Neuroinflammatory Disorders

Acute disseminated encephalomyelitis (ADEM) Features
  • Isolated postinfectious or post vaccinal attack on the CNS
  • Diffuse demyelination, occasionally with fulminant hemorrhagic component (acute hemorrhagic encephalomyelitis or leukoencephalitis
Symptoms
  • Encephalopathy: confusion, irritability, AMS (somnolence to coma)
  • Multifocal deficits, fever, meningismus (headache, photophobia, stiff neck)
Imaging
  • Large (greater than 1 to 2 cm) multifocal, hyperintense, bilateral, asymmetric lesions I the supra-/infratentorial white matter on T2-weighted or MRI FLAIR images
  • Gray matter, especially basal ganglia and thalamus, may be involved
Optic Neuritis (ON) Features
  • Usually a clinically isolated syndrome (CIS) caused by an inflammatory condition or idiopathic, but may be associated with MS or ADEM
Symptoms
  • Headache and painful eye movements followed by vision loss, pupillary defect (Marcus Gunn pupil), or visual field defects
  • Usually unilateral in adults but may be bilateral in children under 12
Imaging
  • Gadolinium MRI shows acute demyelination confined to optic nerve
Transverse Myelitis Features
  • Spinal cord dysfunction typically owing to inflammatory lesion
  • Usually presents as a CIS, but may be associated with MS or ADEM
Symptoms
  • Unilateral or bilateral motor or sensory deficits such as Paresthesias, weakness, sphincter dysfunction; can occasionally be more severe, including paraplegia and urinary retention
Imaging
  • Gadolinium-enhancing lesions on MRI spreading over 1 or more segments
Neuromyelitis Optica (NMO) Features
  • Dx requires ON, myelitis, and 2 out of the following 3: longitudinally extensive spinal cord lesion more than three segments in length, brain MRI non-diagnostic for MS, NMO-IgG seropositivity (Wingerchuk et al., 2007)
  • More common in non-Caucasians, especially Asians
  • Rule out sarcoid, SLE, Sjogrens or other vasculitis
Symptoms
  • Combination of concurrent or sequential bilateral optic neuropathy and transverse myelitis