Cervical Disc Surgery : A Pathway to Better Sleep and Enhanced Quality of Life - A Pre-Post Study Perspective
Article information
Abstract
Objective
Cervical disc herniation (CDH) is one of the most common pathologies that cause pain and functional loss in cervical spine disorders. The primary reasons for cervical disc patients’ presentations are brachialgia, radiculopathy, and myelopathy. Pain leads to a decrease in sleep quality, and the reduction in sleep quality, in turn, negatively affects pain, resulting in a decline in quality of life. In the literature, there are limited studies evaluating pain, sleep quality, quality of life, and daily living activities in patients undergoing CDH surgery. Moreover, these studies do not adequately assess all these criteria together. Our study represents the most homogeneous (disconly) and comprehensive study in the current literature. We believe it will provide clear insights into the effects of CDH surgery and serve as a guide for preoperative patient selection and management.
Methods
This research is a prospective study. Between July 2024 and December 2024, a total of 43 patients underwent surgery for CDH. The patients included in the study were evaluated preoperatively and on the 45th postoperative day using Visual analog scale (VAS), Pittsburgh sleep quality index (PSQI), European quality of life 5 dimensions 3 level version (EQ-5D-3L), Neck disability index (NDI), and Copenhagen neck functional disability scale (CNFDS) scales.
Results
Of the 43 patients included in the study, 28 (65.1%) were female, with a mean age of 43.16±9.82 years. Regarding the levels affected, 25 patients (58.1%) had involvement at the C5-6 level, while 18 patients (41.9%) were at the C6-7 level. Significant improvements were observed in all parameters during the preoperative and postoperative evaluation of VAS, PSQI, EQ-5D-3L, NDI, and CNFDS scales (p<0.001 for each).
Conclusion
In cervical disc patients with ineffective conservative treatment, radicular pain, muscle weakness, and extruded discs, as well as high preoperative scale scores, immediate surgical intervention will result in a reduction in pain and improvements in sleep, quality of life, and daily living activities.
INTRODUCTION
Cervical disc herniation (CDH) is one of the most common pathologies that cause pain and functional loss in cervical spine disorders [17]. Cervical intervertebral disc disease accounts for 36% of all disc disorders and is more common in women [4]. The gradual degeneration of the disc and weakening of the posterior annulus fibrosus lead to disc prolapse, which causes compression of the nerve root [8]. The most common reasons for cervical disc patients’ presentations are brachialgia, radiculopathy, and myelopathy. Sleep disorders rank second after brachialgia, with an incidence of 64% [18].
Pain can lead to a decrease in sleep quality, and the reduction in sleep quality, in turn, negatively affects pain, creating a vicious cycle [22]. Sleep problems lead to a decline in quality of life and can jeopardize an individual’s safety [7]. Sleep plays a vital role in maintaining health and sustaining life effectively. It has also been proposed that sleep disorders may cause neurobiological changes, leading to a reduced pain threshold [15]. The first-line treatment for CDH is conservative management. Although conservative treatments are often effective, surgical interventions are considered when these methods fail, particularly in cases involving motor weakness [8]. In the literature, there are limited studies evaluating pain, sleep quality, quality of life, and daily living activities in patients undergoing CDH surgery. Moreover, these studies do not adequately assess all these criteria together. Our study represents the most homogeneous (disconly) and comprehensive study in the current literature. We believe it will provide clear insights into the effects of CDH surgery and serve as a guide for preoperative patient selection and management.
MATERIALS AND METHODS
Ethical approval was received from Hitit Unıversity Ethics Commitee with the decision number 2024-42 dated 11/July/2024.
Study design
This study was designed as a prospective study involving three different centers. Between July 2024 and December 2024, a total of 43 patients underwent cervical disc surgery (anterior microsurgical discectomy with cage fusion) using the same surgical technique.
Our indications for cervical disc surgery are patients with radicular pain, muscle weakness, arm pain that does not go away with conservative treatment, and patients with an extruded unilateral disc.
The study included patients who met the following criteria : undergoing cervical disc surgery for the first time, aged over 18, experiencing radicular pain and muscle weakness, without trauma-induced disc herniation, unresponsive to conservative treatment, and having unilateral extruded fragments in the foraminal region on cervical magnetic resonance imaging (MRI).
Patients were excluded if they met any of the following criteria : previous cervical disc surgery, under the age of 18, spinal infections, radiological findings of spinal tumors, trauma-induced disc history, cervical MRI findings of bulging or protruded discs, cervical stenosis with associated myelopathy, sleep apnea, advanced heart failure, lung diseases or pathologies, psychiatric disorders, medication for psychiatric conditions, or night-shift workers.
Participants completed the survey twice in total : first, prior to surgery, and second, on the 45th day post-surgery during their follow-up visit to the neurosurgery clinic. The surveys were administered face-to-face by the researchers. The sample size for the study was calculated using the G.Power v3.1 program (Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany), based on the formula for comparing two dependent means, with an alpha error of 0.05, 80% power, and an effect size of 0.4, resulting in a minimum requirement of 42 participants. Only individuals who voluntarily agreed to participate and completed both surveys in full were included in the study.
Data collections
In this study, the following assessment tools were applied to 43 patients preoperatively and on the 45th postoperative day : Visual analog scale (VAS), Pittsburgh sleep quality index (PSQI), European quality of life 5 dimensions 3 level version (EQ-5D-3L), Neck disability index (NDI), and Copenhagen neck functional disability scale (CNFDS).
Our study aimed for early results to capture short-term functional and symptomatic improvement. For this purpose, the routine short-term common control time used in the three clinics where our study was conducted, the 45th day, was selected. Routine long-term follow-up of the patients continued after this process.
In the first section, participants’ age, sex, and diagnosis information were recorded. In the second section, pain levels were determined using the VAS. Participants rated their neck and arm pain intensity on a scale from 0 (no pain) to 10 (worst pain imaginable) [19]. In the third section, sleep quality was assessed using the PSQI. The PSQI is a scale consisting of 24 questions and seven components. Of the 24 questions, 19 are self-reported by the participant and used in the evaluation. The other five questions are answered by a relative and are not included in the evaluation. The 19 questions used in the evaluation are distributed among the seven components. Each component is scored between 0 and 3. The total score is obtained by summing the component scores and ranges between 0 and 21. Higher total scores indicate worsening sleep quality. Although the PSQI does not indicate whether a sleep disorder is present, a total score of 5 or higher indicates poor sleep quality. The PSQI was developed by Buysse et al. [5] in 1989, and its Turkish validity and reliability were established by Ağargün et al. [1] in 1996. In the fourth section, the EQ-5D-3L general quality of life scale was used to assess quality of life. The scale consists of five dimensions : mobility, self-care, usual activities, pain/discomfort, and anxiety/depression. Each dimension is answered as 1 (no problems), 2 (some problems), or 3 (extreme problems). The total score ranges from -0.59 to 1, where 1 represents perfect health, 0 represents death, and scores below 0 represent conditions such as unconsciousness or being bedridden. The scale was developed by the EuroQol Group [9] in 1987 and has been translated into more than 60 languages, including Turkish. In this study, the scoring system described in the study by Golicki et al. [10] was used. In the fifth section, the NDI, which assesses the impact of neck pain on daily living activities, was used. This scale consists of 10 sections : pain intensity, personal care, lifting, reading, headaches, concentration, work, driving, sleeping, and leisure activities. Each section consists of six responses scored from 0 to 5, and patients choose the most suitable option for them. Higher scores indicate greater disability. The total score is calculated by summing the section scores to determine patients’ disabilities. The Turkish validity and reliability of the scale were established by Telci et al. [20] in 2009. In the sixth section, the CNFDS, developed by Jordan et al. [13] in 1998, was used. This scale consists of 15 items. Scores are assigned as “Yes,” “No,” or “Sometimes,” ranging from 0 to 2 points. The maximum score is 30 points [13]. The Turkish validity and reliability of the scale were established by Yapali et al. [23].
Statistical analysis
All Statistical analyses were performed using IBM-SPSS Statistics software, version 25.0 (IBM Corp., Armonk, NY, USA). Descriptive statistics for the participants were presented as frequency, percentage, mean, and standard deviation. Given that the data did not exhibit a normal distribution, the Wilcoxon signed-rank test was employed to assess pre-and postoperative sleep quality, pain scores, daily living activities, and quality of life. The Mann Whitney U test was used to compare the differences in sleep quality, pain score, quality of life and changes in daily living activities between groups according to age, gender and diagnosis. The continuous variable of age was categorized into two groups : 45 years and older and under 45 years. For subgroup analysis, differences between genders (female/male) and changes in quality of life, sleep quality, daily living activities, and pain scores across surgical levels were examined. Statistical significance was determined at a p-value threshold of less than 0.05.
RESULTS
A total of 43 patients included in the study, 28 (65.1%) were female, and the mean age of the group was 43.16±9.82 years. In terms of lesion levels, 25 (58.1%) were at C5-6, and 18 (41.9%) were at C6-7.
The distribution of lesion levels and gender characteristics of the participants are presented in Table 1.
Distribution of lesion levels and gender characteristics of the participants
The EQ-5D-3L, NDI, PSQI, CNFDS, and VAS scores used in the study showed improvements in all parameters when evaluated preoperatively and postoperatively (p<0.001 for each). The preoperative and postoperative evaluation of the EQ-5D-3L, NDI, PSQI, CNFDS, and VAS scores of the participants are presented in Table 2.
Preoperative and postoperative evaluation of EQ-5D-3L, NDI, PSQI, CNFDS, and VAS scores of participants
The evaluation of preoperative and postoperative improvements in EQ-5D-3L, NDI, PSQI, CNFDS, and VAS scores by gender is presented in Table 3. Improvements in EQ-5D-3L scores were significantly higher in the male population (p=0.026), while other parameters showed similar improvements between males and females.
Preoperative and postoperative improvements in EQ-5D-3L, NDI, PSQI, CNFDS, and VAS scores by gender level
The evaluation of preoperative and postoperative improvements in scores for patients with lesions at the C5-6 and C6-7 levels is presented in Table 4. Improvements in all parameters were similar between patients with C5-6 and C6-7 lesions (p>0.05 for each).
Preoperative and postoperative improvements in EQ-5D-3L, NDI, PSQI, CNFDS, and VAS scores by lesion level
The evaluation of preoperative and postoperative improvements in scores for patients younger than 45 and those aged 45 and older is presented in Table 5. NDI score improvements were significantly greater in the population aged 45 and older (p=0.022), while other parameters showed similar improvements between the two age groups.
Preoperative and postoperative improvements in EQ-5D-3L, NDI, PSQI, CNFDS, and VAS scores by age group
DISCUSSION
CDH is most commonly observed in women, with its incidence increasing in the 45–50 age group. It is most frequently found at the C6-C7 level (45–60%), followed by the C5-C6 level (20–25%) [14]. In our study, consistent with the literature, the mean age was 43.16 years, with the condition being most common in women and most frequently observed at the C5-C6 level. Dharmajaya et al. [8] and Samancioglu et al. [18] reported higher age incidences, whereas Parker et al. [16] and Samancioglu et al. [18] found a higher prevalence in men.
Ogden et al. [15], 32 patients were included, with the surgical level not specified (single-level or two-level surgeries), the patients presented with neck and/or arm pain, with midline or foraminal disc herniation as the localization. Dharmajaya et al. [8], 90 patients were included, with the number of surgical levels not specified. Among them, 39 patients had radicular pain, 48 had extruded discs, while the remaining 42 patients presented with 39 protruded discs and three cases of stenosis. Parker et al. [16], 31 patients single-level surgery, 27 two-level surgery and three three-level surgery, although the specific surgical levels were not specified. Among the 61 patients, all had radicular pain; 37 had extruded discs, while of the remaining 24, 23 had stenosis and one had spondylolisthesis [16]. Samancioglu et al. [18], 50 patients were included, with the surgical levels not specified, characteristics of neck and/or arm pain were not detailed and the anatomical orientation of the disc was not evaluated. In our study, single-level surgery was performed on 43 patients, with the most frequently operated level being C5-C6 (25 patients). All patients experienced radicular arm pain and surgery was performed exclusively for extruded foraminal discs. Cervical radiculopathy is a clinical condition caused by the involvement of cervical nerve roots. In patients under the age of 55, the cause is often a herniated disc, while in patients over 55, it is typically foraminal stenosis due to spondyloticchanges [21]. Based on this information, we specifically selected patients with extruded foraminal discs to achieve more accurate results. Since the pathology of stenosis differs from that of disc herniation, we excluded cases of stenosis and aimed to ensure homogeneity in the evaluation measurements. By focusing solely on CDH to evaluate the impact of pre- and postoperative survey results on surgical planning and postoperative outcomes, we believe that more transparent results were obtained.
Our study observed statistically significant improvements in EQ-5D-3L, NDI, PSQI, CNFDS, and VAS scores. These results demonstrate that CDH surgery improves quality of life, sleep quality, reduces pain, and enhances daily living activities.
Henderson et al. [11] found neck and arm pain in 99.4% of 846 patients with cervical radiculopathy. In our study, the VAS scores improved from 8.63 to 1.79 postoperatively, consistent with similar studies that also reported reduced pain after surgery [8,15,16,18]. In CDH cases where conservative treatment is ineffective, surgery provides highly successful outcomes in terms of pain reduction.
One of the most significant indicators of radiculopathy in CDHs is arm pain, which is more prominent than neck pain [2]. Neck pain can arise from various anatomical structures, including tendons, ligaments, paraspinal muscles, intervertebral discs, cervical nerve roots, and facet joints. Since neck pain may result from multifactorial causes such as myofascial pain or degenerative disc disease, it may not be directly affected by surgical intervention [12]. Therefore, the primary aim of our study is to evaluate the effect of CDH surgery on radicular pain. The VAS used to assess pain severity was specifically designed to focus on radicular symptoms directly related to surgery, using a VAS score that evaluates arm pain, rather than including a VAS score for neck pain.
Quality sleep helps maintain our mental health, physical well-being, and quality of life, and is essential for our safety [3]. Accordingly, in our study, consistent with the literature, a postoperative decrease in PSQI scores [15,16,18] and a postoperative increase in EQ-5D-3L scores [16] were observed following CDH surgery.
The lack of regular and quality sleep negatively impacts individuals’ work life, academic performance, daily activities, and overall quality of life [6]. In our study, consistent with Parker and colleagues’ findings [16], improvements were observed in NDI scale results, which evaluate daily living activities, paralleling the decrease in pain and the increase in sleep and quality of life. In addition to the NDI, which we used to evaluate changes in daily living activities before and after surgery, the CNFDS scale was also utilized, and positive improvements were observed in this measure as well. In postoperative improvement for patients over 45 years old, only the NDI scale results were found to be significant (Table 5). As a result, we believe that the NDI, with its questions and scores, serves as a better guide than the CNFDS for preoperative and postoperative evaluation of patients Ogden et al. [15] used the Oswestry disability ındex (ODI) for daily activities. We believe that the NDI, with its more targeted questions for neck pain [20], provides a more accurate and effective tool for assessing the daily living activities of patients with cervical disc disorders compared to the ODI.
Following CDH surgery, improvements in quality of life were observed to be greater in men compared to women. However, no gender-based differences were found in terms of pain relief, sleep quality, or daily living activity improvements. In our study, the greater improvement in quality of life among male individuals compared to females may be explained by sociocultural and work-related differences. Men often engage in more physically demanding or intensive jobs and face greater physical strain in daily activities, which may make the decline in their quality of life more pronounced compared to women. Therefore, the reduction in pain and functional improvement following CDH surgery can be expected to result in a more noticeable increase in perceived quality of life among men.
When examining the surgical levels in terms of improvement following CDH surgery, no significant differences were found. Whether the level was C5-C6 or C6-C7, improvement was achieved regardless of the surgical level, and no significant differences were observed. The successful outcomes of CDH surgery, regardless of lesion level, demonstrate that this treatment method is reliable and effective in patients with appropriate indications. In addition to this study, we believe that including the C4-C5 level and reevaluating this parameter could serve as an additional guide in preoperative planning.
Limitation
Since patients who met the surgical indication criteria were included in the study, a control group could not be included because it was not possible to follow these patients with conservative treatment. Potential confounding variables such as comorbidities and psychosocial factors were not controlled for in this study. Therefore, it cannot be clearly determined whether the observed associations are independently driven or influenced by these confounders. The lack of multivariate analysis represents a limitation of the study. In our study, early results were targeted to achieve short-term functional and symptomatic improvement. Future studies with long-term follow-up and evaluation with statistical subgroup determinations that can be obtained with a larger number of patients may also contribute to the literature.
CONCLUSION
In cervical disc patients with ineffective conservative treatment, radicular pain, muscle weakness, and extruded discs, as well as high preoperative scale scores, immediate surgical intervention will result in a reduction in pain and improvements in sleep, quality of life, and daily living activities. Timely surgical intervention is essential for relieving pain, improving sleep quality, and, above all, safeguarding individuals’ health while enhancing their overall quality of life.
Notes
Conflicts of interest
No potential conflict of interest relevant to this article was reported.
Informed consent
Informed consent was obtained from all individual participants included in this study.
Author contributions
Conceptualization : BT, AY; Data curation : EÜ; Formal analysis : EÜ; Funding acquisition : BT; Methodology : EÇ, ÖFŞ; Project administration : BT, OU; Visualization : MİY; Writing - original draft : BT, OU; Writing - review & editing : BT, OU, EÜ
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