Felix E. Diehn

The Noninferiority of the Nonparticulate Steroid Dexamethasone vs the Particulate Steroids Betamethasone and Triamcinolone in Lumbar Transforaminal Epidural Steroid Injections

OBJECTIVE To assess whether a nonparticulate steroid (dexamethasone, 10 mg) is less clinically effective than the particulate steroids (triamcinolone, 80 mg; betamethasone, 12 mg) in lumbar transforaminal epidural steroid injections (TFESIs) in subjects with radicular pain with or without radiculopathy. DESIGN Retrospective observational study with noninferiority analysis of dexamethasone relative to particulate steroids. SETTING Single academic radiology pain management practice. SUBJECTS Three thousand six hundred forty-five lumbar TFESIs at the L4-5, L5-S1, or S1 neural foramina, performed on 2,634 subjects. METHODS/OUTCOME MEASURES Subjects were assessed with a pain numerical rating scale (NRS, 0-10) and Roland-Morris disability questionnaire (R-M) prior to TFESI, and at 2 weeks and 2 months follow-up. For categorical outcomes, successful pain relief was defined as either ≥50% reduction in NRS or pain 0/10; functional success was defined as ≥40% reduction in R-M score. Noninferiority analysis was performed with δ = -10% as the limit of noninferiority. Continuous outcomes (mean NRS, R-M scores) were analyzed for noninferiority with difference bounds of 0.3 for NRS scores and 1.0 for R-M scores. RESULTS With categorical outcomes, dexamethasone was demonstrated to be noninferior to the particulate steroids in pain relief and functional improvement at 2 months. Using continuous outcomes, dexamethasone was demonstrated to be superior to the particulate steroids in both pain relief and functional improvement at 2 months. CONCLUSION This retrospective observational study reveals no evidence that dexamethasone is less effective than particulate steroids in lumbar TFESIs performed for radicular pain with or without radiculopathy.

Imaging of Spine Infection

This article reviews the imaging and relevant clinical details of infection of the extradural spine. Spine infections are increasing in incidence and in frequency of diagnosis. They are clinically important despite their relative rarity, because they may be life-threatening, and because early diagnosis leads to improved outcomes. The focus is on pyogenic spondylodiscitis. The also typically pyogenic conditions of epidural and subdural abscess, facet joint infection, and pyomyositis are discussed. Nonpyogenic, granulomatous infections are also addressed. Magnetic resonance imaging is emphasized. The radiologists role in performing minimally invasive sampling procedures is highlighted.

Brainstem cavernous malformations: anatomical, clinical, and surgical considerations

Symptomatic brainstem cavernous malformations carry a high risk of permanent neurological deficit related to recurrent hemorrhage, which justifies aggressive management. Detailed knowledge of the microscopic and surface anatomy is important for understanding the clinical presentation, predicting possible surgical complications, and formulating an adequate surgical plan. In this article the authors review and illustrate the surgical and microscopic anatomy of the brainstem, provide anatomoclinical correlations, and illustrate a few clinical cases of cavernous malformations in the most common brainstem areas.

The role of MR myelography with intrathecal gadolinium in localization of spinal CSF leaks in patients with spontaneous intracranial hypotension.

BACKGROUND AND PURPOSE: Localization of spinal CSF leaks in CSF hypovolemia is critical in directing focal therapy. In this retrospective review, our aim was to determine whether GdM was helpful in confirming and localizing spinal CSF leaks in patients in whom no leak was identified on a prior CTM. MATERIALS AND METHODS: Forty-one symptomatic patients with clinical suspicion of SIH were referred for GdM after undergoing at least 1 CTM between February 2002 and August 2010. A retrospective review of the imaging and electronic medical records was performed on each patient. RESULTS: In 17 of the 41 patients (41%), GdM was performed for follow-up of a previously documented leak at CTM. In the remaining 24 patients (59%), in whom GdM was performed for a suspected CSF leak, which was not identified on CTM, GdM localized the CSF leak in 5 of 24 patients (21%). In 1 of these 5 patients, GdM detected the site of leak despite negative findings on brain MR imaging, spine MR imaging, and CTM of the entire spine. Sixteen of 17 patients with previously identified leaks underwent interval treatment, and leaks were again identified in 12 of 17 (71%). CONCLUSIONS: GdM is a useful technique in the highly select group of patients who have debilitating symptoms of SIH, a high clinical index of suspicion of spinal CSF leak, and no demonstrated leak on conventional CTM. Intrathecal injection of gadolinium contrast remains an off-label use and should be reserved for those patients who fail conventional CTM.

MRI Findings of Disc Degeneration are More Prevalent in Adults with Low Back Pain than in Asymptomatic Controls: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE: Imaging features of spine degeneration are common in symptomatic and asymptomatic individuals. We compared the prevalence of MR imaging features of lumbar spine degeneration in adults 50 years of age and younger with and without self-reported low back pain. MATERIALS AND METHODS: We performed a meta-analysis of studies reporting the prevalence of degenerative lumbar spine MR imaging findings in asymptomatic and symptomatic adults 50 years of age or younger. Symptomatic individuals had axial low back pain with or without radicular symptoms. Two reviewers evaluated each article for the following outcomes: disc bulge, disc degeneration, disc extrusion, disc protrusion, annular fissures, Modic 1 changes, any Modic changes, central canal stenosis, spondylolisthesis, and spondylolysis. The meta-analysis was performed by using a random-effects model. RESULTS: An initial search yielded 280 unique studies. Fourteen (5.0%) met the inclusion criteria (3097 individuals; 1193, 38.6%, asymptomatic; 1904, 61.4%, symptomatic). Imaging findings with a higher prevalence in symptomatic individuals 50 years of age or younger included disc bulge (OR, 7.54; 95% CI, 1.28–44.56; P = .03), spondylolysis (OR, 5.06; 95% CI, 1.65–15.53; P < .01), disc extrusion (OR, 4.38; 95% CI, 1.98–9.68; P < .01), Modic 1 changes (OR, 4.01; 95% CI, 1.10–14.55; P = .04), disc protrusion (OR, 2.65; 95% CI, 1.52–4.62; P < .01), and disc degeneration (OR, 2.24; 95% CI, 1.21–4.15, P = .01). Imaging findings not associated with low back pain included any Modic change (OR, 1.62; 95% CI, 0.48–5.41, P = .43), central canal stenosis (OR, 20.58; 95% CI, 0.05–798.77; P = .32), high-intensity zone (OR = 2.10; 95% CI, 0.73–6.02; P = .17), annular fissures (OR = 1.79; 95% CI, 0.97–3.31; P = .06), and spondylolisthesis (OR = 1.59; 95% CI, 0.78–3.24; P = .20). CONCLUSIONS: Meta-analysis demonstrates that MR imaging evidence of disc bulge, degeneration, extrusion, protrusion, Modic 1 changes, and spondylolysis are more prevalent in adults 50 years of age or younger with back pain compared with asymptomatic individuals.

When Should I Do Dynamic CT Myelography? Predicting Fast Spinal CSF Leaks in Patients with Spontaneous Intracranial Hypotension

Which patients with intracranial hypotension will need dynamic CT myelography? The authors assessed brain and spine MRI studies and opening pressure measurements in 150 consecutive patients with intracranial hypotension to see if these can predict fast CSF spine leaks that will require dynamic myelography. Fast leaks were present in 21% and correlated well with the presence of spinal extra-arachnoid fluid. No correlation between fast leaks and brain MRI findings was found. Thus, when spinal extra-arachnoid fluid is documented on MRI studies there is no need for conventional CT myelography but the patient should be directly studied with dynamic CT myelography. BACKGROUND AND PURPOSE: Some patients with SIH have fast CSF leaks requiring dynamic CTM for localization; however, patients generally undergo conventional CTM before a dynamic study. Our aim was to determine whether findings on head MR imaging, spine MR imaging, or opening pressure measurements can predict fast spinal CSF leaks. MATERIALS AND METHODS: A retrospective review was performed on 151 consecutive patients referred for CTM to evaluate for spinal CSF leak. Head MR imaging was evaluated for diffuse dural enhancement and “brain sag,” and spine MR imaging for presence of an extradural fluid collection. The opening pressure was recorded. The CTM was scored as no leak, slow leak localized on conventional CTM, or fast leak that required dynamic CTM. RESULTS: Fast CSF leaks were identified in 32 (21%), slow leaks in 36 (24%), and no leak in 83 (55%) of 151 patients on initial CTM. There was significant association between spinal extra-arachnoid fluid on MR imaging and the presence of a fast leak (sensitivity 85%, specificity 79%, P < .0001). There was not significant association between fast leak and findings on head MR imaging (P = .27) or opening pressure (P = .30). CONCLUSIONS: If all patients with spinal extra-arachnoid CSF on MR imaging had been sent directly to dynamic CTM, repeat myelography would have been avoided in most patients with fast leaks (23 of 27; 85%). However, a minority of patients with slow or no leaks would have been converted from conventional to dynamic CTM (16 of 77; 21%). Spinal MR imaging is helpful in premyelographic evaluation of SIH.

Remote Thermometry to Avoid Complications in Radiofrequency Ablation

Percutaneous image-guided radiofrequency ablation (RFA) of tumors has the potential risk for thermal damage to nearby normal collateral tissues. Thus, the goal of creating a sufficient area of tumor necrosis must be weighed against the risk for injury to collateral tissues. In this study, remote thermistors were used to monitor temperatures near collateral structures during tumor RFA. Four unique cases are described. When temperature-sensitive structures are near the target lesion, remote thermometry could further increase the safety of this evolving minimally invasive procedure.

Clinical effectiveness of single lumbar transforaminal epidural steroid injections

OBJECTIVES To assess the clinical effectiveness of single lumbar transforaminal epidural steroid injections (TFESIs) in subjects with radicular pain with or without radiculopathy. DESIGN Retrospective observational series. SETTING Single academic radiology pain management practice. SUBJECTS Two thousand twenty-four subjects undergoing single lumbar TFESIs at the L4-5, L5-S1, or S1 neural foramina. METHODS / OUTCOME MEASURES Subjects were assessed with a pain numerical rating scale (NRS, 0-10) and Roland-Morris disability questionnaire (R-M, 23-point Deyo modification) prior to TFESI and at 2 weeks and 2 months follow-up. Successful pain relief (responders) was defined as either ≥50% reduction in NRS or pain 0/10; functional success was defined as ≥40% reduction in R-M score. RESULTS There were statistically significant (P < 0.0001) reductions in mean NRS and R-M scores at 2 weeks and 2 months postinjection. For NRS, 40.9% were responders at 2 weeks and 45.6% at 2 months. For R-M, 31.9% were responders at 2 weeks and 41.3% at 2 months. The proportion of responders for NRS and R-M was higher when there was <3 months of pain (odds ratio 2-month NRS = 2.42 [95% confidence interval: 1.82, 3.24], odds ratio 2-month R-M = 2.61 [1.96, 3.48]). For subjects with <3 months of pain, the proportion of responders was 62.4% (56.5, 68.3%) for NRS and 59.3% (53.3, 65.3%) for R-M scores. CONCLUSIONS This retrospective observational study suggests TFESIs are clinically effective in the treatment of lumbar radicular pain. Subjects with a shorter duration of pain are more likely to achieve a successful outcome.

Intramedullary Spinal Cord Metastases: MRI and Relevant Clinical Features From a 13-Year Institutional Case Series

This article reviews the MRI and clinical findings in 70 spinal cord metastases; 20% of patients had multiple metastases and 8% were asymptomatic. Spinal cord metastases were the initial clinical presentation in 20% of patients. Nearly all metastases showed contrast enhancement and had extensive edema. Cysts and hemorrhage were, however, uncommon and nearly 60% of patients had other metastases to the CNS or that were seen in studies in other organs. Accompanying pial metastases were also common. BACKGROUND AND PURPOSE: Because intramedullary spinal cord metastasis is often a difficult diagnosis to make, our purpose was to perform a systematic review of the MR imaging and relevant baseline clinical features of intramedullary spinal cord metastases in a large series. MATERIALS AND METHODS: Consecutive patients with intramedullary spinal cord metastasis with available pretreatment digital MR imaging examinations were identified. The MR imaging examination(s) for each patient was reviewed by 2 neuroradiologists for various imaging characteristics. Relevant clinical data were obtained. RESULTS: Forty-nine patients had 70 intramedullary spinal cord metastases, with 10 (20%) having multiple intramedullary spinal cord metastases; 8% (4/49) were asymptomatic. Primary tumor diagnosis was preceded by intramedullary spinal cord metastasis presentation in 20% (10/49) and by intramedullary spinal cord metastasis diagnosis in 10% (5/49); 98% (63/64) of intramedullary spinal cord metastases enhanced. Cord edema was extensive: mean, 4.5 segments, 3.6-fold larger than enhancing lesion, and ≥3 segments in 54% (37/69). Intratumoral cystic change was seen in 3% (2/70) and hemorrhage in 1% (1/70); 59% (29/49) of reference MR imaging examinations displayed other CNS or spinal (non–spinal cord) metastases, and 59% (29/49) exhibited the primary tumor/non-CNS metastases, with 88% (43/49) displaying ≥1 finding and 31% (15/49) displaying both findings. Patients with solitary intramedullary spinal cord metastasis were less likely than those with multiple intramedullary spinal cord metastases to have other CNS or spinal (non–spinal cord) metastases on the reference MR imaging (20/39 [51%] versus 9/10 [90%], respectively; P = .0263). CONCLUSIONS: Lack of known primary malignancy or spinal cord symptoms should not discourage consideration of intramedullary spinal cord metastasis. Enhancement and extensive edema for lesion size (often ≥3 segments) are typical for intramedullary spinal cord metastasis. Presence of cystic change/hemorrhage makes intramedullary spinal cord metastasis unlikely. Evidence for other CNS or spinal (non–spinal cord) metastases and the primary tumor/non-CNS metastases are common. The prevalence of other CNS or spinal (non–spinal cord) metastases in those with multiple intramedullary spinal cord metastases is especially high.

Safety and Efficacy of CT-Guided Transforaminal Cervical Epidural Steroid Injections Using a Posterior Approach

BACKGROUND AND PURPOSE: Image-guided cervical transforaminal epidural injections play an important role in the management of cervical radicular pain syndromes. The safety and efficacy of these injections via an anterolateral approach has been well-studied. The goal of this retrospective review was to determine the safety and efficacy of CT-guided transforaminal epidural injections by using a posterior approach. MATERIALS AND METHODS: Retrospective review of patient records was used to define VNPS and RMDI of patients undergoing CT-guided transforaminal cervical epidural injections between 2006 and 2010. Pain scores were recorded preprocedure, immediately postprocedure, at 2 weeks, and at 2 months. The RMDI was recorded preprocedure, at 2 weeks, and at 2 months. Data analysis of 247 patients was completed. Differences in VNPS scores and the RMDI were then compared on the basis of a CT-guided approach (anterolateral versus posterior). RESULTS: There was no statistical difference in the degree of pain relief and improvement in the RMDI between the CT-guided transforaminal anterolateral approach and the posterior approach at 2 weeks and at 2 months. Both groups demonstrated a statistically significant improvement in pain scores and the RMDI. Approximately 35% of patients in both groups demonstrated >50% pain relief at 2 months. There were no serious complications in either group. CONCLUSIONS: CT-guided transforaminal cervical epidural injections by using a posterior approach are safe and effective.