Introduction

The importance of Low Back Pain (LBP) is due to its high lifetime prevalence (80%) in the community and its effect on the individual in terms of pain and disability. Thirteen per cent of population suffers with persistent back pain of high intensity, with either moderate or severe disability [1].

Intervertebral disc is the largest avascular tissue in the body [2], and consists of inner nucleus pulposus, outer annulus fibrosus and cartilage located superiorly and inferiorly. Intervertebral disc resists compression because of the osmotic properties of the proteoglycans. The ability of the disc to resist anterior and lateral shears along with compression and flexion makes the intervertebral disc the most important load bearing component of the spine, beside the facets [3].

Signs of degeneration includes one or all of the following: diminished disc height, narrowing of facet, osteophytes and sclerosis of upper and lower endplates, stenosis of spinal canal, narrowing of lateral recess, real or apparent desiccation, fibrosis, diffuse bulging of the annulus beyond the disc space, extensive fissuring (i.e., numerous annular tears), mucinous degeneration of the annulus, defects and sclerosis of the endplates, and osteophytes at the vertebral apophyses [4].

The most common symptom associated with lumbar disc degeneration is low back pain due to the presence of neural tissue around the intervertebral disc. The main symptom of disc degeneration after low back pain is sciatica. Features suggestive of sciatica are unilateral or bilateral leg pain radiating to the feet and toes, numbness in dermatomes distribution and positive straight leg raising test.

Neurogenic claudication (NC) is described as the classic clinical presentation of lumbar spinal stenosis (LSS), a degenerative condition of the lumbar spine normally affecting adults over the age of fifty [5], [6]. Symptoms of NC are described as pain, paraesthesia or cramping of one or both legs, brought on when walking and relieved in sitting [7]. The effect of posture on symptoms is the primary distinguishing feature of NC- symptoms are typically exacerbated when the spine is extended (in upright stance when standing or walking) and eased when the spine is flexed (stooping forwards or sitting). Clinical symptoms are believed to result from stenotic changes (narrowing) exacerbated by posture-related compression causing neural and microvascular compromise of the cauda equina and lumbosacral nerve roots [8],[9].

Exclusion criteria: Patients not giving consent for the study, with history of previous spine surgery, having spinal structural abnormalities, uncontrolled medical illness or psychiatric disorders precluding assessment were excluded from the study.

All the patients were explained about the procedure. Informed written consent was taken from all patients. Examination of spine and neurological examination was done at admission and subsequent follow-ups. X-ray of lumbosacral (LS) spine and magnetic resonance imaging (MRI) of LS spine, complete hemogram and biochemistry was performed.

Intervention: The patient was made to lie in prone position. A 20-gauge needle was passed through the sacral hiatus and needle placement was confirmed by “whoosh” test [15]. The epidural space was injected with 80 mg (2 ml) of Triamcinolone,1 ml Hyaluronidase and 2 ml of 2% Plain Lignocaine diluted in 15 ml normal saline. Following the injection, the patient remained on bed rest for a day in the hospital with regular monitoring of pulse and blood pressure.

Patients were evaluated at baseline, three weeks, three months and six months using Objective Parameters of Straight Leg Raise test (SLRT) and Claudication distance and subjective parameters of pain using Numeric Pain Rating Scale (NPRS) and Disability using Oswestry Disability Index (ODI).

Straight Leg Raising test: The SLR test causes gliding of lumbar nerve roots which get compressed by the herniated disc proximal to neural foramina leading to radiation of pain down the leg in nerve root distribution [16]. SLR less than 30 degree was considered positive.

Neurological Claudication distance: While walking on level ground, the distance at which symptoms of claudication became unbearable and necessitated sitting or taking rest.

Numeric Pain Rating Scale: It is an eleven-point numerical pain rating scale in which patients rate their pain ranging from zero (no pain) to ten (worst imaginable pain). A two point change on the NRS in patients with LBP represents a clinically meaningful change[17].

Oswestry Disability Index : The Oswestry Disability Index is the recommended condition specific outcome measure for spinal disorders. It has ten sections namely pain intensity, personal care, lifting, walking, sitting, standing, sleep, social life, travelling and employment. Total scores can range from zero (highest level of function) to 50 (lowest level of function).

Table 3: The four parameters evaluated at baseline and follow up.

Discussion

The effects of caudal epidural steroid injections were first reported by Goebert and colleagues [19]. They administered three injections of procaine and hydrocortisone into epidural space to 239 patients with sciatica and reported greater than 60% relief of symptoms in 58% of patients. Since that time, technique and indications of epidural steroid injections have been changing constantly. Various studies have observed effects of caudal epidural steroid injections on a single prolapsed intervertebral disc, but studies on multiple disc bulges are infrequent. The search term ‘caudal epidural steroid in multiple disc bulges’ yielded no relevant results on PubMed.

Chronic low backache with MRI findings of multiple disc bulges is a frequent finding in spine clinics across world. We postulated that a caudally injected steroid would spread throughout epidural space and relieve inflammation at multiple levels, leading to a clinically significant result.

We observed significant reduction in pain by Numeric Pain Rating scale after CESI at third week follow-up and no significant change in subsequent follow-ups; however, improvement in pain score persisted till 6 months. Wilson–MacDonald et al also observed significant early reduction in pain in their study but found no long-term effect [20]. Similar results were obtained by Buchner et al with greatest relief in pain in initial two weeks and no significant improvement at six weeks and six months follow-up [21].

A statistically significant improvement in Straight Leg Raise was observed in our study which persisted till 6 months. The mean SLRT of 40.8degrees at baseline increased to a mean of 62.9 degrees at 6 months follow up. Buchner et al observed significant improvement in SLR at two weeks and six weeks follow-up but no significant change at six months follow-up [21].