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Background and purpose: The monogenic forms of Parkinson's disease represent <10% of familial cases and a still lower frequency of sporadic cases. However, guidelines to orient genetic testing are lacking. The aim was to establish the interest of multiplex ligation‐dependent probe amplification (MLPA) as a primary screening test and to propose clinical criteria to guide genetic diagnostic tests for patients with suspected Mendelian Parkinson's disease. Methods: In all, 567 patients with parkinsonism from 547 unrelated families were recruited and two MLPAs were performed for each. All pathogenic G2019S variants in the LRRK2 gene were confirmed by Sanger sequencing and the PRKN gene was screened for a second mutation in the cases of one heterozygous structural variant in the PRKN gene. Results: The performance of MLPA was 51/567 (9%) for the entire cohort and included 27 (4.8%) LRRK2 G2019S mutations, 19 (3.4%) PRKN mutations and five (0.9%) SNCA locus duplications. The variables significantly associated with a positive test in the total cohort were North African ancestry (p < 0.0001), female sex (p = 0.004) and younger age at onset (p < 0.0008). Conclusions: Retrospective analysis allowed us to refine our indication criteria: (i) North African ancestry, (ii) an age at onset <40 years or (iii) a familial history of parkinsonism with at least one affected first‐degree relative. Our study highlights the interest of MLPA testing for other parkinsonism cases with a family history, especially for patients with dementia with Lewy bodies or a multiple‐system‐atrophy‐like phenotype. [ABSTRACT FROM AUTHOR]

Background and purpose: In cervical dystonia, the accuracy of botulinum neurotoxin (BoNT) injections may influence the response to the treatment. Methods: We used ultrasound to evaluate the accuracy of anatomy‐guided injections of BoNT in the neck muscles. Results: A total of 56 consecutive patients and 332 injections were evaluated. The overall accuracy was 76.6%. The lowest accuracy (67.9%) was observed for the splenius capitis muscle. Conclusions: Anatomic guidance of BoNT injections in the neck muscles is often inaccurate. Imaging guidance may improve the accuracy of BoNT injections in cervical dystonia. [ABSTRACT FROM AUTHOR]