Phenotypical Differentiation of Tremor Using Time Series Feature Extraction and Machine Learning.

Background: The clinical diagnosis of tremor disorders depends on the interpretation of subtle movement characteristics, signs, and symptoms. Given the absence of a universally accepted biomarker, differentiation between essential tremor (ET) and tremor-dominant Parkinson's disease (PD) frequently proves to be non-trivial.

Objective: To identify generalizable tremor characteristics to differentiate ET and PD using feature extraction and machine learning (ML).

Rare Movement Disorders-An Approach for Clinicians.

Rare genetic movement disorders usually manifest early in life with dystonia, parkinsonism, chorea, or a combination thereof. These are often associated with neurodevelopmental delay, intellectual disability, speech problems, retinal abnormalities, seizures, ataxia, spasticity, or systemic features. Due to their vast number and pheno-genotypic heterogeneity, the diagnosis of these disorders can be challenging.

Diagnostic and prognostic value of α-synuclein seed amplification assay kinetic measures in Parkinson's disease: a longitudinal cohort study.

Background: α-synuclein seed amplification assay (SAA) positivity has been proposed as a diagnostic biomarker for Parkinson's disease. However, studies of the prognostic value of this biomarker have been limited to small, single-centre studies over short follow-up periods. We aimed to assess the diagnostic and prognostic value of quantitative CSF α-synuclein SAA kinetic measures in Parkinson's disease.

EFNB3 Frameshift Variant in Weimaraner Dogs with a Condition Resembling a Congenital Mirror Movement Disorder.

Background: Congenital mirror movement disorders (CMMs) are clinically and genetically heterogeneous in human patients. CMMs have not been documented to occur spontaneously in animals.

Objective: The objective of this work was to document the first case of CMMs spontaneously occurring in Weimaraner dogs and to identify the underlying genetic cause.

Pathogenic variants in Cause a Spectrum of Neurodevelopmental and Neurodegenerative Disorders with Lysosomal Dysfunction.

encodes a subunit of the BLOC-one-related complex (BORC), which is known to mediate the kinesin-dependent anterograde movement of lysosomes. Using whole-exome sequencing, we identified 12 cases from seven families carrying bi-allelic variants, including four loss-of-function and two missense variants. Carriers of homozygous loss-of-function variants presented with prenatally lethal arthrogryposis multiplex congenita, brain malformations, and neuropathological evidence of diffuse neuroaxonal dystrophy.

Definition and Classification of Dystonia.

Dystonia is a movement disorder with varied clinical features and diverse etiologies. Here we present a revision of the 2013 consensus definition and classification of dystonia in light of subsequent publications and experience with its application during the last decade. A panel of movement disorder specialists with expertise in dystonia reviewed the original document and proposed some revision.

Tics and Parkinson's Disease: Clinical and Pathophysiological Insights from a Rare Syndromic Association.

Background: The coexistence of tics with Parkinson's disease (PD) is rare, as they often emerge at different ages, follow different trajectories and involve contrasting pathophysiological mechanisms related to dopamine availability and function in the brain.

Cases: We present 10 individuals with primary tic disorders who later developed PD. Tic severity remained unchanged with the onset of parkinsonism or dopaminergic treatment.

Basal ganglia calcification: 'Fahr's disease'.

Brain calcification is often detected incidentally, but basal ganglia calcification has a wide differential diagnosis, including genetic and acquired causes. Primary familial brain calcification (PFBC) (formerly 'Fahr's disease') refers to neurological disorders characterised by bilateral, symmetrical deposition of calcium-hydroxyapatite crystals in the basal ganglia and other encephalic regions, with a presumed genetic basis. Its clinical picture encompasses motor, cognitive and psychiatric manifestations in various combinations.

Voluntary and involuntary motor behaviours in the varieties of religious experience.

Religion is a widespread feature of human life. Religions typically include both distinctive varieties of experience and also a set of foundational beliefs. An additional, but often overlooked, part of many religions is their expression through specific actions, which we here designate religious motor behaviours.

-related disorders: expansion of the phenotypic spectrum and long-term efficacy of deep brain stimulation.

Heterozygous mutations in are associated with an early-onset, progressive and often complex dystonia (DYT28). Key characteristics of typical disease include focal motor features at disease presentation, evolving through a caudocranial pattern into generalized dystonia, with prominent oromandibular, laryngeal and cervical involvement. Although -related disease is emerging as one of the most common causes of early-onset genetic dystonia, much remains to be understood about the full spectrum of the disease.

Neurophysiological Insights into the Pathophysiology of Stiff-Person Spectrum Disorders.

Background: Stiff Person Spectrum Disorders (SPSD) are classically defined by the presence of muscle stiffness, spasms and hyperactivity of the central nervous system. There is a notable correlation between neurophysiological features and the clinical hallmark of SPSD, which has greatly encouraged the use of these techniques for diagnostic purposes. Besides, electrophysiological techniques allow for a functional evaluation of the 'hyperactivity of the CNS', thus offering the opportunity to clarify the mechanisms underlying this disorder.

Parkinson's families project: a UK-wide study of early onset and familial Parkinson's disease.

The Parkinson's Families Project is a UK-wide study aimed at identifying genetic variation associated with familial and early-onset Parkinson's disease (PD). We recruited individuals with a clinical diagnosis of PD and age at motor symptom onset ≤45 years and/or a family history of PD in up to third-degree relatives. Where possible, we also recruited affected and unaffected relatives.

Evaluation of Cerebrospinal Fluid α-Synuclein Seed Amplification Assay in Progressive Supranuclear Palsy and Corticobasal Syndrome.

Background: Seed amplification assay (SAA) testing has been developed as a biomarker for the diagnosis of α-synuclein-related neurodegenerative disorders.

Objective: The objective of this study was to assess the rate of α-synuclein SAA positivity in progressive supranuclear palsy (PSP) and corticobasal syndrome (CBS) and to analyze clinical and pathological features of SAA-positive and -negative cases.

Methods: A total of 96 cerebrospinal fluid samples from clinically diagnosed PSP (n = 59) and CBS (n = 37) cases were analyzed using α-synuclein SAA.

Amelioration of Focal Hand Dystonia via Low-Frequency Repetitive Somatosensory Stimulation.

Background: Dystonia presents a growing concern based on evolving prevalence insights. Previous research found that, in cervical dystonia, high-frequency repetitive somatosensory stimulation (RSS; HF-RSS) applied on digital nerves paradoxically diminishes sensorimotor inhibitory mechanisms, whereas low-frequency RSS (LF-RSS) increases them. However, direct testing on affected body parts was not conducted.

Paroxysmal movement disorders.

Paroxysmal movement disorders include two groups of intermittent neurologic disorders: paroxysmal dyskinesia, in which episodes of involuntary hyperkinetic movements (mainly chorea and/or dystonia) occur with preserved consciousness, and episodic ataxias, which are characterized by discrete attacks of cerebellar dysfunction, sometimes associated with progressive ataxia. Since episodic ataxias are individually discussed in Chapter 8 of this volume, we herein provide a deep overview of phenotypic, genetic, pathophysiologic, diagnostic, and treatment aspects of paroxysmal dyskinesia, following the trigger-based nomenclature which distinguishes paroxysmal kinesigenic dyskinesia, paroxysmal nonkinesigenic dyskinesia, and paroxysmal exercise-induced dyskinesia. Emerging paroxysmal dyskinesia not fulfilling the criteria for the above-mentioned subtypes will also be discussed.

Variants in the proteasome regulator PSMF1 cause a phenotypic spectrum from early-onset Parkinson's disease to perinatal lethality and disrupt mitochondrial function.

Dissecting biological pathways highlighted by Mendelian gene discovery has provided critical insights into the pathogenesis of Parkinson's disease (PD) and neurodegeneration. This approach ultimately catalyzes the identification of potential biomarkers and therapeutic targets. Here, we identify as a novel gene implicated in parkinsonism and childhood neurodegeneration.