Introduction
A rare clinical finding, the incidence of spinal cord tumors is estimated at 0.74 per 100,000, with females slightly more affected than males. Spinal tumors can occur at any age, peak incidence is noted between 75 and 84 years, and these are usually accompanied by progressive neurological symptoms. Tumors are classified accordingly to anatomic location as extradural, intradural extramedullary, or intramedullary intradural, as well as intracranial, or specific to the involved spinal level. The majority of tumors are nonmalignant, with meningiomas, nerve sheath tumors, and ependymomas being the three most commonly occurring, respectively (Gembruch et al., 2021; Gerstner & Pajtler, 2018; Hubner et al., 2018; Schellinger et al., 2008; Walha & Fairbanks, 2021).
Ependymomas are intramedullary tumors that arise from ependymal cells. They can occur at any location along the neuroaxis. These tumors account for 3%-6% of all central nervous system tumors and approximately 60% of all intramedullary tumors. In the pediatric population, their occurrence is most commonly intracranial whereas in adults these tend to occur in the spine. The lumbosacral spine is the most commonly affected region. Ependymomas are graded as I, II, or III, with wide variance among outcomes confounding the prognostic relevance of Grade II versus Grade III. Recent literature has indicated distinct molecular markers, in conjunction with spinal level, to be more consistent predictors of prognosis (Gembruch et al., 2021; Gerstner & Pajtler, 2018; Hubner et al., 2018; Oh et al., 2013; Schellinger et al., 2008).
Case Presentation
A 47-year-old woman presented with a primary complaint of chronic low back pain. She described waxing and waning back pain stemming from a motor vehicle accident 10 years prior. On chart review, it was noted the patient had been in the urgent care seven times in the last 9 months with varied complaints of back and leg symptoms. Lumbar radiographs had been obtained 2 months prior showing degenerative disease and so she was referred to orthopaedics for evaluation.
With further probing, the patient noted episodic leg weakness and incoordination that caused multiple falls. She described a feeling of restlessness in her legs, as if little pinpricks or bugbites were occurring up and down them. There were times that she would have intense, shooting pains from her back into the calves. She had tried various over-the-counter medications, oral and topical, with limited relief. Lacking a primary care provider, she had never tried physical therapy or been prescribed any other medications. She noted having seen a chiropractor many years prior and did not recall any notable improvement with those treatments.
Upon presentation was an alert, affect-appropriate female, in no apparent distress. She was obese and shuffled her feet near constantly while seated. She postured with a right trunk lean and protracted shoulders. There was no obvious deformity, scars, or abrasions. Cervical range of motion was grossly symmetrical, with pain noted on extension. Lumbar range of motion was also grossly symmetrical, with pain noted in all planes, especially flexion. Strength was symmetric, 5/5 in bilateral lower extremities with a cogwheeling-type effect with testing of the right quadriceps. She noted abnormal sensation in the nondermatomal pattern of bilateral lower extremities. Distal pulses were palpable with brisk capillary refill. The examiner noted nine beats of clonus on the right and seven on the left. Heel-shin slide was incoordinated. The patient was also found to be hyperreflexive in the lower extremities compared with upper extremities. Hoffman's and inverted brachioradialis signs were normal.
Management
The prior lumbar radiographs (see Figure 1) were reviewed and discussed with the patient in relation to her ongoing low back pain and potential relation to some of her lower extremity symptoms. Initial management for this issue included a referral to physical therapy for core strengthening and lumbar stabilization exercises, pain relief, along with gait and balance training. Gabapentin therapy was also initiated, and the patient was instructed on adverse reactions and side effects. In discussing this, it was explained to the patient that lumbar degenerative findings alone would not explain the entirety of her symptoms.
Given the remaining constellation, with noted progression, of presenting symptoms, in correlation with abnormal neurological examination findings, it was also recommended to the patient to proceed with magnetic resonance imaging (MRI) of the spine. This was revealing for scattered thoracic spinal cord lesions, the predominant focus of which was located at T5-T6 (see Figure 2). With this finding, the patient was referred to colleagues in neurosurgery, subsequently to interventional neuroradiology, for biopsy, which ultimately confirmed a diagnosis of ependymoma (Gembruch et al., 2021; Gerstner & Pajtler, 2018; Hubner et al., 2018; Savoor et al., 2021).
Discussion
Although rare, spinal cord tumors should be considered in the differential for patients with progressive neurological symptoms or abnormal neurological findings on examination. These symptoms will vary depending upon the level of spinal cord involvement and should guide the provider as to what area of the spine to investigate. A thorough history is often revealing for paresthesia of the extremities, clumsiness, or gait instability, or, in more general terms, a patient who reports frequent falls. More significant clinical findings may include weakness, spasticity, or muscle wasting. Any focal neurological finding on examination warrants investigation with advanced imaging in the form of MRI. As with most orthopaedic conditions, appropriate diagnosis is key to optimal treatment outcomes (Gembruch et al., 2021; Gerstner & Pajtler, 2018; Hubner et al., 2018; Savoor et al., 2021).
The mainstay of treatment of ependymoma remains gross total resection of the tumor, with more recent literature pointing to better overall outcomes, as measured by local control, recurrence, and progression-free survival, with adjuvant radiation therapy as compared with resection alone. Controversy remains as to the optimal approach, but consistent positive predictive findings are correlated to optimal resection regardless of the approach used. Newer imaging software, which eliminates potential intra- and interoperator errors, is also being utilized for superior surgical planning to achieve successful complete resection. Given the rarity of spinal cord tumors, with expertise typically only gained through experience, patients are best treated by a multidisciplinary team, including neurology, neurosurgery, radiation oncology, and genetics (Gembruch et al., 2021; Gerstner & Pajtler, 2018; Hubner et al., 2018; Kotecha et al., 2019; Lemay et al., 2021; Savoor et al., 2021; Sun et al., 2019).
References