VITOR MARQUES CALDAS
Projetos de Pesquisa
Unidades Organizacionais
LIM/45 - Laboratório de Fisiopatologia Neurocirúrgica, Hospital das Clínicas, Faculdade de Medicina
6 resultados
Resultados de Busca
Agora exibindo 1 - 6 de 6
- Radiologic and histologic findings in Sjogren's sensory neuronopathy(2019) GRATIVVOL, Ronnyson Susano; CAVALCANTE, Wagner Cid Palmeira; VENTURA, Lais Maria Gomes de Brito; CALDAS, Vitor Marques; LUCATO, Leandro Tavares; LOURENCO, Silvia Vanessa; HEISE, Carlos Otto; NITRINI, Ricardo
- Electrophysiological study of neuromuscular junction in congenital myasthenic syndromes, congenital myopathies, and chronic progressive external ophthalmoplegia(2020) CALDAS, Vitor Marques; HEISE, Carlos Otto; KOUYOUMDJIAN, Joao Aris; ZAMBON, Antonio Alberto; SILVA, Andre Macedo Serafim; ESTEPHAN, Eduardo de Paula; ZANOTELI, EdmarThis study was designed to analyze the sensitivity, specificity, and accuracy of jitter parameters combined with repetitive nerve stimulation (RNS) in congenital myasthenic syndrome (CMS), chronic progressive external ophthalmoplegia (CPEO), and congenital myopathies (CM). Jitter was obtained with a concentric needle electrode during voluntary activation of the Orbicularis Oculi muscle in CMS ( n = 21), CPEO ( n = 20), and CM ( n = 18) patients and in controls ( n = 14). RNS (3 Hz) was performed in six different muscles for all patients ( Abductor Digiti Minimi, Tibialis Anterior, upper Trapezius, Deltoideus, Orbicularis Oculi, and Nasalis). RNS was abnormal in 90.5% of CMS patients and in only one CM patient. Jitter was abnormal in 95.2% of CMS, 20% of CPEO, and 11.1% of CM patients. No patient with CPEO or CM presented a mean jitter higher than 53.6 mu s or more than 30% abnormal individual jitter (> 45 mu s). No patient with CPEO or CM and mild abnormal jitter values presented an abnormal decrement. Jitter and RNS assessment are valuable tools for diagnosing neuromuscular transmission abnormalities in CMS patients. A mean jitter value above 53.6 mu s or the presence of more than 30% abnormal individual jitter (> 45 mu s) strongly suggests CMS compared with CPEO and CM.
- Pearls & Oy-sters: A curable myopathy manifesting as exercise intolerance and respiratory failure(2018) SILVA, Andre M. S.; MENDONCA, Rodrigo H.; SOARES, Diogo C.; CALLEGARO, Dagoberto; CALDAS, Vitor M.; PERISSINOTTI, Iago N.; CARVALHO, Mary S.; ZANOTELI, Edmar
- A common CHRNE mutation in Brazilian patients with congenital myasthenic syndrome(2018) ESTEPHAN, Eduardo de Paula; SOBREIRA, Claudia Ferreira da Rosa; SANTOS, Andre Cleriston Jose dos; TOMASELLI, Pedro Jose; MARQUES JR., Wilson; ORTEGA, Roberta Paiva Magalhes; COSTA, Marcela Camara Machado; SILVA, Andre Macedo Serafim da; MENDONCA, Rodrigo Holanda; CALDAS, Vitor Marques; ZAMBON, Antonio Alberto; ABATH NETO, Osorio; MARCHIORI, Paulo Euripedes; HEISE, Carlos Otto; REED, Umbertina Conti; AZUMA, Yoshiteru; TOPF, Ana; LOCHMULLER, Hanns; ZANOTELI, EdmarThe most common causes of congenital myasthenic syndromes (CMS) are CHRNE mutations, and some pathogenic allelic variants in this gene are especially frequent in certain ethnic groups. In the southern region of Brazil, a study found the c.130dupG CHRNE mutation in up to 33% of families with CMS. Here, we aimed to verify the frequency of this mutation among individuals with CMS in a larger cohort of CMS patients from different areas of Brazil and to characterize clinical features of these patients. Eighty-four patients with CMS, from 72 families, were clinically evaluated and submitted to direct sequencing of the exon 2 of CHRNE. The c.130dupG mutation was found in 32 patients (23 families), with 26 patients (19 families, 26.3%) in homozygosis, confirming its high prevalence in different regions of Brazil. Among the homozygous patients, the following characteristics were frequent: onset of symptoms before 2 years of age (92.3%), little functional restriction (92.3%), fluctuating symptoms (100%), ocular muscle impairment (96.1%), ptosis (100%), limb weakness (88.4%), response to pyridostigmine (100%), facial involvement (77%), and bulbar symptoms (70.8%). The pretest probability of finding at least one allele harbouring the c.130dupG mutation was 38.1%. Selecting only patients with impaired eye movement together with limb weakness and improvement with pyridostigmine, the probability increases to 72.2%. This clinical pre-selection of patients is likely a useful tool for regions where CHRNE mutations have a founder effect. In conclusion, the CHRNE mutation c.130dupG leads to fairly benign natural course of the disease with relative homogeneity.
- Clinical variability of early-onset congenital myasthenic syndrome due to biallelic RAPSN mutations in Brazil(2018) ESTEPHAN, Eduardo de Paula; ZAMBON, Antonio Alberto; MARCHIORI, Paulo Euripedes; SILVA, Andre Macedo Serafim da; CALDAS, Vitor Marques; MORENO, Cristiane Araujo Martins; REED, Umbertina Conti; HORVATH, Rita; TOPF, Ana; LOCHMUELLER, Hanns; ZANOTELI, EdmarMutations in RAPSN are an important cause of congenital myasthenic syndrome (CMS), leading to endplate acetylcholine receptor deficiency. We present three RAPSN earlyonset CMS patients (from a Brazilian cohort of 61 CMS patients). Patient 1 and patient 2 harbor the mutation p.N88K in homozygosity, while patient 3 harbors p.N88K in compound heterozygosity with another pathogenic variant (p.V165M; c.493G > A). At onset, patient 3 presented with more severe symptoms compared to the other two, showing generalized weakness and repeated episodes of respiratory failure in the first years of life. During adolescence, she became gradually less symptomatic and does not require medication anymore, presenting better long-term outcomes than patients 1 and 2. This case series illustrates the variability of RAPSN earlyonset CMS, with patient 3, despite severe onset, revealing an almost complete reversal of myasthenic symptoms, not limited to apneic episodes. Moreover, it suggests that RAPSN CMS may be underdiagnosed in nonEuropean countries.
- A novel ATP1A2 mutation in a patient with hypokalaemic periodic paralysis and CNS symptoms(2018) CASTANEDA, Marisol Sampedro; ZANOTELI, Edmar; SCALCO, Renata S.; SCARAMUZZI, Vinicius; CALDAS, Vitor Marques; REED, Umbertina Conti; SILVA, Andre Macedo Serafim da; O'CALLAGHAN, Benjamin; PHADKE, Rahul; BUGIARDINI, Enrico; SUD, Richa; MCCALL, Samuel; HANNA, Michael G.; POULSEN, Hanne; MANNIKKO, Roope; MATTHEWS, EmmaHypokalaemic periodic paralysis is a rare genetic neuromuscular disease characterized by episodes of skeletal muscle paralysis associated with low serum potassium. Muscle fibre inexcitability during attacks of paralysis is due to an aberrant depolarizing leak current through mutant voltage sensing domains of either the sarcolemmal voltage-gated calcium or sodium channel. We report a child with hypokalaemic periodic paralysis and CNS involvement, including seizures, but without mutations in the known periodic paralysis genes. We identified a novel heterozygous de novo missense mutation in the ATP1A2 gene encoding the alpha 2 subunit of the Na+/K+-ATPase that is abundantly expressed in skeletal muscle and in brain astrocytes. Pump activity is crucial for Na+ and K+ homeostasis following sustained muscle or neuronal activity and its dysfunction is linked to the CNS disorders hemiplegic migraine and alternating hemiplegia of childhood, but muscle dysfunction has not been reported. Electrophysiological measurements of mutant pump activity in Xenopus oocytes revealed lower turnover rates in physiological extracellular K+ and an anomalous inward leak current in hypokalaemic conditions, predicted to lead to muscle depolarization. Our data provide important evidence supporting a leak current as the major pathomechanism underlying hypokalaemic periodic paralysis and indicate ATP1A2 as a new hypokalaemic periodic paralysis gene.