Nurick S. The pathogenesis of the spinal cord disorder associated with cervical spondylosis. Brain. 1972;95(1):87–100. doi: 10.1093/brain/95.1.87 5023093

9. Nurick S. The natural history and the results of surgical treatment of the spinal cord disorder associated with cervical spondylosis. Brain. 1972;95(1):101–8. doi: 10.1093/brain/95.1.101 5023079

10. Kamper DG, Rymer WZ. Quantitative features of the stretch response of extrinsic finger muscles in hemiparetic stroke. Muscle Nerve. 2000;23(6):954–61. doi: 10.1002/(sici)1097-4598(200006)23:6<954::aid-mus17>;2-0 10842274

11. Mathiowetz V, Kashman N, Volland G, Weber K, Dowe M, Rogers S. Grip and pinch strength: normative data for adults. Arch Phys Med Rehabil. 1985;66(2):69–74. 3970660

12. Hoffmann G, Kamper DG, Kahn JH, Rymer WZ, Schmit BD. Modulation of stretch reflexes of the finger flexors by sensory feedback from the proximal upper limb poststroke. J Neurophysiol. 2009;102(3):1420–9. doi: 10.1152/jn.90950.2008 19571191

13. Taylor JL, Fogel W, Day BL, Rothwell JC. Ipsilateral cortical stimulation inhibited the long- latency response to stretch in the long finger flexors in humans. J Physiol. 1995 Nov 1;488 (Pt 3):821–31.

14. Nagata K, Yoshimura N, Hashizume H, et al. The prevalence of cervical myelopathy among subjects with narrow cervical spinal canal in a population-based magnetic resonance imaging study: the Wakayama Spine Study. Spine J. 2014;14(12):2811–7. doi: 10.1016/j.spinee.2014.03.051 24709229

15. Kang Y, Lee JW, Koh YH, et al. New MRI grading system for the cervical canal stenosis. AJR Am J Roentgenol. 2011;197(1):W134–40. doi: 10.2214/AJR.10.5560 21700974

16. Chang V, Ellingson BM, Salamon N, Holly LT. The Risk of Acute Spinal Cord Injury After Minor Trauma in Patients With Preexisting Cervical Stenosis. Neurosurgery. 2015;77(4):561–5; discussion 5. doi: 10.1227/NEU.0000000000000888 26191975

17. Pavlov H, Torg JS, Robie B, Jahre C. Cervical spinal stenosis: determination with vertebral body ratio method. Radiology. 1987;164(3):771–5. doi: 10.1148/radiology.164.3.3615879 3615879

18. Fehlings MG, Tetreault LA, Riew KD, et al. A Clinical Practice Guideline for the Management of Patients With Degenerative Cervical Myelopathy: Recommendations for Patients With Mild, Moderate, and Severe Disease and Nonmyelopathic Patients With Evidence of Cord Compression. Global Spine J. 2017;7(3 Suppl):70S–83S. doi: 10.1177/2192568217701914 29164035

19. Ono K, Ebara S, Fuji T, Yonenobu K, Fujiwara K, Yamashita K. Myelopathy hand. New clinical signs of cervical cord damage. J Bone Joint Surg Br. 1987;69(2):215–9. 3818752

20. Takayama H, Muratsu H, Doita M, Harada T, Kurosaka M, Yoshiya S. Proprioceptive recovery of patients with cervical myelopathy after surgical decompression. Spine (Phila Pa 1976). 2005;30(9):1039–44.

21. Takayama H, Muratsu H, Doita M, Harada T, Yoshiya S, Kurosaka M. Impaired joint proprioception in patients with cervical myelopathy. Spine (Phila Pa 1976). 2005;30(1):83–6.

22. Doita M, Sakai H, Harada T, et al. The influence of proprioceptive impairment on hand function in patients with cervical myelopathy. Spine (Phila Pa 1976). 2006;31(14):1580–4.

23. Akutagawa T, Tani T, Kida K, et al. A new method for characterizing hand dysfunction in cervical spondylotic myelopathy: a preliminary study. Spinal Cord. 2016;54(3):221–5. doi: 10.1038/sc.2015.123 26215908

24. Houten JK, Noce LA. Clinical correlations of cervical myelopathy and the Hoffmann sign. J Neurosurg Spine. 2008;9(3):237–42. doi: 10.3171/SPI/2008/9/9/237 18928217

25. Nemani VM, Kim HJ, Piyaskulkaew C, Nguyen JT, Riew KD. Correlation of cord signal change with physical examination findings in patients with cervical myelopathy. Spine (Phila Pa 1976). 2015;40(1):6–10.

26. Maki S, Koda M, Saito J, et al. Tract-Specific Diffusion Tensor Imaging Reveals Laterality of Neurological Symptoms in Patients with Cervical Compression Myelopathy. World Neurosurg. 2016;96:184–90. doi: 10.1016/j.wneu.2016.08.129 27609442

27. Cloney MB, Smith ZA, Weber KA 2nd, Parrish TB. Quantitative Magnetization Transfer MRI Measurements of the Anterior Spinal cord Region are Associated with Clinical Outcomes in Cervical Spondylotic Myelopathy. Spine (Phila Pa 1976). 2017.

28. Hopkins BS, Weber KA 2nd, Cloney MB, Paliwal M, Parrish TB, Smith ZA. Tract-Specific Volume Loss on 3T MRI in Patients with Cervical Spondylotic Myelopathy. Spine (Phila Pa 1976). 2018.

29. Nagata K, Kiyonaga K, Ohashi T, Sagara M, Miyazaki S, Inoue A. Clinical value of magnetic resonance imaging for cervical myelopathy. Spine (Phila Pa 1976). 1990;15(11):1088–96.

30. Acharya S, Srivastava A, Virmani S, Tandon R. Resolution of physical signs and recovery in severe cervical spondylotic myelopathy after cervical laminoplasty. Spine (Phila Pa 1976). 2010;35(21):E1083–7.

Článek vyšel v časopise


2019 Číslo 10