Cerebrospinal fluid protein markers in PD patients after DBS-STN surgery-A retrospective analysis of patients that underwent surgery between 1993 and 2001.

OBJECTIVE: Cerebrospinal fluid (CSF) markers of neurodegeneration [neurofilament light chain (NFL), total Tau (T-Tau)], tau pathology [phosphorylated tau (p-Tau)], glial cell damage or activation [glial fibrillary acidic protein (GFAP)], and brain amyloidosis [ß-amyloid 1-42 (Aß42)] are useful for diagnosis and prognosis in several neurodegenerative disorders. In this paper we investigate these markers and their relationship to key clinical milestones in patients with advanced Parkinson´s disease (PD) operated at our center with subthalamic nucleus deep brain stimulation (STN-DBS) for at least 15 years ago. PATIENTS AND METHODS: Retrospective analysis of available cerebrospinal fluid and clinical data in PD-patients, 15 years or more after they underwent STN-DBS surgery. All PD-patients implanted with STN-DBS at Sahlgrenska University Hospital before January 1, 2001, were regularly assessed until January 10, 2018, or until death, or until lost to follow-up. RESULTS: Twenty three PD patients were operated with STN-DBS. Sixteen of these (six females and ten males) underwent at least one lumbar puncture (LP) immediately prior to or after STN-DBS. Their age at the latest available LP was 64 (55-75) years [median (range)], PD duration 20 (11-33) years, and Hoehn & Yahr (H&Y) stage 3 (2-4). Time between DBS operation and the last LP was 4.5 (0.3-10.8) years. Time from the last LP to the last follow up was 6 (0.1-18) years, and for the entire cohort 115 person-years. On January 10, 2018, four PD-patients (25%) were still alive. All preoperative CSF marker levels were normal. Between two days and six months after DBS, NFL and GFAP levels increased sharply but they normalized thereafter in most patients, and were normal up to almost 11 years after neurosurgery. Over time, all patients deteriorated slowly. At the last follow up, H&Y was 5 (3-5) and 12/16 were demented. There was no significant correlation between postoperative (> 6 months) CSF NFL, GFAP, T-Tau, p-Tau, ß-amyloid levels and the presence of dementia, psychosis, inability to walk or need for nursing home at the time for LP, nor for presence of dementia at the last follow up or for death as of January 10, 2018. CONCLUSION: CSF protein biomarkers remain normal despite long PD duration, severe disability, and chronic STN-DBS. They cannot be used for PD staging or prognostication but may indicate brain damage caused by other pathological factors.

Key clinical milestones 15 years and onwards after DBS-STN surgery-A retrospective analysis of patients that underwent surgery between 1993 and 2001.

OBJECTIVE: Subthalamic nucleus deep brain stimulation (STN-DBS) is an effective treatment for motor fluctuations in Parkinson's disease (PD), but does not halt disease progression. The long-term deterioration of key functions such as cognition, speech, ability to swallow, gait, urinary bladder control, orientation and reality perception is decisive for patients' independency in daily life. In this paper we investigated patients with advanced PD operated at our center with STN-DBS for at least 15 years ago, in respect to key clinical milestones reflecting their overall function in daily living. PATIENTS AND METHODS: Retrospective analysis of clinical data concerning key clinical milestones including death in PD-patients, 15 years or more after they underwent STN-DBS surgery. All PD-patients implanted with STN-DBS at Sahlgrenska Hospital before January 1, 2001, were regularly assessed until death, drop-out, or January 11, 2016. RESULTS: Sixteen men and seven women with a median (range) disease duration of 18 (10-28) years were operated with STN-DBS. The median (range) follow-up time post-surgery was 12 (2-18) years and 692 person-years of disease duration were observed. In January 2016, nine PD-patients (39%) were still alive (eight with active STN-DBS). Initially, motor symptoms improved in all patients. Sustained benefit (implying active stimulation at the last follow up) was maintained in 19 of them (83%) but STN-DBS was inactivated in four (17%) due to inefficacy. Over time, all patients deteriorated slowly, and a majority developed severe non-motor and axial symptoms such as dementia, inability to talk, swallow and walk, urinary incontinence, psychosis, and need for nursing home care. At the last follow up, 16/23 (70%) patients were treated with antidepressants. CONCLUSION: A majority of PD-patients experience sustained motor benefit with continuous STN-DBS. However, over time, non-motor and axial symptoms slowly and severely restrict PD-patients' function in their daily living.

Quantitative methods for evaluating the efficacy of thalamic deep brain stimulation in patients with essential tremor.

BACKGROUND: Deep brain stimulation (DBS) of the thalamus is a safe and efficient method for treatment of disabling tremor in patient with essential tremor (ET). However, successful tremor suppression after surgery requires careful selection of stimulus parameters. Our aim was to examine the possible use of certain quantitative methods for evaluating the efficacy of thalamic DBS in ET patients in clinical practice, and to compare these methods with traditional clinical tests. METHODS: We examined 22 patients using the Essential Tremor Rating Scale (ETRS) and quantitative assessment of tremor with the stimulator both activated and deactivated. We used an accelerometer (CATSYS tremor Pen) for quantitative measurement of postural tremor, and a eurythmokinesimeter (EKM) to evaluate kinetic tremor in a rapid pointing task. RESULTS: The efficacy of DBS on tremor suppression was prominent irrespective of the method used. The agreement between clinical rating of postural tremor and tremor intensity as measured by the CATSYS tremor pen was relatively high (rs = 0.74). The agreement between kinetic tremor as assessed by the ETRS and the main outcome variable from the EKM test was low (rs = 0.34). The lack of agreement indicates that the EKM test is not comparable with the clinical test. DISCUSSION: Quantitative methods, such as the CATSYS tremor pen, could be a useful complement to clinical tremor assessment in evaluating the efficacy of DBS in clinical practice. Future studies should evaluate the precision of these methods and long-term impact on tremor suppression, activities of daily living (ADL) function and quality of life.

Evaluation of the objective posturo-locomotor-manual method in patients with parkinsonian syndromes.

Objective methods for quantifying patients' movement capacity would be useful in evaluating progression and interventions in neurodegenerative diseases. The Posturo-Locomotor-Manual (PLM) test is a standardized automated movement test developed to measure hypokinetic movements in patients with Parkinsonism. Our hypotheses were that the PLM movement time (MT) correlates with the Unified Parkinson's disease rating scale (UPDRS III) motor section, and that the components of the PLM test correlate with the corresponding constructed domains of UPDRS III. We also evaluated the coherence between the results of the two assessment methods after a test dose of levodopa (l-DOPA). We assessed motor function using the PLM method and UPDRS III in parallel, in the absence of medication and after administration of 200 mg l-DOPA, in 73 patients with moderate to advanced Parkinsonism: 47 with Parkinson's disease (PD), 17 with multiple system atrophy (MSA), and 9 with progressive supranuclear palsy (PSP). There was a fair correlation between the two assessment tools in the PD patients but not in the MSA or PSP patients. In the full dataset, there was a fair to good correlation between UPDRS III and the PLM MT. At group level, the UPDRS III l-DOPA test differentiated PD from MSA/PSP, whereas the PLM l-DOPA test differentiated between all three diagnoses.

Reflexive limb selection and control of reach direction to moving targets in cats, monkeys, and humans.

When we reach for an object, we have to decide which arm to use and the direction in which to move. According to the established view, this is voluntarily controlled and programmed in advance in time-consuming and elaborate computations. Here, we systematically tested the motor strategy used by cats, monkeys, and humans when catching an object moving at high velocity to the left or right. In all species, targets moving to the right selectively initiated movement of the right forelimb and vice versa for targets moving to the left. Movements were from the start directed toward a prospective target position. In humans, the earliest onset of electromyographic activity from start of motion of the target ranged from 90 to 110 ms in different subjects. This indicates that the selection of the arm and specification of movement direction did not result from the subject's voluntary decision, but were determined in a reflex-like manner by the parameters of the target motion. As a whole the data suggest that control of goal-directed arm movement relies largely on an innate neuronal network that, when activated by the visual signal from the target, automatically guides the arm throughout the entire movement toward the target. In the view of the present data, parametric programming of reaching in advance seems to be superfluous.

Consecutive analyses of cerebrospinal fluid axonal and glial markers in Parkinson's disease and atypical Parkinsonian disorders.

Cerebrospinal fluid (CSF) levels of neurofilament light protein (NFL), a marker of neuronal damage, are normal in Parkinson's disease (PD) but elevated in multiple system atrophy (MSA) and progressive supranuclear palsy (PSP). Therefore, CSF NFL can help differentiate between PD on one hand and MSA/PSP on the other. In the present study of 10 patients with PD, 21 with MSA, 14 with PSP, 11 with corticobasal degeneration (CBD), and 59 healthy controls, this previous observation is confirmed and also extended to include CBD by showing that similarly high CSF NFL levels are seen not only in MSA and PSP but also in CBD. CSF levels of glial fibrillary acidic protein (GFAP), a protein expressed mainly in fibrillary astrocytes, were similar in all investigated groups. In addition, consecutive analyses of CSF NFL and CSF GFAP levels showed relatively stable levels over time in all the investigated parkinsonian disorders, suggesting that the rate of neuronal degeneration is rather constant over time. Our results suggest that measurements of CSF NFL but not GFAP can be useful in the differential diagnosis of PD versus atypical parkinsonian disorders (APD). However they do not help differentiate between the different APD.

Cyclooxygenase-2 polymorphisms in Parkinson's disease.

Accumulating evidence indicate that cyclooxygenase-2 (COX-2) is of pathophysiological importance for the neurodegeneration in Parkinson's disease (PD). For example, in a large epidemiological study, use of NSAIDs was associated with a lower risk of PD. Genetic variants of the COX-2 gene might therefore influence the risk of developing the disease. The genotype distribution of four common single nucleotide polymorphisms (SNPs) in the COX-2 gene (rs689466:A496G, rs20417:G926C, rs5277:G3050C, rs5275:C8473T) was analyzed in PD patients and control subjects in a Swedish population. No differences could be seen between the PD-patient and controls regarding the A496G, G926C, and G3050C SNPs, but the allele frequency of the C8473T SNP was found to differ when male patients were compared to controls (P = 0.007). In females no difference could be seen between PD-patients and controls. In conclusion, the results suggest a possible influence of the COX-2 C8473T SNP in PD, although it only seems to be of importance in men.

Optoelectronic movement analysis to measure motor performance in patients with chronic low back pain: test of reliability.

OBJECTIVE: To assess test-retest reliability of the Posturo-Locomotion-Manual(PLM) test in patients with chronic low back pain. DESIGN: A controlled study in which the PLM test was used repeatedly on patients with chronic low back pain and persons without back pain. SUBJECTS: Twelve patients with treatment-resistant chronic low back pain, selected by 2 orthopaedic spine surgeons and 12 age- and sex-matched individuals with no back pain history. METHODS: An optoelectronic camera and a computer were used to quantify the performance during a simple test in which subjects picked up an object from the floor and transported it up to a shelf, thereby forcing the body through postural, locomotor and manual movements. The outcome measures were: movement time, simultaneity index and phase times for postural, locomotion and arm movement phases. Statistical analyses regarding intra-individual agreement between the measurements (reliability analysis) and changes over time were carried out. RESULTS: The effect of test movement habituation was minimized when the lowest mean value of any of 3 consecutive measures (tri-average) was used. In the control group, variation between test occasions was small. In the group of patients with chronic low back pain there was a random measurement error before intervention (sensory motor learning). After intervention the PLM test had the same precision in both groups. CONCLUSION: When the tri-average measure is used, the influence of test movement habituation is minimized and the optoelectronic PLM test is found to be reliable and responsive. It proved to be a useful tool to quantify dynamic performance in freely moving patients with chronic low back pain.

Three-dimensional kinematic motion analysis of a daily activity drinking from a glass: a pilot study.

BACKGROUND: Development of reliable and objective evaluation methods is required, particularly for natural and goal-oriented upper-extremity tasks. Three-dimensional imaging measurement techniques have turned out to be a powerful tool for a quantitative and qualitative assessment of multijoint movements. The purpose of this study was to develop and test a method of three-dimensional motion analysis for the activity "drinking from a glass" and describe the drinking task with kinematic variables in control subjects. METHODS: A protocol was developed for the drinking activity including the set-up of cameras and positions of the markers and the subject. The drinking task included reaching, forward transport with glass, drinking, back transport and returning the hand to the initial position. An optoelectronic system was used for the three-dimensional kinematic motion capture. Movement times, velocities, joint angles and interjoint coordination for shoulder and elbow were computed and analyzed for twenty control subjects. Test-retest consistency was evaluated for six subjects. RESULTS: The test protocol showed good consistency in test-retest. Phase definitions for the drinking task were defined and verified. Descriptive kinematic variables were obtained for movement times, positions, velocities and joint angles for shoulder and elbow joint. Interjoint coordination between shoulder and elbow joint in reaching phase showed a high correlation. CONCLUSION: This study provides a detailed description of the three-dimensional kinematic analysis of the drinking task. Our approach to investigate and analyze a goal-oriented daily activity has a great clinical potential. Consequently, the next step is to use and test this protocol on persons with impairments and disabilities from upper extremities.

Parkinson's disease in diphenyl-exposed workers--a causal association?

We report a cluster of five cases of Parkinson's disease (PD) among paper mill workers exposed to a fungicide, diphenyl. The cause of PD is still unknown, but epidemiological studies have indicated an elevated risk of developing PD after exposure to pesticides. The five cases of PD were found in a group of 255 diphenyl-exposed workers, and the number of expected cases in the exposed group was estimated to be 0.9, resulting in a relative risk of 5.6 (95% CI 1.8-13). Exposure to diphenyl may have contributed to this PD cluster, but chance is an alternative explanation.

Sensory motor learning in patients with chronic low back pain: a prospective pilot study using optoelectronic movement analysis.

STUDY DESIGN: The effect of sensory motor learning (SML) on chronic low back pain (CLBP) patients' movement capacity was evaluated with the optoelectronic Posturo-Locomotion-Manual (PLM) test. OBJECTIVE: To study SML changes of an intentional dynamic behavior of daily life in a group of CLBP patients and compare the performance with an age- and sex-matched group of back-healthy individuals. SUMMARY OF BACKGROUND DATA: In a previous study, the PLM test was found reliable when used in CLBP patients. SML addresses dynamic movement capacity. There is little scientific evidence of the effectiveness of educational interventions in improving motor behavior. METHODS: Twelve patients with treatment-resistant CLBP were selected by two orthopedic spine surgeons. Twelve back-healthy age- and sex-matched individuals were included as controls. The patients participated in weekly SML lessons during a maximum of 12 months. All study participants were investigated with the PLM test, before intervention, directly after intervention, and 10 to 12 months after completion of the intervention, and patients were compared with controls. RESULTS: Before intervention significant differences in performance were found between the group of patients and the healthy control group. After the intervention, the CLBP patients had improved their performance so there were no longer any significant differences between the groups. The results were retained 12 months after intervention. CONCLUSIONS: The study shows that the CLBP patients had learned and retained a more efficient behavior. The results suggest that SML is an effective intervention for nonspecific CLBP patients.

Interaction of polymorphisms in the genes encoding interleukin-6 and estrogen receptor beta on the susceptibility to Parkinson's disease.

The multifunctional cytokine interleukin-6 (IL-6) is involved in inflammatory processes in the central nervous system and increased levels of IL-6 have been found in patients with Parkinson's disease (PD). It is known that estrogen inhibits the production of IL-6, via action on estrogen receptors, thereby pointing to an important influence of estrogen on IL-6. In a previous study, we reported an association between a G/A single nucleotide polymorphism (SNP) at position 1730 in the gene coding for estrogen receptor beta (ERbeta) and age of onset of PD. To investigate the influence of a G/C SNP at position 174 in the promoter of the IL-6 gene, and the possible interaction of this SNP and the ERbeta G-1730A SNP on the risk for PD, the G-174C SNP was genotyped, by pyrosequencing, in 258 patients with PD and 308 controls. A significantly elevated frequency of the GG genotype of the IL-6 SNP was found in the patient group and this was most obvious among patients with an early age of onset (

A rare truncating mutation in ADH1C (G78Stop) shows significant association with Parkinson disease in a large international sample.

BACKGROUND: Alcohol dehydrogenases (ADHs) may be involved in the pathogenesis of neurodegenerative disorders because of their multiple roles in detoxification pathways and retinoic acid synthesis. In a previous study, significant association of an ADH class IV allele with Parkinson disease (PD) was found in a Swedish sample. PATIENTS: The previously associated single-nucleotide polymorphism plus 12 further polymorphisms in the ADH cluster on human chromosome 4q23 were screened for association in an extension of the original sample that now included 123 Swedish PD patients and 127 geographically matched control subjects. A rare nonsense single-nucleotide polymorphism in ADH1C (G78stop, rs283413) was identified in 3 of these patients but in no controls. To obtain sufficient power to detect a possible association of this rare variant with disease, we screened a large international sample of 1076 PD patients of European ancestry and 940 matched controls. RESULTS: The previously identified association with an ADH class IV allele remained significant (P<.02) in the extended Swedish study. Furthermore, in the international collaboration, the G78stop mutation in ADH1C was found in 22 (2.0%) of the PD patients but only in 6 controls (0.6%). This association was statistically significant (chi(2)(1) = 7.5; 2-sided P = .007; odds ratio, 3.25 [95% confidence interval, 1.31-8.05]). In addition, the G78stop mutation was identified in 4 (10.0%) of 40 Caucasian index cases with PD with mainly hereditary forms of the disorder. CONCLUSION: Findings presented herein provide further evidence for mutations in genes encoding ADHs as genetic risk factors for PD.

Investigation of genes coding for inflammatory components in Parkinson's disease.

Several findings obtained recently indicate that inflammation may contribute to the pathogenesis in Parkinson's disease (PD). Genetic variants of genes coding for components involved in immune reactions in the brain might therefore influence the risk of developing PD or the age of disease onset. Five single nucleotide polymorphisms (SNPs) in the genes coding for interferon-gamma (IFN-gamma; T874A in intron 1), interferon-gamma receptor 2 (IFN-gamma R2; Gln64Arg), interleukin-10 (IL-10; G1082A in the promoter region), platelet-activating factor acetylhydrolase (PAF-AH; Val379Ala), and intercellular adhesion molecule 1 (ICAM-1; Lys469Glu) were genotyped, using pyrosequencing, in 265 patients with PD and 308 controls. None of the investigated SNPs was found to be associated with PD; however, the G1082A polymorphism in the IL-10 gene promoter was found to be related to the age of disease onset. Linear regression showed a significantly earlier onset with more A-alleles (P = 0.0095; after Bonferroni correction, P = 0.048), resulting in a 5-year delayed age of onset of the disease for individuals having two G-alleles compared with individuals having two A-alleles. The results indicate that the IL-10 G1082A SNP could possibly be related to the age of onset of PD.

High-level language difficulties in Parkinson's disease.

Twenty-six subjects with idiopathic Parkinson's disease (PD) and normal cognitive status (as measured by the Mini-Mental State Examination) were examined with a battery of tests selected to reveal subtle and/or high-level language impairments. The test battery included 'repetition of long sentences', 'recreating sentences', 'making inferences', 'comprehension of logico-grammatical sentences', 'comprehension of ambiguous sentences' and 'comprehension of metaphors', 'word definitions', 'word fluency', 'naming', 'sentence analysis' and 'morphological completion'. Comparisons were made between the PD subjects and 26 control subjects matched for age, gender and level of education. Significant differences in performance between the PD subjects and the control subjects were found in the ability to make inferences and to analyse sentences (state the correct number of words in a read sentence). An additional four subjects with different degrees of cognitive dysfunction were also investigated and were found to have particular problems in making inferences, recreating sentences and comprehending metaphors and ambiguities. The results suggest that processing implied information might be a specific problem in this group and that the task of making inferences could be a particularly sensitive test of high-level language dysfunction.

Manual transport in Parkinson's disease.

We analyze hand dexterity in Parkinson's disease patients (PD) and control subjects using a natural manual transport task (moving an object from one place to another). Eight PD patients and 10 control subjects carried out the task repeatedly at maximum speed both in off and on medicated status. The movement parameters and the grip and load forces were recorded. Using the force and velocity signals, 10 subsequent phases of the transport movement were defined and their durations were measured. The difference between the control group and the test group in off and on was established statistically using non-parametric methods. There was slowed reaching and a striking disturbance of establishing the precision grip in PD. The transport capabilities were impaired differentially. Although acceleration and reaching sufficient height of the lift were disturbed in PD subjects, transport of the object toward the target position was almost normal. A partial disturbance was observed when cancelling the grip. Dopaminergic medication improved only specific hand skills, especially establishment of the precision grip and one of the four transport phases. A long movement path was more sensitive for movement disturbance in Parkinson's disease than a short one.

Long-term efficacy of thalamic deep brain stimulation for tremor: double-blind assessments.

Thalamic deep brain stimulation (DBS) is proven to suppress tremor in Parkinson's disease (PD) and essential tremor (ET). However, there are few reports on its long-term efficacy. We studied the efficacy of DBS at 2 years and 6-7 years after electrode implantations in the ventrointermediate nucleus of the thalamus in 39 patients (20 PD, 19 ET) with severe tremor. Twenty-five of the patients completed the study. Evaluations were done in a double-blind manner with the Unified Parkinson's Disease Rating Scale (UPDRS) and Essential Tremor Rating Scale (ETRS). DBS decreased tremor sum scores in PD (P < 0.025) compared to the preoperative baseline (median, 7; Q25-75, 6-9) both at 2 years (median, 2; Q25-75, 2-3.5; n = 16) and at 6 to 7 years (median, 2.5; Q25-75, 0.5-3; n = 12). Stimulation on improved tremor sum as well as sub scores (P < 0.025) compared to stimulation off conditions. In ET, thalamic stimulation improved (P < 0.025) kinetic and positional tremor at both follow-up periods (n = 18 and n = 13, respectively) with significant improvements (P < 0.025) in hand-function tests. PD but not ET patients showed a general disease progression. Stimulation parameters were remarkably stable over time. We conclude that high-frequency electric thalamic stimulation can efficiently suppress severe tremor in PD and ET more than 6 years after permanent implantation of brain electrodes.

Cerebrospinal fluid Abeta42 is reduced in multiple system atrophy but normal in Parkinson's disease and progressive supranuclear palsy.

The 42-amino-acid isoform of beta-amyloid Abeta42 in the cerebrospinal fluid (CSF) has recently been proposed as a biochemical marker for Alzheimer's disease (AD) and subcortical white-matter dementia (SWD). In both of these conditions, concentration of CSF-Abeta42 is reduced. We quantified CSF-Abeta42 from patients fulfilling strict clinical criteria for multiple system atrophy (MSA; n = 36), Parkinson's disease (PD; n = 48) and progressive supranuclear palsy (PSP; n = 15). The study groups were consecutively recruited among patients referred to a movement disorder unit, and 32 healthy, age-matched volunteers were used as controls. The CSF concentration of Abeta42 was significantly reduced in the MSA group (P < 0.001), whereas the PD and PSP groups did not differ from controls. On an individual basis, low content of Abeta42 was seen in 9 MSA patients regardless of age and disease duration. Three PD patients with long disease duration also had low concentrations but all PSP patients were normal. We conclude that the reduced CSF-Abeta42 concentration may be a clue to the pathogenesis of MSA. There is a decreased production, or more possible, an increased consumption of CSF-Abeta42. The analysis of this protein may also become a supplement to the clinical differentiation of parkinsonian syndromes in a movement disorder unit.