Logo: to the web site of Uppsala University

Deep brain stimulation (DBS) is a therapy widely used for treating the symptoms of neurological disorders. Electrical pulses are chronically delivered in DBS to a disease-specific brain target via a surgically implanted electrode. The stimulating contact configuration, stimulation polarity, as well as amplitude, frequency, and pulse width of the DBS pulse sequence are utilized to optimize the therapeutic effect. In this paper, the utility of therapy individualization by means of patient-specific mathematical modeling is investigated with respect to a specific case of a patient diagnosed with Essential tremor (ET). Two computational models are compared in their ability to elucidate the impact of DBS stimulation on the Dentato-Rubro-Thalamic tract (DRTT): (i) a conventional model of volume of tissue activated (VTA) and (ii) a well-established, open-source simulation (OSS) neural fiber activation modeling framework known as OSS-DBS. The simulation results are compared with tremor measured in the patient under different DBS settings using a smartphone application. The findings of the study highlight that temporally static VTA models do not adequately describe the differences in the outcomes of bipolar stimulation settings with switched polarity, whereas neural fiber activation models hold potential in this regard. However, it is noted that neither of the investigated models fully accounts for the measured symptom pattern, particularly regarding a bilateral effect produced by unilateral stimulation.

Background

Improvement of activity and participation for the disabled and chronically ill is an important aim of rehabilitation. Cervical dystonia is a neurological movement disorder characterized by involuntary contractions of the neck muscles. Until now, research has identified factors contributing to disability rather than factors which may make it easier to be active and participate in the community.

Objective

Explore and describe perceived experiences of activity and participation in daily life as experienced by persons with cervical dystonia.

Methods

Sixteen informants participated in this semi-structured interview study. Inductive qualitative content analysis was performed to understand and interpret experiences shared by the informants.

Results

Results from the analysis generated two themes “An active life” and “A challenging life” and six sub-themes: Using helpful coping strategies, Accepting a new life situation, Adhering to BT treatment, Facing the negative impact of stress, Experiencing a negative self-image and Suffering from pain and fatigue.

Conclusions

Our results support the importance of actions using a rehabilitation approach that consider both motor and non-motor symptoms. Future studies should compare the effects of physiotherapy taking into account wishes and challenges in patients’ everyday life versus traditional physiotherapy addressing mostly the motor disorder.

Background

Levodopa–entacapone–carbidopa intestinal gel (LECIG) was introduced on the Swedish market in 2019. The therapy is aimed at patients with Parkinson's disease (PD) with fluctuations and dyskinesias. Long-term efficacy and safety data are lacking.

Objective

To investigate the efficacy, tolerability, and safety of LECIG in regular clinical practice for Parkinson's disease in Sweden.

Methods

Real-world data were collected from the Swedish registry for Parkinson's disease (ParkReg) for all patients reported to receive LECIG during the period from 2019 until 31 August 2022.

Results

A total of 150 patients were identified. Sixty-one (41%) of 150 patients were females. At the start of treatment, the median age was 73 years (range: 43–86). The median duration since motor symptoms onset was 17 years (IQR: 9). Fifty (33%) of 150 patients switched from another device-assisted therapy, mostly LCIG (39 patients).

Reported complications were mainly related to PEG-J tube and stoma (30%). Twenty (13.3%) of 150 patients discontinued LECIG and 11 (7.3%) patients died while on LECIG.

The Parkinson KinetiGraph scores for bradykinesia, dyskinesia, fluctuations, tremor, and immobility for 53 patients during LECIG showed good therapy control. The median (IQR) p-Hcy during LECIG was 12 (4.6) μmol/L (n = 44). The median (IQR) PDQ-8 summary index during LECIG was 31 (17) (n = 52). The median (IQR) EQ5D during LECIG was 0.62 (0.32) (n = 41).

Conclusions

Data from ParkReg covering 150 patients over 3 years show LECIG to be an effective and safe device-aided therapy for advanced PD. However, the long-term efficacy and tolerability of LECIG need to be further investigated.

Background Levodopa-entacapone-carbidopa intestinal gel (LECIG) infusion was introduced to the Swedish market in 2019 for Parkinson's disease (PD) with motor fluctuations. Long-term data are lacking.

Objectives To study long-term data on LECIG treatment.

Methods A retrospective analysis of the first 24 patients receiving LECIG in Sweden from 2019 to 2023.

Results Five of 24 (21%) patients discontinued LECIG because of side effects, mostly diarrhea. Eight of the 24 (33%) patients died while receiving LECIG. Eleven of 24 (46%) patients were still on LECIG. Median (range) for disease and treatment duration was 19 (9–30) and 3.6 (3.1–4.0) years, respectively, whereas health-related quality of life scales showed median (interquartile range; n) Parkinson's Disease Questionnaire 8-item summary index scores of 38 (4; n = 7), EuroQol 5D scores of 0.59 (0.17; n = 7), and EQ-5D visual analogue scale scores of 65 (10; n = 7).

Conclusions LECIG infusion is a viable treatment option for PD patients with motor fluctuations, for up to 4 years in our cohort.

PET/MR systems demanded great efforts for accurate attenuation correction (AC) but differences in technology, geometry and hardware attenuation may also affect quantitative results. Dedicated PET systems using transmission-based AC are regarded as the gold standard for quantitative brain PET. The study aim was to investigate the agreement between quantitative PET outcomes from a PET/MR scanner against a stand-alone PET system.Nine patients with Parkinsonism underwent two 80-min dynamic PET scans with the dopamine transporter ligand [11C]PE2I. Images were reconstructed with resolution-matched settings using 68Ge-transmission (standalone PET), and zero-echo-time MR (PET/MR) scans for AC. Non-displaceable binding potential (BPND) and relative delivery (R1) were evaluated using volumes of interest and voxel-wise analysis.Correlations between systems were high (r >= 0.85) for both quantitative outcome parameters in all brain regions. Striatal BPND was significantly lower on PET/MR than on stand-alone PET (-7%). R1 was significantly overestimated in posterior cortical regions (9%) and underestimated in striatal (-9%) and limbic areas (-6%). The voxel-wise evaluation revealed that the MR-safe headphones caused a negative bias in both parametric BPND and R1 images. Additionally, a significant positive bias of R1 was found in the auditory cortex, most likely due to the acoustic background noise during MR imaging. The relative bias of the quantitative [11C]PE2I PET data acquired from a SIGNA PET/MR system was in the same order as the expected test-retest reproducibility of [11C]PE2I BPND and R1, compared to a stand-alone ECAT PET scanner. MR headphones and background noise are potential sources of error in functional PET/MR studies.

Background:

It has been suggested that carbidopa at high blood concentrations may counter the therapeutic effect of levodopa in Parkinson's disease by entering the brain and blocking central levodopa conversion to dopamine. We previously demonstrated equivalent plasma levodopa concentration in patients with Parkinson's disease during 16 h of (1) intravenous carbidopa/levodopa (DIZ101) infusion, (2) subcutaneous carbidopa/levodopa (DIZ102) infusion or (3) intestinal carbidopa/levodopa gel infusion. Plasma levels of carbidopa were however approximately four times higher with DIZ101 and DIZ102 than with LCIG, and higher than those usually observed with oral levodopa/carbidopa.

Objectives:

To investigate if high carbidopa blood concentrations obtained with parenteral levodopa/carbidopa (ratio 8:1) counter the effect of levodopa on motor symptoms.

Methods:

Eighteen patients with advanced Parkinson's disease were administered DIZ101, DIZ102, and intestinal levodopa/carbidopa gel for 16 h on different days in randomized order. Video recordings of a subset of the motor examination in the Unified Parkinson's Disease Rating Scale (UPDRS) were evaluated by raters blinded for treatment and time. Motor function was also measured using a wrist-worn device monitoring bradykinesia, dyskinesia, and tremor (Parkinson KinetiGraph).

Results:

There was no tendency for poorer levodopa effect with DIZ101 or DIZ102 as compared to LCIG.

Conclusion:

Although DIZ101 or DIZ102 causes approximately four times higher plasma carbidopa levels than LCIG, patients responded equally well to all treatments. The results do not indicate that high plasma carbidopa levels hamper the motor efficacy of levodopa.

Deep Brain Stimulation (DBS) is an established and powerful treatment method in various neurological dis-orders. It involves chronically delivering electrical pulses to a certain stimulation target in the brain in order to alleviate the symptoms of a disease. Traditionally, the effect of DBS on neural tissue has been modeled based on the geometrical intersection of the static Volume of Tissue Activated (VTA) and the stimulation target. Recent studies suggest that the Dentato Rubro Thalamic Tract (DRTT) may serve as a potential common underlying stimulation target for tremor control in Essential Tremor (ET). However, clinical observations highlight that the therapeutic effect of DBS, especially in ET, is strongly influenced by the dynamic DBS parameters such as pulse width and frequency, as well as stimulation polarity. This study introduces a computational model to elucidate the effect of the stimulation signal shape on the DRTT under neural input. The simulation results suggest that achieving a specific pulse amplitude threshold is necessary before eliciting the therapeutic effect through adjustments in pulse widths and frequencies becomes feasible. Longer pulse widths proved more likely to induce firing, thus requiring a lower stimulation amplitude. Additionally, the modulation effect of bipolar configurations on neural traffic was found to vary significantly depending on the chosen stimulation polarity and the direction of neural traffic. Further, bipolar configurations demonstrated the ability to selectively influence firing patterns in different fiber tracts.

Objectives

To describe levels of pain over time during disease progression in individual patients and for a total sample of patients with motor neuron disease (MND), respectively, and to examine associations between pain, disease severity, health-related quality of life (HRQOL), and depression.

Methods

A prospective cohort study was conducted on 68 patients with MND, including data collected on five occasions over a period of 2 years. Pain was assessed using the Brief Pain Inventory – Short Form. Depression was assessed using the Amyotrophic Lateral Sclerosis (ALS)-Depression-Inventory (ADI-12). Disability progression was measured using the Amyotrophic Lateral Sclerosis Functional Rating Scale – Revised Version (ALSFRS-R). HRQOL was assessed using the Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-5).

Results

Participants reported great individual variation over time. The median level of pain was 4 (min 0 and max 10). Higher levels of pain during the last 24 h were associated with higher depression scores (ADI-12), poorer quality of life (ALSAQ-5), and lower reporting of fine and gross motor skills (ALSFRS-R). Baseline pain levels did not predict future values of depression and function. Individuals reporting average pain >3 experienced more hopelessness toward the future and reported higher depression scores compared with participants reporting average pain <3.

Significance of results

Great within-individual variation of pain intensity was reported. Pain intensity was associated with depression, function and HRQOL cross-sectionally, but it did not have a strong prognostic value for future depression, function, or HRQOL. Patients with MND should be offered frequent assessment of pain and depressive symptoms in person-centered care, allowing for individualization of treatment.

Bsckground and Purpose: Differentiating idiopathic normal pressure hydrocephalus (iNPH) from neurodegenerative disorders such as progressive supranuclear palsy (PSP), Multiple System Atrophy-parkinsonian type (MSA-P), and vascular dementia (VaD) is challenging due to overlapping clinical and neuroimaging findings. This study assesses if quantitative brain stem and cerebellum metrics can aid in this differentiation.

Methods: We retrospectively compared the sagittal midbrain area, midbrain to pons ratio, MR parkinsonism index (MRPI), and cerebellar atrophy in 30 PSP patients, 31 iNPH patients, 27 MSA-P patients, 32 VaD patients, and 25 healthy controls. Statistical analyses determined group differences, sensitivity, specificity, and the area under the receiver operating characteristic curves.

Results: There was an overlap in midbrain morphology between PSP and iNPH, as assessed with MRPI, midbrain to pons ratio, and midbrain area. A cutoff value of MRPI > 13 exhibited 84% specificity in distinguishing PSP from iNPH and 100% in discriminating PSP from all other conditions. A cutoff value of midbrain to pons ratio at <0.15 yielded 95% specificity for differentiating PSP from iNPH and 100% from all other conditions. A cutoff value of midbrain area at <87 mm² exhibited 97% specificity for differentiating PSP from iNPH and 100% from all other conditions. All measures showed low sensitivity. Cerebellar atrophy did not differ significantly among groups.

Conclusion: Our study questions MRPI's diagnostic performance in distinguishing PSP from iNPH. Simpler indices such as midbrain to pons ratio and midbrain area showed similar or better accuracy. However, all these indices displayed low sensitivity despite significant differences among PSP, MSA-P, and VaD.

Background: Neuroinflammatory processes have been suggested to play a role in the pathophysiology of neurodegenerative diseases and post-hemorrhagic hydrocephalus, but have rarely been investigated in patients with idiopathic normal pressure hydrocephalus (iNPH). The aim of this study was to investigate whether levels of inflammatory proteins in CSF are different in iNPH compared to healthy controls and patients with selected neurodegenerative disorders, and whether any of these markers can aid in the differential diagnosis of iNPH.

Methods: Lumbar CSF was collected from 172 patients from a single center and represented iNPH (n = 74), Alzheimer's disease (AD) (n = 21), mild cognitive impairment (MCI) due to AD (n = 21), stable MCI (n = 22), frontotemporal dementia (n = 13), and healthy controls (HC) (n = 21). Levels of 92 inflammatory proteins were analyzed using a proximity extension assay. As a first step, differences between iNPH and HC were investigated, and proteins that differed between iNPH and HC were then compared with those from the other groups. The linear regressions were adjusted for age, sex, and plate number.

Results: Three proteins showed higher (MCP-1, p = 0.0013; CCL4, p = 0.0008; CCL11, p = 0.0022) and one lower (PD-L1, p = 0.0051) levels in patients with iNPH compared to HC. MCP-1 was then found to be higher in iNPH than in all other groups. CCL4 was higher in iNPH than in all other groups, except in MCI due to AD. PD-L1 was lower in iNPH compared to all other groups, except in stable MCI. Levels of CCL11 did not differ between iNPH and the differential diagnoses. In a model based on the four proteins mentioned above, the mean area under the receiver operating characteristic curve used to discriminate between iNPH and the other disorders was 0.91.

Conclusions: The inflammatory cytokines MCP-1 and CCL4 are present at higher-and PD-L1 at lower-levels in iNPH than in the other investigated diagnoses. These three selected cytokines may have diagnostic potential in the work-up of patients with iNPH.