New Variant of MELAS Syndrome With Executive Dysfunction, Heteroplasmic Point Mutation in the MT-ND4 Gene (m.12015T>C; p.Leu419Pro) and Comorbid Polyglandular Autoimmune Syndrome Type 2.

Background: Mitochondrial diseases are caused by dysfunctions in mitochondrial metabolic pathways. MELAS syndrome is one of the most frequent mitochondrial disorders; it is characterized by encephalopathy, myopathy, lactic acidosis, and stroke-like episodes. Typically, it is associated with a point mutation with an adenine-to-guanine transition at position 3243 of the mitochondrial DNA (mtDNA; m.3243A>G) in the mitochondrially encoded tRNA leucine 1 (MT-TL1) gene. Other point mutations are possible and the association with polyglandular autoimmune syndrome type 2 has not yet been described. Case presentation: We present the case of a 25-year-old female patient with dysexecutive syndrome, muscular fatigue, and continuous headache. Half a year ago, she fought an infection-triggered Addison crisis. As the disease progressed, she had two epileptic seizures and stroke-like episodes with hemiparesis on the right side. Cerebral magnetic resonance imaging showed a substance defect of the parieto-occipital left side exceeding the vascular territories with a lactate peak. The lactate ischemia test was clearly positive, and a muscle biopsy showed single cytochrome c oxidase-negative muscle fibers. Genetic testing of blood mtDNA revealed a heteroplasmic base exchange mutation in the mitochondrially encoded NADH:ubiquinone oxidoreductase core subunit 4 (MT-ND4) gene (m.12015T>C; p.Leu419Pro; heteroplasmy level in blood 12%, in muscle tissue: 15%). The patient suffered from comorbid autoimmune polyglandular syndrome type 2 with Hashimoto's thyroiditis, Addison's disease, and autoimmune gastritis. In addition, we found increased anti-glutamic acid decarboxylase 65, anti-partial cell, anti-intrinsic factor, and anti-nuclear antibodies. Conclusion: We present an atypical case of MELAS syndrome with predominant symptoms of a dysexecutive syndrome, two stroke-like episodes, and fast-onset fatigue. The symptoms were associated with a not yet described base and aminoacid exchange mutation in the MT-ND4 gene (m.12015T>C to p.Leu419Pro). The resulting changed protein complex in our patient is part of the respiratory chain multicomplex I and might be the reason for the mitochondriopathy. However, different simulations for pathogenetic relevance are contradictory and rather speak for a benign variant. To our knowledge this case report is the first reporting MELAS syndrome with comorbid polyglandular autoimmune syndrome type 2. Screening for autoimmune alterations in those patients is important to prevent damage to end organs.

Facioscapulohumeral muscular dystrophy presenting with isolated axial myopathy and bent spine syndrome.

Several subtypes of facioscapulohumeral muscular dystrophy (FSHD) with atypical clinical presentation have been described. We report a new, distinct phenotype with progressive bent spine syndrome solely affecting the paraspinal muscles. Magnetic resonance imaging study of the lumbar spine revealed marked atrophy of the paraspinal muscles. The diagnosis was confirmed by DNA testing, which revealed shortened restriction fragments of the D4Z4 repeat on haplotype A in connection with a positive family history.

Maturation of inhibitory and excitatory motor cortex pathways in children.

OBJECTIVE: To study intracortical inhibition and facilitation with paired-pulse transcranial magnetic stimulation in children, adolescents and adults. METHODS: Paired-pulse transcranial magnetic stimulation (interstimulus intervals (ISI): 1, 3, 5, 10 and 20 ms) was applied over the primary motor cortex (M1) in 30 healthy subjects (range 6-30 years, median age 15 years and 8 months, SD 7,9) divided in three groups: adults (>or=18 years), adolescents (> 10 and < 18 years) and children (

Portosystemic myelopathy: spastic paraparesis after portosystemic shunting.

Portosystemic encephalopathy (PSE) is a well-known, common complication of portal hypertension. It is thought to be caused by nitrogenous substances such as ammonia, which are normally cleared from the blood stream by the liver. In cirrhosis and other hepatic disorders with portosystemic shunting (PSS)-- either surgical portosystemic anastomoses (PSA) or spontaneous PSS-- the collateral vessels bypass the liver allowing the accumulation of toxic, ammoniacal substances in the blood and tissues. PSE is characterized by encephalopathy; portosystemic myelopathy (PSM) is characterized by paresis of the extremities, Babinski signs and muscle spasticity in patients with cirrhosis and/or PSS. Usually only the lower extremities are involved. This report presents the first case of this syndrome observed 5 years after a transjugular intrahepatic portosystemic shunt. The 31 year old man with chronic Hepatitis B developed complete spastic paraparesis within 4 weeks after onset of clinical/neurological symptoms, accompanied by an episode of severe hepatic encephalopathy. The transcortical magnetic stimulation showed normal motoric stimulation times to the abductor digiti minimi muscles but no stimulation to the tibialis muscles was seen. Lumbar stimulation to the tibialis muscles, however, was normal. This indicates loss of motor neurons in the spinal cord, a characteristic finding in patients with portosystemic myelopathy. We performed a search of the literature for all reported cases of cirrhosis and/or PSS that developed PSM. However, the intervals between the construction of a shunt and the diagnosis of portosystemic myelopathy were shorter in total portacaval shunts (median 16 months) than in partial, non-portacaval shunts (median 60 months, p < 0.01). This suggests that not only the shunt itself but also the shunted volume contributes to the development of the syndrome Sixty-one patients with PSM have been reported in the literature since 1944. PSE had developed before PSM in almost all cases. PSM occurred from 1 month to 10 years after the creation of portacaval anastomoses (PCA) or splenorenal shunts (SRS) or in cirrhotic patients without shunts. No one type of liver disease or type of shunt appears to predispose to PSM. The mechanisms of PSE and PSM are thought to be similar and of nitrogenous origin, but their pathogenesis remains unknown. Lathyrism, a toxic syndrome with similar symptoms and signs, is caused by the ingestion of a legume, Lathyrus sativa, which contains beta-N-oxalo-L amino-L-alanine (BOAA). This animal model with or without BOAA appears to offer a reliable way of studying PSM experimentally.