Botulinum toxin type-A effect as a preemptive treatment in a model of acute trigeminal pain: a pre-clinical double-blind and placebo-controlled study.

The purpose of this study was to investigate if botulinum neurotoxin type-A (BoNT/A) had a preemptive antinociceptive effect in a formalin-induced orofacial pain model (FT). To test this hypothesis, male Rattus norvegicus were injected with isotonic saline solution 0.9% or BoNT/A administered as a 40 µl bolus, lateral to their nose, at 24 hours, 8, 15, 22, 29 or 36 days pre-FT. The procedures were repeated 42 days later. Influence on motor activity was assessed through the open-field test. Pain scores corresponded to the time spent rubbing and flicking the injected area. Animals pre-treated with BoNT/A at the first protocol (8 days subgroup) showed reduced inflammatory scores (p=0.011). For the other groups no significant results were observed at any phase. Motor activity was similar in both groups. BoNT/A showed to be effective preventing inflammatory pain up to eight days after the first treatment, an effect not reproduced on the second dose administration.

Botulinum toxin type-A effect as a preemptive treatment in a model of acute trigeminal pain: a pre-clinical double-blind and placebo-controlled study / Toxina botulínica do tipo-A no tratamento preemptivo da dor trigeminal aguda: estudo pré-clínico duplo cego placebo controlado

The purpose of this study was to investigate if botulinum neurotoxin type-A (BoNT/A) had a preemptive antinociceptive effect in a formalin-induced orofacial pain model (FT). To test this hypothesis, male Rattus norvegicus were injected with isotonic saline solution 0.9 percent or BoNT/A administered as a 40 μl bolus, lateral to their nose, at 24 hours, 8, 15, 22, 29 or 36 days pre-FT. The procedures were repeated 42 days later. Influence on motor activity was assessed through the open-field test. Pain scores corresponded to the time spent rubbing and flicking the injected area. Animals pre-treated with BoNT/A at the first protocol (8 days subgroup) showed reduced inflammatory scores (p=0.011). For the other groups no significant results were observed at any phase. Motor activity was similar in both groups. BoNT/A showed to be effective preventing inflammatory pain up to eight days after the first treatment, an effect not reproduced on the second dose administration.

O objetivo deste estudo foi investigar o efeito preemptivo da neurotoxina botulínica do tipo/A (NTBo/A) através de um modelo de dor orofacial induzida pelo teste da formalina (TF). Rattus norvegicus machos foram injetados no lábio superior com solução salina isotônica 0,9 por cento (SSI) ou NTBo/A (subgrupos 24 horas, 8, 15, 22, 29 ou 36 dias) antes do TF, em dois tratamentos farmacológicos e respectivas avaliações intercalados por 42 dias. Os escores da dor corresponderam ao tempo de fricção da região injetada. Após o primeiro pré-tratamento com NTBo/A no subgrupo 8 dias os escores da fase inflamatória foram menores do que no grupo SSI (p=0,011). Todas as outras comparações não foram significativas. Nos testes de atividade motora não ocorreram diferenças entre SSI e NTBo/A. A NTBo/A pode ser considerada como tratamento preemptivo das dores orofaciais quando utilizada até oito dias antes do estímulo álgico, não havendo consistência terapêutica após um segundo tratamento.

Botulinum neurotoxin type-A for primary stabbing headache: an open study.

Primary stabbing headache is an ultra-short headache, associated with primary headaches, more prevalent in women and with a poor response to therapy. The effect of botulinum neurotoxin type-A (BoNTA) on primary stabbing headache was investigated in 24 patients. Three patients showed complete remission. Nineteen patients showed a decrease in their primary stabbing headaches that started in the second week, and that was sustained during approximately 63 days. In two patients BoNTA showed no therapeutic effect. The BoNTA seems to be an excellent therapeutic option for primary stabbing headache.

Botulinum neurotoxin type-A for primary stabbing headache: an open study / Toxina botulínica do tipo-A para o tratamento da cefaléia primária em punhaladas: um estudo aberto

Primary stabbing headache is an ultra-short headache, associated with primary headaches, more prevalent in women and with a poor response to therapy. The effect of botulinum neurotoxin type-A (BoNTA) on primary stabbing headache was investigated in 24 patients. Three patients showed complete remission. Nineteen patients showed a decrease in their primary stabbing headaches that started in the second week, and that was sustained during approximately 63 days. In two patients BoNTA showed no therapeutic effect. The BoNTA seems to be an excellent therapeutic option for primary stabbing headache.

Cefaléia primária em punhaladas (CPP) é uma cefaléia ultra-rápida, associada a cefaléias primárias, mais frequente em mulheres e com discreta resposta terapêutica. O efeito da neurotoxina botulínica do tipo A (NTBo-A) sobre a CPP foi investigado em 24 pacientes. Três pacientes apresentaram completa remissão dos sintomas. Dezenove pacientes mostraram uma redução que começou na segunda semana e que manteve-se por um período de 63 dias. Em dois pacientes a NTBo-A não apresentou nenhum efeito terapêutico. A NTBo-A parece ser uma excelente opção terapêutica no tratamento da CPP.

Uncontrolled headache induced by oxcarbazepine.

Headache induced by acute exposure to a specific drug constitutes an idiosyncratic side effect. Metabolic imbalance appears as the leading aetiology, among several other hypotheses. Either primary headaches show a higher susceptibility to this idiosyncratic reaction or a drug-induced primary headache evolves in intensity and duration, becoming uncontrolled until the complete discontinuation of the drug in consideration. The goal of this study is to describe three patients diagnosed with migraine and epilepsy (both under control) who evolved into status migrainosus after the introduction of oxcarbazepine (OXC), as part of a switch off from carbamazepine (CBZ). Twenty-four to seventy-two hours following the switch, all patients developed intractable headache, despite the use of different symptomatic drugs. Complete recovery of the headache symptoms occurred only after OXC was discontinued. We discuss the potential mechanisms associated to OXC and status migrainosus, drug-induced headaches and uncontrolled headaches.

Ataxias cerbelares hereditárias: do martelo ao gen / Hereditary cerebellar ataxias from neurological hammer to genetics

As heredoataxias constituem grupo complexo de doenças neurodegenerativas hereditárias, para o qual várias formas de classificaçäo clínica e patológica foram propostas com sucesso variável. O desenvolvimento das tTcnicas de biologia molecular trouxe informaçöes importantes que têm permitido caracterizar geneticamente as ataxias cerebelares hereditárias. O reconhecimento das doenças causadas por expansöes de trinucleotídeos abre novo capítulo para a pesquisa sobre outros mecanismos de doenças, como na ataxia de Friedreich e nas várias formas de ataxia cerebelar autossômica dominante(SCA1 a SCA7), das quais a doença de Machado-Joseph/SCA3 parece ser a mais comum no nosso meio. A deficiência familial de vitamina E (cromossomo 8q) leva a quadro semelhante ao da ataxia de Friedreich (cromossomo 9p), mas responde à reposiçäo oral de tocoferol. Formas familiais de ataxia periódica com (cromossomo 12p) ou sem (cromossomo 19p) mioquimia foram caracterizadas, a primeira resultado de mutaçöes dos gens de canais de potássio. Os portadores do gen da ataxia-teleangiectasia (cromossomo 11q) representam 1-3 por cento da populaç1 e säo suscetíveis aos efeitos oncogânicos da radiaçäo iônica. Sem olvidar da importância da avaliaçäo clínica neurológica, a avaliaçäo genética laboratorial passa a ser valiosa ferramenta para o diagnóstico e aconselhamento genético, além do melhor entendimento da patogênese dessas doenças.

Síndrome de Isaacs: relato de um caso / Isaacs syndrome: report of a case

Relato do caso de paciente do sexo feminino com 40 anos de idade, com quadro progressivo de diminuiçäo de força, disfonia, disfagia, dispnéia e hiperidrose. O exame físico revelava contratura em flexäo das mäos, déficit de força muscular, fasciculaçöes, mioquimia facial e pseudomiotonia nas mäos. A eletromiografia mostrou atividade elétrica contínua em repouso. O estudo histoquímico muscular revelou atrofia de fibras do tipo II, enquanto a microscopia eletrônica mostrou dilataçäo importante das cisternas do retículo sarcoplasmático. O diagnóstico de síndrome de Isaacs foi firmado. Excelente resposta clínica ao emprego de carbamazepina foi observada. Säo discutidos e revistos vários aspectos relacionados a essa rara síndrome