Dados do Trabalho

Título

INITIAL MANIFESTATIONS OF MITOCHONDRIAL MYOPATHY, ENCEPHALOPATHY, LACTIC ACIDOSIS AND STROKE-LIKE EPISODES (MELAS) AT AN INFANT

Apresentação do caso

The following case is a description of two-year-old girl whose diagnostic for Mitochondrial Myopathy was considered after presenting two episodes of impaired consciousness. At first, she was admitted at a paediatric emergency with fever, nasal discharge and sleepiness, at eight months old. Cerebrospinal Fluid analysis came normal. After a short period of clinical observation, consciousness was improved and the patient was discharged. Ten days later, the girl presented irritability alternating with sleepiness. Computerized Tomography head scan showed hypodense areas: cortex- subcortical in anterior convexity of frontal lobes, in parietal parasagittal area in left cerebral hemisphere and in right cerebellar hemisphere (suggesting stroke-like episodes, not limited to a vascular territory). No mass effect was seen. The patient was admitted for meningoencephalitis’ treatment while clinical condition progressed to neurodevelopmental regression with irresponsiveness events and choreic movements. Valproic acid, carbamazepine and clonazepam were prescribed for seizures suppression without satisfactory results. Haloperidol was used to control the chorea. Increased serum levels of Creatine Phosphokinase was found as well as high lactate levels in Cerebrospinal Fluid (CSF), suggesting a Metabolic disease. Levetiracetam was initiated to replace valproic acid and carbamazepine. Food supplements were prescribed. Muscular biopsy evinced abnormal subsarcolemmal accumulations of eosinophilic material (that may correspond to mitochondria) when coloured by Gomori’s modified Trichrome.

Discussão

Initially described in 1984 and still with uncertain prevalence in global population, Mitochondrial myopathy, Encephalopathy, Lactic Acidosis and Stroke-like episodes (MELAS) has been widely used as a model to study Mitochondrial diseases. The adenine-t-guanine transition at point 3243 of the mitochondrial genome (m.3243A>G) is described as responsible for up to eighty per cent of this metabolic disease, but the same mutation was found in other genetic diseases, and some other mutations were found in MELAS. Three almost invariable criteria were described for diagnosis of MELAS: Stroke-like episodes before age of 40 years old, encephalopathy (dementia, seizures or both) and Lactic Acidosis or Ragged-red fibres (or both).

Comentários finais

The exposed case fulfils all the three criterion. The patient had eventually stopped taking Levetiracetam and is currently neurologically stable.

Referências (se houver)

Lorenzoni PJ, Werneck LC, Kay CS, Silvado CE, Scola RH. When should MELAS (Mitochondrial myopathy, Encephalopathy, Lactic Acidosis, and Stroke-like episodes) be the diagnosis? Arq Neuropsiquiatr. 2015 Nov;73(11):959-67. doi: 10.1590/0004-282X20150154. PMID: 26517220.
Sproule DM, Kaufmann P. Mitochondrial encephalopathy, lactic acidosis, and strokelike episodes: basic concepts, clinical phenotype, and therapeutic management of MELAS syndrome. Ann N Y Acad Sci. 2008 Oct;1142:133-58. doi: 10.1196/annals.1444.011. Erratum in: Ann N Y Acad Sci. 2009 Apr;1161:601. PMID: 18990125.
El-Hattab AW, Adesina AM, Jones J, Scaglia F. MELAS syndrome: Clinical manifestations, pathogenesis, and treatment options. Mol Genet Metab. 2015 Sep-Oct;116(1-2):4-12. doi: 10.1016/j.ymgme.2015.06.004. Epub 2015 Jun 15. PMID: 26095523.
Tetsuka S, Ogawa T, Hashimoto R, Kato H. Clinical features, pathogenesis, and management of stroke-like episodes due to MELAS. Metab Brain Dis. 2021 Dec;36(8):2181-2193. doi: 10.1007/s11011-021-00772-x. Epub 2021 Jun 12. PMID: 34118021.
Malhotra K, Liebeskind DS. Imaging of MELAS. Curr Pain Headache Rep. 2016 Sep;20(9):54. doi: 10.1007/s11916-016-0583-7. PMID: 27477183.

Declaração de conflito de interesses de TODOS os autores

No conflit of interest were declared