The nature of culture-specific startles syndromes such as "Latah" in Indonesia and Malaysia is ill understood. Hypotheses concerning their origin include sociocultural behavior, psychiatric disorders, and neurological syndromes. The various disorders show striking similarities despite occurring in diverse cultural settings and genetically distant populations. They are characterized clinically by exaggerated startle responses and involuntary vocalizations, echolalia, and echopraxia. Quantifying startle reflexes may help define Latah within the 3 groups of startle syndromes: (1) hyperekplexia, (2) startle-induced disorders, and (3) neuropsychiatric startle syndromes. Twelve female Latah patients (mean age, 44.6 years; SD, 7.7 years) and 12 age-, sex- and socioeconomically matched controls (mean age, 42.3 year; SD, 8.0) were studied using structured history taking and neurological examination including provocation of vocalizations, echolalia, and echopraxia. We quantified auditory startle reflexes with electromyographic activity of 6 left-sided muscles following 104-dB tones. We defined 2 phases for the startle response: a short latency motor startle reflex initiated in the lower brain stem <100/120 ms) and a later, second phase more influenced by psychological factors (the "orienting reflex," 100/120-1000 ms after the stimulus). Early as well as late motor startle responses were significantly increased in patients compared with controls (P ≤ .05). Following their startle response, Latah patients showed stereotyped responses including vocalizations and echo phenomena. Startle responses were increased, but clinically these proved insignificant compared with the stereotyped behavioral responses following the startle response. This study supports the classification of Latah as a "neuropsychiatric startle syndrome."

Apart from tics, echopraxia or echophenomena (EP), i.e., automatic imitation of observed movements, are common in patients with Gilles de la Tourette syndrome (TS). The supplementary motor area (SMA) has been shown to be overactive before the onset of tics in these patients, and it is possible that this area might also play a key role in the generation of echopraxia. We wondered whether EP can also be evoked in healthy controls (HC) by modifying neural activity of this cortical region. To this end, we modulated activity of the SMA in 30 HC by repetitive transcranial magnetic stimulation (rTMS) in an attempt to induce EP. We used both 5 Hz (which can temporarily increase neural activity) and 1 Hz (which disrupts or reduces cortical activity) rTMS. Video clips were presented to 30 HC before and after stimulation. Each clip showed one single movement, either a tic of a TS patient or a spontaneous movement of a HC. During the whole presentation, participants were videotaped in order to detect EP. Video films of participants' responses were rated by two independent raters with respect to EP frequency. Our results reveal an increase of EP following 5 Hz stimulation but no effect following 1 Hz stimulation. This finding implies that the SMA is a relay mediating EP.

Echopraxia and echolalia are subsets of imitative behavior. They are essential developmental elements in social learning. Their persistence or reemergence after a certain age, though, can be a sign of underlying brain dysfunction. Although echophenomena have been acknowledged as a typical sign in Gilles de la Tourette syndrome (GTS) since its first description, their clinical significance and neural correlates are largely unknown. Here, we review the course of their scientific historical development and focus on their clinical phenomenology and differential diagnosis with a particular view to GTS. The neural basis of echophenomena will also be addressed. © 2012 Movement Disorder Society.

Tourette syndrome patients are reported to show automatic imitation (echopraxia), but this has not yet been proven experimentally.Video clips showing either tics of other Tourette patients or spontaneous movements of healthy subjects were presented to Tourette patients and healthy subjects. Participants' responses were assessed using blinded review of video recordings by 2 independent raters and related to stimuli presented.Both raters detected more echoes in patients. In a permutation analysis, no healthy subject had echoes above chance level. In contrast, 6 and 5 patients were classified as echoers according to rater 1 and rater 2, respectively, in 1 analysis, and 9 patients were so classified in a second analysis (according to rater 2 only). Concordance between raters was high. Patients echoed both following stimuli showing tics and following stimuli showing spontaneous movements. Most echoes were part of patients' individual tic repertoire.Echopraxia is a hallmark of Tourette syndrome.

Repetitive and stereotyped behaviours in the form of stereotyped interests or specific routine activities are one ofthe diagnostic criteria in pervasive developmental disorders. The occurrence of repetitive behaviours in patients with pervasive developmental disorders is a starting point for questions about the type and classification criteria of such behaviours. The aim of the article is to present case studies of patients with pervasive developmental disorders and co-morbid symptoms in the form of routine activities, tics, obsessive-compulsive symptoms or stereotyped behaviours. The first case study describes a patient with Asperger's syndrome and obsessive compulsive symptoms. The diagnostic problems regarding complex motor tics are discussed in the second case study which describes a patient with Asperger's syndrome and Gilles de la Tourette syndrome. The third and fourth case study describes mono-zygotic twins with so called High Functioning Autism whose repetitive activities point to either obsessive compulsive symptoms, stereotypic movements, need for absolute consistency or echopraxia. The possible comorbidity of pervasive developmental disorders and symptoms in the form of repetitive behaviours, possible interactions as well as diagnostic challenges is discussed in the article.

Anecdotal evidence has noted that individuals with autism spectrum conditions (ASC) frequently exhibit heightened spontaneous imitative behavior, with symptoms of echolalia and echopraxia. This is contrasted by empiric reports that ASC results in decreased imitation and an underlying deficit in the mirror system, leading to impaired social understanding. Thus, it remains unclear whether automatic imitation is enhanced in ASC and how this is related to poorer social abilities.This study investigated spontaneous imitation in 18 high-functioning adults with ASC and 18 age- and IQ-matched control participants during a simple imitation inhibition task. Mentalizing was experimentally assessed in the same participants using both behavioral and functional magnetic resonance imaging measures, as was social interaction using an observational measure.Individuals with ASC showed increased imitation of hand actions compared with control participants and this was associated with reduced mentalizing and poorer reciprocal social interaction abilities. In the functional magnetic resonance imaging mentalizing paradigm, ASC participants with increased imitation scores showed less brain activation in areas often found to be active in mental state attribution, namely the medial prefrontal cortex and temporoparietal junction.The results confirm the presence of hyperimitation in ASC, which is accompanied by reduced social cognition, suggesting that a general imitation impairment and a global mirror system deficit are absent. These findings offer an explanation for echopractic features based on theories of atypical functioning of top-down modulation processes in autism.

A 41-year-old man with multiple sclerosis (MS) complained of nocturnal enuresis at the third exacerbation. Neurological examination revealed echopraxia, forced grasp reflexes and palmo-mental reflexes. The urodynamic studies showed neither spinal cord nor peripheral nerve involvements. His brain magnetic resonance images (MRIs) revealed new lesions at the bilateral medial frontal lobes. The intravenous methylprednisolone therapy improved nocturnal enuresis and made brain MRI lesions smaller and gone. In addition to frequently observed spinal cord lesions, we should consider some medial frontal lesions to be responsible for micturitional disturbance in patients with MS.

Palilalia is a relatively rare pathologic speech behavior and has been reported in various neurologic and psychiatric disorders. We encountered a case of palilalia, echolalia, and echopraxia-palipraxia as ictal phenomena of left frontal lobe epilepsy. A 55-year-old, right-handed man was admitted because of frequent episodes of rapid reiteration of syllables. Video-electroencephalography monitoring revealed stereotypical episodes of palilalia accompanied by rhythmic head nodding and right-arm posturing with ictal discharges over the left frontocentral area. He also displayed echolalia or echopraxia-palipraxia, partially responding to an examiner's stimulus. Magnetic resonance imaging revealed encephalomalacia on the left superior frontal gyrus and ictal single photon emission computed tomography showed hyperperfusion just above the lesion, corresponding to the left supplementary motor area (SMA), and subcortical nuclei. This result suggests that the neuroanatomic substrate involved in the generation of these behaviors as ictal phenomena might exist in the SMA of the left frontal lobe.

Whenever we observe a movement of a conspecific, our mirror neuron system becomes activated, urging us to imitate the observed movement. However, because such automatic imitation is not always appropriate, an inhibitive component keeping us from imitating everything we see seems crucial for an effective social behavior. This becomes evident from neuropsychological conditions like echopraxia, in which this suppression is absent. Here, we unraveled the neurodynamics underlying this proposed inhibition of automatic imitation by measuring and manipulating brain activity during the execution of a stimulus-response compatibility paradigm. Within the identified connectivity network, right middle/inferior frontal cortex sends neural input concerning general response inhibition to right premotor cortex, which is involved in automatic imitation. Subsequently, the fully prepared imitative response is sent to left opercular cortex that functions as a final gating mechanism for intentional imitation. We propose an informed neurocognitive model of inhibition of automatic imitation, suggesting a functional dissociation between automatic and intentional imitation.

The aim of the current study was to present a possible mechanism underpinning echopraxia in schizophrenia. It is proposed that echopraxia occurs in schizophrenia when the mirror neuron system provides a representation to the inferior frontal gyrus (IFG) and the motor cortex (and via the IFG, to the anterior cingulate cortex) and that this potential becomes executed movement, when the disorder is associated with decreased inhibition and increased arousal.