c l i n i c a l a r t i c l e

Neurological Signs: Echo Phenomena

A number of echo phenomena are described in including the supplementary motor area with a the neurological literature,1 some of which are non-fluent output typical of transcortical motor AJ Larner briefly considered here. .6 Cognitive Function Clinic, In “dynamic aphasia” speech output is char- Walton Centre for Neurology Echophenomena/Imitation behaviour acterised by a difficulty in initiation, with the and Neurosurgery, Liverpool, Much acquired human social behaviour is imita- phenomenon of “incorporational ” L9 7LJ, UK. tive in origin, both adaptive and maladaptive, when the patient uses the examiner’s question Correspondence to: but in neurological practice the term “imitation to help to form an answer. This has sometimes Email: a.larner@ behaviour” is reserved for the reproduction by been conceptualised as a form of transcortical thewaltoncentre.nhs.uk the patient of the examiner’s words or gestures motor aphasia, and may sometimes be seen in To cite: without preliminary instruction to do so (“naive progressive supranuclear palsy. Larner AJ. imitation behaviour”) or even despite explicit ACNR 2015;15(3):16. instruction not to do so (“obstinate imitation behaviour”).2 The term echophenomena has Echopraxia is the involuntary repetition of an sometimes been used interchangeably with interviewer’s movements or gestures. As with imitation behaviour. echolalia, this may be seen in frontal lobe To be labelled as such, the behaviours must disorders, , ,4 and be consistent and, as implied in the “obstinate” rarely as an ictal phenomenon.5 A mechanism terminology, have a compulsive quality to them. for echopraxia in has been postu- Echophenomena may be accompanied by lated which invokes activity in mirror neurons REFERENCES frontal release signs and utilisation behaviour providing representation to the inferior frontal (another reflection of environmental depend- gyrus and motor cortex which becomes an 1. Larner AJ. A dictionary of neuro- logical signs (3rd edition). New ency), and are usually attributed to frontal lobe executed movement due to decreased inhib- York: Springer, 2011:125-126 dysfunction, though have been associated on ition and/or increased arousal.7 2. Lhermitte F, Pillon B, Serdaru M. occasion with either basal ganglia or thalamic Human autonomy and the frontal lesions, and exceptionally with parietal lesions. Echolocation lobes. Part I: imitation and utili- zation behavior: a neuropsycho- Kahlbaum’s 1874 description of catatonia An entirely separate echophenomenon is echo- logical study of 75 patients. Ann included the symptoms of echophenomena, location. Neurol 1986;19:326-334. and echolalia and echopraxia feature amongst Visiting the Liverpool Asylum for the Blind in 3. Shimomura T, Mori E. Obstinate the symptoms listed in the criteria for catatonia 1805, the American chemist Benjamin Silliman imitation behaviour in differenti- ation of frontotemporal in DSM-5. Obstinate imitation behaviour has (1779-1864) reported: from Alzheimer’s disease. Lancet been reported to distinguish frontotemporal “How ... can we account for the acuteness of 1998;352:623-624. dementia from Alzheimer’s disease,3 but I think hearing which enabled a particular blind man, 4. Ganos C, Ogrzal T, Schnitzler A, Münchau A. The pathophysiology this is likely to be a specific (few false positives) by means of the echo produced by his whist- of echopraxia/echolalia: relevance but not very sensitive (many false negatives) ling, to decide when he was approaching any to Gilles de la Tourette syndrome. sign. object of some magnitude ...”.8 Mov Disord 2012;27:1222- 1229. Echolocation is the comparison of outgoing 5. Cho YJ, Han SD, Song SK, Lee BI, Echolalia sound pulses with the returning echoes in Heo K. , echolalia, and Echolalia is the involuntary repetition of an order to navigate or hunt. Though echoloca- echopraxia-palipraxia as ictal interviewer’s speech utterances (as opposed tion is most familiar (and studied) in bats manifestations in a patient with a 9 left frontal lobe . Epilepsia to the voluntary mickey-taking which charac- and dolphins, some blind individuals have 2009;50:1616-1619. terises an irritating game typical of childhood, developed the ability to use self-generated 6. Hadano K, Nakamura H, but sometimes indulged in by adults). As well sounds, such as tongue clicks or finger snaps, Hamanaka T. Effortful echolalia. as frontal lobe lesions, catatonia, and dementia as a form of sensory substitution to perceive the Cortex 1998;34:67-82. syndromes, echolalia may also be encountered environment (Youtube has some informative 7. Pridmore S, Brune M, Ahmadi J, Dale J. Echopraxia in schiz- in children with , in Tourette syndrome,4 videos). Sighted individuals can also be trained ophrenia: possible mecha- and rarely as an ictal phenomenon, possibly to do this. nisms. Aust NZ J 5 2008;42:565-571. with a left supplementary motor area origin. A possible answer to Silliman’s question has 8. Seed D (ed.). American travellers Echolalia may also occur in certain aphasia been provided by a functional MR imaging in Liverpool. Liverpool: Liverpool syndromes, for example in transcortical sensory study of two blind echolocators which found University Press, 2008:8. aphasia, a fluent aphasia with well-preserved that calcarine (“visual”) but not auditory cortex 9. Jones G. Echolocation. Curr Biol repetition skills. The aphasia of Alzheimer’s was activated when the subjects listened to 2005;15:R484-488. disease has sometimes been likened to transcor- recordings of echolocation clicks and echoes, 10. Thaler L, Arnott SR, Goodale MA. Neural correlates of natural tical sensory aphasia, and a “mixed transcor- suggesting a possible role for cross-modal brain human echolocation in early and tical aphasia” with echolalia has been reported plasticity in the development of this faculty of late blind echolocation experts. in Creutzfeldt-Jakob disease. compensatory enhancement.10 It would be PLoS One 2011;6:e20162. In contrast, “effortful echolalia” has been interesting to learn if this was also the case in reported in left medial frontal lobe infarction sighted individuals trained to echolocate.

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