Abstract Body

Tics and Tourette affect 1% of the childhood population and are characterised by chronic (more than 12 months) or motor and vocal tics. Tourette is considered a neurodevelopmental disorder and commonly co-exists with ADHD, OCD and also other emotional disorders.

Regarding aetiology, although a genetic contribution is manifest, it is clear that the genomics of Tourette is extremely complex with 100s of genes providing small contibrutions. It is increasingly clear that environmental factors play a significant role in disease expression, and there is increasing interest in the role of maternal factors in pregnancy and early life factors that increase the expression of disease, which is also true for other neurodevelopmental disodrers such as ADHD and autism.

A therapeutic approach to Tourette should involve defining comorbidity, functional impairment and therapeutic priorities. Often psychoeducation is all that is required in many patients with tics and low level comorbid impairments. However in children with significant impairments, treatment of the ADHD, OCD or tics should be considered using psychological, behavioural or medical strategies.

Abstract Body

Dystonia is a complex movement disorder characterized by irregular and involuntary movement patterns and contractions leading to twisted postures with or without a tremulous component. Focal dystonia is the most frequent form of adult-onset dystonia. The current pathophysiological model posits focal dystonia as a network disorder. Neurophysiological and neuroimaging investigations have identified functional abnormalities in two networks involved in movement control: the basal ganglia sensorimotor network and the cerebello-thalamo-cortical network, with the basal ganglia and thalamus playing a central role. Sensory abnormalities have been described in adult-onset focal dystonia, and changes in sensory information processing have been proposed to play a role in motor dysfunction pathophysiology. Afferent proprioceptive information may not be correctly integrated in the sensorimotor system, thus inducing cortical and subcortical neural structure reorganization. This may result in impaired movement control and perception of the body in its environment. Sensory tricks, i.e., alleviating maneuvers that transiently improve dystonic symptoms, also support the role of sensory function in dystonia pathophysiology. Recent neurophysiological evidence based on orthodromic sensory stimulation suggests that sensory network activation may stabilize sensorimotor networks and restore balance in the altered communication between network nodes. A better understanding of the role of sensory abnormalities and sensorimotor integration in focal dystonia pathophysiology may introduce new therapeutic scenarios based on non-invasive neuromodulatory strategies.

Abstract Body

FUNCTIONAL MOVEMENT DISORDERS

Functional motor disorders (FMDs) are abnormal movements (e.g. functional limb weakness, tremor, dystonia) that are significantly altered by distractive maneuvers and are incongruent with movement disorders seen in typical neurological diseases. FMDs have a high prevalence, are still misunderstood, diagnosed with a long delay and not properly treated, causing high degrees of disability and poor quality of life with increasing social and economic costs for both patients and the National Health System. Although movements of patients with FMDs show features physiologically associated with voluntary movement (distractibility, resolution with placebo), these patients report them as being involuntary and not under their control. Stressful life events have been associated with FMDs, but a clear psychological causation may be also absent. Accordingly, in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition,psychological stressors preceding the onset of symptoms are not needed for the diagnosis of functional neurological disorders (FNDs), but positive symptoms and signs should be taken into account.

The pathophysiology of FMDs remains largely unknown. In this last decade several neurophysiological and neuroimaging studies have shown dysfunction in attentional focus, in beliefs/expectations, and in sense of agency as the three key pathogenetic processes.

Future research is needed to develop new methods aimed at detecting and quantifying functional processes, at delineating their underlying pathophysiological mechanisms and at understanding how these mechanisms result in functional symptoms.