Spinal ependymoma presenting as subtle neurological findings in a VA chiropractic clinic: a case report in differential diagnosis and appropriate use of diagnostic imaging

Abstract

Background

Lhermitte’s sign is a nonspecific historical and exam finding that carries with it a differential diagnosis of cervical myelopathy, multiple sclerosis, intradural tumors, or other central nervous system pathology. Regardless of the suspected diagnosis, further diagnostic investigation is indicated to determine etiology of symptoms.

Case presentation

In this case, a 67-year-old male Veteran presents to a Veterans Affairs (VA) outpatient chiropractic clinic with an insidious 6-month onset of neck pain with historical description of a positive Lhermitte’s sign, a single episode of bladder incontinence, and mild changes in upper extremity manual dexterity. These subtle historical findings prompted referral for a brain and cervical spine MRI, revealing an ependymoma in the cervical spine. Urgent neurosurgical referral was made, and the patient underwent C3-C7 laminectomy, C3-T2 fusion, and tumor resection.

Summary

This case represents an example of clinical reasoning in a VA chiropractic clinic when presented with subtle neurologic findings, and discusses the differential diagnoses and decision-making process to pursue imaging that resulted in appropriate neurosurgical management.

Introduction

Lhermitte’s sign is described as an electrical shock down the spine with neck flexion and can involve the upper or lower extremities. It is a nonspecific clinical finding that suggests central spinal cord compression or compromise.¹ The differential diagnosis for a positive Lhermitte’s sign includes, but is not limited to, multiple sclerosis, subacute combined systems degeneration, space occupying lesions, and infection, but is most commonly associated with cervical myelopathy (97% specificity).^1–3

Ependymomas are intramedullary tumors accounting for a small percentage of all primary central nervous system tumors (1.6–1.8%), with 65% of adult ependymomas occurring in the spinal cord.⁴ Half of spinal cord ependymomas occur in the lumbosacral region and the other half in the thoracic or cervical region.⁵ Tumor classification is outlined by the World Health Organization based on molecular features, histology, and tumor location. WHO grade I spinal ependymomas are typically asymptomatic and incidental findings on imaging, whereas the WHO grade II and III are the more common molecular grade found in the adult population.⁴ They are non-differentiated in molecular composition, are considered to be slow growing and do not commonly metastasize.⁴ Prognosis is dependent upon the size of the tumor and the neurological status of the patient, with tumors of WHO grade II or III providing a 70% survival rate at five years following total tumor resection.^4,5 Neurologic dysfunction distal to the lesion is a common sequela, overlapping in presentation with other signs of cord compression.⁴ This includes neck pain, upper or lower extremity paresthesia, extremity weakness, and bowel or bladder dysfunction.^1,2,6–8 These symptoms are often subtle, making clinical decisions regarding further diagnostic testing challenging, as the use of imaging that is not concordant with guidelines can potentially have a strong iatrogenic effect, and may escalate downstream care unnecessarily. There is a high probability of finding anatomic abnormalities with diagnostic imaging, even in the absence of symptoms, with cervical disc bulges present in 87% and normal age-related cervical spine changes present in 46.8% of asymptomatic patients.^9–10 Therefore, symptoms presenting with clinical ambiguity should be carefully managed to avoid potential iatrogenic effects of advanced imaging if it is not expected to be high yield.

In this report, we will outline the case of a Veteran patient who presented to a chiropractic clinic with subtle neurologic findings, in addition to a historical description of a positive Lhermitte’s sign which was unable to be reproduced with a traditional Lhermitte’s provocation maneuver of passive cervical flexion, but was able to be produced with a seated Slump test. We will discuss the clinical decision-making process, and subsequent referral for advanced imaging.

Case presentation

A 67-year-old male Navy Veteran was referred by their primary care provider to a Veterans Affairs (VA) community-based outpatient chiropractic clinic for evaluation of neck pain with a description of episodic shock-like pain in the upper and lower extremities with cervical flexion. This complaint began six months prior with no known cause. The patient believed that they may have slept in an uncomfortable position and woke up with these symptoms. Three months following onset, a referral from their primary care provider was made for an electromyography/nerve conduction velocity test of the bilateral upper extremity which revealed evidence of a left demyelinating median neuropathy at the wrist, mild left ulnar sensory neuropathy and left mild chronic C6-C7 radiculopathy. His primary care provider also ordered radiographs with flexion and extension views of the cervical spine which showed moderate degenerative changes, 2mm retrolisthesis of C3 on neutral and extension, and bilateral carotid artery calcification (Figure 1a – 1d). After completion of the radiographs and EMG/NCV, a referral to the chiropractic clinic was made by the primary care provider for evaluation of neck pain.

Figure 1.

Radiographs of the cervical spine, lateral neutral (a), flexion (b), extension (c), and anterior (d). Moderate degenerative changes noted at C3-4 and C6-7 (white arrows). 2mm retrolisthesis noted at C3 on neutral and extension (black arrows). No other malalignment or dynamic instability. Bilateral carotid calcification appreciated, right more than left (white arrow heads).

The patient’s neck pain was located at the cervicothoracic junction and right periscapular region, which he described as a “dull ache”. Intermittent upper extremity paresthesia was located in the ulnar distribution bilaterally and intermittent lower extremity paresthesia diffusely encompassed his entire thigh and leg bilaterally. Both upper and lower extremity paresthesia were historically provoked by cervical flexion and accompanied by a shock-like sensation down the spine. Sitting for less than 30 minutes was also provocative to neck pain and limb paresthesia. Ibuprofen, heat, stretching, and raising both arms overhead alleviated these symptoms. Of note, this patient was observed to frequently raise both hands overhead while eliciting their history in the chiropractic clinic, demonstrating a positive Bakody sign suggestive of cervical neuropathy. Standing is palliative, and walking has no effect on symptoms. He denies frank weakness of all extremities. He denies changes in handwriting, or difficulty buttoning shirts, but describes a history of mild clumsiness with eating utensils which he attributes to his neuropathy, thought to be secondary to poorly controlled Type II Diabetes. He endorsed one episode of cramping in the left hand a week prior that resolved after 20 minutes, which he attributed to dehydration. He had one episode of urinary incontinence about one week before the chiropractic visit with no further events. He denied experiencing dizziness, difficulty with vision, eye pain, history of neurogenic or overactive bladder, bladder retention or bowel incontinence.

The patient has a medical history significant for hyperlipidemia, diabetes mellitus, obesity, insomnia, and tobacco use. The patient denies a personal surgical history or history of cancer. Reported alcohol use consists of three pints of beer per week and the patient denied illicit drug use. He was vague in reporting dietary habits, endorsing a variety in food types but did not report to nutritional quality. Patient reported sleep was often disturbed due to pain and endorsed being woken three times per night since this complaint began six months prior.

Neurological exam revealed myotomes C5-T1 and L1-S1 graded 5/5 bilaterally. Dermatomal sensation C5-T1 and L1-S1 was intact and symmetrical bilaterally to pinprick. No clonus was appreciated with rapid ankle dorsiflexion or wrist extension, plantar reflex was absent, and Hoffman’s and Tromner’s signs were also absent bilaterally. Patellar reflex was graded 2+ and Achilles reflex was graded 1+ bilaterally. Upper extremity reflexes of biceps, brachioradialis, and triceps were graded 2+ bilaterally. No notable pronator drift or sway appreciated with Romberg’s test.

Active cervical rotation provoked contralateral upper extremity paresthesia bilaterally in the ulnar distribution. Active extension provoked local cervicothoracic junction pain and lateral flexion provoked a stretch of the contralateral upper trapezius. Seated active range of motion in cervical flexion, as well as seated Slump test with full knee extension, provoked a shock-like sensation down the spine as well as the upper and lower extremity paresthesia, creating the previously described Lhermitte’s sign. It should be noted that during performance of range of motion, patient had a mild slouched posture with slightly rounded shoulders and anterior head carriage. Of interest, a traditional Lhermitte’s provocation maneuver (in this case, passive cervical flexion seated with erect posture and with clinician overpressure), did not reproduce the extremity paresthesias. At this point in the visit, additional orthopedic testing was deferred to pursue neuroimaging of the cervical spine and brain (to exclude cervical myelopathy or multiple sclerosis) and a laboratory test to evaluate vitamin B12 levels (to exclude subacute combined degeneration).

Results

Vitamin B12 was found to be within normal limits. The MRI of the brain and cervical spine (Figures 2a– 2c) revealed an intraspinal cystic mass from mid C4 to C7 measuring 4.9 cm x 1.4 cm x 0.9 cm with some edema above and below these levels, noted by neurosurgeon to be expansive and taking up “pretty much all of the spinal canal”. The hemosiderin cap, an area of T2 hypointense hemosiderin due to previous hemorrhage, present at the caudal margin of the mass indicates that it is most likely an ependymoma as it is present in 20–33% of all ependymomas. ¹¹ Upon review of these images, the patient’s primary care provider ordered an urgent neurosurgical referral and instructed the patient to wear a cervical collar. The patient was immediately discharged from the chiropractic clinic.

Figure 2a.

Sagittal MRI of the cervical spine, STIR-weighted image. Cystic mass seen at mid-C4 to C7 with fluid level seen within the mass (white arrow). Hemosiderin cap appreciated at caudal end of the mass (black arrow). Mild edema in the spinal cord appreciated superiorly to C2-3 and inferiorly to T2 (arrowheads).

Figure 2b.

T2 weighted MRI of the cervical spine, sagittal view. Cystic mass seen at mid-C4 to C7 with fluid level seen within the mass (white arrow). Hemosiderin cap appreciated at caudal end of the mass (black arrow). Mild edema in the spinal cord appreciated superiorly to C2-3 and inferiorly to T2 (arrowheads).

Figure 2c.

STIR-weighted MRI of the cervical spine, coronal view. Cystic mass appreciated from C4-C7 in this view, notable for the amount of space it occupies within the spinal cord.

Neurosurgery evaluated the patient and documented the patient was fortunate they were not worse off neurologically given the size and extent of the tumor. Neurosurgical examination corroborated our findings with the exception of noted brisk 3+ patellar reflex. They also found the patient’s proprioception was intact, noted good muscle bulk and tone, and that the patient was able to ambulate well but did have difficulty completing a tandem gait. The recommendation was to perform a C3-C7 laminectomy and C3-T2 fusion as well as tumor resection to avoid more catastrophic decline, which he underwent four weeks after the MRI was completed. Pathology report of the tumor confirmed the presence of a WHO grade II ependymoma. Following the initial surgery, documentation indicates the patient experienced ongoing and progressively worsening dysesthesia and paresthesia in all four extremities with ongoing myelopathic features to include significant proprioceptive deficits and balance disturbances. One week following surgery, follow-up imaging revealed the pedicle screws at C3 had withdrawn out of the bone and the patient underwent subsequent surgical revision three weeks after the initial surgery during which there was also an infection of pansensitive staphylococcus lugdunensis. Following the revision surgery, he was discharged to an inpatient neurological rehabilitation facility for nine days, then discharged to his home with IV antibiotics. Most recent documentation indicates he continues to recover at home with follow-up scheduled with his primary care provider.

Discussion

Ependymomas appear to be a rare presentation in the chiropractic clinic, with only seven published cases available in the literature.^13–19 In these cases, diagnosis was most often made after a failed trial of conservative care or the development of new neurological deficits, prompting a referral for MRI; however, there were also cases where the MRI was a first-line intervention and the ependymoma was essentially an incidental finding.^13–19 In this case, the discrepancy between the reproduction of Lhermitte’s sign with active cervical range of motion and Slump testing, but inability to reproduce the sign with traditional Lhermitte’s provocation maneuver of passive cervical flexion created ambiguity in diagnosis as well. Though the patient was neurologically intact, the combination of the new onset urinary incontinence (although this was only one reported episode a week prior with no further events), description of a positive Lhermitte’s sign on history, and questionable changes in manual dexterity elevated the clinical suspicion for cervical pathology or neurodegenerative disease. In place of pursuing a trail of conservative care or watchful waiting, further diagnostic testing was pursued. The brain and cervical MRIs were intended to evaluate for central nervous system and cervical spine pathology with differential including degenerative cervical myelopathy or a neurodegenerative disease process such as multiple sclerosis. The vitamin B12 lab study was ordered out of caution to rule out a nutritional deficiency that could result in a positive Lhermitte’s sign due to demyelination of the dorsal columns of the spinal cord that can occur in vitamin B12 deficiencies, a subacute combined systems degeneration.²

Degenerative cervical myelopathy is the result of chronic compression of the spinal cord secondary to degenerative changes in the spine, congenital central canal stenosis, or a combination of both. The average age of diagnosis of degenerative cervical myelopathy is approximately 64 years old, and the most common level of involvement being C5-C6.⁸ Between 20–60% of patients with degenerative cervical myelopathy will experience neurological deterioration that will typically progress without surgical intervention.⁸ Signs and symptoms of degenerative cervical myelopathy are neck pain, gait changes, upper extremity paresthesia, fine motor weakness, and bowel and bladder dysfunction in severe cases.⁸ Physical examination will typically reveal muscle atrophy of the upper extremity, particularly intrinsic hand musculature, hyperreflexia, and gait impairment.⁸ Long tract signs of Babinski, Hoffman, and clonus are also common and considered a hallmark of cervical myelopathy.⁸ The patient’s age, positive Lhermitte’s sign and history of difficulty using eating utensils could fit a clinical picture of degenerative cervical myelopathy, however, physical exam was unremarkable for features of myelopathy and there were inconsistencies with reproduction of the patient’s symptoms.

Although the most common association with a Lhermitte’s sign is cervical myelopathy, in this case our Veteran did not present with the hallmark findings that would suggest this as a diagnosis, therefore multiple sclerosis was considered in the differential.⁸ Multiple sclerosis is a chronic autoimmune disease that causes focal demyelination, degeneration, and inflammation of the nervous system. ^6–7 There is debate regarding the origin of the inflammation in multiple sclerosis, whether it is created inside or outside the central nervous system.⁶ Signs and symptoms of multiple sclerosis are variable as they are dependent upon the region nervous system affected.⁴ Even with the variability in presentation, common symptoms include sensory disturbances, motor and gait impairment, optic neuritis, bowel and bladder dysfunction, and a Lhermitte’s sign.^6–7 As the patient presented with a positive Lhermitte’s sign, urinary incontinence, and mild impairment of manual dexterity, multiple sclerosis was a reasonable differential diagnosis. This diagnosis become less favorable due to the absence of classical multiple sclerosis symptoms such as optic neuritis, balance disturbances, or a pattern of relapse and recurrence of symptoms, and the patient did not fit the classic demographic for multiple sclerosis onset of a young Caucasian female.^6–7 Even so, the patient’s presentation raised enough clinical suspicion to include multiple sclerosis in the differential diagnosis as late-onset multiple sclerosis has been reported to be diagnosed in 5% of cases in patients aged over 50 years old.²⁰

Subacute combined systems degeneration is characterized by the degeneration of the dorsal and lateral columns of the spinal cord secondary to a vitamin B12 deficiency.² The lack of vitamin B12 in the body can be due to many reasons, such as nutritional deficiencies, gastrointestinal malabsorption, pancreatic disease, or may be drug-induced. ² Cobalamin, known as vitamin B12, plays a crucial role in the maintenance of the myelin sheath of the nervous system and a deficiency can lead to neural demyelination. ² Neurological manifestations of subacute combined systems degeneration include impaired proprioception, paresthesia, upper and lower motor neuron signs, sensory ataxia, and a Lhermitte’s sign.² Historical questions to be considered when evaluating for suspected subacute combined systems degeneration are dietary habits, alcohol intake, past history of malabsorption disorders, and medication use.² As the patient in this case presented only with a Lhermitte’s sign without neurological deficit, did not have a history of alcohol abuse as confirmed by normal liver enzymes on bloodwork, and did not have a history of gastrointestinal malabsorption issues, subacute combined systems degeneration was low on the list of differential diagnoses.

The American College of Radiology published a series of articles regarding appropriateness criteria regarding imaging in cases of neck pain and cervical radiculopathy in 2019 and myelopathy in 2021.^21–22 Although there is a difference in consensus regarding the use of MRI in uncomplicated neck pain, it is recommended that clinicians investigate the etiology of chronic or progressive myelopathy with an MRI.^21–22 Delay in care has been shown to result in deterioration of neurological status in 20–62% cases of cervical myelopathy within 1–3 years, it is important to determine the etiology of the symptoms. ^{18, 23} In this case-a relatively neurologically intact and stable patient-the Lhermitte’s sign with questionable changes in manual dexterity made the MRI a high yield study.

Appropriate utilization of advanced imaging is important in the management of musculoskeletal conditions, as the use of non-guideline concordant imaging has been shown to increase risk for the development of chronic pain, increase downstream costs, and increase healthcare utilization in low back pain.^24–25 Although the literature is lacking in documenting similar risks of non-guideline concordant imaging for neck pain, one could speculate findings are similar as we do know there is evidence showing the presence of abnormal cervical MRI pathology in healthy/asymptomatic individuals.^9–10 Though advanced imaging has been overutilized in musculoskeletal conditions, which can result in poorer outcomes, it remains a necessary and essential tool in diagnosis and management when applied appropriately.²²

Limitations

Limitations of this case report are that it is a singular patient with a unique presentation. The presentation of this patient is likely not generalizable to many other cases. This case may also create bias in the reader of this report, as the advanced imaging ordered revealed relatively rare pathology and may leave the reader more apt to order advanced imaging out of caution. However, this is not the aim of this case report as it is designed to highlight how subtle historical findings led to the decision to pursue advanced imaging, therefore appropriate referral and treatment for this patient.

Summary

Ependymomas are a rare diagnosis in the chiropractic clinic and may first be discovered by a positive Lhermitte’s sign. However, diagnosis can be challenging when clinical symptoms and physical examination are inconsistent. In this case, a patient presented to the chiropractic clinic with a positive Lhermitte’s sign, one episode of bladder incontinence, and mild changes in manual dexterity. Though the patient was neurologically intact during his examination, the chiropractic clinician recognized that subtle historical findings may be signs of myelopathic or neurodegenerative changes. Prompt referral for an MRI revealed a cervical ependymoma which was urgently treated with neurosurgery. Through using good clinical judgment and understanding the guidelines regarding appropriate use of advanced imaging, this patient was able to receive timely neurosurgical referral for appropriate treatment of his condition.