Cerebrospinal fluid and blood serum biomarkers in neurodegenerative proteinopathies: A prospective, open, cross-correlation study.

Neurodegenerative diseases are a broad heterogeneous group affecting the nervous system. They are characterized, from a pathophysiological perspective, by the selective involvement of a subpopulation of nerve cells with a consequent clinical picture of a disease. Clinical diagnoses of neurodegenerative diseases are quite challenging and often not completely accurate because of their marked heterogeneity and frequently overlapping clinical pictures. Efforts are being made to define sufficiently specific and sensitive markers for individual neurodegenerative diseases or groups of diseases in order to increase the accuracy and speed of clinical diagnosis. Thus said, this present research aimed to identify biomarkers in the cerebrospinal fluid (CSF) and serum (α-synuclein [α-syn], tau protein [t-tau], phosphorylated tau protein [p-tau], ß-amyloid [Aß], clusterin, chromogranin A [chromogrA], cystatin C [cyst C], neurofilament heavy chains [NFH], phosphorylated form of neurofilament heavy chains [pNF-H], and ratio of tau protein/amyloid beta [Ind tau/Aß]) that could help in the differential diagnosis and differentiation of the defined groups of α-synucleinopathies and four-repeat (4R-) tauopathies characterized by tau protein isoforms with four microtubule-binding domains. In this study, we analyzed a cohort of 229 patients divided into four groups: (1) Parkinson's disease (PD) + dementia with Lewy bodies (DLB) (n = 82), (2) multiple system atrophy (MSA) (n = 25), (3) progressive supranuclear palsy (PSP) + corticobasal syndrome (CBS) (n = 30), and (4) healthy controls (HC) (n = 92). We also focused on analyzing the biomarkers in relation to each other with the intention of determining whether they are useful in distinguishing among individual proteinopathies. Our results indicate that the proposed set of biomarkers, when evaluated in CSF, is likely to be useful for the differential diagnosis of MSA versus 4RT. However, these biomarkers do not seem to provide any useful diagnostic information when assessed in blood serum.

Imaging Modalities Used for Frameless and Fiducial-Less Deep Brain Stimulation: A Single Centre Exploratory Study among Parkinson's Disease Cases.

Deep brain stimulation (DBS) is a beneficial procedure for treating idiopathic Parkinson's disease (PD), essential tremor, and dystonia. The authors describe their set of imaging modalities used for a frameless and fiducial-less method of DBS. CT and MRI scans are obtained preoperatively, and STN parcellation is done based on diffusion tractography. During the surgery, an intraoperative cone-beam computed tomography scan is obtained and merged with the preoperatively-acquired images to place electrodes using a frameless and fiducial-less system. Accuracy is evaluated prospectively. The described sequence of imaging methods shows excellent accuracy compared to the frame-based techniques.

Lewy body disease or diseases with Lewy bodies?

The current nosological concept of α-synucleinopathies characterized by the presence of Lewy bodies (LBs) includes Parkinson's disease (PD), Parkinson's disease dementia (PDD), and dementia with Lewy bodies (DLB), for which the term "Lewy body disease" (LBD) has recently been proposed due to their considerable clinical and pathological overlap. However, even this term does not seem to describe the true nature of this group of diseases. The subsequent discoveries of α-synuclein (αSyn), SNCA gene, and the introduction of new immunohistochemical methods have started intensive research into the molecular-biological aspects of these diseases. In light of today's knowledge, the role of LBs in the pathogenesis and classification of these nosological entities remains somewhat uncertain. An increasingly more important role is attributed to other factors as the presence of various LBs precursors, post-translational αSyn modifications, various αSyn strains, the deposition of other pathological proteins (particularly ß-amyloid), and the discovery of selective vulnerability of specific cells due to anatomical configuration or synaptic dysfunction. Resulting genetic inputs can undoubtedly be considered as the main essence of these factors. Molecular-genetic data indicate that not only in PD but also in DLB, a unique genetic architecture can be ascertained, predisposing to the development of specific disease phenotypes. The presence of LBs thus remains only a kind of link between these disorders, and the term "diseases with Lewy bodies" therefore results somewhat more accurate.

Deep brain stimulation electrode position impact on parkinsonian non-motor symptoms.

BACKGROUND: In this study we evaluated the impact of location of deep brain stimulation electrode active contact in different parts of the subthalamic nucleus on improvement of non-motor symptoms in patients with Parkinson's disease. METHODS: The subthalamic nucleus was divided into two (dorsolateral/ventromedial) and three (dorsolateral, medial, ventromedial) parts. 37 deep brain stimulation electrodes were divided according to their active contact location. Correlation between change in non-motor symptoms before and one and four months after deep brain stimulation electrode implantation and the location of active contact was made. RESULTS: In dividing the subthalamic nucleus into three parts, no electrode active contact was placed ventromedially, 28 active contacts were located in the medial part and 9 contacts were placed dorsolaterally. After one and four months, no significant difference was found between medial and dorsolateral positions. In the division of the subthalamic nucleus into two parts, 13 contacts were located in the ventromedial part and 24 contacts were placed in the dorsolateral part. After one month, significantly greater improvement in the Non-motor Symptoms Scale for Parkinson's disease (P=0.045) was found on dorsolateral left-sided stimulation, but no significant differences between the ventromedial and dorsolateral positions were found on the right side. CONCLUSION: This study demonstrated the relationship between improvement of non-motor symptoms and the side (hemisphere, left/right) of the deep brain stimulation electrode active contact, rather than its precise location within specific parts of the subthalamic nucleus in patients treated for advanced Parkinson's disease.

Botulinum toxin injection changes resting state cerebellar connectivity in cervical dystonia.

In cervical dystonia, functional MRI (fMRI) evidence indicates changes in several resting state networks, which revert in part following the botulinum neurotoxin A (BoNT) therapy. Recently, the involvement of the cerebellum in dystonia has gained attention. The aim of our study was to compare connectivity between cerebellar subdivisions and the rest of the brain before and after BoNT treatment. Seventeen patients with cervical dystonia indicated for treatment with BoNT were enrolled (14 female, aged 50.2 ± 8.5 years, range 38-63 years). Clinical and fMRI examinations were carried out before and 4 weeks after BoNT injection. Clinical severity was evaluated using TWSTRS. Functional MRI data were acquired on a 1.5 T scanner during 8 min rest. Seed-based functional connectivity analysis was performed using data extracted from atlas-defined cerebellar areas in both datasets. Clinical scores demonstrated satisfactory BoNT effect. After treatment, connectivity decreased between the vermis lobule VIIIa and the left dorsal mesial frontal cortex. Positive correlations between the connectivity differences and the clinical improvement were detected for the right lobule VI, right crus II, vermis VIIIb and the right lobule IX. Our data provide evidence for modulation of cerebello-cortical connectivity resulting from successful treatment by botulinum neurotoxin.

The Central Effects of Botulinum Toxin in Dystonia and Spasticity.

In dystonic and spastic movement disorders, however different in their pathophysiological mechanisms, a similar impairment of sensorimotor control with special emphasis on afferentation is assumed. Peripheral intervention on afferent inputs evokes plastic changes within the central sensorimotor system. Intramuscular application of botulinum toxin type A (BoNT-A) is a standard evidence-based treatment for both conditions. Apart from its peripheral action on muscle spindles, a growing body of evidence suggests that BoNT-A effects could also be mediated by changes at the central level including cerebral cortex. We review recent studies employing electrophysiology and neuroimaging to investigate how intramuscular application of BoNT-A influences cortical reorganization. Based on such data, BoNT-A becomes gradually accepted as a promising tool to correct the maladaptive plastic changes within the sensorimotor cortex. In summary, electrophysiology and especially neuroimaging studies with BoNT-A further our understanding of pathophysiology underlying dystonic and spastic movement disorders and may consequently help develop novel treatment strategies based on neural plasticity.

Contemporary clinical neurophysiology applications in dystonia.

The complex phenomenological understanding of dystonia has transcended from the clinics to genetics, imaging and neurophysiology. One way in which electrophysiology will impact into the clinics are cases wherein a dystonic clinical presentation may not be typical or a "forme fruste" of the disorder. Indeed, the physiological imprints of dystonia are present regardless of its clinical manifestation. Underpinnings in the understanding of dystonia span from the peripheral, segmental and suprasegmental levels to the cortex, and various electrophysiological tests have been applied in the course of time to elucidate the origin of dystonia pathophysiology. While loss of inhibition remains to be the key finding in this regard, intricacies and variabilities exist, thus leading to a notion that perhaps dystonia should best be gleaned as network disorder. Interestingly, the complex process has now spanned towards the understanding in terms of networks related to the cerebellar circuitry and the neuroplasticity. What is evolving towards a better and cohesive view will be neurophysiology attributes combined with structural dynamic imaging. Such a sound approach will significantly lead to better therapeutic modalities in the future.

O-Arm Navigated Frameless and Fiducial-Less Deep Brain Stimulation.

OBJECT: Deep brain stimulation (DBS) is a very useful procedure for the treatment of idiopathic Parkinson's disease (PD), essential tremor, and dystonia. The authors evaluated the accuracy of the new method used in their center for the placing of DBS electrodes. Electrodes are placed using the intraoperative O-arm™ (Medtronic)-controlled frameless and fiducial-less system, Nexframe™ (Medtronic). Accuracy was evaluated prospectively in eleven consecutive PD patients (22 electrodes). METHODS: Eleven adult patients with PD were implanted using the Nexframe system without fiducials and with the intraoperative O-arm (Medtronic) system and StealthStation™ S8 navigation (Medtronic). The implantation of DBS leads was performed using multiple-cell microelectrode recording, and intraoperative test stimulation to determine thresholds for stimulation-induced adverse effects. The accuracy was checked in three different steps: (1) using the intraoperative O-arm image and its fusion with preoperative planning, (2) using multiple-cell microelectrode recording and counting the number of microelectrodes with the signal of the subthalamic nucleus (STN) and finally, (3) total error was calculated according to a postoperative CT control image fused to preoperative planning. RESULTS: The total error of the procedure was 1.79 mm; the radial error and the vector error were 171 mm and 163 mm. CONCLUSIONS: Implantation of DBS electrodes using an O-arm navigated frameless and fiducial-less system is a very useful and technically feasible procedure with excellent patient toleration with experienced Nexframe users. The accuracy of the method was confirmed at all three steps, and it is comparable to other published results.

Deep Brain Stimulation Effects on Gait Pattern in Advanced Parkinson's Disease Patients.

BACKGROUND: Gait disturbance accompanies many neurodegenerative diseases; it is characteristic for Parkinson's disease (PD). Treatment of advanced PD often includes deep brain stimulation (DBS) of the subthalamic nucleus. Regarding gait, previous studies have reported non-significant or conflicting results, possibly related to methodological limitations. OBJECTIVE: The objective of this prospective study was to assess the effects of DBS on biomechanical parameters of gait in patients with PD. METHODS: Twenty-one patients with advanced PD participated in this prospective study. Gait was examined in all patients using the Zebris FDM-T pressure-sensitive treadmill (Isny, Germany) before DBS implantation and after surgery immediately, further immediately after the start of neurostimulation, and 3 months after neurostimulator activation. We assessed spontaneous gait on a moving treadmill at different speeds. Step length, stance phase of both lower limbs, double-stance phase, and cadence were evaluated. RESULTS: In this study, step length increased, allowing the cadence to decrease. Double-stance phase duration, that is, the most sensitive parameter of gait quality and unsteadiness, was reduced, in gait at a speed of 4.5 km/h and in the narrow-based gaits at 1 km/h (tandem gait), which demonstrates improvement. CONCLUSION: This study suggests positive effects of DBS treatment on gait in PD patients. Improvement was observed in several biomechanical parameters of gait.

The Prevalence of Dystonic Tremor and Tremor Associated with Dystonia in Patients with Cervical Dystonia.

The link between dystonia and tremor has been known for decades, but the question of whether they are two separate illnesses or just different manifestations of one disease with the same pathophysiological background remains unanswered. We distinguish two types of tremor in dystonia: dystonic tremor (DT), which appears on the body part affected by dystonia, and tremor associated with dystonia (TAWD), which appears in locations where the dystonia does not occur. In this study, the frequency of occurrence of different forms of tremor was determined by clinical examination in a group of adult-onset isolated cervical dystonia (CD) patients treated with regular local injections of botulinum toxin A in our department. In total, 120 patients were included in the study, of which 70 (58.3%) had DT of the head. TAWD was, in all 14 cases (11.7%), observed on the upper limbs, in the form of static or intentional tremor. The aim of this study was to point out the presence of TAWD as one of the clinical signs of CD. DT occurred in more than half of the patients and appears to be a relatively common part of the clinical picture in patients with CD.

Changes in sensorimotor network activation after botulinum toxin type A injections in patients with cervical dystonia: a functional MRI study.

Botulinum toxin type A (BoNT) is considered an effective therapeutic option in cervical dystonia (CD). The pathophysiology of CD and other focal dystonias has not yet been fully explained. Results from neurophysiological and imaging studies suggest a significant involvement of the basal ganglia and thalamus, and functional abnormalities in premotor and primary sensorimotor cortical areas are considered a crucial factor in the development of focal dystonias. Twelve BoNT-naïve patients with CD were examined with functional MRI during a skilled hand motor task; the examination was repeated 4 weeks after the first BoNT injection to the dystonic neck muscles. Twelve age- and gender-matched healthy controls were examined using the same functional MRI paradigm without BoNT injection. In BoNT-naïve patients with CD, BoNT treatment was associated with a significant increase of activation in finger movement-induced fMRI activation of several brain areas, especially in the bilateral primary and secondary somatosensory cortex, bilateral superior and inferior parietal lobule, bilateral SMA and premotor cortex, predominantly contralateral primary motor cortex, bilateral anterior cingulate cortex, ipsilateral thalamus, insula, putamen, and in the central part of cerebellum, close to the vermis. The results of the study support observations that the BoNT effect may have a correlate in the central nervous system level, and this effect may not be limited to cortical and subcortical representations of the treated muscles. The results show that abnormalities in sensorimotor activation extend beyond circuits controlling the affected body parts in CD even the first BoNT injection is associated with changes in sensorimotor activation. The differences in activation between patients with CD after treatment and healthy controls at baseline were no longer present.

Bilateral subthalamic deep brain stimulation initial impact on nonmotor and motor symptoms in Parkinson's disease: An open prospective single institution study.

Numerous studies document significant improvement in motor symptoms in patients with Parkinson's disease (PD) after deep brain stimulation of the subthalamic nucleus (STN-DBS). However, little is known about the initial effects of STN-DBS on nonmotor domains.Our objective was to elucidate the initial effects of STN-DBS on non-motor and motor symptoms in PD patients in a 4-month follow-up.This open prospective study followed 24 patients with PD who underwent STN-DBS. The patients were examined using dedicated rating scales preoperatively and at 1 and 4 months following STN-DBS to determine initial changes in motor and nonmotor symptoms. Patients at month 1 after STN-DBS had significantly reduced the Parkinson's disease Questionnaire scores (P = .018) and Scales for Outcomes in Parkinson's disease - Autonomic scores (P = .002); these scores had increased at Month 4 after DBS-STN. Nonmotor Symptoms Scale for Parkinson's Disease had improved significantly at Month 1 (P < .001); at Month 4, it remained significantly lower than before stimulation (P = .036). There was no significant difference in The Parkinson's Disease Sleep Scaleat Month 1 and significant improvement at Month 4 (P = .026). There were no significant changes in The Female Sexual Function Index or International Index of Erectile Function. Movement Disorder Society Unified Parkinson's Disease Rating Scale, Part III scores show significant improvements at Month 1 (P < .001) and at Month 4 (P < .001).STN-DBS in patients with advanced PD clearly improves not only motor symptoms, but also several domains of nonmotor functions, namely sleep, autonomic functions and quality of life quickly following the start of stimulation.

Familial atypical parkinsonism with rare variant in VPS35 and FBXO7 genes: A case report.

BACKGROUND: A higher prevalence of parkinsonism was recently identified in southeastern Moravia (Czech Republic). Further research confirmed 3 large pedigrees with familial autosomal-dominant parkinsonism spanning 5 generations. METHODS: This case report concerns a patient belonging to one of these 3 pedigrees, in whom motor and oculomotor symptoms were accompanied by frontal-type dementia, who finally developed a clinical phenotype of progressive supranuclear palsy. Molecular genetic examinations were performed due to the positive family history. RESULTS: No previously described causal mutation was found. After filtering against common variants (minor allele frequency (MAF) < 0.01), 2 noncoding and 1 synonymous rare mutation potentially associable with parkinsonism were identified: GIGYF2-GRB10 Interacting GYF Protein 2, PARK11 (c.*2030G > A, rs115669549); VPS35 gene-vacuolar protein sorting 35, PARK17 (c.102 + 33G > A, rs192115886); and FBXO7-F-box only protein 7 gene, PARK15 (c.540A > G, rs41311141). CONCLUSION: As to the changes in the FBXO7 and VPS35 genes (despite phylogenetic conservation in primates), probably neither the FBXO7 nor the VPS35 variants will be direct causal mutations. Both described variants, and possibly the influence of their combination, could increase the risk of the disease.

Tau protein and beta-amyloid(1-42) CSF levels in different phenotypes of Parkinson's disease.

Parkinson's disease (PD) is a neurodegenerative disorder with highly heterogeneous clinical manifestations. This fact has prompted many attempts to divide PD patients into clinical subgroups. This could lead to a better recognition of pathogenesis, improving targeted treatment and the prognosis of PD patients. The aim of the present study was to obtain cerebrospinal fluid (CSF) samples in PD patients and to search for a relationship between neurodegenerative CSF markers (tau protein, beta-amyloid(1-42) and index tau protein/beta-amyloid(1-42)) and the clinical subtypes. PD patients were divided into three subgroups: early disease onset (EDO), tremor-dominant PD (TD-PD), and non-tremor dominant PD (NT-PD) according to the previously published classification. Neurodegenerative markers in the CSF were assessed in these three groups of patients suffering from PD (EDO-17, TD-15, NT-16 patients) and in a control group (CG) of 19 patients suffering from non-degenerative neurological diseases and 18 patients with Alzheimer's disease (AD). The NT-PD patients were found to have significantly higher levels of CSF tau protein and index tau/beta than the control subjects and other Parkinsonian subgroups, but no significant differences in these markers were found between AD and NT-PD patients. In the context of more rapid clinical progression and more pronounced neuropathological changes in the NT-PD patient group, our results corroborate the opinion that CSF level of tau protein may be regarded as a potential laboratory marker of the presence and severity of neurodegeneration.

CSF markers of neurodegeneration in Parkinson's disease.

Parkinson's disease (PD) is a chronic, progressive, neurodegenerative disease with a multifactorial etiology. Protein accumulation is speculated by some to play a prominent role in the pathogenesis of PD. The severity of neurodegeneration should correlate with cerebrospinal fluid (CSF) levels of these neurodegenerative markers (NDMs). The aims of the study were to assess the CSF levels of tau protein, beta-amyloid (1-42), cystatin C, and clusterin in patients suffering from PD and in a control group, to compare the CSF levels between the two groups and to correlate them to PD duration. NDMs in the CSF were assessed in 32 patients suffering from PD and in a control group (CG) of 30 patients. The following statistically significant differences in the CSF were found: higher tau protein (p = 0.045) and clusterin levels (p = 0.004) in PD patients versus CG; higher tau protein levels (p = 0.033), tau protein/beta-amyloid (1-42) ratio (p = 0.011), and clusterin (p = 0.044) in patients suffering from PD for <2 years versus patients suffering PD for more than 2 years. No differences between beta-amyloid (1-42) and cystatin C CSF levels were found in the CG and PD patients groups. Significantly higher tau protein and clusterin CSF levels in the group of PD patients with disease duration of <2 years probably reflect the fact that most neurodegenerative changes in PD patients occur in the initial stage of disease.

Effect of entacapone on plasma homocysteine levels in Parkinson's disease patients.

Peripheral metabolism of L-DOPA via enzyme catechol-O-methyltransferase (COMT) is one of the possible sources of homocysteine (HCY). The aim of this study was to assess plasma HCY levels in L-DOPA-treated Parkinson's disease (PD) patients and its influence by adding the inhibitor COMT (entacapone). Patients were divided into two groups: (1) patients long term treated with L-DOPA but were naïve to entacapone, (2) L-DOPA naïve patients, in whom a combined treatment with L-DOPA and entacapone was started. The HCY levels were higher in Group 1 than in Group 2. No statistically significant changes of HCY concentrations were found in both patient groups after adding entacapone to their L-DOPA treatments. Results of this study confirm that patients treated with L-DOPA for a long term have increased plasma HCY concentrations. We believe combined L-DOPA and entacapone therapy could be a possible protective mechanism against hyperhomocysteinemia in early PD.

Peripheral nerve involvement and severity of motor disorder in Parkinson's disease: a correlational study.

BACKGROUND: The aim of this study was to test the hypothesis that there is concomitant peripheral nerve involvement in patients suffering from neurodegenerative disorders by correlating motor and peripheral nerve involvement in Parkinson's disease. METHODS AND RESULTS: A total of 23 patients suffering from Parkinson's disease diagnosed strictly according to the UKPDBB criteria were examined. The group comprised 14 males (mean age: 57 years, mean age at onset: 51 years, mean duration of disease: 7 years, mean duration of dopaminergic treatment: 4 years) and 9 females (mean age: 67 years, mean age at onset: 63 years, mean duration of disease: 4 years, mean duration of dopaminergic treatment: 1 year). CONCLUSION: Polyneuropathy was clinically present and confirmed using EMG examination in 10 patients (43.5 %), 5 males and 5 females. This suggests that the neurodegenerative process involves both the central and the peripheral nervous system in Parkinson's patients.