Placebo and nocebo effects in the neurological practice.

Knowledge of placebo and nocebo effects is essential to identify their influence on the results in clinical practice and clinical trials, and thereby properly interpret their results. It is known that the gold standard of clinical trials research is the double-blind, placebo-controlled, randomized clinical study. The objective of this review is to distinguish specific from non-specific effects, so that the presence of positive effects in the group that received placebo (placebo effect) and the presence of adverse effects in the group receiving placebo (nocebo effect) lead to confounding in interpreting the results. Placebo and nocebo effects have been considered in neurological diseases such as depression, pain, headache, multiple sclerosis, epilepsy. As placebo and nocebo effects are also present in clinical practice, the purpose of this review is to draw attention to their influence on neurological practice, calling attention to the development of measures that can minimize them.

Placebo and nocebo effects in the neurological practice / Efeitos placebo e nocebo na prática neurológica

Knowledge of placebo and nocebo effects is essential to identify their influence on the results in clinical practice and clinical trials, and thereby properly interpret their results. It is known that the gold standard of clinical trials research is the double-blind, placebo-controlled, randomized clinical study. The objective of this review is to distinguish specific from non-specific effects, so that the presence of positive effects in the group that received placebo (placebo effect) and the presence of adverse effects in the group receiving placebo (nocebo effect) lead to confounding in interpreting the results. Placebo and nocebo effects have been considered in neurological diseases such as depression, pain, headache, multiple sclerosis, epilepsy. As placebo and nocebo effects are also present in clinical practice, the purpose of this review is to draw attention to their influence on neurological practice, calling attention to the development of measures that can minimize them.

O conhecimento dos efeitos placebo e nocebo é essencial para identificar a sua influência sobre os resultados na prática clínica e ensaios clínicos, e, assim, interpretar corretamente seus resultados. Sabe-se que o padrão-ouro dos estudos clínicos de pesquisa é o ensaio clínico randomizado, placebo-controlado, duplo-cego. O objetivo da revisão é distinguir os efeitos específicos e não específicos, de modo que a presença de efeitos positivos no grupo que recebeu placebo (efeito placebo) e a presença de efeitos adversos no grupo que recebeu placebo (efeito nocebo) levam à confusão na interpretação dos resultados. Placebo e nocebo são descritos em doenças neurológicas como a depressão, dor, cefaleia, esclerose múltipla, epilepsia. Como os efeitos placebo e nocebo também se projetam na prática clínica, o objetivo desta revisão é o de destacar sua influência na prática neurológica, chamando a atenção para o desenvolvimento de medidas que possam minimizá-los.

Palm to Finger Ulnar Sensory Nerve Conduction.

Ulnar neuropathy at the wrist (UNW) is rare, and always challenging to localize. To increase the sensitivity and specificity of the diagnosis of UNW many authors advocate the stimulation of the ulnar nerve (UN) in the segment of the wrist and palm. The focus of this paper is to present a modified and simplified technique of sensory nerve conduction (SNC) of the UN in the wrist and palm segments and demonstrate the validity of this technique in the study of five cases of type III UNW. The SNC of UN was performed antidromically with fifth finger ring recording electrodes. The UN was stimulated 14 cm proximal to the active electrode (the standard way) and 7 cm proximal to the active electrode. The normal data from amplitude and conduction velocity (CV) ratios between the palm to finger and wrist to finger segments were obtained. Normal amplitude ratio was 1.4 to 0.76. Normal CV ratio was 0.8 to 1.23.We found evidences of abnormal SNAP amplitude ratio or substantial slowing of UN sensory fibers across the wrist in 5 of the 5 patients with electrophysiological-definite type III UNW.

Familial adult spinal muscular atrophy associated with the VAPB gene: report of 42 cases in Brazil.

Familial spinal muscular atrophy (FSMA) associated with the vesicle-associated membrane protein-associated protein B (VAPB) gene is a rare autosomal dominant disease with late onset and slow progression. We studied 10 of 42 patients from 5 families by taking clinical histories and performing physical exams, electrophysiological studies, and genetic tests. All patients presented late onset disease with slow progression characterized by fasciculations, proximal weakness, amyotrophy, and hypoactive deep tendon reflex, except two who exhibited brisk reflex. Two patients showed tongue fasciculations and respiratory insufficiency. Electrophysiological studies revealed patterns of lower motor neuron disease, and genetic testing identified a P56S mutation of the VAPB gene. Although it is a rare motor neuron disease, FSMA with this mutation might be much more prevalent in Brazil than expected, and many cases may be undiagnosed. Genetic exams should be performed whenever it is suspected in Brazil.

Familial adult spinal muscular atrophy associated with the VAPB gene: report of 42 cases in Brazil / Atrofia espinhal progressiva familiar associada ao gene VAPB: relato de 42 casos no Brasil

Familial spinal muscular atrophy (FSMA) associated with the vesicle-associated membrane protein-associated protein B (VAPB) gene is a rare autosomal dominant disease with late onset and slow progression. We studied 10 of 42 patients from 5 families by taking clinical histories and performing physical exams, electrophysiological studies, and genetic tests. All patients presented late onset disease with slow progression characterized by fasciculations, proximal weakness, amyotrophy, and hypoactive deep tendon reflex, except two who exhibited brisk reflex. Two patients showed tongue fasciculations and respiratory insufficiency. Electrophysiological studies revealed patterns of lower motor neuron disease, and genetic testing identified a P56S mutation of the VAPB gene. Although it is a rare motor neuron disease, FSMA with this mutation might be much more prevalent in Brazil than expected, and many cases may be undiagnosed. Genetic exams should be performed whenever it is suspected in Brazil.

A atrofia espinhal progressiva familiar associada (AEPF) ao gene VAPB é uma doença autossômica dominante rara, de início tardio e lentamente progressiva. Estudamos 10 de 42 pacientes entre cinco famílias com AEPF, considerando a história clínica,o exame físico, a eletroneuromiografia e o teste genético. Todos os pacientes apresentaram inicio tardio, progressão lenta, fasciculações, fraqueza proximal, atrofia muscular e diminuição dos reflexos, exceto em um paciente em que os reflexos estavam vivos. Dois pacientes apresentavam fasciculações de língua e dois tinham fraqueza da musculatura respiratória. A eletroneuromiografia mostrou padrão de doença do segundo neurônio motor e o teste genético identificou a mutação P56S no gene VAPB. Embora seja uma doença rara, a AEPF associada a esta mutação pode ser mais prevalente no Brasil do que se acredita. Esta doença pode estar subdiagnosticada, devendo o teste genético ser realizado sempre que houver a suspeita diagnóstica.