Cauda Equina Enhancement, Diffuse



Cauda Equina Enhancement, Diffuse


Jeffrey S. Ross, MD



DIFFERENTIAL DIAGNOSIS


Common



  • Spinal Meningitis


  • CSF Disseminated Metastases


  • Guillain-Barré Syndrome


  • CMV Polyradiculopathy


Less Common



  • Sarcoidosis


  • Arachnoiditis


  • Lymphoma


  • Chronic Inflammatory Demyelinating Polyneuropathy (CIDP)


  • Spinal Stenosis Compression


  • Disc Herniation Compression


  • Hereditary Motor & Sensory Neuropathies


Rare but Important



  • Viral Radiculomyelitis


  • Rabies


  • Tick-Borne Encephalitis


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Limited imaging differential considerations include single vs. multiple root involvement, smooth vs. nodular enhancement



    • Multiple root involvement most common and least specific for a single diagnosis


    • Single root involvement over long segment favors radiculitis secondary to disc herniation or stenosis


    • Smooth enhancement most common and least specific


    • Nodular enhancement much more likely with tumor or sarcoidosis


Helpful Clues for Common Diagnoses



  • Spinal Meningitis



    • Shows diffuse, smooth enhancement of multiple roots and distal pial surface of cord


    • Look for additional lesions such as subdural spinal empyema, epidural abscess or phlegmon


    • Nonspecific appearance for etiology, whether pyogenic, granulomatous, fungal


    • Clinical history critical ⇒ LP mandatory


  • CSF Disseminated Metastases



    • Metastatic disease may show either diffuse smooth enhancement or more nodular form


    • Lung, breast carcinoma most common for systemic primaries


    • PNET, GBM most common for CNS primaries


    • Look for bony metastases, retroperitoneal lymphadenopathy


  • Guillain-Barré Syndrome



    • Acute inflammatory demyelinating polyradiculopathy (AIDP)


    • 1-2 cases/100,000 per year


    • Monophasic demyelinating polyneuropathy related to prior infection, esp. Campylobacter jejuni enteritis



      • GB characterized by ascending limb weakness and areflexia


      • Cranial nerve involvement in 50%


      • Back pain 30-50%


      • Respiratory failure


      • Autonomic instability with labile BP, cardiac arrhythmias


      • Progression to plateau in 2 weeks


    • Number of variants described



      • Miller Fisher syndrome (MF) ⇒ ophthalmoplegia, ataxia, areflexia


      • ⇒ Bickerstaff encephalitis appears closely related to MF with addition of alteration of consciousness or long tract signs


      • Acute post-infectious axonal polyradiculoneuropathy (AMSAN)


      • Acute motor axonal neuropathy (AMAN)


      • Acute sensory ataxic neuropathy (ASAN)


      • Relapsing variants


    • Treat with plasma exchange and IVIg


    • 10% have permanent disability



      • Poor prognosis can be predicted based on age, preceding diarrhea, and disability score 2 weeks from presentation


    • Molecular mimicry ⇒ infectious agent sharing epitopic determinants with nerve tissue incites immune response leading to nerve inflammation


    • GB & variants represent autoimmune disease to glycolipid structures



      • Campylobacter jejuni ⇒ GM1, GM1b, GD1a, GalNac-GD1a, GQ1b


      • Haemophilus influenza ⇒ GM1, GT1a


      • Mycoplasma pneumoniae ⇒ Galacterocerebroside



      • Cytomegalovirus ⇒ GM2


    • Microbial genetic polymorphism can determine clinical presentation of human autoimmune disease



      • C. jejuni strain with gene cst-II(Thr51) has GM1 or GD1a epitope ⇒ Guillain-Barré


      • C. jejuni strain with gene cst-II(Asn51) has GQ1b epitope ⇒ Miller Fisher syndrome


  • CMV Polyradiculopathy



    • Infection in AIDS, impaired cell mediated immunity


    • Assess for other infectious lesions ⇒ Toxo, crypto, TB, PML


    • May progress rapidly with anesthesia and weakness, variable amount of pain


    • Estimated 10% of AIDS patients have clinical deterioration related to CMV


    • CMV radiculitis in 3% of autopsies of AIDS patients


Helpful Clues for Less Common Diagnoses

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Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Cauda Equina Enhancement, Diffuse

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