Magnetic resonance spectroscopy in MELAS syndrome: correlation with CSF and plasma metabolite levels and change after glutamine supplementation.

Purpose: MELAS syndrome is a genetic disorder caused by mitochondrial DNA mutations. We previously described that MELAS patients had increased CSF glutamate and decreased CSF glutamine levels and that oral glutamine supplementation restores these values. Proton magnetic resonance spectroscopy (H-MRS) allows the in vivo evaluation of brain metabolism.

Delayed Diagnosis of Congenital Myasthenic Syndromes Erroneously Interpreted as Mitochondrial Myopathies.

Background: Congenital myasthenic syndromes (CMSs) and primary mitochondrial myopathies (PMMs) can present with ptosis, external ophthalmoplegia, and limb weakness.

Methods: Our method involved the description of three cases of CMS that were initially characterized as probable PMM.

Results: All patients were male and presented with ptosis and/or external ophthalmoplegia at birth, with proximal muscle weakness and fatigue on physical exertion.

Serum GDF-15 Levels Accurately Differentiate Patients with Primary Mitochondrial Myopathy, Manifesting with Exercise Intolerance and Fatigue, from Patients with Chronic Fatigue Syndrome.

Primary mitochondrial myopathies (PMM) are a clinically and genetically highly heterogeneous group that, in some cases, may manifest exclusively as fatigue and exercise intolerance, with minimal or no signs on examination. On these occasions, the symptoms can be confused with the much more common chronic fatigue syndrome (CFS). Nonetheless, other possibilities must be excluded for the final diagnosis of CFS, with PMM being one of the primary differential diagnoses.

High-dose oral glutamine supplementation reduces elevated glutamate levels in cerebrospinal fluid in patients with mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes syndrome.

Background And Purpose: Mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes (MELAS) syndrome is a genetically heterogeneous disorder caused by mitochondrial DNA mutations. There are no disease-modifying therapies, and treatment remains mainly supportive. It has been shown previously that patients with MELAS syndrome have significantly increased cerebrospinal fluid (CSF) glutamate and significantly decreased CSF glutamine levels compared to controls.

New Cerebellar Ataxia, Neuropathy, Vestibular Areflexia Syndrome cases are caused by the presence of a nonsense variant in compound heterozygosity with the pathogenic repeat expansion in the RFC1 gene.

The biallelic pathogenic repeat (AAGGG) intronic expansion in the RFC1 gene has been recently described as the cause of cerebellar ataxia, neuropathy, vestibular areflexia syndrome (CANVAS) and as a major cause of late-onset ataxia. Since then, many heterozygous carriers have been identified, with an estimated allele frequency of 0.7% to 4% in the healthy population.

Elevated glutamate and decreased glutamine levels in the cerebrospinal fluid of patients with MELAS syndrome.

Background: Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome is a genetically heterogeneous disorder caused by mitochondrial DNA (mtDNA) mutations in the MT-TL1 gene. The pathophysiology of neurological manifestations is still unclear, but neuronal hyperexcitability and neuron-astrocyte uncoupling have been suggested. Glutamatergic neurotransmission is linked to glucose oxidation and mitochondrial metabolism in astrocytes and neurons.

Antisaccades and memory-guided saccades in genetic generalized epilepsy and temporal lobe epilepsy.

Objective: Oculomotor tasks can be used to measure volitional control of behavior sensitive to frontal dysfunction. This study aimed to examine the saccadic eye movement in Genetic Generalized Epilepsy (GGE) which could correlate with the abnormality of the frontal lobe or the thalamo-frontal network.

Methods: Twenty-one patients with GGE were compared with 22 patients with Temporal Lobe Epilepsy (TLE) and 39 healthy controls.

Pure alexia: two cases and a new neuroanatomical classification.

Pure alexia without visual or language accompanying deficits (isolated pure alexia), represents an infrequent finding in clinical practice. It has been linked to lesions involving the splenium of the callosal corpus in classical descriptions; however, it has also been reported after occipito-temporal cortex damage in the absence of white matter implication. In this regard, a functional region called the visual word form area has been recently related to the posterior aspect of the occipitotemporal gyrus.