Intramedullary Lesion, Diffuse/Ill-Defined Enhancement



Intramedullary Lesion, Diffuse/Ill-Defined Enhancement


Jeffrey S. Ross, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Multiple Sclerosis


  • Transverse Myelitis (ATM)


  • ADEM


  • Viral Myelitis


  • Neuromyelitis Optica (NMO)


Less Common



  • Type I Spinal Dural A-V Fistula


  • Dural A-V Fistula (Brain)


  • Arterial Infarction


  • Spinal Cord Metastases


  • Astrocytoma


Rare but Important



  • Radiation Myelopathy


  • Abscess/Myelitis


  • Parasitic or Bacterial Infections


ESSENTIAL INFORMATION


Helpful Clues for Common Diagnoses



  • Multiple Sclerosis



    • Patchy or confluent enhancement


    • Cervical > thoracic


    • Small focal areas of T2 signal abnormality


    • Dorsal cord at C1-2 common location


  • Transverse Myelitis (ATM)



    • Can be secondary to known cause (e.g., MS, ADEM, cord ischemia)


    • Can be idiopathic (unknown cause) 15%


    • Thoracic > cervical


    • Imaging normal in up to 50%


  • ADEM



    • Immune-mediated, inflammatory white matter disorder



      • Para/post-infectious


      • Post-immunization


    • Typically monophasic illness


    • Any age (more common in child, young adult)


    • Brain affected more than spinal cord


    • Can be multifocal, patchy, or confluent


    • Check brain for multifocal white matter lesions with relatively little mass effect


  • Viral Myelitis



    • Acute/subacute viral infection (e.g., HIV, enteroviruses, HHSV6)


    • Usually multisegmental


    • Variable enhancement from subtle to profound


  • Neuromyelitis Optica (NMO)



    • Autoimmune, inflammatory disorder involving myelin of optic nerves and spinal cord


    • Longitudinally extensive (> 3 vertebral segments) T2 hyperintensity within cord


    • Presence of brain WM lesions does not exclude NMO


    • May reflect autoimmune targeting of Aquaporin-4 transmembrane channel proteins


    • Respiratory failure due to extensive cervical involvement in up to 1/3 cases (very uncommon in MS)


    • Radicular pain in 35% (uncommon in MS)


    • Lhermitte symptom common in MS and NMO


Helpful Clues for Less Common Diagnoses



  • Type I Spinal Dural A-V Fistula



    • Causes venous hypertension


    • Intradural flow voids on cord surface from arterialized veins


    • Swollen, edematous cord


    • Multisegmental T2 signal abnormality


    • Variable enhancement


  • Arterial Infarction



    • Sudden onset weakness, loss of sensation


    • Rapidly progressive


    • Causes



      • Anterior spinal or radicular artery occlusion


      • Hypotension


    • Thoracic (conus) > cervical


    • Nonspecific T2 hyperintensity ± ill-defined cord enhancement


  • Spinal Cord Metastases



    • Focal, enhancing cord lesion(s) with extensive edema


    • Lung, breast most common primary


    • Rapidly progressive flaccid paraparesis


    • Full craniospinal imaging when focal cord lesion found


    • Edema out of proportion to focal small cord lesion suggests metastasis, even if solitary


  • Astrocytoma



    • Enhancing infiltrating mass expanding cord


    • Cervical > thoracic


    • Usually < 4 segments


    • Occasionally asymmetric, even exophytic



    • 80-90% low grade


    • Slow onset of myelopathy


Helpful Clues for Rare Diagnoses



  • Radiation Myelopathy



    • Spindle-shaped cord swelling with irregular, focal rind of enhancement


    • Typically with doses over 50 Grey (Gy)


    • Demyelination in lateral, dorsal tracts


    • Concurrent chemotherapy may be a predisposing factor, especially if intrathecal


  • Parasitic or Bacterial Infections



    • Typical is well-defined, ring-enhancing mass within cord, with appropriate clinical history of inflammation/infection


    • More uncommon ill-defined or patchy enhancement


    • Schistosomiasis ill-defined punctate enhancement of conus


Other Essential Information



  • Long (multisegmental) cord enlargement with edema, patchy enhancement favors infection/inflammation over neoplasm


  • Do sagittal FLAIR or T2WI of brain in patients with unexplained myelopathy, cord lesions!



    • MS, ADEM usually have coexisting brain lesions


Alternative Differential Approaches

Tags:
Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Intramedullary Lesion, Diffuse/Ill-Defined Enhancement

Full access? Get Clinical Tree
Get Clinical Tree app for offline access