Phenotypic variability of PINK1 expression: 12 Years' clinical follow-up of two Italian families.

BACKGROUND: Mutations in the PINK1 gene are the second most frequent cause of autosomal recessive early-onset parkinsonism. METHODS: We evaluated five affected PINK1 homozygous and 14 heterozygous mutation carriers from two large Italian families over a 12-year follow-up period. Motor, nonmotor, cognitive, psychiatric, and behavioral profiles were systematically assessed. Four homozygotes and eight heterozygotes underwent magnetic resonance imaging. RESULTS: All homozygotes showed a mild progression of motor signs and a persistent excellent response to levodopa. All but one patient complained of nonmotor symptoms and sleep impairment. Three presented impulse control disorders and two anxiety and apathy. All obtained abnormal scores at Montreal Cognitive Assessment (MoCA) and in tests sensitive to frontal functions; one presented a global cognitive impairment. Three heterozygotes showed motor signs and were diagnosed as possibly affected. They had nonmotor symptoms and cognitive impairment, and two of them showed mild bilateral temporal atrophy. Five unaffected heterozygotes reported abnormal scores at MoCA and low performances at tests sensitive to frontal functions. CONCLUSION: We expanded the phenotypic profile of PINK1-related parkinsonism, including psychiatric and cognitive features as part of clinical presentation.

Efficacy and safety of long-term botulinum toxin treatment for acquired cervical dystonia: a 25-year follow-up.

Botulinum toxin A (BoNT/A) is the first-line treatment for idiopathic cervical dystonia (ICD) and is widely used in the clinical setting. To date, scanty data are available on the effectiveness of BoNT in treating acquired cervical dystonia (ACD). Here we present a long-term follow-up of ACD patients treated with BoNT/A that focused on safety and efficacy. The study included subjects who had received at least six treatments of three commercially available BoNT/A drugs [abobotulinumtoxinA (A/Abo), incobotulinumtoxinA (A/Inco) and onabotulinumtoxinA (A/Ona)]. Safety and efficacy were assessed based on patients' self-reports regarding adverse effects (AE), duration of improvement of dystonia and/or pain relief. Global clinical improvement was measured on a six-point scale. 23 patients with ACD were administered 739 treatments (A/Abo in 235, A/Inco in 72, A/Ona in 432) with a mean number of treatments of 31 ± 20 (range 6-76) and duration of 10 ± 6 weeks (range 2-25). The mean dose was 737 ± 292 U for A/Abo, 138 ± 108 U for A/Inco and 158 ± 80 U for A/Ona. The average benefit duration was 89 ± 26 (A/Abo), 88 ± 30 days (A/Inco), and 99 ± 55 days (A/Ona) (p = 0.011); global clinical improvement for all sessions was 4 ± 1. ANOVA one-way analysis indicated that A/Ona had the best profile in terms of duration (p < 0.05), whereas A/Abo had the best pain relief effect (p = 0.002). Side effects were reported in 9% of treatments (67/739), with ten treatments (1%) complicated by two side effects. Most side effects were rated mild to moderate; severe side effects occurred following three treatments with the three different BoNT; two required medical intervention. No allergic reactions were reported. Even after 25 years of repeated treatments, all serotypes of BoNT demonstrate positive effects in treating ACD with long-lasting efficacy and safety.

Retrospective evaluation of the dose equivalence of Botox(®) and Dysport (®) in the management of blepharospasm and hemifacial spasm: a novel paradigm for a never ending story.

Botox(®) and Dysport(®) are the preparations of botulinum neurotoxin most widely used for therapeutic purposes. Several studies have addressed the topic of the equivalency ratio (D/B ratio) to be used in clinical practice and whether a reliable value exists is still a matter of debate. To this purpose, we ideated a novel paradigm by retrospectively examining the patients affected by hemifacial spasm and blepharospasm. We compared the pairs of treatments with a switch from one brand to the other undergone by the same patient in consecutive sessions with overlapping clinical outcome. Out of 2006 treatments, we found 51 treatment pairs. D/B ratio was extremely variable (range 1.2-13.3) and in most cases (65%) it was between 1:3 and 1:5. In conclusion, even if the 1:4 ratio might be reliable for clinical purpose, a true bioequivalence between Dysport(®) and Botox(®) might not exist due to the intrinsic difference in their pharmacokinetic properties.

Botulinum toxin A versus B in sialorrhea: a prospective, randomized, double-blind, crossover pilot study in patients with amyotrophic lateral sclerosis or Parkinson's disease.

BACKGROUND: Either botulinum toxins (BoNTs) A and B have been used for improving drooling in different neurological conditions. METHODS: Consecutive patients affected by Amyotrophic Lateral Sclerosis (ALS) or Parkinson's Disease (PD) accompanied by severe drooling were randomized to receive botulinum neurotoxin type A (BoNT-A) or B (BoNT-B) injections into the salivary glands. Following the first treatment, when sialorrhea returned to baseline (at least three months after the first injection), subjects were re-treated with the other serotype. Ultrasound-guided injections into parotid and submandibular glands were bilaterally performed: total doses were 250 U BoNT-A (Dysport) and 2500 U BoNT-B (Neurobloc). Objective (cotton roll weight) and subjective (ad hoc clinical scales) evaluations were performed at baseline, after 1 and 4 weeks, and every 4 weeks until drooling returned to baseline. RESULTS: Twenty-seven patients (15 ALS and 12 PD) were enrolled, fourteen completed the study. BoNT-A and BoNT-B treatments gave both subjective and objective improvements in all patients. The latency was significantly shorter after BoNT-B treatments (3.2 ± 3.7 days) compared to BoNT-A (6.6 ± 4.1 days; P = 0.002). The mean benefit duration was similar at 75 and 90 days for BoNT-A and BoNT-B, respectively (P = NS). The only toxin-related side effect was a change to saliva thickness. CONCLUSIONS: Either 250 U Dysport or 2500 U Neurobloc have similar effectiveness and safety in controlling sialorrhea. BoNT-B has a shorter latency and comparable duration. Cost analysis, considering the doses used in this study protocol favored BoNT-B treatment.

An Italian Neurology Outpatient Clinic Facing SARS-CoV-2 Pandemic: Data From 2,167 Patients.

Objective: Neurological sequelae of SARS-CoV-2 infection have already been reported, but there is insufficient data about the impact of the pandemic on the management of the patients with chronic neurological diseases. We aim to analyze the effect of COVID-19 pandemic and social restriction rules on these fragile patients. Methods: Patients with chronic neurologic diseases routinely followed at the outpatient clinic of Gemelli University Hospital, Rome, were assessed for symptoms suggestive of SARS-CoV-2 infection in the pandemic period, consequences of social restrictions, and neurological disease features, concomitant medical conditions, current medical and disease-specific treatments. Data source: a dedicated telephone survey designed to encompass questions on COVID-19 symptoms and on pandemic effects in chronic neurologic conditions. Results: Overall, 2,167 individuals were analyzed: 63 patients reported contact with COVID-19 positive cases, 41 performed the swab, and 2 symptomatic patients tested positive for COVID-19 (0.09%). One hundred fifty-eight individuals (7%) needed urgent neurological care, deferred due to the pandemic; 641 patients (30%) suspended hospital treatments, physiotherapy or other support interventions; 405 individuals (19%) reported a subjective worsening of neurological symptoms. Conclusions: In our population, the presence of neurological chronic diseases did not increase the prevalence of COVID-19 infection. Nevertheless, the burden of neurological disorders has been worsened by the lockdown.

Olfactory dysfunction in Parkinsonism caused by PINK1 mutations.

Hyposmia is a common nonmotor feature of Parkinson's disease (PD) and has been variably detected in monogenic Parkinsonisms. To assess olfactory dysfunction in PINK1-related Parkinsonism, we evaluated olfactory detection threshold, odor discrimination, and odor identification in five groups of subjects: sporadic PD (n = 19), PINK1 homozygous (n = 7), and heterozygous (n = 6) parkinsonian patients, asymptomatic PINK1 heterozygous carriers (n = 12), and Italian healthy subjects (n = 67). All affected subjects and all healthy heterozygotes but one resulted hyposmic, with most patients in the range of functional anosmia or severe hyposmia. Detection threshold was more preserved and discrimination more impaired in patients with PINK1 mutations than in PD cases. Alterations of detection and discrimination were observed also in PINK1 asymptomatic heterozygotes. On the contrary, odor identification appeared to be mostly related to the disease status, as it was impaired in nearly all patients (including PD and PINK1 cases) and preserved in healthy heterozygotes. Our data indicate that olfactory dysfunction is common in PINK1 Parkinsonism and consists typically in defective odor identification and discrimination. A milder olfactory deficit, mostly involving discrimination, can be found in asymptomatic heterozygotes, possibly indicating an underlying preclinical neurodegenerative process.

Mutation screening of the DYT6/THAP1 gene in Italy.

Mutations in the THAP1 gene on chromosome 8p21-p22 (DYT6 locus) have been recently reported as causative of autosomal dominant primary torsion dystonia (PTD) in four Amish-Mennonite families and in 12 additional probands of different ancestry. We sequenced the THAP1 gene in 158 patients with DYT1-negative PTD who had onset of symptoms below 30 years and/or positive family history. One sporadic Greek male patient, aged 57 years, was found to carry a novel heterozygous missense variant in THAP1 exon 3 (p.Cys170Arg), of likely pathogenic significance. This subject first presented with right writer's cramp at age of 10 years and, subsequently, developed left arm dystonia and an extremely severe left laterocollis, without further spreading to other body districts. Our findings expand the genotypic spectrum of THAP1 and strengthen the association with upper body involvement, including the cranial and cervical districts that are usually spared in DYT1-PTD.

PINK1 heterozygous rare variants: prevalence, significance and phenotypic spectrum.

Heterozygous rare variants in the PINK1 gene, as well as in other genes causing autosomal recessive parkinsonism, have been reported both in patients and healthy controls. Their pathogenic significance is uncertain, but they have been suggested to represent risk factors to develop Parkinson disease (PD). The few large studies that assessed the frequency of PINK1 heterozygotes in cases and controls yielded controversial results, and the phenotypic spectrum is largely unknown. We retrospectively analyzed the occurrence of PINK1 heterozygous rare variants in over 1100 sporadic and familial patients of all onset ages and in 400 controls. Twenty patients and 6 controls were heterozygous, with frequencies (1.8% vs. 1.5%) not significantly different in the two groups. Clinical features of heterozygotes were indistinguishable to those of wild-type patients, with mean disease onset 10 years later than in carriers of two mutations but worse disease progression. A meta-analysis indicated that, in PINK1 heterozygotes, the PD risk is only slightly increased with a non significant odds ratio of 1.62. These findings suggest that PINK1 heterozygous rare variants play only a minor susceptibility role in the context of a multifactorial model of PD. Hence, their significance should be kept distinct from that of homozygous/compound heterozygous mutations, that cause parkinsonism inherited in a mendelian fashion.

Subclinical sensory abnormalities in unaffected PINK1 heterozygotes.

BACKGROUND: Mutations in the PINK1 gene, encoding a mitochondrial protein kinase, represent the second cause of autosomal recessive parkinsonism (ARP) after Parkin. While homozygous or compound heterozygous mutations in these genes are unequivocally causative of ARP, the role of single heterozygous mutations is still largely debated. An intriguing hypothesis suggests that these mutations could represent a risk factor to develop parkinsonism, by contributing to nigral cell degeneration. Since the substantia nigra plays an important role in temporal processing of sensory stimuli, as revealed from studies in idiopathic PD, we sought to investigate whether any subclinical sensory abnormalities could be detected in patients with PINK1- related parkinsonism and in unaffected PINK1 heterozygous carriers. METHODS: We adopted a psychophysical method, the temporal discrimination paradigm, to assess PINK1 homozygous patients, unaffected relatives who were heterozygous carriers of the same mutations and healthy control subjects. Temporal discrimination threshold (TDT) and temporal order judgement (TOJ) for pairs of tactile, visual or visuo-tactile stimuli were measured according to a standardized protocol. FINDINGS: Higher mean tactile and visuo-tactile TDTs and TOJs were detected in PINK1 mutation carriers, including not only homozygous patients but also healthy heterozygotes, compared to control subjects (for all comparisons, p < 0.001). INTERPRETATION: In clinically unaffected subjects, the mere presence of a heterozygous PINK1 mutation is sufficient to determine sensory alterations which can be disclosed by a psychophysical task. Deficits in temporal processing might be considered as subclinical signs of alteration at least in PINK1-related parkinsonism.

Whole gene deletion and splicing mutations expand the PINK1 genotypic spectrum.

Autosomal recessive parkinsonism is a genetic condition closely resembling Parkinson disease, the only distinguishing features being an earlier age at onset and a slower disease progression. Three causative genes have been identified so far. While exon rearrangements are frequently encountered in the Parkin gene, most PINK1 mutations are represented by single nucleotide changes. We report a sporadic parkinsonian patient carrying a deletion of the entire PINK1 gene and a splice site mutation (g.15445_15467del23) which produces several aberrant mRNAs. This report expands the genotypic spectrum of PINK1 mutations, with relevant implications for molecular analysis of this gene.

Computerized gait analysis of botulinum toxin treatment in children with cerebral palsy.

PURPOSE: Intramuscular botulinum toxin A (BTA) injection is a local reversible treatment with a wide range of therapeutic applications, including temporary reduction of spasticity. The aim of this work was a quantitative, computerized objective evaluation of BTA-induced improvement of the walking functional ability in a group of children with cerebral palsy (CP). METHODS: Fifteen children with CP and 20 healthy children were evaluated. All patients were equinus walkers without fixed contractures of triceps surae muscles and they were evaluated before and after about 1.5 months from BTA injections into the calf muscles. The effectiveness of treatment was evaluated by 3D computerized gait analysis. RESULTS: Data analysis revealed a significant improvement of equinus foot and ankle range of motion during gait after BTA injection. Positive effects were evident also at the knee joint as documented by the improvement of kinetics characteristics (moment and power). CONCLUSIONS: Computerized gait analysis is a valid method for quantification of BTA effect on walking in children with CP, allowing a detailed evaluation of improvement at each joint and a quantitative evaluation of treatment outcome.

Clinical differences between botulinum neurotoxin type A and B.

In humans, the therapeutic use of botulinum neurotoxin A (BoNT/A) is well recognized and continuously expanding. Four BoNTs are widely available for clinical practice: three are serotype A and one is serotype B: onabotulinumtoxinA (A/Ona), abobotulinumtoxinA (A/Abo) and incobotulinumtoxinA (A/Inco), rimabotulinumtoxinB (B/Rima). A/Abo, A/Inco, A/Ona and B/Rima are all licensed worldwide for cervical dystonia. In addition, the three BoNT/A products are approved for blepharospasm and focal dystonias, spasticity, hemifacial spasm, hyperhidrosis and facial lines, with remarkable regional differences. These toxin brands differ for specific activity, packaging, constituents, excipient, and storage. Comparative literature assessing the relative safety and efficacy of different BoNT products is limited, most data come from reports on small samples, and only a few studies meet criteria of evidence-based medicine. One study compared the effects of BoNT/A and BoNT/B on muscle activity of healthy volunteers, showing similar neurophysiological effects with a dose ratio of 1:100. In cervical dystonia, when comparing the effects of BoNT/A and BoNT/B, results are more variable, some studies reporting roughly similar peak effect and overall duration (at a ratio of 1:66, others reporting substantially shorter duration of BoNT/B than BoNT/A (at a ratio 1/24). Although the results of clinical studies are difficult to compare for methodological differences (dose ratio, study design, outcome measures), it is widely accepted that: BoNT/B is clinically effective using appropriate doses as BoNT/A (1:40-50), injections are generally more painful, in most of the studies on muscular conditions, efficacy is shorter, and immunogenicity higher. Since the earliest clinical trials, it has been reported that autonomic side effects are more frequent after BoNT/B injections, and this observation encouraged the use of BoNT/B for sialorrhea, hyperhidrosis and other non-motor symptoms. In these indications the efficacy of toxins A and B are comparable and dose ratio is 1:25-30.

Botulinum Toxin A and B in sialorrhea: Long-term data and literature overview.

INTRODUCTION AND OBJECTIVES: In recent years, Botulinum Toxin has been shown to be efficacious and safe in the treatment of sialorrhea, but scanty data are available on its long term use. The aim of this study was to investigate adverse events, discriminate differences in safety, and evaluate the efficacy of long-term use of both abobotulinumtoxinA and rimabotulinumtoxinB ultrasound-guided injections for sialorrhea in a retrospective trial. Moreover we review the literature on this topic. PATIENTS AND METHODS: Consecutive patients with severe sialorrhea and receiving at least two ultrasound-guided intrasalivary glands abobotulinumtoxinA 250 U or rimabotulinumtoxinB 2500 U injections were included. Clinical and demographic data were collected. Safety and tolerability were assessed on the basis of patients' self-reports. Efficacy was assessed by recording the duration of benefit and by the Drooling Severity Scale and Drooling Frequency Scale 4 weeks after intervention. A review of literature was performed using 'Botulinum Toxin' and/or 'drooling' and/or 'sialorrhea' and/or 'hypersalivation' as keywords. RESULTS: Sixty-five patients (32 Amyotrophic Lateral Sclerosis and 33 Parkinson's Disease) were treated in a total of 317 sessions (181 rimabotulinumtoxinB and 136 abobotulinumtoxinA). Both serotypes induced a clear-cut benefit in 89% of injections. Mean benefit duration was 87 days (range 30-240), similar for abobotulinumtoxinA and rimabotulinumtoxinB but significantly shorter in Amyotrophic Lateral Sclerosis group compared to Parkinson's Disease (p < 0.001). Older age was positively correlated to benefit duration (p = 0.003). Botulinum Toxin-related and injection-related side effects complicated respectively 8,2% and 1,5% of treatments. The only Botulinum Toxin-related adverse event was a change of saliva thickness, mostly rated mild to moderate and more frequent in Amyotrophic Lateral Sclerosis patients (p = NS). CONCLUSIONS: Both 250 U abobotulinumtoxinA and 2500 U rimabotulinumtoxinB administered by ultrasound-guided intrasalivary gland injection are safe and effective in treating sialorrhea, even in long-term follow-up. Older age is significantly associated with longer benefit duration. Parkinson's Disease patients showed a more favorable safety-efficacy ratio than did Amyotrophic Lateral Sclerosis patients, due to lower adverse events (p = NS) and longer benefit duration (p < 0.001).

Frequency and phenotypes of LRRK2 G2019S mutation in Italian patients with Parkinson's disease.

To evaluate the frequency of the LRRK2 G2019S mutation in Italy, we tested 1,072 probands with Parkinson's disease (PD; 822 sporadic and 250 familial): 20 patients (1.9%) carried the G2019S mutation, 11 patients (1.3%) were sporadic, and 9 (4.3%) had a positive family history. Considering only probands with autosomal dominant inheritance, the G2019S frequency raises to 5.2%. All presented a typical phenotype with variable onset and shared the common ancestral haplotype. Mutation frequency raised from 1.2% in early onset PD to 4.0% in late onset PD.

Phenotypic characterization of DYT13 primary torsion dystonia.

We describe the phenotype of DYT13 primary torsion dystonia (PTD) in a family first examined in 1994. A complete neurological evaluation was performed on all available family members: 8 individuals were definitely affected by dystonia. The family was re-evaluated in March 2000: at that time, 3 more individuals had developed symptoms of dystonia. Inheritance of PTD was autosomal dominant, with affected individuals spanning three consecutive generations and male-to-male transmission. Age at onset ranged from 5 to 43 years. Onset occurred either in the craniocervical region or in upper limbs. Progression was mild, and the disease course was benign in most affected individuals; generalization occurred only in 2 cases. We did not find anticipation of age at onset or of disease severity through generations. Most subjects presented with jerky, myoclonic-like dystonic movements of the neck or shoulders. DYT13-PTD is an autosomal dominant disease, with incomplete penetrance (58%). Clinical presentation and age at onset were more variable than in DYT1-PTD, and the neck was involved in most of those affected. Moreover, the individuals with generalised dystonia were not severely disabled and were able to lead independent lives. To date, this is the only family with DYT13-PTD.

Phenotypic variability of DYT1-PTD: does the clinical spectrum include psychogenic dystonia?

Primary torsion dystonia (PTD) is a clinically and genetically heterogeneous group of movement disorders, usually inherited in an autosomal dominant manner with reduced (30-40%) penetrance. The DYT1 gene on chromosome 9q34 is responsible for most cases of early limb-onset PTD. DYT1-PTD clinical spectrum is broad, as the disease may present with several degrees of body involvement and severity. We identified an Italian family with 4 members definitely affected by PTD, genetically diagnosed as carriers of the GAG mutation at DYT1 gene. Phenotype was homogeneous when considering the presentation at onset (limb involvement and early onset), the disease progression was variable; in the subjects of the last generation, the disease progressed to a severe, generalized PTD; in the remaining 2 subjects, dystonia presented with writer's cramp or upper body segmental dystonia of mild severity. One family member, carrier of the GAG mutation on DYT1 gene and mother of the most severely affected individual, presented with a clinically established psychogenic movement disorder resembling dystonia initially diagnosed as a severe generalized PTD. Psychogenic movement disorders are among the most controversial and challenging diseases to diagnose, in particular when the affected individual belongs to a family with an inherited movement disorder.

PINK1 mutations are associated with sporadic early-onset parkinsonism.

We have recently reported homozygous mutations in the PINK1 gene in three consanguineous families with early-onset parkinsonism (EOP) linked to the PARK6 locus. To further evaluate the pathogenic role of PINK1 in EOP and to draw genotype-phenotype correlates, we performed PINK1 mutation analysis in a cohort of Italian EOP patients, mostly sporadic, with onset younger than 50 years of age. Seven of 100 patients carried missense mutations in PINK1. Two patients had two PINK1 mutations, whereas in five patients only one mutation was identified. Age at onset was in the fourth-fifth decade (range, 37-47 years). The clinical picture was characterized by a typical parkinsonian phenotype with asymmetric onset and rare occurrence of atypical features. Slow progression and excellent response to levodopa were observed in all subject. Two of 200 healthy control individuals also carried one heterozygous missense mutation. The identification of a higher number of patients (5%) than controls (1%) carrying a single heterozygous mutation, along with previous positron emission tomography studies demonstrating a preclinical nigrostriatal dysfunction in PARK6 carriers, supports the hypothesis that haploinsufficiency of PINK1, as well as of other EOP genes, may represent a susceptibility factor toward parkinsonism. However, the pathogenetic significance of heterozygous PINK1 mutations still remains to be clarified.