The Effect of Central Sensitization on Interlaminar Epidural Steroid Injection Treatment Outcomes in Patients with Cervical Disc Herniation: An Observational Study

BACKGROUND

Central sensitization (CS) is a hyperexcitability that is manifested by the increased response of the central nervous system to sensory stimuli. It has been shown that the presence of CS may have a negative effect on the clinical picture in some musculoskeletal diseases and also have a negative effect on spinal procedures.

OBJECTIVES

To investigate the effect of CS on interlaminar epidural steroid injection (ILESI) treatment outcomes in patients with cervical disc herniation (CDH).

STUDY DESIGN

An observational study.

SETTING

A university hospital pain management center.

METHODS

Patients, who underwent ILESI between 2020-2021 due to CDH, were included in the study. The Numeric Rating Scale (NRS-11), Neck Pain and Disability Scale (NPDS), Self-Administered Leeds Assessment of Neuropathic Symptoms and Signs (S-LANSS), and Short Form-12 (SF-12) were used for evaluation of patients. Patients were assessed before the procedure, at the first hour, and 3 months after the procedure. The presence of CS was investigated by the Central Sensitization Inventory (CSI).

RESULTS

A total of 51 patients were included in the study. Twenty-three of the patients had CS, as assessed by the CSI. Although, patients who underwent ESI, had significantly lower NRS-11, S-LANSS, and NPDS scores, and higher SF-12 scores at all follow-up points. The first and third months, NRS-11, S-LANSS, and NPDS were significantly higher, and SF-12 scores were lower in the CS group compared to patients without CS.

LIMITATIONS

The short follow-up period and relatively low number of patients can be considered as a limitation. The fact that CS is not evaluated with a more objective method, such as Quantitative Sensory Testing (QST), can be considered as another limitation. Since most clinicians use CSI, so from a "real world" perspective the lack of QST may be observed as a strength of the study. The third limitation is that we did not evaluate the patients' pre- and posttreatment analgesic consumption. Finally, we did not include patients with a history of psychiatric illness, but not evaluating the current psychiatric conditions of the patients could be considered a limitation. Nevertheless, the main strengths of this study are its prospective design and, to our knowledge, it is the first study to explore the effects of CS on cervical ESI treatment.

CONCLUSIONS

The presence of CS has a negative effect on pain scores, disability, and quality of life in patients undergoing cervical ESI due to CDH.

Does the presence of neuropathic pain affect the outcomes of the interlaminar epidural steroid injection for cervical disc herniation?: A prospective clinical study

Epidural steroid injections (ESI) are commonly performed for the treatment of chronic cervical disc herniation (CDH). Although they are considered to be effective for both nociceptive and neuropathic types of pain, there is a lack of data regarding the impact of neuropathic pain (NP) and nociceptive pain components on treatment outcomes. The aim of this study is to compare the effectiveness of interlaminar epidural steroid injection (ILESI) between patients with predominantly NP and nociceptive pain due to CDH.Sixty five participants were initially included in the study and assessed by numeric rating scale (NRS), neck pain and disability scale (NPDS), short form-12 (SF-12), and self-reported Leeds assessment of neuropathic symptoms and signs (S-LANSS) pain scale at baseline and 1 month, 3 months, 6 months after ILESI.All patients were evaluated at 1st month and 3rd month follow-up periods while 54 of patients achieved to complete 6th month follow-up. There were significant improvements in all outcome measures for all time periods when compared with the pre-intervention scores. At baseline 24 (36.9%) of patients had predominantly NP in accordance with S-LANSS pain scale. The ratio of NP predominant patients reduced to 7.6% at 1st month, 12.3% at 3rd month, and 12.9% at 6th month with a significant difference for each follow-up period when compared with the baseline. Although all NRS and NPDS scores at baseline were significantly higher in patients with NP, improvement was significant at all follow-up periods in both groups. Minimal clinically important change in NRS was observed in >75% of patients at 1st, 3rd, and 6th month in both groups.The results of this study showed that NP is present in one-third of the patients suffering from neck and radiating arm pain due to CDH and cervical ILESI is an effective treatment approach for both neuropathic and nociceptive components of pain.Clinical Trials Registration Number: NCT04235478.

Are Foraminal Stenosis Severity and Herniation Level Associated with the Treatment Success of Cervical Interlaminar Epidural Steroid Injection?

BACKGROUND

Foraminal stenosis, defined as a narrowing of the cervical neural foramen, is one of the most common causes of upper extremity radicular pain.

OBJECTIVES

The aim of our study was to determine the effects of the severity of neural foraminal stenosis and spinal herniation level on treatment success in patients treated with interlaminar epidural steroid injections (ILESI) due to cervical disc herniation-related radiculopathy and their possible predictive roles.

STUDY DESIGN

A retrospective assessment.

SETTING

A university hospital interventional pain management center.

METHODS

We performed our study between August 2017 and February 2019, retrospectively. All patients' demographic characteristics, clinical and demographic data, including pain scores before and after cervical ILESI in the first hour, third week, and third month follow-ups, presence of motor deficits, symptom side, symptom duration before cervical ILESI, and whether there was progression to surgery in the 3-month period after injection, were collected.

RESULTS

We evaluated 61 patients in the final analysis. When the spinal herniation levels and foraminal stenosis grades were compared, there was a significant difference between the groups (P = 0.003, P = 0.005). We reported significant correlations between foraminal stenosis grade (odds ratio [OR], -0.425, P = 0.038) and spinal herniation level (OR, -0.925, P = 0.001) and treatment success.

LIMITATIONS

Our study's design was retrospective.

CONCLUSIONS

Cervical ILESI is a reliable treatment option that provides a significant reduction in pain of patients with cervical radiculopathy. However, the success of ILESI treatment may be negatively affected in these patients in the presence of high spinal level cervical disc herniation and severe foraminal stenosis. Therefore considering these 2 parameters in predicting the patient population who will benefit from cervical ILESI is of importance in terms of decreasing potential complications.

KEY WORDS

Interlaminar epidural steroid injections, foraminal stenosis, spinal level, cervical disc herniation, radicular pain.