Effaced Sulci, Generalized



Effaced Sulci, Generalized


Anne G. Osborn, MD, FACR



DIFFERENTIAL DIAGNOSIS


Common



  • Generalized Cerebral Edema



    • Cerebral Edema, Traumatic


    • Hypoxic-Ischemic Encephalopathy


    • Hypotensive Cerebral Infarction


    • Toxic/Metabolic Encephalopathies (Many)


  • Subdural Hematoma, Subacute


  • Acute Obstructive Hydrocephalus


  • Meningitis


  • Aneurysmal Subarachnoid Hemorrhage


Less Common



  • Metastases, Skull and Meningeal


  • Encephalitis


  • Thrombosis, Dural Sinus


  • Thrombosis, Deep Cerebral Venous


  • Acute Hypertensive Encephalopathy, PRES


  • Status Epilepticus


  • Intracranial Hypertension, Idiopathic


Rare but Important



  • Neurosarcoid


  • Contrast Complications


  • Brain Death


  • Cerebral Hyperperfusion Syndrome


ESSENTIAL INFORMATION


Key Differential Diagnosis Issues



  • Generalized whole brain or hemispheric sulcal effacement


  • Is sulcal effacement primary (abnormality within sulci) or secondary (brain mass effect)?



    • Secondary sulcal obliteration > primary (meningitis, hemorrhage, metastases within sulci)


Helpful Clues for Common Diagnoses



  • Generalized Cerebral Edema



    • Trauma, hypoxia, drugs, inherited/acquired metabolic disorders


    • Hypodense brain, sulcal/cisternal obliteration on NECT ± decreased gray-white matter differentiation


    • Hyperintense brain on T2WI/FLAIR with compressed sulci


  • Subdural Hematoma, Subacute



    • Isodense with brain on NECT; look for compressed/displaced sulci, gray-white interface


    • Easy to miss; when in doubt get CECT (look for enhanced cortical veins displaced away from skull) or MR (hyperintense on T1WI)


  • Acute Obstructive Hydrocephalus



    • Can be intra- or extraventricular



      • Intraventricular (look for discrepancy in size of ventricles indicating mass, aqueductal stenosis, etc.)


      • Extraventricular (CSF absorption alterations, e.g., with acute aneurysmal SAH or meningitis): All ventricles enlarged ± transependymal CSF flow


    • Any unexplained hydrocephalus on NECT scan should prompt CECT scan or MR without, with contrast


  • Meningitis



    • Pyogenic, granulomatous (even neoplastic) meningitis appear similar on imaging



      • Normal CSF spaces filled with pus or neoplasm → isodense/isointense with brain


      • Typically enhance strongly, uniformly


    • Beware: Meningitis is clinical/laboratory diagnosis; early meningitis may have normal imaging!


  • Aneurysmal Subarachnoid Hemorrhage



    • Basal, generalized vs. localized (with traumatic SAH)


    • Hyperdense on NECT scans


    • Beware: Acute aSAH is isointense with brain on T1WI (fills normal hypointense CSF spaces), isointense with CSF on T2WI (may be difficult to detect)


Helpful Clues for Less Common Diagnoses



  • Metastases, Skull and Meningeal



    • May fill, obliterate normal CSF spaces


    • Enhance; look for adjacent skull, dura lesions


  • Encephalitis



    • Temporal lobe, insula/cingulate gyrus swelling, hyperintensity: Suspect herpes


    • Other encephalitides may be nonspecific but look for predilection (e.g., West Nile in basal ganglia, thalamus)


  • Thrombosis, Dural Sinus



    • SSS > TS as cause for diffuse brain swelling


    • TS + vein of Labbe may cause extensive venous ischemia, hemorrhage, frank infarct



    • NECT shows hyperdense sinus; CECT → “empty delta sign”


    • Beware: Hyperacute thrombus is isointense on T1WI, hypointense on T2WI (may mimic “flow void”)!


    • T2* (GRE, SWI) best MR sequence to show blooming clot


  • Thrombosis, Deep Cerebral Venous



    • Hyperdense ICVs, straight sinus


    • Hyperdense thrombosed ICVs can make NECT look like CECT scan!


    • Hypodensity in thalami, basal ganglia, internal capsules, deep periventricular white matter


  • Acute Hypertensive Encephalopathy, PRES



    • Bioccipital cortical/subcortical edema, sulcal obliteration most common


    • May affect brainstem, cerebellum, basal ganglia, watershed (sometimes ONLY these areas without classic posterior cerebral territory involvement)


    • Hypodense on NECT, hyperintense on T2WI/FLAIR


    • Typically does not restrict on DWI


  • Status Epilepticus



    • Prolonged seizure causes hypermetabolic state, blood-brain-barrier leakage


    • Imaging within 24 hours after ictus



      • Cerebral edema (gyral swelling, sulcal obliteration)


      • May cause transient enhancement


      • May cause DWI restriction


    • May mimic encephalitis, ischemic stroke, even neoplasm!


    • Follow-up scan shows resolution


  • Intracranial Hypertension, Idiopathic



    • Severe “pseudotumor cerebri” may cause diffuse brain swelling, papilledema, small ventricles


    • Look for “empty sella” plus dilated optic nerve sheaths indenting posterior globe


Helpful Clues for Rare Diagnoses

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Aug 7, 2016 | Posted by in NEUROLOGY | Comments Off on Effaced Sulci, Generalized

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