Validation of the UPDRS section IV for detection of motor fluctuations in Parkinson's disease

IntroductionThe UPDRS-IV represents the most common screening tool to assess motor fluctuations in patients with PD despite the lack of a clinimetric validation.ObjectivesWe evaluated sensitivity and specificity of UPDRS-IV using a 12-h waking-day motor assessment as the gold standard.MethodsWe consecutively enrolled PD patients who underwent a 12-h waking-day motor assessment in the study. Patients were clinically evaluated every 2 h for 12 h using the UPDRS-III. Motor scores were reported as a line graph and six blinded raters classified patients as having or not having motor fluctuations. The UPDRS-IV was used in order to assess the presence of predictable and unpredictable motor fluctuations according to items 36–38.ResultsSixty two PD patients were enrolled in the study. According to the raters' evaluations, 39 (62.9%) were classified as having motor fluctuations, while according to the UPDRS-IV 47 (75.8%) presented a motor fluctuation giving a sensitivity of 87.2% (95%CI 72.6–95.7) and a specificity of 43.5% (95%CI 23.2–65.5).ConclusionOur study results confirm the high level of sensitivity with a lower level of specificity of UPDRS-IV to screen motor fluctuations in PD patients.     

Interaction between affordance and handedness recognition: a chronometric study

The visualization of tools and manipulable objects activates motor-related areas in the cortex, facilitating possible actions toward them. This pattern of activity may underlie the phenomenon of object affordance. Some cortical motor neurons are also covertly activated during the recognition of body parts such as hands. One hypothesis is that different subpopulations of motor neurons in the frontal cortex are activated in each motor program; for example, canonical neurons in the premotor cortex are responsible for the affordance of visual objects, while mirror neurons support motor imagery triggered during handedness recognition. However, the question remains whether these subpopulations work independently. This hypothesis can be tested with a manual reaction time (MRT) task with a priming paradigm to evaluate whether the view of a manipulable object interferes with the motor imagery of the subject''s hand. The MRT provides a measure of the course of information processing in the brain and allows indirect evaluation of cognitive processes. Our results suggest that canonical and mirror neurons work together to create a motor plan involving hand movements to facilitate successful object manipulation.     

Do children with autism spectrum disorders have motor learning difficulties?

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social and communication impairments as well as a wide range of behavioral symptoms. For years, motor disturbance reported in ASD has not been treated as a core deficit because of the overwhelming problems in sociability and communication. Recent studies, however, reveal that motor deficits are also fundamental to ASD presentation and contribute to the core symptoms of ASD. Untreated motor problems can persist well into adolescence and adulthood, resulting in long-term physical, psychological, and behavioral issues in individuals with ASD. Thus, the ability to understand and address the overall picture of a child with ASD, including motor dysfunction, has become a critical need. This review focuses on sensorimotor adaptation and motor sequence learning in children with ASD and presents related evidence that compromised motor learning may play a critical role in motor dysfunctions of ASD. It addresses possible factors that explain controversial findings in the literature and discusses potential strategies for facilitating motor learning. Future intervention studies should address the importance of motor learning beyond social and language domains in ASD.     

High-frequency repetitive transcranial magnetic stimulation over the primary motor cortex relieves musculoskeletal pain in patients with Parkinson's disease: A randomized controlled trial

BackgroundPain is common in Parkinson's disease, and there is no effective treatment. We conducted a clinical trial to determine whether high-frequency repetitive transcranial magnetic stimulation over the primary motor cortex alleviates musculoskeletal pain in patients with Parkinson's disease.MethodsIn this single-center and double-blind trial, 52 patients with Parkinson's disease and musculoskeletal pain were randomly allocated to 26-member groups receiving 5 sessions of either 20-Hz repetitive transcranial magnetic stimulation or sham stimulation over the primary motor cortex. The participants underwent assessments in the “ON” medication state at baseline, after the fifth session, and at 2- and 4-week follow-up timepoints. The primary outcomes were pain scores on a numeric rating scale. The secondary outcomes were scores on clinical scales assessing motor symptoms, depression, anxiety, autonomic symptoms, sleep quality, and the overall severity of Parkinson's disease.ResultsAnalyses revealed significant group × time interactions for numeric rating scale pain scores (p < 0.001), motor symptom scores (p < 0.001), depression scores (p = 0.009), anxiety scores (p = 0.013), and overall disease severity scores (p < 0.001). Post hoc analyses confirmed that the repetitive transcranial magnetic stimulation group, but not the sham stimulation group, exhibited significant improvements in numeric rating scale pain scores, motor symptom scores, depression scores, anxiety scores, and overall disease severity scores.ConclusionHigh-frequency repetitive transcranial magnetic stimulation over the primary motor cortex may be an effective adjunct therapy for alleviating musculoskeletal pain in patients with Parkinson's disease.     

Altered sensorimotor cortex noradrenergic function in idiopathic REM sleep behaviour disorder – A PET study

IntroductionNoradrenergic denervation is thought to aggravate motor dysfunction in Parkinson's disease (PD). In a previous PET study with the norepinephrine transporter (NART) ligand ¹¹C-MeNER, we detected reduced NART binding in primary sensorimotor cortex (M1S1) of PD patients. Idiopathic rapid-eye-movement sleep behaviour disorder (iRBD) is a phenotype of prodromal PD. Using ¹¹C-MeNER PET, we investigated whether iRBD patients showed similar NART binding reductions in M1S1 cortex as PD patients. Additionally, we investigated whether ¹¹C-MeNER binding and loss of nigrostriatal dopamine storage capacity measured with ¹⁸F-DOPA PET were correlated.Methods17 iRBD patients, 16 PD patients with (PD^RBD+) and 14 without RBD (PD^RBD−), and 25 control subjects underwent ¹¹C-MeNER PET. iRBD patients also had ¹⁸F-DOPA PET. Volume-of-interest analyses and voxel-level statistical parametric mapping were performed.ResultsPartial-volume corrected ¹¹C-MeNER binding potential (BP^ND) values in M1S1 differed across the groups (P = 0.022) with the iRBD and PD^RBD+ groups showing significant reductions (controls vs. iRBD P = 0.007; control vs. PD^RBD+ P = 0.008). Voxel-wise comparisons confirmed reductions of M1S1 ¹¹C-MeNER binding in PD and iRBD patients. Significant correlation was seen between putaminal ¹⁸F-DOPA uptake and thalamic ¹¹C-MeNER binding in iRBD patients (r² = 0.343, P = 0.013).ConclusionsThis study found altered noradrenergic neurotransmission in the M1S1 cortex of iRBD patients. The observed reduction of M1S1 ¹¹C-MeNER binding in iRBD may represent noradrenergic terminal degeneration or physiological down-regulation of NARTs in this prodromal phenotype of PD. The correlation between thalamic ¹¹C-MeNER binding and putaminal ¹⁸F-DOPA binding suggests that these neurotransmitter systems degenerate in parallel in the iRBD phenotype of prodromal PD.     

Drezotomía en el tratamiento del dolor por desaferentización: revisión de resultados y análisis de factores predictores de éxito

Background and objectivesThe treatment of deafferentation pain by spinal DREZotomy is a proven therapeutic option in the literature. In recent years, use of DREZotomy has been relegated to second place due to the emergence of neuromodulation therapies. The objectives of this study are to demonstrate that DREZotomy continues to be an effective and safe treatment and to analyse predictive factors for success.Patients and methodsA retrospective study was conducted of all patients treated in our department with spinal DREZotomy from 1998 to 2018. Bulbar DREZotomy procedures were excluded. A visual analogue scale (VAS) and the reduction of routine medication were used as outcome variables. Demographic, clinical and operative variables were analysed as predictive factors for success.ResultsA total of 27 patients (51.9% female) with a mean age of 53.7 years underwent DREZotomy. The main cause of pain was brachial plexus injury (BPI) (55.6%) followed by neoplasms (18.5%). The mean time of pain evolution was 8.4 years with a mean intensity of 8.7 according to the VAS, even though 63% of the patients had previously received neurostimulation therapy. Favourable outcome (≥ 50% pain reduction in the VAS) was observed in 77.8% of patients during the postoperative period and remained in 59.3% of patients after 22 months average follow-up (mean reduction of 4.9 points). This allowed for a reduction in routine analgesic treatment in 70.4% of them. DREZotomy in BPI-related pain presented a significantly higher success rate (93%) than the other pathologies (41.7%) (p = .001). No association was observed between outcome and age, gender, DREZ technique, duration of pain or previous neurostimulation therapies. There were six neurological complications, four post-operative transient neurological deficits and two permanent deficits.ConclusionDorsal root entry zone surgery is effective and safe for treating patients with deafferentation pain, especially after brachial plexus injury. It can be considered an alternative treatment after failed neurostimulation techniques for pain control. However, its indication should be considered as the first therapeutic option after medical therapy failure due to its good long-term results.     

How clerks understand the requests of people living with aphasia in service encounters

ABSTRACT

Aphasia often restricts participation. People living with aphasia (PLWA) engage in fewer activities, which leads to fewer interactions than before aphasia. Analyses of interactions with non-familiar people in activities of daily life could provide knowledge about how to integrate these situations in rehabilitation and facilitate ongoing PLWA participation post-rehabilitation. This qualitative study is the first to examine how PLWA make their requests understood in service encounters despite aphasia. Six people living with moderate or severe aphasia were video-recorded in situations of service encounters, e.g., pharmacies, specialised shops, restaurants, and others. We identified fifty-nine occurrences with one or several difficulties in the formulation of the request. They were examined, including the clerks’ responses and ensuing interaction using multimodal conversation analysis. Results showed that PLWA used nonverbal communication within the physical environment and the context of the interaction to support verbal production. In the majority of situations, the clerks understood the request promptly. In other situations, they both collaborated to achieve a clear understanding of the request. Moreover, the findings attest to the competence of people living with moderate or severe aphasia in engaging in service encounters and add to the knowledge base about interaction and social participation in aphasia.     

Pinging the brain with transcranial magnetic stimulation reveals cortical reactivity in time and space

BackgroundSingle-pulse transcranial magnetic stimulation (TMS) elicits an evoked electroencephalography (EEG) potential (TMS-evoked potential, TEP), which is interpreted as direct evidence of cortical reactivity to TMS. Thus, combining TMS with EEG can be used to investigate the mechanism underlying brain network engagement in TMS treatment paradigms. However, controversy remains regarding whether TEP is a genuine marker of TMS-induced cortical reactivity or if it is confounded by responses to peripheral somatosensory and auditory inputs. Resolving this controversy is of great significance for the field and will validate TMS as a tool to probe networks of interest in cognitive and clinical neuroscience.ObjectiveHere, we delineated the cortical origin of TEP by spatially and temporally localizing successive TEP components, and modulating them with transcranial direct current stimulation (tDCS) to investigate cortical reactivity elicited by single-pulse TMS and its causal relationship with cortical excitability.MethodsWe recruited 18 healthy participants in a double-blind, cross-over, sham-controlled design. We collected motor-evoked potentials (MEPs) and TEPs elicited by suprathreshold single-pulse TMS targeting the left primary motor cortex (M1). To causally test cortical and corticospinal excitability, we applied tDCS to the left M1.ResultsWe found that the earliest TEP component (P25) was localized to the left M1. The following TEP components (N45 and P60) were largely localized to the primary somatosensory cortex, which may reflect afferent input by hand-muscle twitches. The later TEP components (N100, P180, and N280) were largely localized to the auditory cortex. As hypothesized, tDCS selectively modulated cortical and corticospinal excitability by modulating the pre-stimulus mu-rhythm oscillatory power.ConclusionTogether, our findings provide causal evidence that the early TEP components reflect cortical reactivity to TMS.