Anodal Transcranial Direct Current Stimulation over the Cerebellum Enhances Sadness Recognition in Parkinson's Disease Patients: a Pilot Study.

Emotional processing impairments, resulting in a difficulty to decode emotions from faces especially for negative emotions, are characteristic non-motor features of Parkinson's disease (PD). There is limited evidence about the specific contribution of the cerebellum to the recognition of emotional contents in facial expressions even though patients with cerebellar dysfunction often lose this ability. In this study, we aimed to evaluate whether the recognition of facial expressions can be modulated by cerebellar transcranial direct current stimulation (tDCS) in PD patients. Nine PD patients were enrolled and received anodal and sham tDCS (2 mA, 20 min), for 5 consecutive days, in two separate cycles at intervals of at least 1 month. The facial emotion recognition task was administered at baseline (T0) and after cerebellar tDCS on day 5 (T1). Our preliminary study showed that anodal cerebellar tDCS significantly enhanced emotional recognition in response to sad facial expressions by about 16%, but left recognition of anger, happiness, and neutral facial expressions unchanged. Despite the small sample size, our preliminary results show that anodal tDCS applied for five consecutive days over the cerebellum modulates the way PD patients recognize specific facial expressions, thus suggesting that the cerebellum plays a crucial role in recognition of negative emotions and corroborating previous knowledge on the link between social cognition and the cerebellum.

Effective Connectivity During Rest and Music Listening: An EEG Study on Parkinson's Disease.

Music-based interventions seem to enhance motor, sensory and cognitive functions in Parkinson's disease (PD), but the underlying action mechanisms are still largely unknown. This electroencephalography (EEG) study aimed to investigate the effective connectivity patterns characterizing PD in the resting state and during music listening. EEG recordings were obtained from fourteen non-demented PD patients and 12 healthy controls, at rest and while listening to three music tracks. Theta- and alpha-band power spectral density and multivariate partial directed coherence were computed. Power and connectivity measures were compared between patients and controls in the four conditions and in music vs. rest. Compared to controls, patients showed enhanced theta-band power and slightly enhanced alpha-band power, but markedly reduced theta- and alpha-band interactions among EEG channels, especially concerning the information received by the right central channel. EEG power differences were partially reduced by music listening, which induced power increases in controls but not in patients. Connectivity differences were slightly compensated by music, whose effects largely depended on the track. In PD, music enhanced the frontotemporal inter-hemispheric communication. Our findings suggest that PD is characterized by enhanced activity but reduced information flow within the EEG network, being only partially normalized by music. Nevertheless, music capability to facilitate inter-hemispheric communication might underlie its beneficial effects on PD pathophysiology and should be further investigated.

Spinal direct current stimulation (tsDCS) in hereditary spastic paraplegias (HSP): A sham-controlled crossover study.

Objective: Hereditary spastic paraplegia (HSP) represents a heterogeneous group of neurodegenerative diseases characterized by progressive spasticity and lower limb weakness. We assessed the effects of transcutaneous spinal direct current stimulation (tsDCS) in HSP.Design: A double-blind, randomized, crossover and sham-controlled study.Setting: Fondazione IRCCS Cà Granda, Ospedale Maggiore Policlinico, Milan.Participants: eleven patients with HSP (six men, mean age ± SD: 37.3 ± 8.1 years), eight affected by spastin/SPG4,1 by atlastin1/SPG3a, 1 by paraplegin/SPG7 and 1 by ZFYVE26/SPG15.Interventions: tsDCS (anodal or sham, 2.0 mA, 20', five days) delivered over the thoracic spinal cord (T10-T12).Outcome measures: Motor-evoked potentials (MEPs), the H-reflex (Hr), F-waves, the Ashworth scale for clinical spasticity, the Five Minutes Walking test and the Spastic Paraplegia Rating Scale (SPRS) were assessed. Patients were evaluated before tsDCS (T0), at the end of the stimulation (T1), after one week (T2), one month (T3) and two months (T4).Results: The score of the Ashworth scale improved in the anodal compared with sham group, up to two months following the end of stimulation (T1, P = .0137; T4, P = .0244), whereas the Five Minutes Walking test and SPRS did not differ between the two groups. Among neurophysiological measures, both anodal and sham tsDCS left Hr, F-waves and MEPs unchanged over time.Conclusions: Anodal tsDCS significantly decreases spasticity and might be a complementary strategy for the treatment of spasticity in HSP.

The impaired diaphragmatic function after bilateral lung transplantation: A multifactorial longitudinal study.

BACKGROUND: Lung transplantation is a complex but effective treatment of end-stage pulmonary disease. Among the post-operative complications, phrenic nerve injury, and consequent diaphragmatic dysfunction are known to occur but are hitherto poorly described. We aimed to investigate the effect of lung transplantation on diaphragmatic function with a multimodal approach. METHODS: A total of 30 patients were studied at 4 time points: pre-operatively, at discharge after surgery, and after approximately 6 and subsequently 12 months post surgery. The diaphragmatic function was studied in terms of geometry (assessed by the radius of the diaphragmatic curvature delineated on chest X-ray), weakness (considering changes in forced vital capacity when the patient shifted from upright to supine position), force (maximal pressure during sniff), mobility (excursion of the dome of the diaphragm delineated by ultrasound), contractility (thickening fraction assessed by ultrasound), electrical activity (latency and area of compound muscle action potential during electrical stimulation of phrenic nerve), and kinematics (relative contribution of the abdominal compartment to tidal volume). RESULTS: Despite good clinical recovery (indicated by spirometry and 6 minutes walking test), a reduction of the diaphragmatic function was detected at discharge; it persisted 6 months later to recover fully 1 year after transplantation. Diaphragmatic dysfunction was demonstrated in terms of force, weakness, electrical activity, and kinematics. Our data suggest that the dysfunction was caused by phrenic nerve neurapraxia or moderate axonotmesis, potentially as a consequence of the surgical procedure (i.e., the use of ice and pericardium manipulation). CONCLUSIONS: The occurrence of diaphragmatic dysfunction in patients with a good clinical recovery indicates that the evaluation of diaphragmatic function should be included in the post-operative assessment after lung transplantation.

Spino-cerebellar tDCS modulates N100 components of the P300 event related potential.

OBJECTIVE: To evaluate the role of the cerebellum and spinal cord in cognitive processes, we assessed changes in event-related potentials (ERPs), before and after different combinations of spinal and cerebellar direct current stimulation (tDCS) in healthy subjects. METHOD: We enrolled 37 volunteers (11 males and 26 females, aged 20-50 years), who were subsequently randomly assigned to one of four stimulation conditions: i) anodal cerebellar tDCS, with the reference electrode over the right shoulder; ii) anodal spinal tDCS, with the reference electrode over the right shoulder; iii) anodal spinal tDCS with cathodal cerebellar tDCS, and iv) sham stimulation. Stimulation intensity was set at 2 mA and delivered for 20 min. ERPs were assessed in an auditory oddball task before (T0) and 5 (T1) and 30 min (T2) after tDCS offset. RESULTS: In condition iii, spino-cerebellar tDCS, the N100 component at T2 increased in amplitude by 60% (p = 0.019), whereas the sham stimulation left the N100 amplitude unchanged (p > 0.05). CONCLUSION: The N100 wave reflects pre-attentive processes and correlates with arousal due to a specific stimuli and selective attention. Because spino-cerebellar tDCS induces electric fields in the brainstem, the facilitation of the N100 may be due to the modulation of the reticular formation. Regardless of the underlying mechanism, spino-cerebellar tDCS can help patients with deficits at the pre-attentive or selective attentional level.