"I swear it is Tourette's!": On functional coprolalia and other tic-like vocalizations.

Coprolalia in neuropsychiatry is typically associated with tic disorders, in particular Gilles de la Tourette syndrome. To date, there has been no report of functional coprolalia. Here, we provide the clinical characteristics of 13 adolescent and adult patients with coprolalic and other functional tic-like complex vocalizations who, on the basis of these symptoms, were misdiagnosed with a primary tic disorder, most commonly Gilles de la Tourette syndrome. We describe similarities and highlight the differences from primary tic disorders in order to provide a pragmatic list of clinical clues that will facilitate correct diagnostic labeling and thereby treatment. Finally, we emphasize that the distinction between a primary and a functional tic disorder should rely on a combination of neuropsychiatric symptoms and signs and not on the presence of single, however striking, abnormal behaviors, such as coprolalia

Learning volition: A longitudinal study of developing intentional awareness in Tourette syndrome

Tourette syndrome (TS) is characterized by the presence of involuntary movements (tics) which are, at least partly, generated within ‘voluntary’ motor pathways. Here we reassess 16 TS patients (age 19 ± 2.3 years) who participated in a mental chronometry study of volition 5.5 years previously (Ganos C et al. Cortex. 2015 Mar.; 64:47–54), and 16 age-matched controls. Participants estimated the time of their own voluntary movements (Libet's M judgement), or of conscious intention to make voluntary movements (Libet's W judgement), in separate blocks. We considered M judgement as a control condition. Therefore, the experience of an intention to move occurring prior to actual movement onset, as measured by the W-M gap, was taken as the cardinal feature of volition. Time estimates of the TS group did not differ significantly from controls, for either M or W judgement. Further, M and W time estimates in the TS group had not changed significantly between the two assessments. However, exploratory analyses revealed a strong relation between disease duration and the development of M- and W-judgements: the longer was the disease duration, the less was the developmental increase in the W-M gap (linear regression, p = .003). In conclusion, our results suggest compromised development of experience of volition in developing TS patients. The developmental difficulty in processing internal premotor signals for voluntary actions could reflect the chronic persistence of tics from adolescence to adulthood

Oculogyric crises: Etiology, pathophysiology and therapeutic approaches

Oculogyric crisis (OGC) describes the clinical phenomenon of sustained dystonic, conjugate and typically upward deviation of the eyes lasting from seconds to hours. It was initially observed in patients with postencephalitic parkinsonism, but since then a number of conditions have been associated with OGC. These include drug-induced reactions, hereditary and sporadic movement disorders, and focal brain lesions. Here, we systematically review the literature and discuss the spectrum of disorders associated with OGC in order to aid clinicians place this rare but distinctive clinical sign into the appropriate diagnostic context. We also provide a brief synthesis of putative pathophysiological mechanisms, as well as therapeutic recommendations based on the literature and our own experience

Mental rotation and working memory in musicians' dystonia

BACKGROUND: Mental rotation of body parts engages cortical-subcortical areas that are actually involved in the execution of a movement. Musicians’ dystonia is a type of focal hand dystonia that is grouped together with writer’s cramp under the rubric of “occupational dystonia”, but it is unclear to which extent these two disorders share common pathophysiological mechanisms. Previous research has demonstrated patients with writer’s cramp to have deficits in mental rotation of body parts. It is unknown whether patients with musicians’ dystonia would display similar deficits, reinforcing the concept of shared pathophysiology. METHODS: Eight patients with musicians’ dystonia and eight healthy musicians matched for age, gender and musical education, performed a number of tasks assessing mental rotation of body parts and objects as well as verbal and spatial working memories abilities. RESULTS: There were no differences between patients and healthy musicians as to accuracy and reaction times in any of the tasks. CONCLUSIONS: Patients with musicians’ dystonia have intact abilities in mentally rotating body parts, suggesting that this disorder relies on a highly selective disruption of movement planning and execution that manifests only upon playing a specific instrument. We further demonstrated that mental rotation of body parts and objects engages, at least partially, different cognitive networks

The Phenomenon of Exquisite Motor Control in Tic Disorders and its Pathophysiological Implications

The unifying characteristic of movement disorders is the phenotypic presentation of abnormal motor outputs, either as isolated phenomena or in association with further clinical, often neuropsychiatric, features. However, the possibility of a movement disorder also characterized by supranormal or enhanced volitional motor control has not received attention. Based on clinical observations and cases collected over a number of years, we here describe the intriguing clinical phenomenon that people with tic disorders are often able to control specific muscle contractions as part of their tic behaviors to a degree that most humans typically cannot. Examples are given in accompanying video documentation. We explore medical literature on this topic and draw analogies with early research of fine motor control physiology in healthy humans. By systematically analyzing the probable sources of this unusual capacity, and focusing on neuroscientific accounts of voluntary motor control, sensory feedback, and the role of motor learning in tic disorders, we provide a novel pathophysiological account explaining both the presence of exquisite control over motor output and that of overall tic behaviors. We finally comment on key questions for future research on the topic and provide concluding remarks on the complex movement disorder of tic behaviors

Feedforward somatosensory inhibition is normal in cervical dystonia

Background: Insufficient cortical inhibition is a key pathophysiological finding in dystonia. Subliminal sensory stimuli were reported to transiently inhibit somatosensory processing. Here we investigated whether such subliminal feedforward inhibition is reduced in patients with cervical dystonia. Methods: Sixteen cervical dystonia patients and 16 matched healthy controls performed a somatosensory detection task. We measured the drop in sensitivity to detect a threshold-level digital nerve shock when it was preceded by a subliminal conditioning shock, compared to when it was not. Results: Subliminal conditioning shocks reduced sensitivity to threshold stimuli to a similar extent in both patients and controls, suggesting that somatosensory subliminal feedforward inhibition is normal in cervical dystonia. Conclusion: Somatosensory feedforward inhibition was normal in this group of cervical dystonia patients. Our results qualify previous concepts of a general dystonic deficit in sensorimotor inhibitory processing

The spectrum of involuntary vocalizations in humans: A video atlas

In clinical practice, involuntary vocalizing behaviors are typically associated with Tourette syndrome and other tic disorders. However, they may also be encountered throughout the entire tenor of neuropsychiatry, movement disorders, and neurodevelopmental syndromes. Importantly, involuntary vocalizing behaviors may often constitute a predominant clinical sign, and, therefore, their early recognition and appropriate classification are necessary to guide diagnosis and treatment. Clinical literature and video‐documented cases on the topic are surprisingly scarce. Here, we pooled data from 5 expert centers of movement disorders, with instructive video material to cover the entire range of involuntary vocalizations in humans. Medical literature was also reviewed to document the range of possible etiologies associated with the different types of vocalizing behaviors and to explore treatment options. We propose a phenomenological classification of involuntary vocalizations within different categorical domains, including (1) tics and tic‐like vocalizations, (2) vocalizations as part of stereotypies, (3) vocalizations as part of dystonia or chorea, (4) continuous vocalizing behaviors such as groaning or grunting, (5) pathological laughter and crying, (6) vocalizations resembling physiological reflexes, and (7) other vocalizations, for example, those associated with exaggerated startle responses, as part of epilepsy and sleep‐related phenomena. We provide comprehensive lists of their associated etiologies, including neurodevelopmental, neurodegenerative, neuroimmunological, and structural causes and clinical clues. We then expand on the pathophysiology of the different vocalizing behaviors and comment on available treatment options. Finally, we present an algorithmic approach that covers the wide range of involuntary vocalizations in humans, with the ultimate goal of improving diagnostic accuracy and guiding appropriate treatment