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1.  Glucocerebrosidase mutations in primary parkinsonism 
Parkinsonism & Related Disorders  2014;20(11):1215-1220.
Introduction
Mutations in the lysosomal glucocerebrosidase (GBA) gene increase the risk of Parkinson's Disease (PD). We determined the frequency and relative risk of major GBA mutations in a large series of Italian patients with primary parkinsonism.
Methods
We studied 2766 unrelated consecutive patients with clinical diagnosis of primary degenerative parkinsonism (including 2350 PD), and 1111 controls. The entire cohort was screened for mutations in GBA exons 9 and 10, covering approximately 70% of mutations, including the two most frequent defects, p.N370S and p.L444P.
Results
Four known mutations were identified in heterozygous state: 3 missense mutations (p.N370S, p.L444P, and p.D443N), and the splicing mutation IVS10+1G>T, which results in the in-frame exon-10 skipping. Molecular characterization of 2 additional rare variants, potentially interfering with splicing, suggested a neutral effect. GBA mutations were more frequent in PD (4.5%, RR = 7.2, CI = 3.3–15.3) and in Dementia with Lewy Bodies (DLB) (13.8%, RR = 21.9, CI = 6.8–70.7) than in controls (0.63%). but not in the other forms of parkinsonism such as Progressive Supranuclear Palsy (PSP, 2%), and Corticobasal Degeneration (CBD, 0%). Considering only the PD group, GBA-carriers were younger at onset (52 ± 10 vs. 57 ± 10 years, P < 0.0001) and were more likely to have a positive family history of PD (34% vs. 20%, P < 0.001).
Conclusion
GBA dysfunction is relevant for synucleinopathies, such as PD and DLB, except for MSA, in which pathology involves oligodendrocytes, and the tauopathies PSP and CBD. The risk of developing DLB is three-fold higher than PD, suggesting a more aggressive phenotype.
Highlights
•We screened a large case–control cohort with parkinsonism for common GBA mutations.•GBA mutations in the Italian population are a risk factor for Lewy Bodies Diseases (PD and DLB).•GBA mutations were not increased in the other forms of parkinsonism: PSP, CBD and MSA.•GBA dysfunction does not seem to be involved in MSA and tauopathies.
doi:10.1016/j.parkreldis.2014.09.003
PMCID: PMC4228056  PMID: 25249066
Parkinson's disease; GBA; Parkinsonism; Association analysis; Splicing mutation; Functional characterization
2.  LRRK2 mutations in Parkinson's disease: Confirmation of a gender effect in the Italian population 
Parkinsonism & Related Disorders  2014;20(8):911-914.
Background
The relative risk of developing idiopathic PD is 1.5 times greater in men than in women, but an increased female prevalence in LRRK2-carriers has been described in the Ashkenazi Jewish population. We report an update about the frequency of major LRRK2 mutations in a large series of consecutive patients with Parkinson's disease (PD), including extensive characterization of clinical features. In particular, we investigated gender-related differences in motor and non-motor symptoms in the LRRK2 population.
Methods
2976 unrelated consecutive Italian patients with degenerative Parkinsonism were screened for mutations on exon 41 (G2019S, I2020T) and a subgroup of 1190 patients for mutations on exon 31 (R1441C/G/H). Demographic and clinical features were compared between LRRK2-carriers and non-carriers, and between male and female LRRK2 mutation carriers.
Results
LRRK2 mutations were identified in 40 of 2523 PD patients (1.6%) and not in other primary parkinsonian syndromes. No major clinical differences were found between LRRK2-carriers and non-carriers. We found a novel I2020L missense variant, predicted to be pathogenic. Female gender was more common amongst carriers than non-carriers (57% vs. 40%; p = 0.01), without any gender-related difference in clinical features. Family history of PD was more common in women in the whole PD group, regardless of their LRRK2 status.
Conclusions
PD patients with LRRK2 mutations are more likely to be women, suggesting a stronger genetic load compared to idiopathic PD. Further studies are needed to elucidate whether there is a different effect of gender on the balance between genetic and environmental factors in the pathogenesis of PD.
doi:10.1016/j.parkreldis.2014.04.016
PMCID: PMC4144811  PMID: 24816003
Parkinson disease; Genetics; LRRK2; Gender
3.  The modern pre-levodopa era of Parkinson’s disease: insights into motor complications from sub-Saharan Africa 
Brain  2014;137(10):2731-2742.
Delaying the initiation of levodopa has been proposed to reduce the risk of motor complications in Parkinson’s disease. In a 4-year multicentre study in Ghana, Cilia et al. find that motor fluctuations and dyskinesias are predicted by disease duration and levodopa dose, but not by the duration of levodopa therapy.
During the past decade, a number of large drug trials suggested that the initiation of levodopa therapy should be delayed to reduce the risk of motor complications in patients with Parkinson’s disease. However, the relative contribution of the cumulative exposure to levodopa and of disease progression to the pathophysiology of motor fluctuations and dyskinesias is still poorly understood. In this 4-year multicentre study, we investigated a large cohort of patients with Parkinson’s disease in a sub-Saharan African country (Ghana), where access to medication is limited and the initiation of levodopa therapy often occurs many years after onset. The primary objective was to investigate whether the occurrence of motor complications is primarily related to the duration of levodopa therapy or to disease-related factors. Study design included a cross-sectional case-control analysis of data collected between December 2008 and November 2012, and a prospective study of patients followed-up for at least 6 months after the initiation of levodopa therapy. Ninety-one patients fulfilled criteria for clinical diagnosis of idiopathic Parkinson’s disease (58 males, mean age at onset 60.6 ± 11.3 years). Demographic data were compared to those of 2282 consecutive Italian patients recruited during the same period, whereas nested matched subgroups were used to compare clinical variables. Demographic features, frequency and severity of motor and non-motor symptoms were comparable between the two populations, with the only exception of more frequent tremor-dominant presentation in Ghana. At baseline, the proportion of Ghanaian patients with motor fluctuations and dyskinesias was 56% and 14%, respectively. Although levodopa therapy was introduced later in Ghana (mean disease duration 4.2 ± 2.8 versus 2.4 ± 2.1 years, P < 0.001), disease duration at the occurrence of motor fluctuations and dyskinesias was similar in the two populations. In multivariate analysis, disease duration and levodopa daily dose (mg/kg of body weight) were associated with motor complications, while the disease duration at the initiation of levodopa was not. Prospective follow-up for a mean of 2.6 ± 1.3 years of a subgroup of 21 patients who were drug-naïve at baseline [median disease duration 4.5 (interquartile range, 2.3–5) years] revealed that the median time to development of motor fluctuations and dyskinesias after initiation of levodopa therapy was 6 months. We conclude that motor fluctuations and dyskinesias are not associated with the duration of levodopa therapy, but rather with longer disease duration and higher levodopa daily dose. Hence, the practice to withhold levodopa therapy with the objective of delaying the occurrence of motor complications is not justified.
doi:10.1093/brain/awu195
PMCID: PMC4163032  PMID: 25034897
Parkinson’s disease; dyskinesias; levodopa; pathophysiology
4.  DJ1 analysis in a large cohort of Italian early onset Parkinson Disease patients☆ 
Neuroscience Letters  2013;557(PB):165-170.
Highlights
•DJ1 is a recessive gene involved in early onset PD.•We tested 163 Italian EOPD.•We did not find any mutation in our population.•DJ1 PD causing mutations are very rare in Italian population.
We analyzed the DJ1 gene in a large consecutive series (N = 163) of Italian unrelated Early Onset Parkinson Disease (EOPD: onset ≤40 years of age) patients and 100 healthy controls (mean age 64 ± 7 years). No homozygous or compound heterozygous mutations with an obvious pathogenic effect were found. Several variants were identified, some of which were novels. All variants had similar frequency in patients and in controls. Our data suggest that DJ1 mutations are very rare in Italian EOPD. Other genes and risk factors for PD are still to be identified.
doi:10.1016/j.neulet.2013.10.048
PMCID: PMC3878804  PMID: 24176883
DJ1; Early Onset Parkinson Disease; Mutation analysis
5.  Continuous theta burst stimulation of right dorsolateral prefrontal cortex induces changes in impulsivity level 
Brain stimulation  2009;3(3):170-176.
There is evidence that the right dorsolateral prefrontal cortex (DLPFC) may play a certain role in decision making related to reward value and time perception and, in particular, in the inhibitory control of impulsive decision making. Using the theta burst stimulation (TBS) and a delay discounting (DD) task, we investigated the potential role of right DLPFC in impulsive decision making defined by the rate of discounting delayed reward. Healthy right-handed volunteers underwent three stimulation sessions, intermittent TBS (iTBS), continuous TBS (cTBS), and sham. The steepness of the discount function (k-value), reaction time for choice and consistency were measured for each subjects. cTBS of the DLPFC reduced by 36.88 % the k-value of the DD task compared to sham condition. In contrast, iTBS did not affect impulsivity level. There were no changes neither in reaction time for choice nor consistency after either the iTBS or cTBS compared with the sham stimulation. These results demonstrate that cTBS-induced modulation of cortical excitability of the right DLPFC may affect and reduce impulsive decision making. These observations may provide some insights into the role of the right DLPFC in modulating impulsivity level and calculating reward value at different time scales under less ambiguous circumstances.
doi:10.1016/j.brs.2009.10.002
PMCID: PMC3707839  PMID: 20633446 CAMSID: cams3169
rTMS; theta burst stimulation; dorsolateral prefrontal cortex; decision making; impulsivity; delay discounting task
6.  Impulse control disorders in Parkinson’s disease: seeking a roadmap toward a better understanding 
Brain Structure & Function  2011;216(4):289-299.
The development of an impulse control disorder (ICD) is now recognized as a potential nonmotor adverse effect of dopamine replacement therapy in Parkinson’s disease (PD). Here, recent epidemiological, neurophysiological and genetic advances are summarized to outline potential mechanisms involved. It is safe to say that dopaminergic drugs, particularly dopamine agonists, are able to induce ICDs only in a minority of patients, while the majority are somehow protected from this adverse effect. While it seems clear that men with early-onset PD are more vulnerable, other predisposing factors, such as various current or pre-PD personality traits, are a matter of debate. In terms of neurophysiological advances, one may find striking analogies to the addiction literature suggesting a causal chain beginning with certain predisposing conditions of striatal dopamine synapses, an “unnatural” increase of dopamine stimulation and a characteristic pattern of resulting functional changes in remote networks of appetitive drive and impulse control. Future prospects include potential add-on medications and the possible identification of genetic predispositions at a genome-wide scale. Functional imaging of pharmacogenetic interactions (imaging pharmacogenomics) may be an important tool on that road.
doi:10.1007/s00429-011-0314-0
PMCID: PMC3197927  PMID: 21541715
Imaging; Gambling; Addiction; Impulsive; Compulsive; Dopamine agonist
7.  Dopamine Transporter SPECT Imaging in Corticobasal Syndrome 
PLoS ONE  2011;6(5):e18301.
Objective
To investigate dopaminergic function in a large cohort of patients with corticobasal syndrome (CBS) and describe its relationship with clinical features in comparison to Parkinson's disease and healthy control subjects. In addition, we assessed prevalence and features of individuals with CBS and in vivo evidence of preserved nigral neuronal density.
Background
Substantia nigra pars compacta (SNc) neuronal degeneration is a mandatory pathological criterion for definite corticobasal degeneration, though sporadic autopsy-proven cases with ante-mortem imaging evidence of preserved nigral terminals have been recently described.
Methods
In this multicenter study, we investigated presynaptic nigrostriatal function in 36 outpatients fulfilling clinical criteria for “probable corticobasal degeneration” (age 71±7.3 years; disease duration 3.9±1.6 years), 37 PD and 24 healthy control subjects using FP-CIT single photon emission computed tomography. Clinical, neuropsychological, and magnetic resonance imaging assessment was performed to characterize CBS patients. Linear discriminant analysis was used to categorize normal vs. pathological scans.
Results
FP-CIT binding reduction in patients with CBS was characterized by larger variability, more uniform reduction throughout the striatum and greater hemispheric asymmetry compared to PD. Moreover, there was no significant correlation between tracer uptake values and clinical features such as disease duration and severity. Despite all CBS subjects showed obvious bilateral extrapyramidal signs, FP-CIT uptake was found to be normal bilaterally in four CBS patients and only unilaterally in other four cases. Extensive clinical, neuropsychological and imaging assessment did not reveal remarkable differences between CBS subjects with normal vs. pathological FP-CIT uptake.
Conclusions
Our findings support the hypothesis that extrapyramidal motor symptoms in CBS are not invariably associated with SNc neuronal degeneration and that supranigral factors may play a major role in several cases. CBS individuals with normal FP-CIT uptake do not show any clinical or cognitive feature suggesting a different pathology than CBD.
doi:10.1371/journal.pone.0018301
PMCID: PMC3085517  PMID: 21559307
8.  Sleep in Genetically Confirmed Pantothenate Kinase-Associated Neurodegeneration: A Video-Polysomnographic Study 
Parkinson's Disease  2010;2010:342834.
Pantothenate kinase-associated neurodegeneration (PKAN) is a familial or sporadic disease characterized by extrapyramidal and corticospinal signs with dementia. Patients show iron accumulation in the basal ganglia, with neuronal loss and gliosis. A mutation of pantothenate kinase (PANK2) gene localized on chromosome 20p13 has been described in familiar forms, as well as in sporadic patients. We sought to assess sleep characteristics, including muscle activity during REM sleep, in three patients with PANK2 gene mutation-confirmed diagnosis of PKAN. Sleep architecture was altered in all patients with reduced total time of sleep in two and lack of SWS in one. No significant apnea/hypopnea were detected, and mild PLMS were observed in one patient (PLMS index:10.7/h). In contrast with other neurodegenerative diseases, no REM sleep abnormalities, especially REM sleep behavior disorder, were observed in PKAN patients, and percentage of both REM sleep atonia and phasic EMG activity were within normal ranges. Sleep studies may phenotypically differentiate PKAN from other neurodegenerative disorders.
doi:10.4061/2010/342834
PMCID: PMC2957192  PMID: 20976082

Results 1-8 (8)