Deep brain stimulation in the caudal zona incerta versus best medical treatment in patients with Parkinson's disease: a randomised blinded evaluation.

BACKGROUND: Several open-label studies have shown good effect of deep brain stimulation (DBS) in the caudal zona incerta (cZi) on tremor, including parkinsonian tremor, and in some cases also a benefit on akinesia and axial symptoms. The aim of this study was to evaluate objectively the effect of cZi DBS in patients with Parkinson's disease (PD). METHOD: 25 patients with PD were randomised to either cZi DBS or best medical treatment. The primary outcomes were differences between the groups in the motor scores of the Unified Parkinson's Disease Rating Scale (UPDRS-III) rated single-blindly at 6 months and differences in the Parkinson's Disease Questionnaire 39 items (PDQ-39). 19 patients, 10 in the medical arm and 9 in the DBS arm, fulfilled the study. RESULTS: The DBS group had 41% better UPDRS-III scores off-medication on-stimulation compared with baseline, whereas the scores of the non-surgical patients off-medication were unchanged. In the on-medication condition, there were no differences between the groups, neither at baseline nor at 6 months. Subitems of the UPDRS-III showed a robust effect of cZi DBS on tremor. The PDQ-39 domains 'stigma' and 'ADL' improved only in the DBS group. The PDQ-39 summary index improved in both groups. CONCLUSION: This is the first randomised blinded evaluation of cZi DBS showing its efficacy on PD symptoms. The most striking effect was on tremor; however, the doses of dopaminergic medications could not be decreased. cZi DBS in PD may be an addition to existing established targets, enabling tailoring the surgery to the needs of the individual patient.

Association of glucocerebrosidase polymorphisms and mutations with dementia in incident Parkinson's disease.

INTRODUCTION: Both polymorphisms and mutations in glucocerebrosidase (GBA) may influence the development of dementia in patients with Parkinson's disease. METHODS: Four hundred forty-two patients and 419 controls were followed for 7 years. Dementia was diagnosed using established criteria. Participants were analyzed for GBA genetic variants, including E326K, T369M, and L444P. Associations between GBA carrier status and dementia were assessed with Cox survival analysis. RESULTS: A total of 12.0% of patients with Parkinson's disease carried a GBA variant, and nearly half (22/53) of them progressed to dementia during follow-up. Carriers of deleterious GBA mutations (adjusted hazard ratio 3.81, 95% confidence interval 1.35 to 10.72; P = .011) or polymorphisms (adjusted hazard ratio 1.79; 95% confidence interval 1.07 to 3.00; P = .028) progressed to dementia more rapidly than noncarriers. DISCUSSION: GBA variants are of great clinical relevance for the development of dementia in Parkinson's disease, especially due to the relatively higher frequency of these alleles compared with other risk alleles.

Fine mapping and resequencing of the PARK16 locus in Parkinson's disease.

The PARK16 locus, spanning five genes on chromosome 1, was among the first genetic regions to show genome-wide association in Parkinson's disease (PD). Subsequent investigations have found variability in PARK16 top-hits and association patterns across populations, and the implicated genes and mechanisms are currently unclear. In the present study, we aimed to explore the contribution of PARK16 variability to PD risk in a Scandinavian population. We genotyped 17 single-nucleotide polymorphisms in a case-control sample set of 2570 individuals from Norway and Sweden to fine map the locus. Targeted resequencing of the full coding regions of SLC45A3, NUCKS1, RAB7L1, SLC41A1 and PM20D1 was performed in DNA pools from a subset of 387 patient samples. We find evidence for an association with PD for rs1775143 as well as a haplotype located around the 5' region of RAB7L1, implicating variants which are not in high linkage disequilibrium with the strongest signal from a recent large meta-analysis in Caucasians. We also provide suggestive support for epistasis between RAB7L1 and LRRK2 as previously hypothesized by others. Comparing our results with previous work, allelic heterogeneity at PARK16 appears likely, and further studies are warranted to disentangle the complex patterns of association and pinpoint the functionally relevant variants.

Laterality and deep brain stimulation of the subthalamic nucleus: applying a dichotic listening task to patients treated for Parkinson's disease.

Ear advantage during a dichotic listening task tends to mirror speech lateralization. Previous studies in stroke patients have shown that lesions in the dominant hemisphere often seem to produce changes in ear advantage. In this study six Parkinson's disease (PD) patients treated for motor symptoms with deep brain stimulation (DBS) of the left subthalamic nucleus (STN) were tested preoperatively and at approximately 6 and 18 months postoperatively with a dichotic listening task. Results show a significant decline of the right ear advantage over time. In three of the patients a right ear advantage preoperatively changed to a left ear advantage 18 months postoperatively. This suggests the possibility that additional longitudinal studies of this phenomenon could serve as a model for understanding changes in indirect measures of speech lateralization in stroke patients.

The role of TREM2 R47H as a risk factor for Alzheimer's disease, frontotemporal lobar degeneration, amyotrophic lateral sclerosis, and Parkinson's disease.

A rare variant in TREM2 (p.R47H, rs75932628) was recently reported to increase the risk of Alzheimer's disease (AD) and, subsequently, other neurodegenerative diseases, i.e. frontotemporal lobar degeneration (FTLD), amyotrophic lateral sclerosis (ALS), and Parkinson's disease (PD). Here we comprehensively assessed TREM2 rs75932628 for association with these diseases in a total of 19,940 previously untyped subjects of European descent. These data were combined with those from 28 published data sets by meta-analysis. Furthermore, we tested whether rs75932628 shows association with amyloid beta (Aß42) and total-tau protein levels in the cerebrospinal fluid (CSF) of 828 individuals with AD or mild cognitive impairment. Our data show that rs75932628 is highly significantly associated with the risk of AD across 24,086 AD cases and 148,993 controls of European descent (odds ratio or OR = 2.71, P = 4.67 × 10(-25)). No consistent evidence for association was found between this marker and the risk of FTLD (OR = 2.24, P = .0113 across 2673 cases/9283 controls), PD (OR = 1.36, P = .0767 across 8311 cases/79,938 controls) and ALS (OR = 1.41, P = .198 across 5544 cases/7072 controls). Furthermore, carriers of the rs75932628 risk allele showed significantly increased levels of CSF-total-tau (P = .0110) but not Aß42 suggesting that TREM2's role in AD may involve tau dysfunction.

Verbal fluency in patients receiving bilateral versus left-sided deep brain stimulation of the subthalamic nucleus for Parkinson's disease.

The purpose of this study was to investigate the relative effects of unilateral (left-sided) versus bilateral deep brain stimulation (DBS) of the subthalamic nucleus (STN) on verbal fluency. To do this, 10 Parkinson's disease patients with predominantly bilateral motor symptoms who received bilateral STN DBS were compared with 6 patients suffering from predominantly unilateral symptoms who received STN DBS on the left side only. The results suggest that unilateral STN DBS of the speech dominant hemisphere is associated with significantly less declines in measures of verbal fluency as compared to bilateral stimulation.

Dietary intake and olfactory function in patients with newly diagnosed Parkinson's disease: a case-control study.

OBJECTIVE: To evaluate energy and nutrient intake in newly diagnosed Parkinson's disease (PD) patients and association between olfaction and nutrient density of the diet. DESIGN: Baseline data from a prospective cohort study. SUBJECTS: Eighty-seven patients and 28 age- and sex-matched controls participated in the study. METHODS: Dietary intake was assessed by using 3-day dietary records and 24-hour dietary recalls. The Brief Smell Identification Test (B-SIT) was used to test olfaction. RESULTS: Patients, compared with controls, had lower intake of polyunsaturated fatty acids (P = 0.024) and a higher intake of carbohydrates (P = 0.027) in energy percent (E%). Lower intake of protein (E%) (P = 0.045), and a low nutrient density of folate (P = 0.022), magnesium (P = 0.012), and phosphorus (P = 0.029) were associated with lower B-SIT score in both patients and controls. PD patients had a lower B-SIT score than controls (P < 0.001). CONCLUSION: The results indicate a higher relative contribution of energy from carbohydrates in PD patients. An association between low protein, folate, magnesium, and phosphorus density of the diet and olfaction was seen in the whole population.

Deep brain stimulation of the subthalamic nucleus versus the zona incerta in the treatment of essential tremor.

BACKGROUND: Deep brain stimulation (DBS) is an effective treatment for essential tremor (ET). Currently the ventrolateral thalamus is the target of choice, but the posterior subthalamic area (PSA), including the caudal zona incerta (cZi), has demonstrated promising results, and the subthalamic nucleus (STN) has been suggested as a third alternative. The objective of the current study was to evaluate the effect of STN DBS in ET and to compare this to cZi DBS. METHODS: Four patients with ET were implanted with two ipsilateral electrodes, one in the STN and one in the cZi. All contacts were evaluated concerning the acute effect on tremor, and the effect of chronic DBS in either target was analyzed. RESULTS: STN and cZi both proved to be potent targets for DBS in ET. DBS in the cZi was more efficient, since the same degree of tremor reduction could here be achieved at lower energy consumption. Three patients became tremor-free in the treated hand with either STN or cZi DBS, while the fourth had a minor residual tremor after stimulation in either target. CONCLUSION: In this limited material, STN DBS was demonstrated to be an efficient treatment for ET, even though cZi DBS was more efficient. The STN may be an alternative target in the treatment of ET, pending further investigations to decide on the relative merits of the different targets.

Pre- and postsynaptic dopamine SPECT in the early phase of idiopathic parkinsonism: a population-based study.

PURPOSE: The aim of this study was to assess the diagnostic contribution of pre- and postsynaptic dopamine SPECT in drug-naïve patients with early idiopathic parkinsonism and to investigate possible differences between idiopathic Parkinson's disease (PD) and atypical parkinsonian syndromes (APS) and possible differences in motor subtypes of parkinsonism. METHODS: A group of 128 newly diagnosed idiopathic parkinsonian patients and 48 healthy controls was studied. Presynaptic baseline SPECT with (123)I-FP-CIT was performed in all patients and in 120 patients also a baseline postsynaptic SPECT with (123)I-IBZM. Clinical diagnoses were reassessed after 12 months. RESULTS: Presynaptic uptake in the putamen and caudate was significantly reduced in patients compared to controls. Presynaptic uptake ratios were not different between PD patients and patients with APS, and postsynaptic uptake in APS was not significantly reduced compared to PD or controls. In half of the APS patients both pre- and postsynaptic uptake ratios were reduced on the same side in the striatum. Impaired motor performance was associated with decreased presynaptic uptake in the putamen in PD. The postural instability and gait difficulty (PIGD) subtype of PD had lower presynaptic uptake ratios than patients with tremor-dominated (TD) symptoms. CONCLUSION: Not only presynaptic putamen uptake ratios, but also caudate ratios were reduced in a majority of the patients in our study. At baseline scan, i.e. in an early stage of the disease, the accuracy of excluding APS in the whole study population was 85% using a combination of pre- and postsynaptic SPECT. Already at baseline, lower presynaptic SPECT ratios were seen in PD with PIGD at onset compared to those with TD subtype.

Incidence of Parkinson's disease and parkinsonism in northern Sweden: a population-based study.

The differential diagnosis of parkinsonian disorders is difficult, especially early in the course of the diseases. The clinical subtypes of Parkinson's disease (PD) have not so far been described in newly diagnosed patients. We present a prospective incidence cohort study of patients with idiopathic parkinsonian syndromes in the Umeå region in northern Sweden identified over a 4-year period. The clinical diagnoses were re-evaluated at follow-up visits at 12 months. We found 138 patients with parkinsonism: 112 PD, 12 multiple system atrophy with predominant parkinsonism (MSA-P), six progressive supranuclear palsy (PSP) and eight unclassifiable patients. The crude incidences for all age ranges per 100,000 were: PD 19.7 (95% confidence interval 16.1-23.3); MSA-P 2.1 (1.1-3.7); PSP 1.1 (0.4-2.4); idiopathic parkinsonism 24.3 (20.2-28.4). Age-standardized to the average Swedish population 2004-2007: PD 22.5 (18.3-26.7); MSA-P 2.4 (1.2-4.2); PSP 1.2 (0.4-2.6); idiopathic parkinsonism 27.5 (22.9-32.1). The crude annual incidence rate for PD, with exclusion of patients with normal dopamine receptor uptake (FP-CIT-SPECT), was 18.8 per 100,000 (95% confidence interval 15.2-22.4), age-adjusted to the average Swedish population 2004 to 2007: 21.5 (17.4-25.6). The incidence rates did not differ significantly between men and women. The cumulative incidence of PD up to 89 years of age was for men 3.4%, for women 2.6%, and for both sexes combined 2.9%. The annual incidence rates found for PD, idiopathic parkinsonism, MSA-P and PSP are among the highest reported.

Temporal dynamics of basal ganglia under-recruitment in Parkinson's disease: transient caudate abnormalities during updating of working memory.

Using hybrid-blocked/event-related fMRI and the 2-back task we aimed to decompose tonic and phasic temporal dynamics of basal ganglia response abnormalities in working memory associated with early untreated Parkinson's disease. In view of the tonic/phasic dopamine hypothesis, which posits a functional division between phasic D(2)-dependent striatal updating processes and tonic D(1)-dependent prefrontal context-maintenance processes, we predicted that newly diagnosed, drug-naïve Parkinson's disease patients, with selective striatal dopamine deprivation, would demonstrate transient rather than sustained activation changes in the basal ganglia during 2-back performance. Task-related activation patterns within discrete basal ganglia structures were directly compared between patients and healthy elderly controls. The obtained results yielded uniquely transient underactivation foci in caudate nuclei, putamen and globus pallidus in Parkinson's disease patients, which indicates suboptimal phasic implementation of striatal D(2)-dependent gating mechanisms during updating. Sustained underactivation was only seen in the anterior putamen, which may reflect initial signs of tonic control impairment. No significant changes were exhibited in prefrontal cortex. The present findings resonate well with the tonic/phasic dopamine account and suggest that basal ganglia under-recruitment associated with executive dysfunction in early Parkinson's disease might predominantly stem from deficiencies in phasic executive components subserved by striatum.

NfL as a biomarker for neurodegeneration and survival in Parkinson disease.

OBJECTIVE: To determine whether neurofilament light chain protein in CSF (cNfL), a sensitive biomarker of neuroaxonal damage, reflects disease severity or can predict survival in Parkinson disease (PD). METHODS: We investigated whether disease severity, phenotype, or survival in patients with new-onset PD correlates with cNfL concentrations around the time of diagnosis in the population-based New Parkinsonism in Umeå (NYPUM) study cohort (n = 99). A second, larger new-onset PD cohort (n = 194) was used for independent validation. Association of brain pathology with the cNfL concentration was examined with striatal dopamine transporter imaging and repeated diffusion tensor imaging at baseline and 1 and 3 years. RESULTS: Higher cNfL in the early phase of PD was associated with greater severity of all cardinal motor symptoms except tremor in both cohorts and with shorter survival and impaired olfaction. cNfL concentrations above the median of 903 ng/L conferred an overall 5.8 times increased hazard of death during follow-up. After adjustment for age and sex, higher cNfL correlated with striatal dopamine transporter uptake deficits and lower fractional anisotropy in diffusion tensor imaging of several axonal tracts. CONCLUSIONS: cNfL shows usefulness as a biomarker of disease severity and to predict survival in PD. The present results indicate that the cNfL concentration reflects the intensity of the neurodegenerative process, which could be important in future clinical trials. CLASSIFICATION OF EVIDENCE: This study provides Class II evidence that in patients with PD, cNfL concentrations are associated with more severe disease and shorter survival.

Voice Tremor Outcomes of Subthalamic Nucleus and Zona Incerta Deep Brain Stimulation in Patients With Parkinson Disease.

OBJECTIVES: We aimed to study the effect of deep brain stimulation (DBS) in the subthalamic nucleus (STN) and caudal zona incerta (cZi) on level of perceived voice tremor in patients with Parkinson disease (PD). STUDY DESIGN: This is a prospective nonrandomized design with consecutive patients. METHODS: Perceived voice tremor was assessed in patients with PD having received either STN-DBS (8 patients, 5 bilateral and 3 unilateral, aged 43.1-73.6 years; median = 61.2 years) or cZi-DBS (14 bilateral patients, aged 39.0-71.9 years; median = 56.6 years) 12 months before the assessment. Sustained vowels that were produced OFF and ON stimulation (with simultaneous l-DOPA medication) were assessed perceptually in terms of voice tremor by two raters on a four-point rating scale. The assessments were repeated five times per sample and rated in a blinded and randomized procedure. RESULTS: Three out of the 22 patients (13%) were concluded to have voice tremor OFF stimulation. Patients with PD with STN-DBS showed mild levels of perceived voice tremor OFF stimulation and a group level improvement. Patients with moderate/severe perceived voice tremor and cZi-DBS showed marked improvements, but there was no overall group effect. Six patients with cZi-DBS showed small increases in perceived voice tremor severity. CONCLUSIONS: STN-DBS decreased perceived voice tremor on a group level. cZi-DBS decreased perceived voice tremor in patients with PD with moderate to severe preoperative levels of the symptom.

Low prevalence of known pathogenic mutations in dominant PD genes: A Swedish multicenter study.

OBJECTIVE: To determine the frequency of mutations known to cause autosomal dominant Parkinson disease (PD) in a series with more than 10% of Sweden's estimated number of PD patients. METHODS: The Swedish Parkinson Disease Genetics Network was formed as a national multicenter consortium of clinical researchers who together have access to DNA from a total of 2,206 PD patients; 85.4% were from population-based studies. Samples were analyzed centrally for known pathogenic mutations in SNCA (duplications/triplications, p.Ala30Pro, p.Ala53Thr) and LRRK2 (p.Asn1437His, p.Arg1441His, p.Tyr1699Cys, p.Gly2019Ser, p.Ile2020Thr). We compared the frequency of these mutations in Swedish patients with published PD series and the gnomAD database. RESULTS: A family history of PD in first- and/or second-degree relatives was reported by 21.6% of participants. Twelve patients (0.54%) carried LRRK2 p.(Gly2019Ser) mutations, one patient (0.045%) an SNCA duplication. The frequency of LRRK2 p.(Gly2019Ser) carriers was 0.11% in a matched Swedish control cohort and a similar 0.098% in total gnomAD, but there was a marked difference between ethnicities in gnomAD, with 42-fold higher frequency among Ashkenazi Jews than all others combined. CONCLUSIONS: In relative terms, the LRRK2 p.(Gly2019Ser) variant is the most frequent mutation among Swedish or international PD patients, and in gnomAD. SNCA duplications were the second most common of the mutations examined. In absolute terms, however, these known pathogenic variants in dominant PD genes are generally very rare and can only explain a minute fraction of familial aggregation of PD. Additional genetic and environmental mechanisms may explain the frequent co-occurrence of PD in close relatives.

Whole-Body Biodistribution and Dosimetry of the Dopamine Transporter Radioligand 18F-FE-PE2I in Human Subjects.

18F-(E)-N-(3-iodoprop-2-enyl)-2ß-carbofluoroethoxy-3ß-(4'-methyl-phenyl) nortropane (18F-FE-PE2I) was recently developed and has shown adequate affinity and high selectivity for the dopamine transporter (DAT). Previous studies have shown promising results for 18F-FE-PE2I as a suitable radioligand for DAT imaging. In this study, we investigated the whole-body biodistribution and dosimetry of 18F-FE-PE2I in healthy volunteers to support its utility as a suitable PET imaging agent for the DAT. Methods: Five healthy volunteers were given a mean activity of 2.5 MBq/kg, and 3 PET scans, head to thigh, were performed immediately after injection followed by 4 whole-body PET/CT scans between 0.5 and 6 h after injection. Blood samples were drawn in connection with the whole-body scans, and all urine was collected until 6 h after injection. Volumes of interest were delineated around 17 organs on all images, and the areas under the time-activity curves were calculated to obtain the total number of decays in the organs. The absorbed doses to organs and the effective dose were calculated using the software IDAC. Results: The highest activity concentration was observed in the liver (0.9%-1.2% injected activity/100 g) up to 30 min after injection. At later time points, the highest concentration was seen in the gallbladder (1.1%-0.1% injected activity/100 g). The activity excreted with urine ranged between 23% and 34%, with a mean of 28%. The urinary bladder received the highest absorbed dose (119 µGy/MBq), followed by the liver (46 µGy/MBq). The effective dose was 23 µSv/MBq (range, 19-28 µSv/MBq), resulting in an effective dose of 4.6 mSv for an administered activity of 200 MBq. Conclusion: The effective dose is within the same order of magnitude as other commonly used PET imaging agents as well as DAT agents. The reasonable effective dose, together with the previously reported favorable characteristics for DAT imaging and quantification, indicates that 18F-FE-PE2I is a suitable radioligand for DAT imaging.

Early predictors of mortality in parkinsonism and Parkinson disease: A population-based study.

OBJECTIVE: To examine mortality and associated risk factors, including possible effects of mild cognitive impairment, imaging, and CSF abnormalities, in a community-based population with incident parkinsonism and Parkinson disease. METHODS: One hundred eighty-two patients with new-onset, idiopathic parkinsonism were diagnosed from January 2004 through April 2009, in a catchment area of 142,000 inhabitants in Sweden. Patients were comprehensively investigated according to a multimodal research protocol and followed prospectively for up to 13.5 years. A total of 109 patients died. Mortality rates in the general Swedish population were used to calculate standardized mortality ratio and expected survival, and Cox proportional hazard models were used to investigate independent predictors of mortality. RESULTS: The standardized mortality ratio for all patients was 1.84 (95% confidence interval 1.50-2.22, p < 0.001). Patients with atypical parkinsonism (multiple system atrophy or progressive supranuclear palsy) had the highest mortality. In early Parkinson disease, a mild cognitive impairment diagnosis, freezing of gait, hyposmia, reduced dopamine transporter activity in the caudate, and elevated leukocytes in the CSF were significantly associated with shorter survival. CONCLUSION: Although patients presenting with idiopathic parkinsonism have reduced survival, the survival is highly dependent on the type and characteristics of the parkinsonian disorder. Patients with Parkinson disease presenting with normal cognitive function seem to have a largely normal life expectancy. The finding of a subtle CSF leukocytosis in patients with Parkinson disease with short survival may have clinical implications.

Dopamine transporter imaging with [18F]FE-PE2I PET and [123I]FP-CIT SPECT-a clinical comparison.

BACKGROUND: Dopamine transporter (DAT) imaging may be of diagnostic value in patients with clinically suspected parkinsonian disease. The purpose of this study was to compare the diagnostic performance of DAT imaging with positron emission computed tomography (PET), using the recently developed, highly DAT-selective radiopharmaceutical [18F]FE-PE2I (FE-PE2I), to the commercially available and frequently used method with [123I]FP-CIT (FP-CIT) single-photon emission computed tomography (SPECT) in early-stage idiopathic parkinsonian syndrome (PS). METHODS: Twenty-two patients with a clinical de novo diagnosis of PS and 28 healthy controls (HC) participating in an on-going clinical trial of FE-PE2I were analyzed in this study. Within the trial protocol, participants are clinically reassessed 2 years after inclusion. A commercially available software was used for automatic calculation of FP-CIT-specific uptake ratio (SUR). MRI-based volumes of interest combined with threshold PET segmentation were used for FE-PE2I binding potential relative to non-displaceable binding (BPND) quantification and specific uptake value ratios (SUVR). RESULTS: PET with FE-PE2I revealed significant differences between patients with a clinical de novo diagnosis of PS and healthy controls in striatal DAT availability (p < 0.001), with excellent accuracy of predicting dopaminergic deficit in early-stage PS. The effect sizes were calculated for FE-PE2I BPND (Glass's Δ = 2.95), FE-PE2I SUVR (Glass's Δ = 2.57), and FP-CIT SUR (Glass's Δ = 2.29). The intraclass correlation (ICC) between FE-PE2I BPND FP-CIT SUR was high in the caudate (ICC = 0.923), putamen (ICC = 0.922), and striatum (ICC = 0.946), p < 0.001. Five of the 22 patients displayed preserved striatal DAT availability in the striatum with both methods. At follow-up, a non-PS clinical diagnosis was confirmed in three of these, while one was clinically diagnosed with corticobasal syndrome. In these patients, FE-PE2I binding was also normal in the substantia nigra (SN), while significantly reduced in the remaining patients. FE-PE2I measurement of the mean DAT availability in the putamen was strongly correlated with BPND in the SN (R = 0.816, p < 0.001). Olfaction and mean putamen DAT availability was correlated using both FE-PE2I BPND and FP-CIT SUR (R ≥ 0.616, p < 0.001). CONCLUSION: DAT imaging with FE-PE2I PET yields excellent basic diagnostic differentiation in early-stage PS, at least as good as FP-CIT SPECT.

Swallowing safety in Parkinson's disease after zona incerta deep brain stimulation.

OBJECTIVES: The objective of this study was to examine swallowing function in patients with Parkinson's disease before and after caudal zona incerta deep brain (cZI DBS) surgery. The aims were to examine the effect of cZI DBS on swallowing safety regarding liquid and solid food, as well as to identify the effect of cZI DBS on body mass index (BMI) and specific items from part II of the Unified Parkinson's Disease Rating Scale (UPDRS). MATERIALS AND METHODS: The median age of the 14 patients was 57 years (range 46-71), with a median disease duration of 6 years (range 2-13). The present sample is an extension of a previous report, into which six additional patients have been added. Fiber endoscopic examinations of swallowing function, measures of BMI, and evaluation of UPDRS part II items were made before and 12 months after surgery, with and without activated DBS. RESULTS: There were no significant changes due to cZI DBS regarding penetration/aspiration, pharyngeal residue or premature spillage (p > .05). Median BMI increased by +1.1 kg/m2 12 months after surgery (p = .01, r = .50). All reported specific symptoms from the UPDRS part II were slight or mild. A significant improvement regarding handling of utensils was seen 12 months postoperatively (p = .03, r = -.42). CONCLUSIONS: Caudal zona incerta DBS was found not to have a negative impact on swallowing safety. A significant increase in postoperative weight was observed, and speech seemed to be slightly negatively affected, whereas handling of utensils was improved with cZI DBS.

Swallowing Quality of Life After Zona Incerta Deep Brain Stimulation.

OBJECTIVES: The management of Parkinson's disease (PD) has been improved, but management of signs like swallowing problems is still challenging. Deep brain stimulation (DBS) alleviates the cardinal motor symptoms and improves quality of life, but its effect on swallowing is not fully explored. The purpose of this study was to examine self-reported swallowing-specific quality of life before and after caudal zona incerta DBS (cZI DBS) in comparison with a control group. METHODS: Nine PD patients (2 women and 7 men) completed the self-report Swallowing Quality of Life questionnaire (SWAL-QOL) before and 12 months after cZI DBS surgery. The postoperative data were compared to 9 controls. Median ages were 53 years (range, 40-70 years) for patients and 54 years (range, 42-72 years) for controls. RESULTS: No significant differences were found between the pre- or postoperative scores. The SWAL-QOL total scores did not differ significantly between PD patients and controls. The PD patients reported significantly lower scores in the burden subscale and the symptom scale. CONCLUSIONS: Patients with PD selected for cZI DBS showed good self-reported swallowing-specific quality of life, in many aspects equal to controls. The cZI DBS did not negatively affect swallowing-specific quality of life in this study.

PITX3 genotype and risk of dementia in Parkinson's disease: A population-based study.

Dementia is a devastating manifestation of Parkinson's disease (PD). This study investigates whether a common polymorphism in the PITX3 gene (rs2281983), which is of importance for the function of dopaminergic neurons, affects the risk of developing dementia in PD and whether it affects dopamine transporter (DAT) uptake. We PITX3 genotyped 133 patients with new-onset, idiopathic PD, participating in a population-based study in Sweden. Patients were followed prospectively during 6-11years with extensive investigations, including neuropsychology and DAT-imaging with 123I FP-CIT. The primary outcome was the incidence of PD dementia (PDD), diagnosed according to published criteria, studied by the Kaplan-Meier method and Cox proportional hazards. Performance in individual cognitive domains, the incidence of visual hallucinations, disease progression and striatal DAT uptake on imaging was also investigated. PD patients carrying the PITX3 C allele had an increased risk of developing PDD (hazard ratio: 2.87, 95% CI: 1.42-5.81, p=0.003), compared to the PD patients homozygous for the T-allele. Furthermore, the PITX3 C allele carriers with PD had a poorer cognitive performance in the visuospatial domain (p<0.001) and a higher incidence of visual hallucinations. A trend towards a lower striatal DAT uptake in the PITX3 C allele carriers was suggested, but could not be confirmed. Our results show that a common polymorphism in the PITX3 gene affects the risk of developing PDD and visuospatial dysfunction in idiopathic PD. If validated, these findings can provide new insights into the neurobiology and genetics of non-motor symptoms in PD.