Background Meige's syndrome is a type of facial dystonia characterized by the simultaneous occurrence of blepharospasm and oromandibular dystonia. Although botulinum toxin type A (OBTA) injections are the standard treatment, evidence of their effectiveness and safety in this scenario is still lacking. Objective Our research aimed to evaluate the improvement and occurrence of side effects following injections of onabotulinum toxin type A (OBTA) in patients with Meige's syndrome. Methods Patients with Meige's syndrome undergoing botulinum toxin injections were enrolled in this study. We assessed dystonia intensity before and 14 days after OBTA injection using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS) to measure the response of symptoms in the eyes (blepharospasm) and mouth (oromandibular dystonia). Other variables, such as dosage, side effects, and demographic data, were also recorded. Results The study included 41 participants, with a mean age of 67.7 years and a female-to-male ratio of 3.5:1. The mean BFMDRS score before the injections was 8.89, and after 14 days, it was 2.88. The most reported side effect was ptosis, with a 7.3% incidence. OBTA significantly reduced dystonia severity (p < 0.0001). The clinical response for the blepharospasm component was superior to the oromandibular dystonia component. Conclusion Our results support that OBTA seems to be an effective and safe therapeutic option for treating Meige's syndrome. The effect of OBTA was more pronounced in the treatment of blepharospasm than in oromandibular dystonia.

The Movement Disorders Society recommends the DYT/PARK prefix for genes where dystonia and parkinsonism are prominent in approximately half or more of patients. This systematic review explores the genotype–phenotype correlations of GLB1, SLC6A3, SLC30A10, PLA2G6, and SLC39A14—recently classified as DYT SLC39A14 and historically linked to dystonia-parkinsonism. We searched PubMed and the Human Gene Mutation Database using standardized terms, including English-language, peer-reviewed publications up to February 2024. Following the MDSGene protocol, we extracted individual-level data on patients with biallelic pathogenic variants and at least one movement disorder. Features were marked “missing” if not explicitly reported. Of 1828 articles, 128 were eligible. We identified 386 patients and 262 variants. The median age at onset was 3 years for GLB1, 3 months for SLC6A3, 2.5 years for SLC30A10, 1.5 years for SLC39A14, and 16 years for PLA2G6. Missing data may reflect underreporting of negative findings. Case reports/serie, may bias toward atypical presentations. Our analysis showed dystonia-parkinsonism predominates in SLC6A3 and PLA2G6, while GLB1, SLC30A10, and SLC39A1 show predominantly dystonic phenotypes with a low frequency of parkinsonism. Ataxia was common in GLB1 and PLA2G6. Awareness of these phenotypes is essential for early diagnosis and intervention, particularly in treatable conditions like SLC30A10 or SLC39A14. The predominantly dystonic phenotype in GLB1, SLC30A10, and SLC39A14 suggest that the DYT prefix may be more appropriate, highlighting the need to reconsider their nomenclature, and the importance of systematic reviews.