Conus Medullaris Infarction in a Patient With Familial Mediterranean Fever: A Case Report



 

Zoe Robinow, BS1; Kathleen Barnett, BS1; John Geraghty, MD1,2

Perm J 2021;25:21.029

https://doi.org/10.7812/TPP/21.029
E-pub: 06/09/2021

Background: Spontaneous spinal cord infarctions are rare, especially in the conus medullaris (CM). They are a particularly uncommon presentation in patients with familial Mediterranean fever (FMF).

Case Description: Our patient is a 50-year-old man with FMF, controlled with colchicine for 20 years, who presented to the emergency department when he developed the inability to ambulate without assistance. He also had bowel and bladder incontinence after experiencing burning in his thighs, scrotum, and penis that radiated down his legs. A magnetic resonance imaging scan with and without gadolinium showed T2 hyperintensity changes in the CM and L2 vertebral body, with enhancement of the CM and cauda equina. The patient received high-dose steroids while hospitalized without clinical benefit. He noted improved strength over the past several months, particularly in his left leg, but has persistent sensory disturbances in his buttocks, scrotum, and plantar surfaces. He continues to experience bowel and bladder incontinence.

Conclusion: Although CM infarction is rare in patients with FMF, it should be considered in the differential diagnosis when there is a high index of suspicion. The presence of vertebral body infarction with T2 changes on magnetic resonance imaging will indicate similar pathology in the CM.

INTRODUCTION

Spontaneous spinal cord infarctions are infrequent, especially in the conus medullaris (CM) region. It is estimated that 1.6 to 7.2 spinal cord infarctions occur per 100,000 individuals yearly, with a slightly higher occurrence in females than males.1 Affected patients can develop lasting sequelae. CM infarction is a particularly rare presentation in patients with familial Mediterranean fever (FMF).

CASE NARRATIVE

Our patient is a 50-year-old mild to moderately obese male engineer with FMF that was well controlled with colchicine for 20 years. He was in his usual state of health until he noted exhaustion and burning in his legs several hours after riding his stationary bicycle for 50 minutes at a moderate intensity. This sensation resolved that evening. The next morning, he felt stiff and went to stretch when he suddenly felt intense burning of both thighs, the scrotum, and the penis radiating down both legs. He subsequently developed leg weakness, inability to ambulate without assistance, and bowel and bladder incontinence.

Neurologic examination revealed a muscle strength of 4+/5 in the hip extensors, 4/5 in the right tibialis anterior, 5/5 in the left tibialis anterior, 4/5 in the bilateral extensor hallucis longus, 3/5 in the right plantar flexors, and 4/5 in the left plantar flexors. Otherwise, strength was 5/5 with normal tone. Reflexes were 2+ in the arms and knees, with absent ankle reflexes and flexor plantar responses bilaterally. There was decreased pinprick sensation in the left S2-S5 region, but sensation was intact on the right. Vibration sense was impaired in the great toes bilaterally.

The initial differential diagnosis included acute spinal cord infarction, transverse myelitis, and Guillain-Barre syndrome (GBS). Cerebrospinal fluid analysis performed in the emergency department showed a traumatic tap with a protein level of 50, a glucose level of 75, and 4 white blood cells. Serologies were negative for infectious etiology or heavy metal toxicity. Inflammatory markers, including erythrocyte sedimentation rate, C-reactive protein, and antinuclear antibody, and a hypercoagulable workup were within normal limits except for a mildly elevated protein C level. An electrocardiogram showed normal sinus rhythm with left atrial enlargement and evidence of old inferior and anteroseptal myocardial infarctions.

A noncontrast magnetic resonance imaging (MRI) scan of the lumbar spine was unremarkable. Follow-up MRI with and without gadolinium showed T2 hyperintensity changes in the CM and L2 vertebral body, with enhancement of the cauda equina and CM (Figures 1 and 2). These findings indicated an acute spinal cord infarction in the CM.

tpj21029f1

Figure 1. T2 fast recovery fast spin-echo sequence showing signal changes in terminal cord and L2 vertebral body.

tpj21029f2

Figure 2. Short inversion time inversion recovery image showing signal change in the terminal cord and T2 hyperintensity in the conus medullaris.

The patient received high-dose steroids while hospitalized without significant clinical benefit. His strength has slowly improved over the past several months, especially in his left leg. He has persistent sensory impairment in his buttocks, scrotum, and plantar surfaces of both feet. He takes pregabalin 100 mg 3 times daily for this, which provides modest benefit. However, he continues to experience bowel and bladder incontinence (Table 1).

Table 1. Timeline of the patient’s clinical course

Date Summary Diagnostic testing Interventions  
April 12, 2020 Patient notes exhaustion and burning in legs, which later resolved. n/a n/a  
April 13, 2020 Patient develops burning, weakness, and incontinence. Goes to the ED and is admitted. • Traumatic lumbar puncture but protein level of 50, glucose level of 75, and 4 WBCs • High-dose steroids given in hospital; no significant clinical benefit  
• Slightly elevated protein C; otherwise hypercoagulable, inflammatory, infectious, and heavy metal serologies unremarkable  
• Prescribed pregabalin (Lyrica)  
• ECG shows normal sinus rhythm, left atrial enlargement, old inferior MI, and old anteroseptal MI  
• CT negative for abdominal aortic aneurysm  
• Initial noncontrast MRI negative  
• Follow-up MRI with and without Gd demonstrates infarction in the conus medullaris  
July 21, 2020 At follow-up visit, the patient continues to experience sensory deficits and bowel and bladder incontinence. Strength is improved. n/a • Continues to take pregabalin for modest benefit  

CT, computed tomography; ECG = electrocardiogram; ED = emergency department; Gd = gadolinium; MI = myocardial infarction; MRI = magnetic resonance imaging; n/a = not applicable.

DISCUSSION

FMF is an autosomal recessive autoinflammatory disease that presents with recurrent, sporadic attacks of fever and serosal inflammation, including peritonitis, pleuritis, or acute synovitis. Episodes can be triggered by emotional stress, fatigue, surgery, menstruation, exercise, or cold temperature and typically last for 1 to 3 days before spontaneously resolving. A variety of mutations of the MEFV gene on the short arm of chromosome 16 are implicated in FMF. The gene product, pyrin, is suspected to be involved in the regulation of inflammatory responses.

Neurologic complications are rarely seen in FMF, and few studies have examined the occurrence of stroke in affected patients. Of 18 patients with FMF and central nervous system involvement, Kalyoncu et al2 reported 7 with cerebrovascular disease. Topcuoglu et al 3 investigated 17 acute ischemic strokes in 14 patients with FMF. Additionally, Luger et al4 and Aghdashi et al5 discussed 2 young men with FMF who experienced a brain stem infarction and a right periventricular infarction, respectively. In the case of a 13-year-old girl with FMF who suffered a right medullary stroke, Aoun et al6 suggested she may have inherited and acquired prothrombotic risk factors. None of these studies reported on spinal cord infarction in patients with FMF.

The spinal cord is resistant to ischemia because of its strong vascularization. The anterior two-thirds is supplied by the single anterior spinal artery and supplemented with 6-8 radicular arteries from the aorta. The largest radicular artery is the artery of Adamkiewicz, which joins the anterior spinal artery primarily between T8 and L2. The dual posterior spinal arteries supply the posterior one-third of the spinal cord. This anatomy explains why spinal cord infarction most commonly affects the midthoracic area and why CM infarction is among the rarest infarction sites. Among the most common causes of spinal cord infarction in adults are atherosclerosis, thoracoabdominal aneurysms, emboli, hypotension, arteriovenous malformations, and sickle cell disease.7

In our patient, the differential diagnosis included acute spinal cord infarction, transverse myelitis, and GBS. Transverse myelitis is associated with inflammatory diseases and infection. Similarly, GBS is associated with preceding diarrheal illnesses caused by organisms like Campylobacter. All of these pathologies can present with pain, sensory and motor changes, and bowel and bladder dysfunction. An MRI provides the most diagnostic information. Acute spinal cord infarction may show signal change in the vertebral body on T2 images, as seen in this patient. In GBS, there is typically contrast enhancement in the CM and cauda equina nerve roots. MRI findings for transverse myelitis are relatively nonspecific, including poorly delineated hyperintense signal on T2.

CONCLUSION

In summary, it is important to consider spinal cord infarction, including in the CM, in the differential diagnosis when a patient presents with sudden onset of symptoms, suggesting an acute ischemic event. The presence of vertebral body infarction on MRI is diagnostic of a spinal cord infarction.

Disclosure Statement

The author(s) have no conflicts of interest to disclose.

Supplemental Material

aSupplemental Material is available at: www.thepermanentejournal.org/files/2021/tpj21029supp.pdf

Funding 

None.

Author Affiliations

1California Northstate University College of Medicine, Elk Grove, CA

2Kaiser Permanente Medical Center, Roseville, CA

Corresponding Author

Zoe Robinow, BS (Zoe.Robinow6483@cnsu.edu)

Author Contributions

Zoe Robinow, BS, and Kathleen Barnett, BS, assisted in the project design and wrote the manuscript. John Geraghty, MD, supervised the project and helped with data collection.

Abbreviations

CE, cauda equina; CM, conus medullaris; FMF, Familial Mediterranean Fever; GBS, Guillain-Barre syndrome; MRI, magnetic resonance imaging; WBC, white blood cell

Supplemental Material

aSupplemental Material is available at: www.thepermanentejournal.org/files/2021/tpj21.029supp.pdf

References

1. Qureshi AI, Afzal MR, Suri MFK. A population-based study of the incidence of acute spinal cord infarction. J Vasc Interv Neurol 2017 Jun;9(4):44-8. PMID:28702119

2. Kalyoncu U, Eker A, Oguz KK, et al. Familial Mediterranean fever and central nervous system involvement: A case series. Medicine (Baltimore) 2010 Mar;89(2):75-84. DOI: https://doi.org/10.1097/MD.0b013e3181d5dca7, PMID:20517179. PMID: 20517179.

3. Topcuoglu MA, Arsava EM, Kalyoncu U, Gocmen R, Oguz K, Tuncer A. Stroke in familial Mediterranean fever. Eur Stroke J 2017 May;2:98-476. DOI: https://doi.org/10.1177/2396987317705242.

4. Luger S, Harter PN, Mittelbronn M, Wagner M, Foerch C. Brain stem infarction associated with familial Mediterranean fever and central nervous system vasculitis. Clin Exp Rheumatol 2013 May-Jun;31(3 Suppl 77):93-5. PMID:23710607.

5. Aghdashi M, Seidmardani SM, Vossoughian S, Seyed Mokhtari SA. Very rare presentation of cerebrovascular accident in 20-year-old man with familial Mediterranean fever-case report. Clin Med Insights Case Rep 2018 Jan;11:1179547617749208. DOI: https://doi.org/10.1177/1179547617749208. PMID:29326535.

6. Aoun EG, Musallam KM, Uthman I, Beydoun A, El-Hajj T, Taher AT. Childhood stroke in a child with familial Mediterranean fever carrying several prothrombotic risk factors. Lupus 2009 Aug;18(9):845-7. DOI: https://doi.org/10.1177/0961203309103057. PMID: 19578111, PMID:19578111.

7. Yadav N, Pendharkar H, Kulkarni GB. Spinal cord infarction: Clinical and radiological features. J Stroke Cerebrovasc Dis 2018 Oct;27(10):2810-21. DOI: https://doi.org/10.1016/j.jstrokecerebrovasdis.2018.06.008, PMID:30093205.

Keywords: case report, conus medullaris, familial Mediterranean fever, spinal cord infarction

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