Serial Thoracic Transforaminal Epidural Steroid Injections for Post-herpetic Neuralgia: A Case Report

Design

Case presentation

A 78-year-old woman with a history of hypertension and arthritis presented with severe post-herpetic neuralgia (PHN) after a shingles outbreak. Despite initial treatment with oral antivirals, gabapentin, and oxycodone/acetaminophen, her pain persisted. An MRI ruled out other thoracic spine issues. She underwent three thoracic transforaminal epidural steroid injections (TFESIs) with methylprednisolone 80 mg and 0.125% bupivacaine was equally divided and injected into each neuroforamen.

Each procedure was guided fluoroscopically and targeted spinal levels T10-T11, T11-T12, and T12-L1. The first TFESI provided temporary relief, allowing a reduction in analgesics, but pain returned. A second TFESI led to sustained pain relief and a reduction in muscle spasms, enabling medication adjustments to meloxicam and baclofen. Following the third TFESI, she experienced complete resolution of skin sensitivity and further reduction of pain. Gabapentin and amitriptyline were eventually tapered off. Eight months after symptom onset, her regular medications were limited to meloxicam and a lidocaine patch, with minimal residual pain reported.

Study Author Conclusions

Postherpetic neuralgia (PHN) is a prevalent and debilitating form of neuropathic pain that can significantly impact patients' quality of life. Physicians, particularly primary care physicians (PCPs), must recognize the critical nature of early diagnosis and timely referral of PHN patients to interventional specialists. This is imperative, as conventional therapies often fail to alleviate symptoms in up to 50% of patients. Transforaminal epidural steroid injections (TFESIs) offer a targeted approach that mitigates pain by influencing nerve function and reducing deafferentation. Clinical evidence supports the effectiveness of TFESIs, though multiple administrations may be necessary for optimal pain relief and resolution of PHN symptoms. The successful management of PHN with TFESIs underscores the need for their consideration in treatment regimens.

Transforaminal Epidural Steroid Injection for Zoster-Related Pain: The Golden Period for the Best Outcome

Multicenter, retrospective cohort study

N= 302

To identify the golden period by which transforaminal epidural steroid injection (TFESI) yields the best outcome in patients with zoster-related pain (ZRP)

Effective (n= 186)

Not effective (n= 116)

Patients with ZRP in a single dermatome in the thoracic and lumbar region; history of receiving antiviral medications; history of receiving TFESI for ZRP; 3-month follow-up data available

Affected region above the T1 dermatome; 3-month follow-up data unavailable

All TFESIs were performed under fluoroscopic guidance. The patients were positioned prone on a radiologic table, and vital signs such as blood pressure, pulse oximetry, and electrocardiogram are continuously monitored. After preparing the skin aseptically, the fluoroscopic beam is adjusted to an ipsilateral 20-25° oblique angle to ensure precise needle placement.

The entry point was marked just beneath and lateral to the pedicle, and a local anesthetic, 1% lidocaine, was administered to the skin. A Quincke-type, 22-gauge, 12-cm spinal needle is then carefully directed toward the target area using the tunnel vision technique under continuous fluoroscopic observation.

Once the needle tip reaches the desired location at the posterior margin of the vertebral body, 1-2 mL of iohexol (Omnipaque) contrast agent was injected to verify epidural spread and checked for any accidental intravascular or intrathecal distribution. Upon confirmation of correct needle positioning, an injection of 3 mL of 0.18% ropivacaine combined with 5 mg of dexamethasone was administered.

Patients were classified into effective and non-effective groups based on pain intensity changes 3 months after TFESI.

January 2014 to December 2017

Primary: Best cut-off time point for TFESI effectiveness

Secondary: Patient factors associated with successful TFESI

Not effective (n= 116)

p-value

Age, years

Female

Symptom duration, weeks

10.6 ± 17.0

29.3 ± 47.7

<0.001

29.3%

0.001

Number of TFESI injections

1

2

67.7%

32.3%

71.6%

28.4%

0.523

Not effective (n= 116)

Symptom duration ≤ 12 weeks

Symptom duration > 12 weeks

VAS score change from baseline

No specific adverse events reported in the study

Transforaminal epidural steroid injection is more effective when administered within 12 weeks of onset of herpes zoster.

The study's retrospective design limits the ability to establish causality. The lack of a control group for comparison with conservative treatment limits the ability to attribute improvements solely to TFESI. The short follow-up period of 3 months may not capture long-term outcomes.

Parameters associated with efficacy of epidural steroid injections in the management of postherpetic neuralgia: the Mayo Clinic experience

Retrospective, multicenter, observational, cohort study

N= 42

To determine if there are variables that predict the efficacy of epidural steroid injections (ESI) in patients with postherpetic neuralgia (PHN)

All patients (n= 42)

Patients with PHN managed by ESI seen at Mayo Clinic from January 1, 1997, through April 1, 2018

Not specified

This was a retrospective review of patients with PHN who received ESI. Data was taken from three Mayo Clinic centers in 3 states.

January 1, 1997, through April 1, 2018

All patients (n= 42)

Median age at the time of first ESI, years (range)

19 (45.2%)

5 (11.9%)

12 (28.6%)

8 (19.0%)

Concurrent medication

Gabapentin

Opioid

24 (57.1%)

13 (31.0%)

Duration of postherpetic neuralgia, median months (range)

Variable

Age at first intervention, ≤60 years

Age at first intervention, >60 years

Sex - Male

Sex - Female

Diabetes mellitus - No

Diabetes mellitus - Yes

Gabapentin - No

Gabapentin - Yes

Opioid - No

Opioid - Yes

ESI medication - Steroid only

ESI medication - Steroid + local anesthetic

Not specified

For patients with PHN treated with ESI, no demographic characteristics, concurrent medications, or type of ESI were associated with treatment efficacy at 2 or 12 weeks post-intervention. PHN duration <11 months was predictive of moderate-to-good pain relief at 12 weeks.

Treatment of Postherpetic Neuralgia Using a Thoracic Transforaminal Epidural Steroid Injection

Design

Case presentation

A 64-year-old male patient with no significant medical history experienced a shingles outbreak 1.5 years earlier, presenting as blister stripes on his left torso. He was treated with a 2-week course of oral steroids that mitigated the outbreak. Upon presenting to the Spine Pain Center, he reported severe and constant burning pain in the left T10 dermatome along with intermittent electrical shock-like sensations, predominantly exacerbated by overhead lifting and playing basketball. The pain was severe enough to impair daily functioning.

Initial examination revealed skin discoloration, trophic changes, hyperalgesia, and allodynia in the affected dermatome. Previous treatments, including opioids, pregabalin, gabapentin, duloxetine, amitriptyline, lidocaine, and capsaicin cream, were unsuccessful in providing relief. Consequently, intercostal nerve blocks were performed at the left T8 through T10 levels using 3 mL of 0.25% bupivacaine and 3.3 mg of triamcinolone at each level, resulting in temporary relief. However, the symptoms recurred after two weeks.

Due to the persistent refractory pain, a left T10 thoracic transforaminal epidural steroid injection was carried out under fluoroscopic guidance. Following accurate needle placement and confirmation through contrast medium outlining the spinal nerve, 20 mg of dexamethasone was administered. The patient reported complete pain relief at a 2-week follow-up, with the absence of burning and electric-like sensations, enabling him to resume activities like basketball. At a 12-week follow-up, the patient sustained significant improvement, reporting only mild pain (1 out of 10) with no functional limitations.

Study Author Conclusions

Medical management of postherpetic neuralgia (PHN) often fails to provide adequate relief for many patients, prompting exploration of interventional procedures. Techniques such as the interlaminar epidural approach, stellate ganglion blocks, and intrathecal medication administration have been utilized to manage symptoms. While intrathecal steroid administration is notably effective, it carries the risk of inducing arachnoiditis, particularly when employed in the thoracic region, leading to its limited use.

Due to the constraints of these methods, some practitioners have begun utilizing a transforaminal approach to deliver epidural steroids directly to the affected dorsal root ganglion. This technique aims to interrupt the inflammatory cascade associated with PHN, minimizing tissue damage and pain by concentrating medication precisely at the site of pathology. Two case reports have documented its use: one involved a 66-year-old woman with severe refractory PHN in the C5 dermatome, who experienced significant pain relief shortly after injection and maintained pain-free status for up to three months. Another involved a 75-year-old man with PHN and right foot drop, who reported substantial pain reduction and improved motor strength following two injections.