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

McGovern Medical School

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)

McGovern Medical School

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

McGovern Medical School

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

McGovern Medical School

MRI Axial DWI MRI Axial ADC

07/19/19

McGovern Medical School

Normal Brain Axial MRI Slices

http://www.radiologyassistant.nl/en/p48f4c4ccd9682/brain-anatomy.html#i48f4c4cceafbd

McGovern Medical School

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

McGovern Medical School

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

McGovern Medical School

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

McGovern Medical School

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)

McGovern Medical School

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

McGovern Medical School

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

McGovern Medical School

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?