MRI in presumed cervical anterior spinal artery territory infarcts

Pediatric spinal cord infarct: a rare cause of a rare disorder, (wo)man in barrel syndrome

The "man in barrel syndrome" is a condition which resembles the aspect of patient being constrained in a barrel in which patient presents with bilateral upper limb weakness. It has classically been attributed to supratentorial lesions in watershed zones. We present such a case in a 12-year-old child who presented with bibrachial weakness and was noted to have cervical cord infarct on imaging. Spinal cord infarct is a rare cause of this syndrome, and until now only 20 cases have been described in which cervical cord infarct led to this presentation, all of them being adults. We describe first case report of bibrachial diplegia due to cord infarct in a child. Our case adds to the limited literature of cervical cord ischemia as a cause of "(wo) man in barrel syndrome" and re-iterates the fact that imaging of cervical cord should be considered while evaluating these cases.

Aggregation properties of triamcinolone acetonide injection in human serum: considerations when performing epidural steroid injections

Background

Morbidity has been reported as a sequelae of crystalline steroid epidural steroid injections (ESIs), and particulate steroid size, aggregation, and embolization in brain and spinal cord may be the mechanism related to these neurologic effects.

Objective

The objective of the study was to examine the aggregation properties of triamcinolone acetonide in commonly used local anesthetics with and without human serum.

Setting

This study was conducted in an academic tertiary care center.

Hypothesis

Triamcinolone acetonide shows different aggregation characteristics in serum compared to a non-physiologic solution.

Design

Triamcinolone acetonide was mixed with lidocaine 1% (first group) and bupivacaine 0.5% (second group) in a 1:1 ratio and then mixed with either distilled water (control group) or serum ex vivo. A pathologist blinded to our hypothesis inspected all solutions under light microscopy with 100× and 400× magnifications. Total number of particulate steroid aggregates and the number of particles forming each aggregate (recorded as single,1 double,2 triple,3 quadruple,4 or large [>4} crystals) were counted. Particle size and aggregate size were measured (in μm). The ratios of quadruple to total aggregates, large to total, and quadruple with large to total aggregates were calculated. Steroid-serum solutions and steroid-sterile water were then compared.

Results

Triamcinolone aggregates showed an increased crystal and aggregate size when compared with other steroids. Within the triamcinolone subgroup, the mixture of lidocaine 1% and serum resulted in the largest crystal aggregates.

Limitations

Whole blood analysis may have provided a more physiologically accurate model but was not chosen due to poor microscopic analysis. Serum donor variability may also have affected particle characteristics.

Conclusion

Fewer large triamcinolone aggregates were noted in the presence of serum when compared to the non-serum control groups. However, when compared to previously studied particulate steroids, it had the largest aggregates when added to serum.

Man-in-the-barrel. A case of cervical spinal cord infarction and review of the literature

Introduction:

Man-in-the-barrel syndrome was initially observed in patients with signs of serious cerebral hypoperfusion, in the border zone of the anterior and medial cerebral artery, but other causes were communicated later.

Methods:

a healthy 43-year-old woman who showed intense cervical pain, irradiating over both shoulders and arms. Physical examination on admission highlighted notable brachial diparesis, tacto-algesic hypoesthesia of both arms and sensory level C4-D9.

Results:

cervical Magnetic Resonance Imaging (MRI) on admission revealed a hyperintense intramedullar lesion at C3-C7 level, due to a cervical cord infarction.

Conclusions:

our case reveals that conventional neurological consideration about the specific anatomical location of man-in-the-barrel syndrome in the brain should be extended to other locations such as the cervical column and not only the brain area.

Penetration of a cervical radicular artery during a transforaminal epidural injection

BACKGROUND

Inadvertent cannulation or penetration of the cervical radicular arteries during cervical transformaminal epidural injections (TFESIs) is a serious clinical risk, and purportedly, the cause of possible spinal cord injury sustained during this procedure.

CASE

Here, we present a case of inadvertent intravascular penetration of a cervical radicular artery during a C5-6 TFESI and demonstrate the best image capture to date of direct ramification of a cervical radicular artery into the anterior spinal artery.

CONCLUSION

This observation reinforces the need for contrast injection and real-time digital subtraction fluoroscopy during cervical TFESIs for the prevention of spinal cord injury and fatalities.

Size and aggregation of corticosteroids used for epidural injections

OBJECTIVE

The purpose of this study was to document particulate size in commonly used corticosteroid preparations. Inadvertent injection of particulate corticosteroids into a vertebral or foraminal artery can cause brain and spinal cord embolic infarcts and the size of the particles could be directly related to the chance that a clinically significant infarct would occur. One might assume that corticosteroids with particles significantly smaller than red blood cells might be safer.

DESIGN

The following four types of corticosteroid preparations were used in various solutions and evaluated under light microscopy: dexamethasone sodium phosphate injection, triamcinolone acetonide injectable suspension, betamethasone sodium phosphate and betamethasone acetate injectable suspension, and methylprednisolone acetate injectable suspension.

RESULTS

Dexamethasone sodium phosphate particle size was approximately 10 times smaller than red blood cells and the particles did not appear to aggregate; even mixed with 1% lidocaine HCl solution and with contrast dye, the size of the particles were unchanged. Triamcinolone acetonide and betamethasone sodium phosphate showed variable sizes; some particles were larger than red blood cells, and aggregation of particles was evident. Methylprednisolone acetate showed uniformity in size and the majority were smaller than red blood cells which were not aggregated, but the particles were densely packed.

CONCLUSIONS

Compared with the particulate steroid solutions, dexamethasone sodium phosphate had particles that were significantly smaller than red blood cells, had the least tendency to aggregation, and had the lowest density. These characteristics should significantly reduce the risk of embolic infarcts or prevent them from occurring after intra-arterial injection. Until shown otherwise in clinical studies, interventionalists might consider using dexamethasone or another corticosteroid preparation with similar high solubility and negligible particle size when performing epidural injections.

Magnetic resonance imaging appearance of suspected ischemic myelopathy in dogs

Ischemia and infarction of the spinal cord is a known cause of acute spinal injury in dogs. Currently, the diagnosis of spinal cord infarction in small animals is based on history, clinical signs, and the exclusion of other differentials with radiography and myelography. It is a diagnosis only confirmed through necropsy examination of the spinal cord. The aim of this paper is to describe the Magnetic resonance imaging (MRI) findings of the spinal cord of dogs with suspected spinal cord infarcts to utilize this technology for antemortem support of this diagnosis. This retrospective study evaluated the spinal MR examinations of 11 dogs with acute onset of asymmetric nonpainful myelopathies. All patients except one (imaged at 2 months) were imaged within 1 week of clinical signs and managed conservatively with minimal medical and no surgical intervention. They were followed clinically for a minimum of 4 months after discharge. MR findings in all dogs were characterized by focal, intramedullary, hyperintense lesions on T2-weighted images with variable contrast enhancement similar to what is reported in humans. Though it could not be used to diagnose spinal cord infarction definitively, MRI was useful in excluding extramedullary spinal lesions and supporting intramedullary infarction as a cause of the acute neurologic signs. Together with the history and clinical examination findings, MRI is supportive of a diagnosis of spinal cord infarction.

Spinal cord infarction following cervical transforaminal epidural injection: a case report

STUDY DESIGN

Case report.

OBJECTIVE

A review of the literature about spinal cord infarction with epidural steroid injections and report of one case.

SUMMARY OF BACKGROUND DATA

A 53-year-old man with a history of chronic cervical pain and multilevel degenerative disc disease with multiple posterior disc protrusions on cervical imaging. The patient received a left C6 tranforaminal injection for therapeutic pain relief, with fluoroscopic confirmation of left C6 nerve root sheath spread of injectable contrast. Approximately 10 to 15 minutes post-procedure, he noted weakness in his left arm and bilateral lower limbs. Initial cervical magnetic resonance imaging revealed no cord signal change, but a follow-up study 24 hours later demonstrated patchy increased T2 and short tau inversion recovery signal in the cervical cord from the odontoid to C4-C5 vertebral levels. This was consistent with a diffuse vascular infarct to the cervical cord, resulting in motor-incomplete tetraplegia.

RESULTS

This is one of a few reported cases of spinal cord infarction after cervical epidural injections. No direct cord trauma occurred. Previously reported risk factors of spinal infarction, such as hypotension and large injectate volumes, were noncontributory in this case.

CONCLUSIONS

Cervical epidural injections, despite careful localization, carry a risk of vascular infarction to the spinal cord, even in the absence of direct cord trauma. The etiology of these infarctions and identifying those patients at risk remain uncertain.

Spinal cord edema: unusual magnetic resonance imaging findings in cervical spondylosis

OBJECT

Spinal cord edema is a rare radiological finding in chronic degenerative disorders of the spine. Between 1997 and 2001, the authors treated six patients with cervical spondylotic myelopathy in whom postoperative spinal cord edema was demonstrated. The authors describe the radiological and clinical features of this unusual condition.

METHODS

The six patients were all men, and ranged in age from 44 to 72 years. All patients presented with mild quadriparesis and underwent laminoplasty or anterior fusion. Preoperative magnetic resonance (MR) imaging revealed marked spinal cord compression with intramedullary hyperintensity on T2-weighted sequences and spinal cord enhancement at the compression level after administration of Gd. After surgery, spinal cord edema was observed in all patients; the spinal cord appeared swollen on the postoperative MR images. Preoperative and postoperative Gd-enhanced MR imaging demonstrated clear enhancement of the white matter at the compressed segment Neurologically, five of six patients experienced good improvement of symptoms; however, the spinal cord edema as documented on follow-up MR imaging persisted for several months after surgery.

CONCLUSIONS

The radiological characterization of spinal cord edema was based on the reversible white matter lesion most likely caused by disturbed local venous circulation induced by chronic spinal cord compression. Such unusual MR findings in cervical spondylotic myelopathy should be differentiated from intramedullary spinal cord tumors, demyelinating disorders, or inflammatory processes.

Man-in-the-barrel syndrome caused by cervical spinal cord infarction

Acute brachial diplegia with normal findings of the legs, "man-in-the barrel" (MIB) syndrome, is generally thought to be caused by bilateral supratentorial brain lesions of the prerolandic cortical and subcortical area. We report 1 patient with a sudden onset of MIB syndrome with no supratentorial lesion but a hemodynamically induced atypical anterior spinal cord infarction after unilateral vertebral artery dissection. Thus, in MIB syndrome an infratentorial lesion site, including the cervical spinal cord, should also be considered.