Preclinical and clinical study on type 3 metabotropic glutamate receptors in Parkinson's disease.

Metabotropic glutamate (mGlu) receptors are candidate drug targets for therapeutic intervention in Parkinson's disease (PD). Here we focused on mGlu3, a receptor subtype involved in synaptic regulation and neuroinflammation. mGlu3 mice showed an enhanced nigro-striatal damage and microglial activation in response to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP).

Effective connectivity abnormalities in Lewy body disease with visual hallucinations.

Objective: To assess the changes in effective connectivity of important regions of the visual network (VIS) and dorsal attention network (DAN) underlying visual hallucinations (VHs) in Dementia with Lewy Bodies (DLB), Parkinson's Disease (PD) and Parkinson's Disease Dementia (PDD), as measured by a transcranial magnetic stimulation-electroencephalographic technique (TMS-EEG).

Methods: We stimulated the right visual cortex (V1/V2), the right intraparietal sulcus and the right frontal eye fields, two key regions of the DAN, and measured TMS-evoked cortical activation within the VIS and the DAN. We compared 11 patients with VHs and 15 patients without VHs.

Neurological research in Italy from 2020 to 2023.

Background: To assess the state of neurological scientific research in Italy in the time interval 2020-2023.

Methods: Elsevier's modular integrated platform "SciVal" was used to analyze bibliometric research products starting from scientific production data uploaded onto Scopus. We considered the research area "Neurology" in the 01/01/2020-14/06/2023 time interval, and the following variables were extracted: number of published studies, number of citations, Field-Weighted Citation Impact, and percentage of international collaborations.

How does botulinum toxin really work?

Over the past 30 years, Botulinum toxin (BoNT) has emerged as an effective and safe therapeutic tool for a number of neurological conditions, including dystonia. To date, the exact mechanism of action of BoNT in dystonia is not fully understood. Although it is well known that BoNT mainly acts on the neuromuscular junction, a growing body of evidence suggests that the therapeutic effect of BoNT in dystonia may also depend on its ability to modulate peripheral sensory feedback from muscle spindles.

Risk and protective factors in Parkinson's disease: a simultaneous and prospective study with classical statistical and novel machine learning models.

Background: Several environmental/lifestyle factors have been individually investigated in previous Parkinson's disease (PD) studies with controversial results. No study has prospectively and simultaneously investigated potential risk/protective factors of PD using both classical statistical and novel machine learning analyses. The latter may reveal more complex associations and new factors that are undetected by merely linear models.

Cortical mechanisms of sensory trick in cervical dystonia.

Patients with cervical dystonia (CD) often show an improvement in dystonic posture after sensory trick (ST), though the mechanisms underlying ST remain unclear. In this study, we aimed to investigate the effects of ST on cortical activity in patients with CD and to explore the contribution of motor and sensory components to ST mechanisms. To this purpose, we studied 15 CD patients with clinically effective ST, 17 without ST, and 14 healthy controls (HCs) who mimicked the ST.

Dystonia, chorea, hemiballismus and other dyskinesias.

Hyperkinesias are heterogeneous involuntary movements that significantly differ in terms of clinical and semeiological manifestations, including rhythm, regularity, speed, duration, and other factors that determine their appearance or suppression. Hyperkinesias are due to complex, variable, and largely undefined pathophysiological mechanisms that may involve different brain areas. In this chapter, we specifically focus on dystonia, chorea and hemiballismus, and other dyskinesias, specifically, levodopa-induced, tardive, and cranial dyskinesia.

Relationship between risk and protective factors and clinical features of Parkinson's disease.

Background: Non-genetic risk factors play a relevant role in Parkinson's disease (PD) development but the relationship between these factors and PD clinical features is unknown.

Objective: The aim of the present multicenter study was to investigate possible relationship between risk factors and clinical motor and non-motor features in a large sample of PD patients.

Methods: Six hundred ninety-four patients with PD participated.

Transcranial alternating current stimulation modulates cortical processing of somatosensory information in a frequency- and time-specific manner.

Neural oscillations can be modulated by non-invasive brain stimulation techniques, including transcranial alternating current stimulation (tACS). However, direct evidence of tACS effects at the cortical level in humans is still limited. In a tACS-electroencephalography co-registration setup, we investigated the ability of tACS to modulate cortical somatosensory information processing as assessed by somatosensory-evoked potentials (SEPs).

Pathophysiological mechanisms of oromandibular dystonia.

Oromandibular dystonia (OMD) is a rare form of focal idiopathic dystonia. OMD was clinically identified at the beginning of the 20th century, and the main clinical features have been progressively described over the years. However, OMD has several peculiarities that still remain unexplained, including the high rate of oral trauma, which is often related to the onset of motor symptoms.

Longitudinal evaluation of patients with isolated head tremor.

Introduction: Isolated head tremor, a pathological condition characterized by head tremor without dystonic postures or tremor in other body parts, has recently been suggested to be a form of dystonia. It is however still unclear whether isolated head tremor precedes dystonia or remains unmodified overtime.

Methods: We enrolled 20 patients with isolated head tremor.

Long-term changes in short-interval intracortical facilitation modulate motor cortex plasticity and L-dopa-induced dyskinesia in Parkinson's disease.

Background: Abnormal glutamatergic neurotransmission in the primary motor cortex (M1) contributes to Parkinson's disease (PD) pathophysiology and is related to l-dopa-induced dyskinesia (LID). We previously showed that short-term treatment with safinamide, a monoamine oxidase type-B inhibitor with anti-glutamatergic properties, improves abnormally enhanced short-interval intracortical facilitation (SICF) in PD patients.

Objective: To examine whether a long-term SICF modulation has beneficial effects on clinical measures, including LID severity, and whether these changes parallel improvement in cortical plasticity mechanisms in PD.

Bradykinesia in motoneuron diseases.

Objective: Only few studies investigated voluntary movement abnormalities in patients with motoneuron diseases (MNDs) or their neurophysiological correlates. We aimed to kinematically assess finger tapping abnormalities in patients with amyotrophic lateral sclerosis (ALS) and primary lateral sclerosis (PLS), as compared to healthy controls (HCs), and their relationship with motoneuron involvement.

Methods: Fourteen ALS and 5 PLS patients were enrolled.

Cortical mechanisms underlying variability in intermittent theta-burst stimulation-induced plasticity: A TMS-EEG study.

Objective: To test the hypothesis that intermittent theta burst stimulation (iTBS) variability depends on the ability to engage specific neurons in the primary motor cortex (M1).

Methods: In a sham-controlled interventional study on 31 healthy volunteers, we used concomitant transcranial magnetic stimulation (TMS) and electroencephalography (EEG). We compared baseline motor evoked potentials (MEPs), M1 iTBS-evoked EEG oscillations, and resting-state EEG (rsEEG) between subjects who did and did not show MEP facilitation following iTBS.

Motor and non-motor subtypes of cervical dystonia.

Introduction: Cervical dystonia (CD) is a heterogeneous condition. However, while motor subtypes of CD have recently been identified, it is still unknown whether and how non-motor symptoms contribute to CD heterogeneity. In the present cross-sectional study, we aimed to identify clinical CD subtypes on the basis of motor and non-motor symptoms by using a hypothesis-free data-driven approach.

Salivary caffeine in Parkinson's disease.

We aimed to investigate salivary caffeine content, caffeine absorption and metabolism in Parkinson's disease (PD) and verify whether salivary caffeine can be used as a biomarker of PD. We enrolled 98 PD patients and 92 healthy subjects. Caffeine and its major metabolite, paraxanthine, were measured in saliva samples collected before and 4 h after the oral intake of caffeine (100 mg).

The effect of gamma oscillations in boosting primary motor cortex plasticity is greater in young than older adults.

Objective: In healthy subjects, the long-term potentiation (LTP)-like plasticity of the primary motor cortex (M1) induced by intermittent theta-burst stimulation (iTBS) can be boosted by modulating gamma (γ) oscillations through transcranial alternating current stimulation (tACS). γ-tACS also reduces short-interval intracortical inhibition (SICI). We tested whether the effects of γ-tACS differ between young (YA) and older adults (OA).

Motor dysfunction in mild cognitive impairment as tested by kinematic analysis and transcranial magnetic stimulation.

Objective: Previous studies have demonstrated voluntary movement alterations as well as motor cortex excitability and plasticity changes in patients with mild cognitive impairment (MCI). To investigate the pathophysiology of movement abnormalities in MCI, we tested possible relationships between movement abnormalities and primary motor cortex alterations in patients.

Methods: Fourteen amnestic MCI (aMCI) patients and 16 healthy controls were studied.

Painful stimulation increases spontaneous blink rate in healthy subjects.

Spontaneous blink rate is considered a biomarker of central dopaminergic activity. Recent evidence suggests that the central dopaminergic system plays a role in nociception. In the present study, we aimed to investigate whether pain modulates spontaneous blink rate in healthy subjects.