Spinocerebellar Ataxia 36 is a Frequent Cause of Hereditary Ataxia in Eastern Spain.

Background: Autosomal dominant spinocerebellar ataxia 36 (SCA36) is caused by hexanucleotide repeat expansion in the NOP56 gene. Objectives: To assess frequency, clinical and genetic features of SCA36 in Eastern Spain. Methods: NOP56 expansion was tested in a cohort of undiagnosed cerebellar ataxia families (n = 84). Clinical characterization and haplotype studies were performed. Results: SCA36 was identified in 37 individuals from 16 unrelated families. It represented 5.4% of hereditary ataxia patients. The majority were originally from the same region and displayed a shared haplotype. Mean age at onset was 52.5 years. Non-ataxic features included: hypoacusis (67.9%), pyramidal signs (46.4%), lingual fasciculations/atrophy (25%), dystonia (17.8%), and parkinsonism with evidence of dopaminergic denervation (10.7%). Conclusions: SCA36 is a frequent cause of hereditary ataxia in Eastern Spain, and is associated with a strong founder effect. SCA36 analysis should be considered prior to other studies, especially in AD presentations. Parkinsonism reported here broadens SCA36 clinical spectrum.

Gait Function after High-Intensity Focused Ultrasound Thalamotomy for Essential Tremor: Searching for Technique Optimization.

INTRODUCTION: Essential tremor (ET) is one of the most prevalent movement disorders in adults and may be highly disabling for some. Magnetic resonance image-guided high-intensity focused ultrasound (MRIgFUS) has been shown to control tremor efficaciously and with acceptable risk. To date, paresthesia and ataxia are the most common adverse effects (AE). Nevertheless, the impact of MRIgFUS thalamotomy on balance is not well established. METHODS: Thirty-two patients underwent MRIgFUS for ET and completed 6 months of follow-up. Tremor severity and functional disability were assessed using the Essential Tremor Rating Scale and the Quality of Life in Essential Tremor Questionnaire. The Berg Balance Scale (BBS) was applied to objectively measure balance status. RESULTS: All treatments were successful. The sonication target was 1-2 mm above the depth of the intercommissural line. Procedures lasted less the 2 h, with an average of 8 sonications per patient. Twenty-four patients were included in the tremor analysis. The hand tremor score was improved by 76% after 6 months of follow-up and 87% of patients self-reported marked improvement (≥75%). Disability scores showed marked improvement (78%), leading to a significant improvement in quality of life. At the final follow-up, 48% of the patients reported no side effects. When present, AE were generally transient and were considered mild in 96% of affected patients. Paresthesia and subjective feeling of unsteadiness were the most common persistent complaints (23% and 20%, respectively). Regarding objective ataxia, BBS scores remained stable throughout follow-up for most patients. Only 2 patients suffered a mild worsening of balance although no patients experienced moderate or severe ataxia. CONCLUSIONS: Subjective feeling of unsteadiness is one of the most frequent AE after MRIgFUS, although objective ataxia is infrequent and mild. Selecting the most appropriate lesion location and procedural parameters should increase treatment benefits while reducing side effects.

Diagnostic Efficacy of Genetic Studies in a Series of Hereditary Cerebellar Ataxias in Eastern Spain.

Background and Objectives: To determine the diagnostic efficacy of clinical exome-targeted sequencing (CES) and spinocerebellar ataxia 36 (SCA36) screening in a real-life cohort of patients with cerebellar ataxia (CA) from Eastern Spain. Methods: A total of 130 unrelated patients with CA, negative for common trinucleotide repeat expansions (SCA1, SCA2, SCA3, SCA6, SCA7, SCA8, SCA12, SCA17, dentatorubral pallidoluysian atrophy [DRPLA], and Friedreich ataxia), were studied with CES. Bioinformatic and genotype-phenotype analyses were performed to assess the pathogenicity of the variants encountered. Copy number variants were analyzed when appropriate. In undiagnosed dominant and sporadic cases, repeat primed PCR was used to screen for the presence of a repeat expansion in the NOP56 gene. Results: CES identified pathogenic or likely pathogenic variants in 50 families (39%), including 23 novel variants. Overall, there was a high genetic heterogeneity, and the most frequent genetic diagnosis was SPG7 (n = 15), followed by SETX (n = 6), CACNA1A (n = 5), POLR3A (n = 4), and SYNE1 (n = 3). In addition, 17 families displayed likely pathogenic/pathogenic variants in 14 different genes: KCND3 (n = 2), KIF1C (n = 2), CYP27A1A (n = 2), AFG3L2 (n = 1), ANO10 (n = 1), CAPN1 (n = 1), CWF19L1 (n = 1), ITPR1 (n = 1), KCNA1 (n = 1), OPA1 (n = 1), PNPLA6 (n = 1), SPG11 (n = 1), SPTBN2 (n = 1), and TPP1 (n = 1). Twenty-two novel variants were characterized. SCA36 was diagnosed in 11 families, all with autosomal dominant (AD) presentation. SCA36 screening increased the total diagnostic rate to 47% (n = 61/130). Ultimately, undiagnosed patients showed delayed age at onset (p < 0.05) and were more frequently sporadic. Discussion: Our study provides insight into the genetic landscape of CA in Eastern Spain. Although CES was an effective approach to capture genetic heterogeneity, most patients remained undiagnosed. SCA36 was found to be a relatively frequent form and, therefore, should be tested prior to CES in familial AD presentations in particular geographical regions.

Mutations, Genes, and Phenotypes Related to Movement Disorders and Ataxias.

Our clinical series comprises 124 patients with movement disorders (MDs) and/or ataxia with cerebellar atrophy (CA), many of them showing signs of neurodegeneration with brain iron accumulation (NBIA). Ten NBIA genes are accepted, although isolated cases compatible with abnormal brain iron deposits are known. The patients were evaluated using standardised clinical assessments of ataxia and MDs. First, NBIA genes were analysed by Sanger sequencing and 59 patients achieved a diagnosis, including the detection of the founder mutation PANK2 p.T528M in Romani people. Then, we used a custom panel MovDisord and/or exome sequencing; 29 cases were solved with a great genetic heterogeneity (34 different mutations in 23 genes). Three patients presented brain iron deposits with Fe-sensitive MRI sequences and mutations in FBXO7, GLB1, and KIF1A, suggesting an NBIA-like phenotype. Eleven patients showed very early-onset ataxia and CA with cortical hyperintensities caused by mutations in ITPR1, KIF1A, SPTBN2, PLA2G6, PMPCA, and PRDX3. The novel variants were investigated by structural modelling, luciferase analysis, transcript/minigenes studies, or immunofluorescence assays. Our findings expand the phenotypes and the genetics of MDs and ataxias with early-onset CA and cortical hyperintensities and highlight that the abnormal brain iron accumulation or early cerebellar gliosis may resembling an NBIA phenotype.

Clinical and genetic characteristics of 21 Spanish patients with biallelic pathogenic SPG7 mutations.

Spastic paraplegia type 7 (SPG7) is one of the most common hereditary spastic paraplegias. SPG7 mutations most often lead to spastic paraparesis (HSP) and/or hereditary cerebellar ataxia (HCA), frequently with mixed phenotypes. We sought to clinically and genetically characterize a Spanish cohort of SPG7 patients. Patients were recruited from our HCA and HSP cohorts. We identified twenty-one patients with biallelic pathogenic SPG7 mutations. Mean age at onset was 37.4 years (SD ± 14.3). The most frequent phenotype was spastic ataxia (57%), followed by pure spastic paraplegia (19%) and complex phenotypes (19%). Isolated patients presented with focal or multifocal dystonia, subclinical myopathy or ophthalmoplegia. p.Ala510Val was the most frequent pathogenic variant encountered. Compound heterozygous for p.Ala510Val displayed younger onset (p < 0.05) and more complex phenotypes (p < 0.05) than p.Ala510Val homozygotes. Two novel variants were found: p.Lys559Argfs*33 and p.Ala312Glu. In conclusion, spastic ataxia is the most common phenotype found in Spanish patients. Nonetheless, SPG7 analysis should also be considered in patients with less frequent clinical findings such as dystonia or ophthalmoplegia especially when these symptoms are associated with mild spastic ataxia.

Transcranial sonography in atypical parkinsonism: How reliable is it in real clinical practice? A multicentre comprehensive study.

INTRODUCTION: Substantia nigra hyperechogenicity (SN+) in transcranial sonography (TCS) is frequent in Parkinson's disease (PD), while lenticular nucleus hyperechogenicity (LN+) and 3rd ventricle enlargement (3V+) are typical of Atypical Parkinsonisms (AP). However, there are no studies assessing the diagnostic yield of all TCS biomarkers in the three AP (progressive supranuclear palsy, PSP, multiple system atrophy, MSA, corticobasal degeneration, CBD). Previous references lack homogeneous criteria and data are incomprehensive. METHODS: Analysis of TCS performed in routine clinical practice in AP and PD patients from two tertiary hospitals. Expert recommendations were strictly followed. Previous literature was critically analysed. RESULTS: 155 AP (98 PSP, 40 MSA, 14 CBD), 254 PD, 145 control subjects were included. We confirmed good sensitivity for SN+ in PD (80%), but specificity was lower than reported (61%). LN+ and 3V + had moderate sensitivity for AP and PSP diagnosis respectively (65%, 63%), but specificity was higher than reported (87%, 91%). We confirmed high specificity and positive predictive value of the combination SN/LN (98%, 93% AP; 83%, 86% PD). The combinations of two or three echofeatures, previously unreported, showed high specificity but lower sensitivity (SN/3V: 75% sensitivity, 87% specificity PD; 42% sensitivity, 98% specificity PSP) (SN + LN+: 79% sensitivity, 86% specificity CBD) (SN/3V/LN: 67% sensitivity, 89% specificity PD; 29% sensitivity, 99% specificity PSP; 41% sensitivity, 95% specificity MSA; 57% sensitivity 91% specificity CBD). CONCLUSIONS: We present a large comprehensive study of TCS, confirming its usefulness and certain limitations in AP diagnosis. Adherence to consensus criteria is critical to implement TCS for clinical and research purposes.

Mesencephalic area measured by transcranial sonography in the differential diagnosis of parkinsonism.

BACKGROUND: Transcranial B-mode sonography (TCS) has become an important tool in the differential diagnosis of parkinsonism given that current technology enables an adequate assessment of brain structures. In this study we aimed at evaluating the usefulness of midbrain area measured by TCS in the differential diagnosis between Parkinson's Disease (PD) and Progressive Supranuclear Palsy (PSP). METHODS: Patients with a diagnosis of PD or PSP according to current clinical criteria were recruited. PSP patients were classified as Richardson's syndrome and PSP-parkinsonism. TCS was performed and the mesencephalic area and third ventricle width were measured offline by an examiner blinded to clinical diagnosis. RESULTS: TCS was performed in 60 patients (75% PD, 25% PSP). Eight patients (13,3%) had inadequate acoustic window. Patients with PSP had a smaller mesencephalic area (3.58 cm(2) vs 5.28 cm(2), p < 0.001). A mesencephalic area ≥4.27 cm(2) discriminates PD from PSP with a positive predictive value 100%. Patients with PSP also had a higher third ventricle diameter (8.84 mm vs 5.11 mm, p < 0.001). Within the PSP group patients with Richardson's syndrome had a wider third ventricle than patients with PSP-Parkinsonism phenotype (9.57 mm vs 7 mm, p = 0.01), but no differences were found in the mesencephalic area between both phenotypes. CONCLUSIONS: Measurement of the mesencephalic area and the third ventricle width by TCS is a non-invasive, easily accessible technique that is useful in the differential diagnosis between PD and PSP, at least in the late stages of the disease.

Evaluación de la sustancia negra mediante ultrasonografía transcraneal / Evaluation of the substantia nigra by means of transcranial ultrasound imaging

Objetivo. Describir la prevalencia de la hiperecogenicidad de la sustancia negra en dos muestras de pacientes, unos con diagnóstico de enfermedad de Parkinson (EP) según los criterios de la United Kingdom Parkinson’s Disease Society, y una población control, con el fin de establecer los propios valores de referencia para nuestro laboratorio de neurosonología. Sujetos y métodos. Se seleccionaron dos muestras de pacientes compuestos por controles sanos sin enfermedad neurodegenerativa y pacientes con EP. Se realizaron mediciones planimétricas del área de ecogenicidad de la sustancia negra en ambos grupos. Se consideró la mayor área de ecogenicidad medida en cada lado en cada paciente. Se realizaron estadísticos descriptivos de la muestra. Se construyó la curva ROC para mostrar la precisión global, la sensibilidad y la especificidad del Doppler transcraneal en comparación con el diagnóstico clínico de EP. Resultados. Se analizaron en total 45 pacientes con EP y 91 controles. Empleando nuestro propio punto de co e (percentil 90 de los controles = 0,22 cm2), presentaban hiperecogenicidad de la sustancia negra un 73,33% de los pacientes con EP y un 8,79% de los controles (p = 0). Se pudo apreciar un área bajo la curva del 93%, lo que expresa una buena precisión global del Doppler transcraneal en el diagnóstico de EP. Conclusiones. La evaluación ultrasonográfica de la sustancia negra consigue detectar en nuestro laboratorio diferencias significativas entre los sujetos con EP y los sujetos normales. Los valores obtenidos en nuestro laboratorio están ligeramente por debajo de los establecidos como referencia internacional, y ofrecen unos excelentes valores de especificad y una aceptable sensibilidad en nuestro medio (AU)

Aim. To describe the prevalence of hyperechogenicity of the substantia nigra in two samples of patients: one group who had been diagnosed with Parkinson’s disease (PD) in accordance with United Kingdom Parkinson’s Disease Society criteria and a control population, so as to be able to establish the reference values for our neurosonology laboratory Subjects and methods. Two samples of patients consisting of healthy controls with no neurodegenerative disease and patients with PD were selected. Planimetric measurements of the area of echogenicity in the substantia nigra were performed in both groups. The greatest area of echogenicity measured on each side of each patient was considered. Descriptive statistics of the sample were carried out. The ROC curve was constructed in order to show the overall precision, sensitivity and specificity of transcranial Doppler ultrasonography in comparison to the clinical diagnosis of PD. Results. Altogether 45 patients with PD and 91 controls were analysed. Using our own cut-off point (percentile 90 of the controls = 0.22 cm2), hyperechogenicity of the substantia nigra was observed in 73.33% of patients with PD and 8.79% of the controls (p = 0). An area below the curve of 93% was seen, which represents good overall precision for transcranial Doppler ultrasonography in the diagnosis of PD. Conclusions. The evaluation of the substantia nigra conducted in our laboratory using ultrasound imaging reveals significant differences between subjects with PD and normal subjects. The values obtained in our laboratory are slightly below those established as an international reference and offer excellent values for specificity and an acceptable level of sensitivity in our locale (AU)

[Evaluation of the substantia nigra by means of transcranial ultrasound imaging]. / Evaluacion de la sustancia negra mediante ultrasonografia transcraneal.

AIM. To describe the prevalence of hyperechogenicity of the substantia nigra in two samples of patients: one group who had been diagnosed with Parkinson's disease (PD) in accordance with United Kingdom Parkinson's Disease Society criteria and a control population, so as to be able to establish the reference values for our neurosonology laboratory. SUBJECTS AND METHODS. Two samples of patients consisting of healthy controls with no neurodegenerative disease and patients with PD were selected. Planimetric measurements of the area of echogenicity in the substantia nigra were performed in both groups. The greatest area of echogenicity measured on each side of each patient was considered. Descriptive statistics of the sample were carried out. The ROC curve was constructed in order to show the overall precision, sensitivity and specificity of transcranial Doppler ultrasonography in comparison to the clinical diagnosis of PD. RESULTS. Altogether 45 patients with PD and 91 controls were analysed. Using our own cut-off point (percentile 90 of the controls = 0.22 cm2), hyperechogenicity of the substantia nigra was observed in 73.33% of patients with PD and 8.79% of the controls (p = 0). An area below the curve of 93% was seen, which represents good overall precision for transcranial Doppler ultrasonography in the diagnosis of PD. CONCLUSIONS. The evaluation of the substantia nigra conducted in our laboratory using ultrasound imaging reveals significant differences between subjects with PD and normal subjects. The values obtained in our laboratory are slightly below those established as an international reference and offer excellent values for specificity and an acceptable level of sensitivity in our locale.