1. eEdE
Pediatric spinal nerve root enhancement: Clinical and differential considerations
Marinos Kontzialis1, Hans Michell2,
Andrea Poretti2, Thierry A.G.M. Huisman2
1Division of Neuroradiology and 2Pediatric Radiology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
ASNR 53rd Annual Meeting, Chicago, April 25-30, 2015

2. Disclosure We have nothing to disclose
No relevant financial relations interfering with our presentation

3. Purpose Case-based review of pediatric nerve root enhancement
Clinical and differential considerations

4. Introduction Pediatric spinal nerve root enhancement:
Indicates blood-nerve-barrier disruption
Is a nonspecific finding

5. 2-year-old with ascending weakness
Case 1
2-year-old with ascending weakness A B C
Diffuse nerve root enhancement in the cervical (A), thoracic (B) and lumbar spine (C)

6. Guillain-Barré syndrome (GBS)
Autoantibody-mediated acute motor weakness:
Pathogenesis = molecular mimicry and cross reactive immune reaction
Prevalence: /100,000
Usually preceding upper respiratory or GI infection (Campylobacter jejuni)
Maximum weakness within 4 weeks
Progressive weakness > 8 weeks  chronic inflammatory demyelinating polyneuropathy (CIDP)
CSF = albumin-cytological dissociation

7. Guillain-Barré syndrome: MRI
Nerve root enhancement: > 90%
Different patterns of enhancement
Diffuse = 68%
Ventral roots = 27%
Dorsal roots = 5%

8. Guillain-Barré syndrome: MRI
Cranial nerve (CN) involvement = 50%
Bilateral CN V enhancement (arrows)

9. Differential diagnosis 1
Transverse myelitis:
Quicker presentation compared to GBS (hours- few days vs. several days)
Sensory-motor level (not present in GBS)
MRI: spinal cord signal abnormalities + enhancement
10-year-old with transverse myelitis presenting with quadriplegia over h

10. Differential diagnosis 2
Guillain-Barré syndrome
West-Nile virus radiculitis
Poliomyelitis-like syndrome with acute flaccid paralysis + sensory sparing
MRI: most often normal, but ventral nerve roots enhancement is possible
Can look identical to GBS

11. Case 2 8-year-old with congenital HIV infection A B C
Bilateral CN III enhancement (A) and diffuse nerve root enhancement and mild thickening (B, C)

12. Chronic inflammatory demyelinating polyneuropathy (CIDP)
Inflammation mediated demyelination
Prevalence: 1-7.7/100,000
Clinically heterogeneous, grossly symmetric sensory and/or motor neuropathy
Develops over > 8 weeks (GBS < 4 weeks)
No preceding infection
CSF = increased protein, normal cell count  supportive of nerve root inflammation

13. Chronic inflammatory demyelinating polyneuropathy
CIDP may occur in the context of:
Hepatitis C
Inflammatory bowel disease
Monoclonal gammopathy of undetermined significance (MGUS)
HIV/AIDS
Organ transplant
Connective tissue disorders

14. Chronic inflammatory demyelinating polyneuropathy
MRI: enhancement + hypertrophy of root + plexus possible  widespread inflammation
Can mimic neurofibromatosis type 1
16-year-old with thickening and mild enhancement of lumbar plexus (arrowheads) and sacral nerve roots (arrows)

15. Case 3
9-month-old from El Salvador with a 2-week Hx of fever, lethargy, and emesis A B C D
Diffuse meningeal enhancement in the posterior fossa (B), around the cord (B),
and cauda equina nerve roots (D). Minimal clumping of the nerve roots (D).

16. Case 3 A B C Basilar meningitis CN V enhancement
CN VI, VII, VIII enhancement +
rim enhancing lesion in the right middle cerebellar peduncle

17. Tuberculosis
Most common infectious cause of spinal arachnoiditis (= inflammation of the meninges)
CSF: increased protein, decreased glucose, increased cells (mainly lymphocytes)
Nerve root enhancement = 30%, predominantly smooth

18. Case 4
3-year-old with subacute onset of bilateral facial weakness and dysarthria A B C
Diffuse nerve root enhancement in the cervical (A),
thoracic (B) and lumbar spine (C)

19. CN VII + VIII enhancement
Case 4
CN III enhancement
CN V enhancement
CN VII + VIII enhancement

20. Bannwarth syndrome
Lyme meningo-radiculo-neuritis caused by spirochete Borrelia burgdorferi
Most common tick-borne disease in the US
Geography, recreational habits, season (peak in the summer) are clues!
Confirmed by serum + CSF antibodies
CSF = lymphocytic meningitis
Erythema migrans in 89% of children = facilitates the diagnosis

21. Bannwarth syndrome MRI:
MS-like periventricular white matter lesions
Cranial nerve enhancement
Nerve root enhancement
In the appropriate geographic + seasonal setting  facial diplegia/palsy = highly suggestive of Lyme disease, especially when coupled with erythema migrans

22. Case 5 13-year-old with progressive polyneuropathy
Thickening of the cauda equina nerve roots without evidence of enhancement (not shown)

23. Case 5 CN III thickening + enhancement CN V thickening + enhancement
CN VII, VIII thickening + enhancement

24. Charcot-Marie-Tooth disease
Hereditary motor + sensory neuropathies
Symmetric + predominately distal motor + sensory disturbances, slowly progressive course
MRI: typically associated with marked thickening of the nerves (hypertrophic neuropathies)

25. Differential diagnoses
Metachromatic leukodystrophy (MLD) + Krabbe disease
Can present with diffuse cranial nerve and cauda equina enhancement
May be simultaneous or precede typical white matter abnormalities
 Consider measuring arylsulfatase A + galactocerebrosidase in all children with unexplained cranial nerve and caudal nerve root enhancement
MLD
Krabbe disease

26. Case 6 3-year-old with developmental delay + failure to thrive
Diffuse leptomeningeal + subarachnoid enhancement
Diffuse thickening of the nerve roots

27. Leptomeningeal enhancement coating bilateral CN V
Case 6
Avidly enhancing pineal mass with diffuse leptomeningeal enhancement in the posterior fossa + around the cord
Leptomeningeal enhancement coating bilateral CN V

28. Pineoblastoma with leptomeningeal carcinomatosis
Neoplastic causes of nerve root enhancement in the pediatric population:
Medulloblastoma
Germinoma
Pineoblastoma
PNET
Ependymoma
Astrocytoma
Lymphoma
Leukemia

29. Smooth nerve root enhancement
Most common, but least specific
GBS
West Nile virus radiculitis
CIDP
Lyme disease
Tuberculosis

30. Nerve root enhancement + thickening
CIDP
CMT disease
Leptomeningeal carcinomatosis (enhancement can be nodular)

31. Summarizing table Diagnosis Clinical CSF Clues Associations MRI GBS
<4 weeks
 protein
Ascending paralysis,
preceding infection
50% CN involvement
nerve root enhancement
CIDP
>8weeks
Progressive neuropathy
Underlying disorder?
Nerve root enhancement + thickening
Meningitis
Encephalopathy, meningeal signs
Protein
cells
Fever
Empiric treatment + CSF
± leptomeningeal and nerve root enhancement TB
Cells
 Gluc
Think about risk factors of exposure
Pulmonary TB
Meningitis/arachnoiditis,
tuberculomas, nerve root enhancement
Lyme
Rash
CN VII palsy
Season, recreational activities, geography
Tick bite
MS-like lesions, CN and nerve root enhancement
CMT
Hypertrophic neuropathies -
Established diagnostic criteria
Gene testing + nerve biopsy
Nerve root and plexus thickening
MLD
Krabbe
arylsulfatase A
β-galacerebrosidase
CN + nerve root enhancement early on
Neoplastic
Depends on primary
Nodular enhancement
Image entire neural axis

32. Take-home messages Pediatric nerve root enhancement = nonspecific
Clinical presentation, imaging findings and CSF testing will point towards the right direction + guide further management

33. Suggested literature
Zuccoli G et al. Redefining the Guillain-Barre spectrum in children: neuroimaging findings of cranial nerve involvement. AJNR 2011;32(4):
Van Doorn PA et al. Clinical features, pathogenesis, and treatment of Guillain-Barre syndrome. Lancet Neurol 2008;7:
Mulkey SB et al. Nerve root enhancement on spinal MRI in pediatric Guillain-Barre syndrome. Pediatr Neurol 2010;43(4):263-9.
Vallat JM et al. Chronic inflammatory demyelinating polyradiculoneuropathy: diagnostic and therapeutic challenges for a treatable condition. Lancet Neurol 2010;9:
Sharma A et al. MR imaging of tubercular spinal arachnoiditis. AJR 1997;168(3):
Hildenbrand P et al. Lyme neuroborreliosis: manifestations of a rapidly emerging zoonosis. AJNR 2009;30:
Cellerini M et al. Imaging of the cauda equina in hereditary motor sensory neuropathies: correlation with sural nerve biopsy. AJNR 2000;21:
Morana G et al. Enhancing cranial nerves and cauda equina: an emerging magnetic resonance pattern in metachromatic leukodystrophy and Krabbe disease. Neuropediatrics 2009;40:291-4.
Zapadka M. Diffuse cauda equina nerve root enhancement. J Am Osteopath Coll Radiol 2012; Vol. 1, Issue 1.