# Dec 2022

- Link: https://isnr.in/dec-2022/
- Published: 2022-12-01T21:59:45+05:30
- Author: ISNR

## Dec 2022

**CASE HISTORY**:

A 31 year old male presented with history of seizures since 2 months. He was treated
with anti epileptics and was well controlled. Patient again developed breakthrough
seizures. No focal neurological deficits.

Auto immune work up & CSF analysis were unremarkable.

MRI Brain (Plain & Contrast) were performed.

**CASE CONTRIBUTED BY**

Dr Sumana Kedilaya, Registrar, Department of Radiology, Apollo Sheshadripuram Bangalore

Dr Vikram Kamat, Senior consultant Neurologist, Trustwell Hospital, Bangalore

Dr Chaitra Adiga, Consultant, Department of Radiology, Apollo Sheshadripuram Bangalore

| [](https://isnr.in/wp-content/uploads/2022/12/Dec1-1.jpg) | [](https://isnr.in/wp-content/uploads/2022/12/Dec1-2.jpg) | [](https://isnr.in/wp-content/uploads/2022/12/Dec1-3.jpg) | [](https://isnr.in/wp-content/uploads/2022/12/Dec1-4.jpg) | [](https://isnr.in/wp-content/uploads/2022/12/Dec1-5.jpg) | 
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| [](https://isnr.in/wp-content/uploads/2022/12/Dec1-12.jpg) |  |  |  |

## Initial MRI

| [](https://isnr.in/wp-content/uploads/2022/12/dec15a.png) | [](https://isnr.in/wp-content/uploads/2022/12/dec15b.png) | [](https://isnr.in/wp-content/uploads/2022/12/dec15c.png) | [](https://isnr.in/wp-content/uploads/2022/12/dec15d.png) |

| [](https://isnr.in/wp-content/uploads/2022/12/dec15e.jpg) | [](https://isnr.in/wp-content/uploads/2022/12/dec15f.jpg) | [](https://isnr.in/wp-content/uploads/2022/12/dec15g.jpg) | [](https://isnr.in/wp-content/uploads/2022/12/dec15h.jpg) | 
| [](https://isnr.in/wp-content/uploads/2022/12/dec15i.jpg) | [](https://isnr.in/wp-content/uploads/2022/12/dec15j.jpg) | [](https://isnr.in/wp-content/uploads/2022/12/dec15k.jpg) |  |

ØFig A-D (initially performed MRI) shows predominantly cortical T2W/FLAIR hyperintensity
in left parasagittal parieto-occipital lobes. No true restricted diffusion or bleed
noted.

Ø(Repeat MRI after 3 months) Fig E-I  show T2W/FLAIR hyperintensity with high signal
intensity on DWI & ADC representing T2-Shine through in the right parieto-temporal
cortex & subcortical white matter

ØFig J (post contrast administration) did not reveal significant enhancement.

ØFig K (MRS) showed elevated lactate is noted.

**FINAL DIAGNOSIS:**

Ø**MELAS (Mitochondrial Encephalomyopathy with Lactic Acidosis and Stroke like Episodes)**

**BACKGROUND:**

ØMELAS is a rare mitochondrial metabolic disease, and affected patients have maternal
pattern of inheritance.

Ø>80% of MELAS cases are due to point mutation in nucleotide 3243 mtDNA (A to G 
translocation) in MT-TL1 gene which codes for t-RNA^((1))

ØtRNA mutations lead to the absence or deficit of subunits of the respiratory chain
protein complexes, can lead to impaired function of cells/their death.

**CLINICAL FEATURES:**

ØOnset of MELAS is typically during childhood between 2 -20 years, although it can
get delayed until between 10-40 years

ØPresent with symptoms such as stroke like episodes, seizures, recurrent headaches,
failure to thrive, developmental delay, sensorineural hearing loss, lactic acidosis,
cortical blindness^((2))

**IMAGING FEATURES:**

ØStroke Like episodes are probably caused by abnormal mitochondria  in the endothelial
and smooth muscle cells of blood vessels, leading to impairment of the autoregulatory
vascular mechanisms.

ØMust be differentiated from ischemic vascular strokes because different management
is required

ØMELAS lesions are mostly in posterior & lateral brain regions (parieto occipital
lobes & temporal lobes)

ØMigratory T2W hyperintense lesions involving cortex & subcortical white matter^((
3))

ØHigh signal intensity on DWI with varying intensity on ADC map which reflects cytotoxic/
vasogenic edema ^((3))

Ø^(MRS  typically shows elevated lactate and reduced NAA, glutamate, myo-inositol
and total creatine.)

ØNo reduction in regional cerebral blood flow in the affected areas in MELAS ^((
2))

ØCerebral angiography most commonly reveals normal findings ^((1))

## References

1.Primary Mitochondrial Disorders of the Pediatric Central Nervous System: Neuroimaging
Findings Fabrício Guimarães Gonçalves, César Augusto Pinheiro Ferreira Alves, Beth
Heuer, James Peterson, Angela N. Viaene, Sara Reis Teixeira, Juan Sebastián Martín-
Saavedra, Savvas Andronikou, Amy Goldstein, and Arastoo Vossough RadioGraphics 2020
40:7, 2042-2067

2.Pauli W, Zarzycki A, Krzyształowski A, Walecka A. CT and MRI imaging of the brain
in MELAS syndrome. Pol J Radiol. 2013 Jul;78(3):61-5. doi: 10.12659/PJR.884010. 
PMID: 24115962; PMCID: PMC3789935.

3.Cheng W, Zhang Y and He L (2022) MRI Features of Stroke-Like Episodes in Mitochondrial
Encephalomyopathy With Lactic Acidosis and Stroke-Like Episodes. Front. Neurol. 
13:843386.