Probabilistic Refinement of Focused Ultrasound Thalamotomy Targeting for Parkinson's Disease Tremor.

BACKGROUND: There remains high variability in clinical outcomes when the same magnetic resonance image-guided focused ultrasound (MRgFUS) thalamotomy target is used for both essential tremor (ET) and tremor-dominant Parkinson's disease (TDPD). OBJECTIVE: Our goal is to refine the MRgFUS thalamotomy target for TDPD versus ET. METHODS: We retrospectively performed voxel-wise efficacy and structural connectivity mapping using 3-12-month post-procedure hand tremor scores for a multicenter cohort of 32 TDPD patients and a previously published cohort of 79 ET patients, and 24-hour T1-weighted post-MRgFUS brain images. We validated our findings using Unified Parkinson's Disease Rating Scale part III scores for an independent cohort of nine TDPD patients. RESULTS: The post-MRgFUS clinical improvements were 45.9% ± 35.9%, 55.5% ± 36%, and 46.1% ± 18.6% for ET, multicenter TDPD and validation TDPD cohorts, respectively. The TDPD and ET efficacy maps differed significantly (ppermute < 0.05), with peak TDPD improvement (87%) at x = -13.5; y = -15.0; z = 1.5, ~3.5 mm anterior and 3 mm dorsal to the ET target. Discriminative connectivity projections were to the motor and premotor regions in TDPD, and to the motor and somatosensory regions in ET. The disorder-specific voxel-wise efficacy map could be used to estimate outcome in TDPD patients with high accuracy (R = 0.8; R2 = 0.64; P < 0.0001). The model was validated using the independent cohort of nine TDPD patients (R = 0.73; R2 = 0.53; P = 0.025-voxel analysis). CONCLUSION: We demonstrated that the most effective MRgFUS thalamotomy target in TDPD is in the ventral intermediate nucleus/ventralis oralis posterior border region. This finding offers new insights into the thalamic regions instrumental in tremor control, with pivotal implications for improving treatment outcomes. © 2024 The Author(s). Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Evaluation of the complete Sniffin Sticks Test versus its subtests in differentiating Parkinson's disease patients from healthy controls.

BACKGROUND: Hyposmia is one of the most common, as well as the first nonmotor condition in Parkinson disease (PD). The sniffin sticks test (SST) evaluates three different aspects of olfactory function: threshold (T), discrimination (D), and identification (I). The sum of the scores of these three subtests produce a global score of olfaction, the Threshold-Discrimination-Identification (TDI) score. OBJECTIVE: The aim of this study was to investigate if the TDI score or one of its subtests is better to discriminate PD patients from controls. METHODS: We recruited 27 PD patients and 17 healthy age-matched controls (HC) who were evaluated through a clinical interview, the Montreal Cognitive Assessment and Movement Disorders Society - Unified Parkinson Disease Rating Scale. The olfaction was assessed using the complete SST. RESULTS: The performance of PD patients on the olfactory test was significantly worse when compared with the HC (T: 3.0 vs. 6.5, p < 0.001; D: 8.1 vs. 11.2, p < 0.001; I: 7.3 vs. 11.7, p < 0.001; TDI: 18.8 vs. 29.9, p < 0.001). The prevalence of olfaction impairment in our study (PD: 100%, and HC: 56%) was greater than that found in the literature. Cognition influenced the performance on TDI. The olfactory subtests were impaired proportionally between patients and controls. Furthermore, D and I were correlated, but only in PD patients. The TDI showed a tendency to better discriminate PD patients from HC, when compared with its subtests. CONCLUSIONS: Although the complete olfactory evaluation is time consuming, it seems to be a superior tool to identify olfaction impairment in PD patients, when compared with the isolated subtests.

ANTECENDENTES: Hiposmia é um dos sintomas mais comuns da doença de Parkinson (DP), além de ser um de seus primeiros sintomas não-motores. O Sniffin Sticks Test avalia três diferentes aspectos da função olfatória: limiar (L), discriminação (D) e identificação (I). A soma dos escores desses três subtestes produz um escore global do olfato, o Threshold-Discrimination-Identification (TDI). OBJETIVO: O objetivo deste estudo foi investigar se o TDI ou um de seus subtestes seria melhor em discriminar pacientes com DP de controles saudáveis. MéTODOS: Foram recrutados 27 pacientes com DP e 17 controles saudáveis de mesma faixa etária, que foram avaliados através de uma entrevista clínica, a Montreal Cognitive Assessment e Movement Disorders Society ­ Unified Parkinson Disease Rating Scale. O olfato foi examinado através da bateria completa do Sniffin Sticks Test (SST). RESULTADOS: Os pacientes com DP tiveram pior performance no teste olfatório quando comparados com os controles (L: 3,0 vs. 6,5; p < 0,001; D: 8,1 vs. 11,2; p < 0,001; I: 7,3 vs. 11,7; p < 0,001; TDI: 18,8 vs. 29,9; p < 0,001). A prevalência de comprometimento olfatório no nosso estudo (DP: 100%, e controles: 56%) foi maior do que a reportada na literatura. A cognição influenciou a performance no TDI. Os subtestes olfatórios foram afetados proporcionalmente entre pacientes e controles. Além disso, D e I se correlacionaram, mas apenas em pacientes de DP. O TDI mostrou uma tendência em melhor discriminar pacientes de DP dos controles, quando comparado com os seus subtestes. CONCLUSõES: Embora a avaliação olfatória completa consuma tempo, ela parece ser superior aos subtestes isolados para identificar comprometimento olfatório em pacientes com DP.

Evaluation of the complete Sniffin Sticks Test versus its subtests in differentiating Parkinson's disease patients from healthy controls / Avaliação do Sniffin Sticks Test completo versus seus subtestes na diferenciação de pacientes com doença de Parkinson de controles sem a doença

Abstract Background Hyposmia is one of the most common, as well as the first nonmotor condition in Parkinson disease (PD). The sniffin sticks test (SST) evaluates three different aspects of olfactory function: threshold (T), discrimination (D), and identification (I). The sum of the scores of these three subtests produce a global score of olfaction, the Threshold-Discrimination-Identification (TDI) score. Objective The aim of this study was to investigate if the TDI score or one of its subtests is better to discriminate PD patients from controls. Methods We recruited 27 PD patients and 17 healthy age-matched controls (HC) who were evaluated through a clinical interview, the Montreal Cognitive Assessment and Movement Disorders Society - Unified Parkinson Disease Rating Scale. The olfaction was assessed using the complete SST. Results The performance of PD patients on the olfactory test was significantly worse when compared with the HC (T: 3.0 vs. 6.5, p < 0.001; D: 8.1 vs. 11.2, p <0.001; I: 7.3 vs. 11.7, p < 0.001; TDI: 18.8 vs. 29.9, p < 0.001). The prevalence of olfaction impairment in our study (PD: 100%, and HC: 56%) was greater than that found in the literature. Cognition influenced the performance on TDI. The olfactory subtests were impaired proportionally between patients and controls. Furthermore, D and I were correlated, but only in PD patients. The TDI showed a tendency to better discriminate PD patients from HC, when compared with its subtests. Conclusions Although the complete olfactory evaluation is time consuming, it seems to be a superior tool to identify olfaction impairment in PD patients, when compared with the isolated subtests.

Resumo Antecendentes Hiposmia é um dos sintomas mais comuns da doença de Parkinson (DP), além de ser um de seus primeiros sintomas não-motores. O Sniffin Sticks Test avalia três diferentes aspectos da função olfatória: limiar (L), discriminação (D) e identificação (I). A soma dos escores desses três subtestes produz um escore global do olfato, o Threshold-Discrimination-Identification (TDI). Objetivo O objetivo deste estudo foi investigar se oTDI ou um de seus subtestes seria melhor em discriminar pacientes com DP de controles saudáveis. Métodos Foram recrutados 27 pacientes com DP e 17 controles saudáveis de mesma faixa etária, que foram avaliados através de uma entrevista clínica, a Montreal Cognitive Assessment e Movement Disorders Society - Unified Parkinson Disease Rating Scale. O olfato foi examinado através da bateria completa do Sniffin Sticks Test (SST). Resultados Os pacientes com DP tiveram pior performance no teste olfatório quando comparados com os controles (L: 3,0 vs. 6,5; p < 0,001; D: 8,1 vs. 11,2; p <0,001; I: 7,3 vs. 11,7; p <0,001; TDI: 18,8 vs. 29,9; p < 0,001). A prevalência de comprometimento olfatório no nosso estudo (DP: 100%, e controles: 56%) foi maior do que a reportada na literatura. A cognição influenciou a performance no TDI. Os subtestes olfatórios foram afetados proporcionalmente entre pacientes e controles. Além disso, D e I se correlacionaram, mas apenas em pacientes de DP. O TDI mostrou uma tendência em melhor discriminar pacientes de DP dos controles, quando comparado com os seus subtestes. Conclusões Embora a avaliação olfatória completa consuma tempo, ela parece ser superior aos subtestes isolados para identificar comprometimento olfatório em pacientes com DP.