Magnetic resonance imaging of intramedullary spinal cord lesions: A pictorial review

Spinal Ependymomas: An Updated WHO Classification and a Narrative Review

Ependymomas are neuroepithelial tumors that develop from ependymal cells found in the brain parenchyma and can spread to any part of the spinal cord. Three to six percent of all malignancies affecting the central nervous system (CNS) are ependymomas. Even the most talented surgeons are challenged by spinal cord ependymomas; as a result, research into this clinical phenomenon should continue. Since 1979, the World Health Organization (WHO) has published a classification and grading system for CNS malignancies to ensure consistent diagnostic standards worldwide. The WHO prepared an update on these tumors, paying particular attention to molecular techniques to categorize the therapeutic management of each patient with greater accuracy and clarity. We thoroughly reviewed the literature on the epidemiology, etiology, diagnosis, and treatment of spinal ependymomas since there has not been a recent review of these tumors. This included modifications to the 2021 WHO Classification of Tumors of the Central Nervous System.

Intramedullary Schwannoma of the Spinal Cord: A Nationwide Analysis by the Neurospinal Society of Japan

OBJECTIVE

This study was aimed to report the clinical characteristics of intramedullary schwannomas and discuss imaging findings and treatment strategies.

METHODS

The inclusion criterion was consecutive patients with intramedullary schwannomas who were surgically treated at 8 centers between 2009 and 2020. Clinical characteristics included age, sex, clinical presentation, disease duration, and follow-up period. The modified McCormick scale was used to compare the preoperative and postoperative conditions. Pre- and postoperative magnetic resonance images (MRI) of each case were analyzed.

RESULTS

The mean age of the total 11 patients at the operation was 50.2 years. The mean duration of the symptoms was 23 months, with limb paresthesia being the most common clinical presentation. The cervical spine was the most common localization level of the tumor in 6 cases. The mean follow-up duration was 49.4 months. Gross total resection (GTR) and subtotal resection (STR) was achieved in 9 and 2 cases, respectively. According to the modified McCormick scale at 6 months postoperatively, 7 cases (63.6%) had improved and 4 cases (36.3%) had unchanged grades. Typical MRI findings of the intramedullary schwannoma included ring-like enhancement, syringomyelia, cystic formation, intramedullary edema, and hemosiderin deposition. Gadolinium enhancement was homogenous in 8 cases (72.7%). The tumor margins were well demarcated in all cases.

CONCLUSION

Intramedullary schwannoma should be considered when sharp margins and well-enhanced tumors are present at the cervical spine level and the initial symptoms are relatively mild, such as dysesthesia. When GTR cannot be achieved, STR for tumor decompression is recommended.

Diagnostic value of 18F-FDG PET/CT and MRI for intraspinal lesions: A comparative study

The aim of the present study was to investigate the value of the use of fluorine-18 (¹⁸F)-fluorodeoxyglucose (FDG) positron emission tomography (PET)/computed tomography (CT) vs. magnetic resonance imaging (MRI) for the diagnosis of and differentiation between benign and malignant lesions in the spinal canal. For this purpose, a retrospective analysis was performed on the use of MRI and ¹⁸F-FDG PET/CT from January, 2017 to December, 2020, and the final diagnosis was obtained by performing a post-operative pathological examination or following a tissue biopsy (gold standard). The sensitivity, specificity, accuracy, positive predictive value and negative predictive value of the two examination techniques were calculated and comparisons between them were made. The PET metabolic parameters, maximum standardized uptake value (SUVmax), peak standardized uptake value (SUVpeak), mean standardized uptake value (SUVmean), metabolic tumor volume (MTV) and total lesion glycolysis (TLG) in the benign and malignant groups were calculated and compared, and the corresponding ROC curves were plotted. A total of 58 patients were enrolled, including 30 patients with malignant and 28 with benign lesions. The specificity of MRI was significantly higher than that of PET/CT (P<0.05). The sensitivity and negative predictive value of PET/CT were higher than those of MRI, although with no significant difference (P>0.05). The mean ± tandard deviation values of the PET metabolic parameters, SUVmax, SUVpeak, SUVmean, MTV and TLG, were 4.27±1.25, 3.49±1.07, 2.49±0.84, 6.58±5.36 and 17.12±15.50 in the benign, and 8.99±3.75, 7.35±3.26, 5.43±2.40, 12.25±12.18 and 112.41±85.98 in the malignant groups, respectively. The SUVmax, SUVpeak, SUVmean and TLG in the malignant group were higher than those in the benign group. The differences were all statistically significant (all P<0.0001). In distinguishing benign from malignant lesions, the area under the ROC curve (AUC) for SUVmax was 0.919, which was the largest, and the Youden index was 0.762, indicating 83.3% sensitivity and 92.9% specificity. The AUC for SUVpeak was 0.905 and that for SUVmean was 0.899. The aforementioned AUCs were significantly higher than those for MTV and TLG (0.609 and 0.786, respectively) (P<0.001). On the whole, the present study demonstrates that MRI is a reliable imaging technique for the diagnosis of intravertebral lesions. ¹⁸F-FDG PET/CT, as a noteworthy supplement to MRI, has a high sensitivity and accuracy for the qualitative diagnosis and identification of lesions. The synergistic effect of the two examination techniques may be helpful for a more accurate diagnosis.

ACR Appropriateness Criteria® Myelopathy: 2021 Update

Myelopathy is a clinical diagnosis with localization of the neurological findings to the spinal cord, rather than the brain or the peripheral nervous system, and then to a particular segment of the spinal cord. Myelopathy can be the result of primary intrinsic disorders of the spinal cord or from secondary conditions, which result in extrinsic compression of the spinal cord. While the causes of myelopathy may be multiple, the acuity of presentation and symptom onset frame a practical approach to the differential diagnosis. Imaging plays a crucial role in the evaluation of myelopathy with MRI the preferred modality. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision include an extensive analysis of current medical literature from peer reviewed journals and the application of well-established methodologies (RAND/UCLA Appropriateness Method and Grading of Recommendations Assessment, Development, and Evaluation or GRADE) to rate the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where evidence is lacking or equivocal, expert opinion may supplement the available evidence to recommend imaging or treatment.

Multiple Cervical Vertebral Malformations in a 21-Week-Old Kitten

A 21 wk old, 2 kg neutered male domestic shorthair presented with a 24 hr history of acute-onset severe nonambulatory tetraparesis with no known inciting cause. Neurologic examination revealed a C1-C5 myelopathy. Computed tomography of the vertebral column and thorax revealed incomplete ossification of the C2 and C3 vertebrae and lung bullae. After 4 wk of conservative management, the client reported a return to normal ambulation with reluctance to jump up. To the authors' knowledge, this is the first report of a feline case of incomplete ossification of cervical vertebrae. The cervical malformations outlined in this report are differentials to consider in cases of acute-onset tetraparesis in cats.

Exophytic Primary Intramedullary Spinal Cord Glioblastoma: Case Report and Critical Review of Literature

BACKGROUND

Primary intramedullary spinal cord (IMSC) glioblastoma (GBM) is an extremely rare entity; we report the first case of primary IMSC GBM presenting with exophytic involvement. The prognosis of glioblastoma remains poor due to the aggressive nature of the disease and lack of effective treatment.

CASE DESCRIPTION

A 27-year-old Asian female presented to our hospital with a 1-month history of dysuria, incomplete bladder emptying, progressive numbness, and weakness of both lower limbs, as well as a 1-year history of back pain. Spinal magnetic resonance imaging (MRI) revealed an intramedullary lesion and exophytic growth in the T4-T12 and T5-12 regions, respectively. The patient's MRI findings were atypical of spinal glioblastoma. The diagnosis was made on the basis of immunohistochemical and pathologic analyses of tissue samples obtained from an open biopsy. The patient received a standard course of glioblastoma radiotherapy and adjuvant temozolomide chemotherapy, which improved her symptoms in the absence of an apparent reduction in tumor size.

CONCLUSIONS

Although MRI is of indisputable importance in the diagnosis of spinal cord lesions, immunohistochemical and histopathologic studies are often required to establish a definitive diagnosis. It remains unclear how the unusual involvement of exophytic growth will affect the prognosis of primary IMSC GBM.

Intramedullary cervical abscess mimicking a spinal cord tumor in a 10-year-old girl: a case-based review

BACKGROUND

Intramedullary spinal cord abscesses (ISCA) are a rare pathological entity with very few cases reported in the world and may be confused with an intramedullary tumor. Cervical location is the least frequently affected, except for cryptogenic spread, mostly seen in adult patients. Meticulous study of contrast-enhanced MRI pictures has a key role in the diagnosis.

METHOD AND RESULTS

We present a case of a spontaneous cervical ISCA, mimicking a spinal cord tumor, in a pediatric patient with good outcome. A review of the literature shows that this is a life-threatening condition with high chances of rupture and subsequent meningitis.

CONCLUSIONS

We point out that if a solitary cervical spinal cord lesion is surrounded by significant medullar edema associated with fast onset of symptoms, fever, and elevation of WBC, the possibility of a spinal cord abscess should be considered prior to surgery.

[Pain in patients with paraplegia]

Chronic pain is one of the most reported health problems in patients suffering from spinal cord injuries and is described by the patients as one of the most burdensome sequelae of paraplegia. Various types of pain, such as nociceptive, neuropathic and other types of pain can occur. In addition, multiple pathophysiological mechanisms based on the biopsychosocial pain model play a role in the origins of the pain. These aspects necessitate a multimodal pain management approach in this patient group. This article presents an overview of the occurrence, importance and pathophysiology of chronic pain following spinal cord injury as well as diagnostic and therapeutic approaches.

Usefulness of laser-evoked potentials and quantitative sensory testing in the diagnosis of neuropathic spinal cord injury pain: a multiple case study

STUDY DESIGN

A retrospective study.

OBJECTIVES

The aim of this study was to investigate the contribution of laser-evoked potentials (LEPs) and quantitative sensory testing (QST) to the diagnosis of neuropathic pain in patients with spinal cord injury (SCI) and inconclusive magnetic resonance imaging (MRI) findings.

SETTING

A multidisciplinary pain center.

METHODS

QST (DFNS protocol) and Tm-YAG-laser stimulation of the skin were applied within the pain site corresponding with dermatomes of altered sensation. Available MRI scans were reviewed.

RESULTS

Thirteen individuals (50±16 years) with SCI were examined. In four cases with no detectable neural lesion on MRI, all QST but three LEP were abnormal. In four patients with poorly defined spinal lesion on MRI, all QST but three LEP only were abnormal. In four cases where pain was not matching adequately with MRI lesions, all patients had abnormal LEP and QST. In one patient showing a spinal cord atrophy, LEP was normal but QST was abnormal. Findings supported the diagnoses at-level (n=5) and below-level (n=8) SCI pain. Spinothalamic tract function assessed by LEP was normal in three cases, but QST was abnormal in all cases.

CONCLUSIONS

As QST is a psychophysical examination depending on patient cooperation, we suggest that the combination of QST and LEP might be a valuable diagnostic tool to detect lesions of the somatosensory system in a subgroup of patients with neuropathic spinal cord injury pain and inconclusive MRI findings.