Spitting Image
What type of neuroimaging can best identify the CNS compartments involved in suspected autoimmune or inflammatory disease?
MRI
What typically manifests as gyriform or serpentine enhancement following the sulci?
Leptomeningitis
p.260
Prior traumatic events or neurosurgical procedures can lead to meningeal enhancement several years later.
False, this can lead to meningeal enhancement in the short term immediately following the injury
CT angiography provides good anatomic resolution of _______ but has poor resolution for ______.
large and some medium-size vessels;
smaller vessels (MRI is preferred in these cases)
Direct extension of granulomatous inflammation from involved sinuses to the dura is commonly seen in ____.
Antineutrophil cytoplasmic antibody–associated vasculitis (granulomatosis with polyangiitis).
MRI brain in NMDA-R encephalitis is normal in most patients.
TRUE
89% of pts with NMDA-R encephalitis have normal initial MRI, 77% have a normal follow-up MRI (on Day 25)
What is the FIESTA sequence of MRI?
High resolution T2 sequence
Highlights the contrast between CSF and other structures such as BVs or CNs in the basal cisterns.
Helps identify lesions of these structures.
How long do seizure-related MRI changes last?
2 weeks to 5 months
- Commonly seen in the hippocampi and deep white matter
- Can cause T2 hyperintense signals, restricted diffusion on DWI, postcontrast T1 enhancement
- Can completely resolve or turn into gliosis or focal atrophy.
Once viral causes are ruled out, the presence of bilateral temporal lobe FLAIR hyperintensities is sufficient to diagnose definite limbic autoimmune encephalitis even in the absence of neuronal antibodies.
TRUE
MRI differences seen in HSV encephalitis vs limbic autoimmune encephalitis.
Both have a predilection for the mesial temporal lobes. HSV encephalitis is more likely to be unilateral and asymmetric. Also more likely to have DWI restriction and enhancement. When HSV encephalitis MRI changes are bilateral, the initial affected side extends beyond the medial temporal lobe before spreading to the contralateral temporal lobe.
Also, HSV encephalitis presents with a more sudden dz onset and fever at presentation.
Multiple and confluent cortical and subcortical FLAIR hyperintensities are a hallmark of ____.
Encephalitis with autoantibodies to γ-aminobutyric acid type A (GABAA) receptor
What is a more sensitive biomarker than brain MRI for detecting focal or multifocal brain abnormalities in autoimmune encephalitis?
Fludeoxyglucose positron emission tomography (FDG-PET)
Legionella is the most common cause of infectious brainstem encephalitis.
FALSE, Listeria monocytogenes is the MCC of brainstem encephalitis
(rim-enhancing lesions with central restricted diffusion)
Ictal and limbic autoimmune encephalitis MRI changes are similar. What other features can we use to distinguish the two?
Seizures do not present with prodromal symptoms, there is a rapid clinical improvement with antiseizure medications alone, and noninflammatory CSF
What can cause T1 hyperintense signals?
Methemoglobin - subacute hemorrhage
Fatty or highly proteinaceous lesions (laminar necrosis)
Melanin (metastatic melanoma)
What infections can lead to dopamine D2 receptor encephalitis?
β-hemolytic streptococcus and mycoplasma
MRI shows basal ganglia T2 hyperintensities in 50% of patients with this autoantibody
Presents as subacute parkinsonism and dystonia in adolescents
Neuro-Behçet syndrome has a predilection for the spinothalamic tracts in the midbrain and pons.
False, Neuro-Behcet's has a predilection for the corticospinal tracts in the midbrain and pons (spares the red nucleus)