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Echopraxia, a tic disorder is the involuntary repetition of another person’s movements.[1] Imitation and emulation of physical and verbal actions are critical to early development. However, when these behaviors become reactions rather than a means for learning, they are considered echophenomena. Echopraxia has been observed in patients with frontal lobe damage, but the exact cause is currently unknown. Patients with Gilles de la Tourette Syndrome, Schizophrenia, and autism exhibit echopraxia; however, the reason for the link between echopraxia and these disorders is undetermined. Echopraxia is closely related to echolalia, the involuntary repetition of another person’s words or word phrases.[2] Although no medical treatments are available, psychological counseling may help patients who exhibit echophenomena in some cases. The effects of therapy vary depending on the initial cause of echopraxia.
Etymology
Echopraxia, termed in 1904, is derived from Ancient Greek: "ekho" + "praxis", meaning action.[3]
History
Echopraxia was observed in the first case of Tourette's Syndrome. Jean Marc Gaspard Itard described the original case of Marquise de Dampierre in 1825.[4]
Signs and Symptoms
Echopraxia is typically classified by the uncontrollable mirroring of an observed action. Imitated actions are not limited to a specific type. Imitation can be divided into two types: imitative learning and automatic imitation. Imitative learning occurs when a person consciously mimics an observed action in order to learn the mechanism behind that action and perform it himself or herself. According to Jean Piaget, this is essential to the sensorimotor stage.[5] Imitative learning continues to develop as a person ages, and is important as new skills are available to learn. For example, a person may learn to hit a nail with a hammer by watching his or her parent hammering nails. Automatic imitation on the other hand, occurs without a person's consent.[4] Babies begin copying movements soon after birth. It is not possible to diagnose echopraxia at this age, because it is difficult to differentiate between imitative learning and automatic imitation. This normally begins diminishing around the age of 3 years old. If the imitative behavior continues to be present, it is considered echopraxia. Automatic behavior is occasionally present in healthy adults. For instance, when a person observes someone yawning, he or she immediately does the same. These behaviors are not considered echopraxia.
Causes and Pathophysiology
The cause of echopraxia is currently thought to be frontal lobe damage affecting the mirror neuron system, a group of neurons in the F5 region of the brain.[6] These neurons fire action potentials when an action is observed, as well as when the action is being performed. They are primarily located in the inferior frontal gyrus and the inferior lobule of the parietal lobe. When an action is being observed or executed, the path begins at the occipital cortex, where the brain processes the visual input. The action then progresses to the superior temporal sulcus, which plays an important role in perception of biological movements.[7] The parietal cortex is then able to map the action. Finally, the action passes through the inferior frontal gyrus and ends at the primary cortex.[6] Damage to any of these components could cause echopraxia.
Diagnosis
Test reaction times
- Videos comparing echopraxia/control patients.
- Responses to biological stimuli were faster in echopraxia patients than controls.
Treatment
Medical Treatments
- None currently available.
Therapeutic Treatment
- Only in some unique cases.
- Cannot rely on this method.
- Can help if something (family, school, etc. problems) plays a role in echopraxia development.
- Has been seen with other tic disorders as well.
Stress-induced Tic Suppression
- Instances where severe stress "scares tic away".
- Ex. From An Anthropologist on Mars. Surgeon and amateur pilot had severe tics, but disappeared in the operating room or plane.
- Ex. Woman afraid to fly and tics went away in plane.
- Tics re-emerge in normal situations, so not effective means of dealing with tics.
Echopraxia in Neurological Disorders
The reason for the link between echopraxia and the following neurological disorders is unknown. Possible mechanisms, as follows, have been suggested.
Gilles de la Tourette Syndrome
Echophenomena is expressed in 21-46% of patients with Tourette Syndrome.[6] These patients typically experience increased sensitivity to external stimuli, which makes them more susceptible to acquiring tics.[8]
Schizophrenia
Some studies have shown that Schizophrenia is associated with decreased inhibition and increased arousal in the nervous system.[6] A proposed mechanism for echopraxia in Schizophrenia is related to disinhibition, arousal, and the mirror neuron system. Dysfunction of the anterior cingulate cortex, where cognitive and motor processes converge, is common in patients with Schizophrenia. This dysfunction could cause movements to pass throughthe inferior frontal gyrus and automatically be repeated.[6]
Latah
Echopraxia is a common characteristic in individuals affected with Latah, a condition in South Asia triggered by the startle reflex. Patients with Latah perform exaggerated actions when startled.[9]
References
- ^ Pridmore, S., Brüne, M., Ahmadi, J., Dale, J. (2008). "Echopraxia in schizophrenia: possible mechanisms". The Royal Australian and New Zealand College of Psychiatrists: 565–71. PMID 18612859.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Cho, Y., Han, S., Song, S., Lee, B., Heo, K. (2009). "Palilalia, echolalia, and echopraxia-palipraxia as ictal manifestations in a patient with left frontal lobe epilepsy". Epilepsia: 1616–19. PMID 19175395.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ "Online Etymology Dictionary".
- ^ a b Ganos, C., Ogrzal, T., Schnitzler, A., Münchau, A. (2012). "The Pathophysiology of Echopraxia/Echolalia: Relevance to Gilles de la Tourette Syndrome". Movement Disorders. PMID 22807284.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Cook, R., Press, C., Dickinson, A., Heyes, C. (2010). "Acquisition of automatic imitation is sensitive to sensorimotor contingency". Journal of Experimental Psychology: 840–52. PMID 20695703.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ a b c d e Aziz-Zadeh, L., Koski, L., Mazziotta, J., Iacoboni, M. (2006). "Lateralization of the human mirror neuron system". The Journal of Neuroscience: 2964–70. PMID 16540574.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Vander Wyk, B. C., Voos, A., Pelphrey, K. A. (2012). "Action representation in the superior temporal sulcus in children and adults: an fMRI study". Developmental Cognitive Neuroscience. 2 (4): 409–16. PMID 22727762.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Jonas, M., Thomalla, G., Biermann-Ruben, K., Siebner, H. R., Müller-Vahl, K., Baümer, T., Gerloff, C., Schnitzler, A., Orth, M., Münchao, A. (2010). "Imitation in patients with Gilles de la Tourette syndrome--a behavioral study". Movement Disorders. 25 (8): 991–9. PMID 20535824.
{{cite journal}}: CS1 maint: multiple names: authors list (link) - ^ Tanner, C. M., Chamberland, J. (2001). "Latah in Jakarta, Indonesia". Movement Disorders. 16 (3): 526–9. PMID 11391750.
{{cite journal}}: CS1 maint: multiple names: authors list (link)