Review of diffuse cortical injury on diffusion-weighted imaging in acutely encephalopathic patients with an acronym: "CRUMPLED"

Abstract

Purpose: Acute encephalopathic syndromes can present a diagnostic challenge due to the wide range of possible etiologies, which also can have vastly different outcomes. The presence of diffuse cortical injury (DCI) on diffusion-weighted imaging (DWI) can help narrow the differential diagnosis. The aim of this review is to categorize the range of possible etiologies of DCI into a useful acronym, "CRUMPLED".

Methods: A review of the PACS system was completed to find a characteristic example of patients with DCI on DWI from different etiologies. The diagnosis was confirmed for each example via a subsequent review of the electronic medical record used to assess for data such as biopsy results, laboratory values, and clinical correlation. The electronic exhibit intends to demonstrate several sample cases of each letter within the acronym, and to demonstrate which types of DCI are potentially reversible or irreversible.

Findings/discussion: The possible etiologies of DCI on DWI can be organized using the acronym "CRUMPLED": 'C' = Creutzfeldt-jakob disease, 'R' = reversible cerebral vasoconstriction syndrome; 'U' = urea cycle disorders (hyperammonemia) and Uremia; 'M' = mitochondrial (cytopathy/encephalopathy); 'P' = prolonged seizure and posterior reversible encephalopathy (PRES); 'L' = laminar necrosis (hypoxic-ischemic encephalopathy) and liver disease (acute hepatic encephalopathy); 'E' = encephalitis (infectious meningoencephalitis); 'D' = diabetes mellitus (hypoglycemia). Other secondary imaging findings (outside of DWI) can be used to help differentiate between the aforementioned etiologies, such as the use of ADC maps, FLAIR imaging, intravenous contrast.

Conclusion: "CRUMPLED" is proposed as a convenient acronym for the categorization of a diverse range of acute etiologies associated with DCI on DWI, arising from varying degrees of cytotoxic edema. These etiologies can range from being potentially reversible (e.g. hyperammonemia or prolonged seizures) to irreversible (e.g. hypoxic-ischemic injury).

Keywords: AHE, Acute Hepatic/Hyperammonemic Encephalopathy; Acute encephalopathy; CJD, Creutzfeldt-Jakob disease; DCI, Diffuse cortical injury; DWI; Diffuse cortical injury; MELAS, mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes; PRES, Posterior reversible encephalopathy syndrome; RCVS, Reversible cerebral vasoconstriction syndrome; UCD, Urea cycle disorders.

Fig. 1

A 58-year-old female patient with sporadic CJD. 1A: Reduced diffusion is noted in the parasagittal cortices bilaterally as well as the basal ganglia, with additional involvement of the thalami, specifically pulvinar nuclei (arrowheads). 1B: On FLAIR, hyperintensity is noted only in the bilateral parasagittal cerebral cortices.

Fig. 2

A 57-year-old female with RCVS presenting with “thunderclap headache”. 2A-C: several small foci of gyriform reduced diffusion were noted in the parietooccipial cortices (arrows, 2A), but less prominent than the amount of edema on FLAIR (2B), indicative of concomitant PRES, with small amounts of subarachnoid hemorrhage on T2*WI as well (arrows, 2C); MRA (not shown) suggestive mild multifocal segmental narrowing. 2D: On catheter DSA of the right ICA, multifocal areas of narrowing of ACA and MCA segments are noted (arrows), with focal narrowing of the A2 (dotted arrow) and A1 (not shown) segments as well.

Fig. 3

A 38-year-old male patient with Ornithine transcarbamylase deficiency, has reduced diffusion in the bilateral insular and cingulate cortices on DWI (arrows, 3A) and FLAIR images (arrows, 3B). In addition, bilateral thalamic involvement seen in FLAIR images without restricted diffusion (arrowheads 3B).

Fig. 4

A 20-year-old male with altered mental status from uremic encephalopathy, having mildly reduced diffusion in the bilateral insular and caudate nuclei on DWI (arrows, 4A-B), with subtle edema on FLAIR (arrows, 4C-D). Follow-up imaging was not obtained, as the patient’s symptoms improved with correction of the uremia and metabolic acidosis.

Fig. 5

A 1-week-old term female with MELAS, has reduced diffusion in the bilateral perirolandic area on DWI (arrows, 5A) and delayed myelination pattern is seen on T2*WI (arrows, 5B).

Fig. 6

A 58-years-old male with confusion from status epilepticus has reduced diffusion in the right temparoparietal and occipital cortices seen on DWI (arrows, 6A) and FLAIR image (arrows, 6B).

Fig. 7

A 22-years-old female with seizures from PRES due to chronic renal failure and hypertension. 7A-E: Multifocal mildly reduced diffusion and edema is noted on DWI and FLAIR (arrows, 7A, 7C), not having bright vasogenic edema on ADC map (7B); there is also cytotoxic edema within the left temporal lobe on DWI (arrows, 7D), but less visible on FLAIR (7E). After therapy with subsequently resolved seizures, a follow-up FLAIR MRI 40 days later showed resolved multifocal abnormalities (7F).

Fig. 8

A 42-years-old male with hypoxic-ischemic encephalopathy due to cardiac arrest, has reduced diffusion in perirolandic area on DWI (arrows, 8A), also bilateral basal ganglia, posterior insular and visual cortices involvement are seen (arrows, 8B), with subtle findings on FLAIR (arrows, 8C).

Fig. 9

A 48-years-old male with end-stage liver disease, presented with myoclonic jerking, has an ammonium level of 226 μg/dl. He has restricted diffusion in frontal, parietal and occipital cortices seen on DWI and ADC (arrows, 9A-9B).

Fig. 10

A 66-years-old male diagnosed with HSV encephalitis has reduced diffusion and edema on DWI and FLAIR image (arrows, 10A, 10B) in the parasagittal and temporal cortices bilaterally.

Fig. 11

A 66-years-old female with loss of consciousness due to hypoglycemic coma has reduced diffusion and edema on DWI (arrows, 11A) and FLAIR images (arrows, 11B) in the bilateral parasagittal cortices.