INTERESTING IMAGE

Multimodal Imaging-Monitored Progression of Stroke-Like
Episodes in a Case of MELAS Syndrome
Izzie Jacques Namer, MD, PhD,*§ Valérie Wolff, MD,Þ Jean-Louis Dietemann, MD,þ§
and Christian Marescaux, MDÞ
Abstract: We report imaging findings during, between, and after 2 stroke-like
episodes in a 45-year-old woman with mitochondrial myopathy, encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome with an
A32243G mitochondrial mutation 6 years before. In November 2010, for a
first episode, she showed mixed aphasia with logorrhea, disinhibition, agitation, euphoria, and a large left temporoparietal lesion. Symptomatology progressively regressed under L-arginine treatment. She was readmitted in June
2011 for a second episode with great anxiety, disorientation, impaired face
recognition, worsening mixed aphasia, and a new right temporal lesion. After
additional L-carnitine treatment, she remained without relapse for 14 months.
Key Words: MELAS, neuroimaging, FDG PET, SPECT, MRI, MRS
(Clin Nucl Med 2014;39: e239Ye240)

Received for publication September 6, 2012; and revision accepted December 29,
2012.
From the *Service de Biophysique et Médecine Nucléaire, †Unité de Neurovasculaire, and ‡Service de Radiologie, Hôpital de Hautepierre, Hôpitaux
Universitaires de Strasbourg, Strasbourg; and §Université de Strasbourg/
CNRS, UMR 7237, Strasbourg, France.
Conflicts of interest and sources of funding: none declared.
Reprints: Izzie Jacques Namer, MD, PhD, Service de Biophysique et de Médecine
Nucléaire, Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, 1,
avenue Molière, 67098 Strasbourg Cedex 09, France. E-mail:
Izzie.Jacques.NAMER@chru-strasbourg.fr.
Copyright * 2013 by Lippincott Williams & Wilkins
ISSN: 0363-9762/14/3903Ye239

Clinical Nuclear Medicine & Volume 39, Number 3, March 2014

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Namer et al

FIGURE 1. Matched temporal level transverse slices showing multimodal brain imaging during (November 2010 and June 2011)
and after stroke-like episodes in MELAS syndrome: 1H magnetic resonance spectroscopy (MRS) (A, C), fluid-attenuated inversion
recovery magnetic resonance imaging (FLAIR MRI) (B), 18F-FDG PET (D), and 99mTc-HMPAO SPECT (E). In both episodes, 18F-FDG
PET and 99mTc-HMPAO SPECT were performed the same day, and MRI/MRS were performed within 48 hours.In the acute phase of
the first (fifth day) and the second (third day) stroke-like episodes, FLAIR MRI showed a large cortical and subcortical hyperintensity
on the left temporal and later right temporal regions, which does not correspond to a vascular territory.1Y3 These lesions were
characterized by decreased N-acetylaspartate, decreased FDG metabolism, and hyperemia.1,4Y9 We detected a high level of lactate
in all cerebral parenchyma including normal-appearing tissue and in lateral ventricles related to systemic lactic acidosis.1Y4,9 The
hyperemia observed in the acute phase seems to have been caused by vasodilatation due to a passive response to tissue acidosis
resulting from impaired oxidative metabolism in mitochondria and differed from luxury perfusion after ischemic stroke.5In the
chronic phase, we observed a persistently high level of lactate as well as severe and expanded hypometabolized and hypoperfused
areas affecting bilateral temporal regions, despite the decreased FLAIR MRI abnormality and partial recovery of N-acetylaspartate.3,9
Note the appearance of generalized brain atrophy in less than 2 years,4 despite no relapse for 14 months under L-arginine2
and L-carnitine10 treatment.

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Copyright © 2014 Lippincott Williams & Wilkins. Unauthorized reproduction of this article is prohibited.