AMS/Encephalopathy
Andrew Phan
18 September 2019
Diagnostic Radiology – RAD 4001
Manickam Kumaravel, M.D.
McGovern Medical School
A.R.• AA woman in her 60s w/hx of HTN, DM, and recent gastric bypass surgery a
few weeks ago presenting via ambulance for increased somnolence at home
• Per family – EMS called for AMS, LSN 0100 (current time 2300), pt only arouses to sternal rub, will wake up to answer questions sometimes appropriately, then fall asleep. Rest of history unable to obtain from pt
• PEx: • Vitals: 97.1ºF, 155/86 mmHg, 90 bpm, 20 breaths/min, SpO2 – 99%• Gen – somnolent but wakes to loud voice and sternal rub• Abd – soft, nt, nd, surgical scars clean dry and intact• Neuro – a/o x2 (not to year), antigravity in all extremities; wakes to loud voice but
nonsensical conversation• Psych – pleasant, intermittently agitated
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A.R. (cont’d)• Initial labs:
• CBC – mild normocy�c anemia: Hgb 11.6, MCV 92.7, RDW 16.3 (↑), Plt 340, WBC 5.4
• CMP – nl electrolytes (Na 138), Cr 1.64 (unknown baseline), albumin 2.6 (↓), BG 88
• Tox screen (-)
• UDS (+) – benzos and opiates
• UA – (+) ketones, (+) leukocyte ester, (+) nitrites, 11-20 WBCs
• Blood culture – (+) Staph aur.
• Initial workup:1. Toxic metabolic encephalopathy – empiric abx, head CT w/out contrast, brain MRI
w/w/out contrast
2. UTI – empiric abx
3. Drug Overdose – gave Narcan with no improvement
4. Severe Dehydration and AKI – suspected prerenal; aggressive IVF
McGovern Medical SchoolDefault Window, 07/17/19
CT Head w/out
Contrast
Brain/Sinus Window, 07/17/19
1. Periventricular White Matter (Images 17-20)2. Pons (Images 11 – 15)
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Default Window –Imgs 10-15
Brain/Sinus Window – Imgs 10-15
Normal Pons
http://casemed.case.edu/clerkships/neurology/Web%20Neurorad/ComputeTopogrCT/CT%20pons.htm
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MRI Axial T1 MRI Axial T2 FLAIR Post MRI Coronal T2
07/19/19
1. MRI Axial T1 – Img 9-17 – caudate/putamen/internal capsule/periventricular matter2. MRI Axial T2 – Img 8-11 – pons3. MRI Coronal T2 – Image 27, 28 - pons
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MRI Axial DWI MRI Axial ADC
07/19/19
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Normal Brain Axial MRI Slices
http://www.radiologyassistant.nl/en/p48f4c4ccd9682/brain-anatomy.html#i48f4c4cceafbd
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Findings and Correlations
• AA woman in her 60s with intermittent somnolence and nonsensical speech
• CT:1. Questionable ill-defined central pontine hypodensity w/out associated mass effect [series 2, images
11-13]. Basilar artery demonstrates normal density.2. Ill-patchy hypodensity of the periventricular white matter, likely indicating microvascular ischemic
changes
• MRI:1. Chronic microvascular ischemic changes in periventricular deep white matter in shape of
periventricular and deep punctate T2 hyperintensity2. Additional T2/FLAIR hyperintensities seen in caudate, putamen, medial and posterior thalami, and
the hypothalamic walls3. Central hyperintensity sparing the periphery of the pons sparing the cortical spinal tracts on both
sides4. No restricted diffusion, no intracranial hemorrhage, no parenchymal abnormalities, no midline
deviations or evidence of herniation, normal intracranial arterial and venous flow voids
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Trident/Piglet Sign
1. https://prod-images.static.radiopaedia.org/images/21246825/3d4cea3537950b8176628408f266ac_big_gallery.jpeg2. https://www.redbubble.com/people/original04/works/29548100-poseidons-trident?p=poster3. http://www.animalpicturesociety.com/pictures-of-a-pig-3a994. https://prod-images.static.radiopaedia.org/images/18272006/fa10f6c4b63abf4414c62957d9e920_gallery.jpeg
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Differential Diagnosis
Pons
• Demyelination – osmotic demyelination syndrome, multiple sclerosis
• Infarction
• Pontine neoplasms
Basal Ganglia
• Wernicke Encephalopathy• Leigh disease – mamillary bodies are not involved, mitochondrial disorder
• Korsakoff Psychosis
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Diagnosis and Discussion
• CT Impression: Questionable hypodensity of the central pons. Although it might be artifactual, in the context of recent major GI surgery, the differential includes osmotic demyelination syndrome, and less likely brainstem ischemia. MR of the brain without contrast is recommended.
• MRI Impression: 1. Basal ganglia hyperintensities consistent with Wernicke's encephalopathy2. Pontine hyperintensities which are consistent with osmotic demyelination syndrome3. Chronic microvascular ischemic changes and diffuse volume loss
• Wernicke’s encephalopathy and osmotic demyelination syndrome both likely due to malnutrition from recent bariatric surgery
• W.E. if left untreated can have a mortality as high as 20%• Osmotic demyelination syndrome – Of those who survive (most), 1/3 recover fully, 1/3
disabled but independent, 1/3 severely disabled
• Neurology and Psychiatry were consulted – given aggressive rehydration, 3 doses of IV Thiamine/B1, discharged on oral thiamine daily with mental status significantly improved on d/c (A&O x4)
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ACR Appropriateness Criteria
• Acute mental change, delirium, new onset psychosis
• CT Head without contrast: $469
• MRI Head without and with IV Contrast: $1454
1. https://acsearch.acr.org/docs/3102409/Narrative/2. https://www.mdsave.com/procedures/ct-scan-without-contrast/d781f5cd3. https://www.mdsave.com/procedures/mri-with-and-without-contrast/d781f5cb
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Take Home Points
• Surgical history can be very useful in cases of altered mental status
• Basal ganglia hyperintensities can represent Wernicke’s encephalopathy
• Associated T2 FLAIR Hyperintensities in pons in the form of a “trident” or “piglet” can represent osmotic demyelination syndrome
• Prompt administration of IVF, Thiamine, and B1 can quickly ameliorate the patient in some cases
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References
1. http://casemed.case.edu/clerkships/neurology/Web%20Neurorad/ComputeTopogrCT/CT%20pons.htm
2. http://www.radiologyassistant.nl/en/p48f4c4ccd9682/brain-anatomy.html#i48f4c4cceafbd
3. https://prod-images.static.radiopaedia.org/images/21246825/3d4cea3537950b8176628408f266ac_big_gallery.jpeg
4. https://www.redbubble.com/people/original04/works/29548100-poseidons-trident?p=poster
5. http://www.animalpicturesociety.com/pictures-of-a-pig-3a99
6. https://prod-images.static.radiopaedia.org/images/18272006/fa10f6c4b63abf4414c62957d9e920_gallery.jpeg
7. https://acsearch.acr.org/docs/3102409/Narrative/
8. https://www.mdsave.com/procedures/ct-scan-without-contrast/d781f5cd
9. https://www.mdsave.com/procedures/mri-with-and-without-contrast/d781f5cb
10. https://radiopaedia.org/articles/osmotic-demyelination-syndrome?lang=us
11. https://en.wikipedia.org/wiki/Central_pontine_myelinolysis
12. https://radiopaedia.org/articles/wernicke-encephalopathy?lang=us
Questions?