Mri And Emg Findings In Patients With Cervicobrachialgia

Background The aim of this study is to describe the alterations in complementary tests (MRI and EMG) in patients with cervicobrachialgia according to sex and age. Methods Retrospective study of 184 patients with cervicobrachialgia who underwent an MRI and/or EMG. The variables analyzed were gender, age, elements of spondylosis (osteophytes, arthropathy, spondylolisthesis and canal stenosis), the type of disc disease (protrusion and herniated disc) and curvature in the sagittal plane. The EMG was used to evaluate the neurogenic findings in the muscles dependent on the spinal roots of C4 to C8-T1. Results Average age 53.65±11.96 years. The patients were evaluated for the presence of osteophytes (n = 111), arthropathy (n = 76), spondylolisthesis (n = 15) and stenosis of the spinal canal (n = 35). The highest incidences were osteophytes in C5-C6 (n=108), protrusions in C5-C6 (n=58), herniated disc in C5-C6 (n=18) and neurogenic findings in C7 (n=130). The rectification of cervical lordosis appeared in 130 patients. Conclusions Spondylosis increases with age. Disc herniations, disc protrusions and motor radiculopathy were more frequent in the 5th to 6th years of life. In patients with cervicobrachialgia, the sagittal rectification is more common than the normal lordosis.

4 degeneration of the intervertebral discs (loss of water and elasticity) and of the joint facets, which is going to be associated with a bone reaction with the formation of osteophytes and arthritic deformation and in the architecture of the vertebral bodies, hypertrophy of the longitudinal ligaments and the yellow ligament [11]. Among its consequences is the intervertebral foraminal stenosis, which can cause compression of the nerve root and root symptoms with cervicobrachialgia [12].
In addition, the presence of elements of spondylosis and discopathy can affect the vertebral alignment [13], while the misalignment, by incorrect postures, can make an unequal distribution of loads and promote disc degeneration.
There are no universally accepted criteria for diagnosing RAD [14,15], which relies on the patient's medical history, physical examination, and other additional tests such as MRI or electrodiagnosis (EDX). The first test of choice for suspected RAD is MRI [16,17,18], given that it enables the imaging of soft tissue. Since the 1940s, with the report of Hoefer and Guttman in 1944 [18], EDX has been shown to be useful for diagnosing motor radiculopathies, helping to determine the anatomical level, severity and chronicity [6].
The medical histories and diagnostic tests, MRI and electromyography (EMG) of 184 patients with cervicobrachialgia were reviewed in order to analyse the physiopathology underlying the symptoms.
The objectives of this study were two: First, use MRI to describe the appearance of discopathy (DIS), spondylosis elements and sagittal curvature in patients with cervicobrachialgia, and their relationship with gender and age. And second, use the EDX to determine the level and, presumably, the anatomical location of the root motor neurological injury and its relationship to gender and age.

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This is a retrospective study of 184 patients with cervicobrachialgia who, on the clinical suspicion of cervical radiculopathy, underwent cervical MRI and EMG during the period August 2016 to August 2018. The medical histories and the above mentioned diagnostic tests were reviewed. The study was approved by the Hospital Ethics Committee.
Inclusion criteria: patients aged 18 years or over with cervicobrachialgia and clinically suspected cervical RAD attending the University Hospital Lucus Augusti (Lugo, Northwestern Spain), who had initially undergone examination by a consultant from the departments of thraumatology, rehabilitation, neurosurgery, and/or neurology, and later electromyographer. Patients who had undergone MRI in high-field superconducting magnet (1.5 T) Siemens Symphony, Ge Signa HDxt and Signa Excite with Quantum gradients.
Patients who had undergone EMG with concentric needle electrodes using a DANTEC KEYPOINT® system one month after the onset of symptoms. The time lapse between both tests did not exceed the three months.  The following variables were analyzed: gender and age (which was categorized into three groups).
The MRI evaluated the presence or absence of elements of spondylosis (osteophytes, arthropathy, listhesis, and canal stenosis), the osteophytes were describen in every cervical levels from C3-C4 to C7-T1; the number of spaces with disc pathology, and the type of disc pathology (protrusion or herniated disc); and curvature on the sagittal plane (rectification or cervical lordosis).
The analysis and classification of disc pathology was in accordance with the recommendations regarding nomenclature of the North American Spine, American Society of Spine Radiology, and the American Society of Neuroradiology (2001) [20]. Protrusion (PROT) was defined as a subtype of hernia characterized by a maximum diameter of the displaced disc fragment smaller than the disc measured on the same plane. Protrusion could be either focal, when it affects at least 25% of disc circumference (or less than 90º), or broad based, when it affects 25-50% of the disc circumference. Herniated disc (HD) was defined as localized disc displacement beyond the limits of disc space [21], and four degrees had been established: protrusion, extrusion, migration and sequestered. In this study, the variable hernia referred to extrusion, migration, and sequestration of disc fragments (Fig.1). Nerve conduction studies (ENG) and concentric needle EMG were performed on upper limbs (Table I). ENG were used to explore at least one motor nerve and one sensory nerve, in order to exclude compressive mononeuropathies and/or polyneuropathy. EMG was used to evaluate the presence of signs of acute denervation (fibrillations and positive waves), and potential motor unit denervation (MUAPs), chronic neurogens (with an amplitude equal to or greater than 5 mV, and longer than 16 ms in duration). The presence of reinervating polyphasic MUAPs was not evaluated. The following muscles were evaluated as a guide of each cervical root (a minimum of 6 muscles)[24]:

Characteristics of the sample:
Diagnostic tests (MRI and EMG) of 184 patients were analyzed: 125 women (67.9%), and 59 men (32.1%); mean age was 53.65 years, standard deviation (SD) 11.96 years, with a minimum age of 25 years and a maximum age of 84 years. Three age cohorts were

Discopathy: protrusion (PROT) and herniated disc (HD).
The distribution in the number of DIS (the sum of PROT and HD) per spine according to gender and AG was as follows (Table II): The distribution of the disc protrusions according to gender is shown in Table III. The level with the highest percentage of PROT was C5-C6, with 31.7% (n = 58), followed by C6-C7 (n = 41), with 22.4%. The level with the lowest percentage was C7-T1 with 3.8% (n = 7).
Only disc protrusion at level C3-C4, which is more prevalent in males, has had statistical significance (p = 0.014).
The distribution of the disc protrusions according to the age group didn´t presented statistical significance in any of the anatomical levels, from C3-C4 to C7-C8. In any case, disc protrusions were always more prevalent in AG2, for all the intervertebral levels studied, as shown in Table III. The distribution of herniated disc according to gender is shown in Table IV. The level with the highest percentage of HD was C5-C6, with 9.8% followed by C6-C7, with 8.7%. The level with the lowest percentage of HD was C7-T1, with 1.1%. Only the herniated disc at level C3-C4, which was more prevalent in males, had statistical significance (p = 0.014).
The distribution of herniated discs according to the age group did not presented statistical significance in any of the anatomical levels, from C3-C4 to C7-C8. In any case, the disc protrusions were always slightly more prevalent in the AG2, for all the intervertebral levels studied, in a similar way to what happened with the disc protrusions, as shown in Table IV.

Elements of spondylosis:
MRI was used to evaluate the presence of osteophytes (DC), which were positive in 60.3% of patients (n=111); arthropathy, which was positive in 41.3% of patients (n= 76); spondylolisthesis, which was positive in 8.2% (n=15), and spinal canal stenosis, which was positive in 19.0% of patients (n=35) (Fig.2). The number of intervertebral cervical leves with osteophytes per spine was 1.26±1.27 (mean±SD) ( Table V). The distribution of the number of osteophytes per spine in the sample according to AG and gender was as follows:

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The highest means were for AG3 in both men and women. The presence or not of osteophytes in the intervertebral spaces was evaluated and it was greater in the intervertebral space C5-C6, accounting for 58.5% (n=108), followed by the intervertebral space C6-C7, with a 51.1%, (n=94). The space with the fewest osteophytes was C7-T1 accounting for 15.2% (n=28).
The frequency of appearance of the spondylosis elements according to gender has not been statistically significant for any of the variables studied, as is shown in Table VI.
The frequency of appearance of the spondylosis elements, according to the age group, is shown in Table VI. Osteophytes (p=0.000), arthropathy (p=0.000) and spinal canal stenosis (p=0.000) have shown a statistically significant correlation with aging, being the most prevalent variables in the AG 3.

Curvatures on the sagittal plane:
The presence of rectification of the physiological cervical lordosis was assessed by means of MRI in supine decubitus, which was positive in 67.4% of the patients (n=124), while 32.6% of the columns presented the cervical lordotic curvature preserved (n=60
As for the elements of spondylosis, a relationship was observed between root C8 and osteophytes in C7-T1 intervertebral level (p=0.010); arthropathy was related to the appearance of RAD C5 (p=0.029), C6 (p=0.046), and C8 (p=0.004); no correlation was found between spondylolisthesis, but a correlation was observed with spinal canal stenosis, in root C5 (p=0.016) and C8 (p=0.030). A statistically significant correlation was found between osteophytes in C5-C6 and in C4-C5 (

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There have been no differences between genders in terms of discopathies, spondylosis elements or radiculopathies. On the other hand, there have been differences in terms of age. Discopathy and radiculopathy have been more prevalent in AG2, while spondylosis elements, mainly osteophytes, have been more prevalent in AG3.
In our sample we found a greater amount of osteophytes in the C5-C6 space (58.7%), in the same way as in previous reviews by Harrison  The DIS, PROT and HD, apart from the degenerative findings of the disc, with loss of height, density and elasticity, has not presented a statistically significant association with gender or with age. However, for both entities, a greater frequency has been seen in AG2, which is related to the natural history of these injuries. It is known, that both the symptoms and the material herniated to the spinal canal, in most patients, decrease after a few months [29]. For the lumbar region, Adams et al. (2015), argue that some discs degenerate and others do not, because they are subjected to an excessive mechanical load [30]. This principle could be applied to the cervical spine, and more specifically, to the intervertebral disc C5-C6, which is the place where the lordotic curve is inverted, and is subject to greater mechanical stress.
Whereas the incidence of these lesions peaks at the age of 50, spondylosis is most prevalent from the age of 60 onwards [31]. According with the early study of Hadley (1957) [32], the uncovertebral joints of the cervical spine sustain axial loads, and reduce stress on the interverterbal disc; thus, the frequency of PROT or HD is lower than in the lumbar region. The present study has several limitations in this way. First, the study was based on the findings of cervical MRI in the supine position. Second, complete x-rays of the spine were not performed vertically; therefore, the thoracic and lumbar regions were not evaluated.
Third, the results were categorized in terms of the presence or absence of cervical rectification, labelling the spines with kyphosis in the spinal rectification group, as Chiba et al. (2006) in the prospective study about laminoplasty for cervical myelopathy [37].  2005), it is plausible to believe that one of the causes for the loss of curvature is to maintain postures against pain [39], as occurs in patients suffering from temporomandibular joint disorders (Benlidayi et al., 2018) [40].
In our series of 184 patients the root with the most neurogenic findings was C7 which coincides with the work of Radhakrishnan et al. (1994) [4]. However, in our series, the second most frequent RAD engine was the root C8-T1, and the third was the root C6, while in the study by Radhakrishnan et al. (1994), the third was our second root with the highest frequency. Noteworthy is the large number of chronic neurogenics findings found in the muscles dependent on C8-T1, compared to the small proportion of DIS and osteophytes at the C7-T1 level, without foraminal stenosis. This finding was previously reported in the retrospective study by Hehir et al. (2012) of patients with C8 RAD [41], and was attributed to a probable lesion in the C7 root in a prefixed brachial plexus, previously described by Lee et al. (1992)[42] and Uysal et al. (2003) [43]. It has been conjectured, that spinal compression can lead to vascular lesions with degeneration of the anterior horn that simulates a C8 RAD [44].
As for the elements of spondylosis, there was a statistically significant correlation between the root C8 and C7-T1 osteophytes (p = 0.010); the arthropathy was correlated with the appearance of C5 RAD (p = 0.029), C6 (p = 0.046) and C8 (p = 0.004); and a correlation was observed with spinal canal stenosis at the root C5 (p = 0.016) and C8 (p = 0.030), but no correlation was found with spondylolisthesis.
The main limitation for interpreting RAD diagnostic tests is the absence of a gold standard [46]. Nardin et al. (1999) and Soltani et al. (2014) [47,48], in patients with suspected cervical RAD, compared the MRI and EMG findings, in 27 and 31 patients, respectively. He was given a sensitivity to MRI for the diagnosis of cervical RAD of 57% and 74%; while at the EMG of 55% and 54%. They concluded that both tests were complementary to the diagnosis of RAD. According to Soltani et al. (2014) [48], the specificity was 39% for MRI and 61% for EMG. This indicated that the diagnostic performance of the EMG was worse in patients with symptoms of more than one year from onset, clinically intermittent symptoms, and whether the main symptom was pain and not weakness. However, EMG was justified in cases of discrepant clinical-radiological findings.
Lee and Lee (2012) in a retrospective study compared the diagnostic performance of both tests in suspected lumbosacral RAD. The EDX was found to be more consistent with the clinical findings, particularly with muscular weakness that was significantly correlated, with higher specificity than MRI [49]. Arslan et al. (2016) concluded that both tests had a degree of concordance that was significant in severe lumbar and cervical RAD, but not in mild or a moderate cervical RAD [50]. Singh et al. (2018) concluded that the EDX was more correlated to clinical tests than to MRI, and provides a better representation of the functional condition of muscles and nerves [51].
The EMG has certain limitations with false negatives under the following circumstances: in the first 20 days of acute denervation, if the compromise is sensory fibers or if it is mild, since it is a dependent observer [52].
Acute denervation (positive waves and fibrillations) appears at 7-10 days in the paraspinal muscles and then in the muscles of the myotome at 2-3 weeks. The reinnervation MUAPs take 3-6 months. It may be the case to perform an exploration in which acute denervation has been resolved and reinervation is incomplete [52]. In addition, like Chemali and Tsao (2005) recorded, ultimately, it depends on the patient's collaboration [53].
The MRI may also depends on the time of the study since there may be regression in the size of the HD during a 5 to 12-month period, or it may even completely disappear as already described Komori et al. (1996), Bush et al. (1997), and Westmark et al. (1997) [54,55,56]. Moreover, MRI has revealed that most HD are central or paracentral, but only a few affect the intervertebral foramina [57,58]. On the other hand, structural anomalies are not inexorably the cause of symptomatology [59]. The fundamental shortcoming of MRI is the lack of specificity, given that the results often fail to validate the clinical findings[60] and elements of discopathy and spondylosis abound in asymptomatic patients [15].

Conclusions
In short, we can say that the spondylosis has shown an obvious relationship with age, increasing progressively since the 5th decade of life, but not with the gender. Its most 18 characteristic element is the present of osteophytes in C5-C6 level, with clear association with the C6 RAD and with the correction of the physiological lordosis.
Degenerative discopathies also tended to progressively increase with age. In contrast, the frequency of PROT and HD peaked between the ages of 50 to 60 yrs, before tapering off.
In our sample, only PROT and HD in C3-C4 have significance with gender, being more frequent in males.
The highest frequency of RAD was observed between the ages of 50 to 60 yrs, with C7 being the most affected root, and with significance with gender, being more frequent in males. Neither PROT nor HD were related to RAD in any of the levels examined.

FUNDING
Not funding was received.

AVAILABILITY OF DATA AND MATERIALS
No additional data are available.

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The study was approved by the Medical Ethics Committee of Santiago de Compostela -Lugo´s hospitals.

CONSENT FOR PUBLICATION
Not Applicable. 23 e s t a n d a r i z a d a d e l a p a t o l o g í a d i s c a l . R a d i o l o g í a 5 4 : 5 0 3 -5 1 2 .       Figure 1 Sagittal section of the cervical spine in T2 MRI. Rectification. Herniated disc C5-C6.
33 Figure 3 Sagittal ilustration of the cervical spine. EMG neurogenic findings in every nerve root. Discopathy and DC.