Characterization of the nigroestriatal system in a sample of patients with amyotrophic lateral sclerosis.

BACKGROUND: The coexistence of amyotrophic lateral sclerosis (ALS) with clinical forms of Parkinson disease (PD), although uncommon, is found to a greater degree than one would expect by chance. The pathological mechanisms of ALS and PD are still not fully understood, and the coexistence of these two diseases suggests that they could share mechanisms in common. OBJECTIVE: Here we present a sample of patients with clinically definitive or probable ALS who were evaluated with single-photon emission computed tomography SPECT/TRODAT and compared with non-ALS controls. METHODS: Patients with clinically definite or probable ALS were assessed with the amyotrophic lateral sclerosis functional rating scale (ALSFRS) to define severity and had their demographic data collected. The TRODAT results of patients with ALS were compared with those of patients with a diagnosis of PD with less than 10 years of duration, and with patients with a diagnosis of others movement disorders not associated with neurodegenerative diseases. RESULTS: A total of 75% of patients with ALS had TRODAT results below the levels considered normal; that was also true for 25% of the patients in the control group without neurodegenerative disease, and for 100% of the patients in the PD group. A statistically significant difference was found between patients with ALS and the control group without neurodegenerative disease in the TRODAT values < 0.05. CONCLUSIONS: Our study fits with the neuropathological and functional evidence that demonstrates the existence of nigrostriatal dysfunction in patients with ALS. Further research to better understand the role of these changes in the pathophysiological process of ALS needs to be performed.

ANTECEDENTES: A coexistência da esclerose lateral amiotrófica (ELA) com formas clínicas da doença de Parkinson (DP), embora incomum, é encontrada em um grau maior do que seria esperado ao acaso. Os mecanismos patológicos da ELA e da DP ainda não são totalmente compreendidos e a coexistência dessas duas doenças sugere que elas podem compartilhar mecanismos em comum. OBJETIVO: Apresentamos uma amostra de pacientes com ELA clinicamente definida ou provável que foram avaliados com tomografia computadorizada por emissão de fóton único (SPECT)/TRODAT e comparados com controles sem ELA. MéTODOS: Pacientes com ELA clinicamente definida ou provável foram avaliados com a escala funcional de esclerose lateral amiotrófica (ALSFRS) para definir a gravidade e foram coletados os seus dados demográficos. Os resultados do TRODAT de pacientes com ELA foram comparados com aqueles de pacientes com diagnóstico de DP com menos de 10 anos de duração e com pacientes com diagnóstico de outros distúrbios do movimento não associados a doenças neurodegenerativas. RESULTADOS: Um total de 75% dos pacientes com ELA apresentou resultados de TRODAT abaixo dos níveis considerados normais; 25% no grupo controle sem doença neurodegenerativa e 100% no grupo DP. Uma diferença estatisticamente significativa foi encontrada entre os pacientes com ELA e o grupo controle sem doença neurodegenerativa nos valores de TRODAT p < 0,05. CONCLUSõES: Nosso estudo está de acordo com as evidências neuropatológicas e funcionais que demonstram a existência de disfunção nigroestriatal em pacientes com ELA. Mais pesquisas para entender melhor o papel dessas mudanças no processo fisiopatológico da ELA precisam ser realizadas.

Impairments in gait kinematics and postural control may not correlate with dopamine transporter depletion in individuals with mild to moderate Parkinson's disease.

Parkinson's disease (PD) is a progressive neurodegenerative disorder caused by the loss of dopamine, an important neurotransmitter involved in regulating movement. Nuclear medicine imaging methods such as single-photon emission computed tomography (SPECT) combined with radiotracers can obtain the density of this neurotransmitter. This reduced density leads to classic PD symptoms, such as bradykinesia, tremor and stiffness, consequently affecting walking and postural control. The aim of this study was to verify the correlation between disorders of gait kinematics and postural instability with dopamine depletion in individuals with mild to moderate PD. This is a descriptive, observational cross-sectional study. Subjects were assessed for spatiotemporal gait parameters by a three-dimensional motion capture system, for postural control by stabilometry on a force plate. Dopamine depletion was verified through 99mTc-TRODAT-1 (SPECT-CT) examination. The subjects were in the off-stage of levodopa in all analysis. We evaluated 71 individuals, 32 with mild to moderate PD (HY 2 and 2.5) and 39 healthy individuals matched for gender, age, and height. There was a significant difference between the groups regarding the spatiotemporal variables of gait, as well as in the stabilometric variables. However, there was no correlation between these disturbances and the uptake values of 99mTc-TRODAT-1. The results indicate that there is no correlation between gait impairments and postural instability of individuals with mild to moderate PD and the dopaminergic depletion measured through the 99mTc-TRODAT-1 (SPECT-CT).