Neurological Sciences https://doi.org/10.1007/s10072-019-03962-9 BRIEF COMMUNICATION BAccent issue^: foreign accent syndrome following ischemic stroke Vincenzo Di Stefano 1 1 1 1 & Antonella Maria Pia De Novellis & Fedele Dono & Marco Onofrj & Maria Vittoria De Angelis 2 Received: 16 March 2019 / Accepted: 1 June 2019 # Fondazione Società Italiana di Neurologia 2019 Abstract Background Foreign accent syndrome (FAS) is arare syndrome associated with altered speech rhythm and prosody, which listeners perceive as foreign; cerebrovascular accidents, tumors and multiple sclerosis are reported as possible causes of FAS. The pathophysiology of FAS is not yet understood. Case presentation A 68-year-old Italian man was admitted to the EmergencyDepartment for non-fluent aphasia and dysarthria. Computed tomography (CT) scan did not show abnormalities; the patient was treated with systemic thrombolysis. A repeated brain CT and magnetic resonance imaging (MRI) confirmed an infarct in the left primary motor cortex and mild extension to cortico-subcortical frontal regions. In the following days he gradually improved, speaking Italian fluently with a typical German accent. In conclusion, FAS is a rare motor speech disorder, often related to cerebrovascular accidents involving critical regions in the dominant hemisphere. In addition, the present case adds further evidence to the role of the left primary motor cortex in modulation of prosody. In rare cases FAS can be the only sign of stroke or can appear after recovery from post-stroke aphasia. Keywords Foreign accent syndrome . Stroke . Prosody . Speech disorders . Aphasia Background Foreign accent syndrome (FAS) is a rare acquired speech disorder characterized by changes or alterations in rhythm and prosody [1, 2]. Since its first description in 1907 by the French neurologist Pierre Marie [1], the interest about FAS has increased in the last decades, even though the underlying mechanisms remain unknown. In 1982, Whitaker coined the term BForeign Accent Syndrome,^ establishing specific diagnostic criteria [3]. Patients with FAS usually speak their native language with a non-native accent, which listeners perceive as foreign in the absence of any previous personal or family exposure to the foreign accent [4]. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10072-019-03962-9) contains supplementary material, which is available to authorized users. * Vincenzo Di Stefano vincenzo19689@gmail.com 1 Department of Neuroscience, Imaging and Clinical Sciences, University BG. d’Annunzio^ of Chieti-Pescara, Via dei Vestini, 66013 Chieti, Italy 2 Department of Neurology, SS Annunziata Hospital, Chieti, Italy FAS is usually caused by severe brain injury, such as cerebrovascular accidents, tumors, multiple sclerosis, neurodegenerative, and psychiatric diseases [5–9]. However, strokes involving the language-dominant hemisphere represent the most frequent cause of FAS [10]. As reported in Table 1, several sites of lesion in the left hemisphere had been reported in FAS patients, including cortical and subcortical regions, but the left basal ganglia appear to be the most common anatomic region involved [11]. Nevertheless, Bfunctional^ FAS has also been described in patients affected by psychiatric disorders in association with functional movement disorders [12]. In these rare cases, no organic cause can be found, but the variability of the accent during examination and the absence of a brain lesion in the dominant hemisphere support the diagnosis. Alexander et al. described three phases in FAS progression: (1) the acute phase, when neurobiological symptoms and signs appear; (2) the lesion phase (3 weeks up to 3 months after stroke), when language disturbances disappear, without a sufficient compensation [13], and (3) the chronic phase (3 months post stroke), when FAS severity usually decreases due to spontaneous or post-therapeutic functional mechanisms [11]. All cases of FAS caused by an ischemic stroke can be found in Online resource 1 and Table 2 [4, 10, 14–44]. Hereby, we present the first case of an Italian patient developing FAS Neurol Sci Table 1 Overview of the most common site of lesion in the left hemisphere, which may cause FAS in patients reported in literature Site of lesion in the left hemisphere (number of cases) Authors and year of publication Precentral gyrus (9) Berthier 1991 (4 patients), Takayama 1993, Marien 2007, Bhandari 2011, Nishida 2011, Sakurai 2015 Postcentral gyrus (2) Premotor cortex (5) Marien 2007, Karanasios 2011 Graff-Radford 1986, Berthier 1991 (4 patients) Inferior frontal gyrus (2) Marien 2007, Sakurai 2015 Frontal operculum (2) Moreno-Torres 2013, Munson 2005 Parietal lobe (9) Temporal lobe (5) Blumstein 1987, Kurowski 1996, Kwon 2006, Marien 2007, Cohen 2009, Bhandari 2011, Karanasios 2011, Levy 2011, Roy 2012 Blumstein 1987, Kwon 2006, Marien 2007, Karanasios 2011, Levy 2011 Broca’s area (1) Ardila 1988 Corpus callosum (2) Hall 2003, Naidoo 2008 Internal capsule (10) Damasio 1982, Graff-Radford 1986, Blumstein 1987, Gurd 1988, Kurowski 1996, Fridriksson 2005, Naidoo 2008, Coughlan 2004, Ryalls 2006, Scott 2006 Basal ganglia (11) Corona radiate (2) Pons (3) Damasio 1982, Gurd 1988, Seliger 1992, Kurowski 1996, Edwards 2005, Fridriksson 2005, Varley 2006, Marien 2007, Naidoo 2008, Levy 2011, Berthier 2015 Avila 2004, Tetsuo 2002 Fridriksson 2005, Dankovicovà 2011, Tran 2013 Insula (2) Scott 2006, Moreno-Torres 2013 after an ischemic stroke involving the left primary motor cortex extended to cortico-subcortical frontal regions. Case description A 68-year-old right-handed man was admitted to our Emergency Unit for an acute episode characterized by difficulty speaking, with the inability to pronounce sentences and dysarthria. Neurological examination revealed motor aphasia and dysarthria, without sensory-motor deficits. Mental status was fully intact. Aphasia rapid test (ART) [45] confirmed motor aphasia. A National Institutes of Health Stroke Scale (NIHSS) score of 3 (9: 2; 10: 1) was estimated [46]. His past medical history revealed hypertension and mitralic valve surgery. Computed tomography (CT) scan was unremarkable at clinical onset. However, 24-h CT scan showed a subacute infarction, confirmed by brain magnetic resonance imaging (MRI), which demonstrated a left primary motor cortex infarct extended to cortico-subcortical left semiovale centrum (Fig. 1). In the acute setting, the patient was treated with systemic thrombolysis in accordance with current guidelines with a clinical benefit (NIHSS score of 0) [47]. Neurological examination showed a full recovery from aphasia with the appearance of a patient-referred new unrecognized BGerman accent.^ He was aware of the acquired new accent and his relatives also confirmed that there was a change in his prosody. According to current diagnostic criteria, FAS was diagnosed [3]. One week from clinical onset, the Aachener aphasia test (AAT) was within normal limits [48]. The patient underwent diagnostic workup for ischemic stroke, including cardiac rhythm monitoring, which detected atrial fibrillation. Anticoagulant therapy was prescribed and he was discharged at home with close follow-up. Further 6-month and 12-month follow-up showed clinical stability with no aphasia or dysarthria, but persisting slight FAS. Online resource 2 shows FAS feature during reading, singing, and spontaneous speech after a month from stroke. Online resource 3 shows patient’s speech features 1 year before stroke. Discussion We report the case of an Italian patient who developed a typical German accent after an ischemic stroke in the left primary motor cortex, extended to the cortico-subcortical region of the centrum semiovale. At the moment, there is no complete model explaining the pathophysiology of FAS. It is still a matter of debate if FAS results from distorted articulatory planning and coordination processes or Bhic et simpliciter^ from the acquisition of a new accent [28, 49]. A further hypothesis foresees that FAS, dysarthria, and motor aphasia might establish a continuum among language disturbances [43]. Other authors hypothesized that the new accent comes after a long neural suppression due to a vascular accident with neural plasticity effects [2, 11, 21]. This theory finds and confirms the case by Pick, in which there was a previous exposure to the accent during the war [2] and in the case by Seliger, in which the patient was exposed to the accent in the childhood through his relatives [21]. In other words, the patient retains the accent, which has been encountered before, until a stroke makes it emerge as a BFAS.^ In Bpolyglot cases,^ FAS patients can be considered to have reverted to a previously learned accent. Neurol Sci Table 2 FAS cases in the premotor and precentral cortex reported in literature Authors, year, age and gender Site of lesion N. R. Graff-Radford Left premotor cortex et al., 1986 [15] 56 F Left precentral cortex and S. E. Blumstein subcortical white matter et al., 1987 [16] 62 F M. L. Berthier et al., Left precentral cortex 1991 [19] 70 F M. L. Berthier et al., Left subcortical white 1991 [19] matter of precentral 58 M cortex M. L. Berthier et al., Left premotor cortex 1991 [19] 47 F M. L. Berthier et al., Left premotor cortex 1991 [19] 34 F J. Takayama et al., Left precentral cortex 1993 [22] 44 F J. M. Gurd et al., Left inferior frontal corona 2001 [24] radiata 47 F C. Avila et al., 2004 Left inferior frontal corona radiata [26] 51 F Left white matter of S. K. Scott et al., precentral cortex 2006 [32] 54 F Left precentral and inferior P. Marien and J. frontal cortices Verhoeven, 2007 [33] 53 F H. S. Bhandari, Left premotor cortex 2011 [36] 55 M J. P. Roy et al., 2012 Left precentral cortex [41] 63 F Y. Sakurai et al., Left precentral and 2015 [44] premotor cortices 42 F Original accent Acquired accent Associated symptoms and signs American English (Midwestern) Nordic Mild pronator drift and impaired rapid alternating movements of right arm. American English (Boston) Right central facial paresis, mild clumsiness of right hand, increased right-sided reflexes. Spanish (Buenos Aires) Slavic (or generally European) Slavic Spanish Slavic Mutism, severe left faciobrachiocrural paresis with spared sensation and crossed aphemia. Spanish (Buenos Aires) Hungarian (Slavic) Right hemiplegia. Spanish Slavic Sudden severe headache at onset. Meningeal signs and a complete right third cranial nerve palsy. Japanese Korean No data. English (North Yorkshire) French Headache at onset and impaired gait during FAS. 2-day episode of mutism, before FAS Spanish polyglot (French, French English, and Catalan) Right hemiparesis. Scottish Aphasia at onset and right arm hemiparesis. Dutch German, Polish, or South African French or German American (Texas) Cockney (dialect of London) Quebec French (Canada) Alsatian or German Japanese Chinese Moderate right hemiparesis and central facial nerve palsy. FAS reversed after a tonic-clonic generalized seizure. None. Slight right hemiparesis and mild Wernicke’s aphasia, after second stroke. FAS, foreign accent syndrome In Fig. 2, we report the list of the native languages (2a) and the percentage of acquired accents (2b) of patients with FAS described in literature. According to Pick and Selinger’s theory, the acquired accent in FAS should reflect the exposure to most common languages in the world. On the contrary, the incidence of cases of FAS seems to involve people whose languages are not widely spoken. In fact, Slavic, German, and French accents account for more than 70% of FAS reported in literature (Fig. 2b). Although there are millions of people in the world that speak English as a second language, FAS cases with English accent account for less than 20% of all cases. Moreover, it is difficult to define what we mean with the term Bpolyglot^ because of different levels of exposure to the second or third language. In our case, the patient was an Italian who received formal language (English) instruction at school; he had not studied German and never lived or had a holiday in Germany. He developed a German accent in contrast with the previous exposure to English. It is believed that linguistic and phonetic aspects can influence the expression of FAS. Probably, several factors affect the type of acquired accent; moreover, FAS is underdiagnosed Neurol Sci Fig. 1 MRI of the brain shows hyperintense signal in the premotor and precentral cortex in FLAIR sequences (a, b). MRI, magnetic resonance imaging; FLAIR, fluid-attenuated inversion recovery in many countries, thus explaining underreporting of this rare condition. In clinical practice, hardly ever FAS represents an isolated sign, being more often associated with co-existing language disturbances. FAS is more frequent in women than in men and has been linked to frontal executive dysfunctions [11]. There are empirical evidences that primary motor and primary somato-sensory areas are responsible of initiation and Fig. 2 a The most common languages spoken in the world for millions of mother tongue people are listed. b The most common acquired accents in patients with FAS in literature planning of speech and control intonation and articulation of the voice [50, 51]. The cortico-striato-thalamo-cortical network connects different structures including the putamen, thalamus, and premotor and sensory- motor cortices with bulbar nuclei, which allow lip, tongue, and laryngeal movements [52]: disruption of this pathway can cause an important disconnection between planning and production of speech, resulting in FAS [53]. Neurol Sci Probably, there is not a single region responsible for total speech control of intonation and accent, but most of patients present a lesion involving basal ganglia or premotor and precentral areas (Tables 1 and 2) [15, 17, 19, 22, 33, 36, 40, 42, 44, 49, 54, 55]. Recovery from FAS can be different from a patient to another: every patient should undergo a complete assessment of language skills with appropriate instruments and a follow-up of months and years post stroke, to detect all language improvements and to build the best speech therapies over time [56]. Moreover, FAS recovery mainly depends on the site of lesion [11]; paradoxical facilitation has been reported after cerebellar hemorrhage in patients with FAS [35, 43]. It has been hypothesized that maladaptive interactions between the two cerebral hemispheres could control rhythm and prosody and cerebellum can modulate such interhemispheric imbalance. Further evidence for a role of the cerebellum in motor speech planning emerges from functional neuroimaging [33]. Of interest, in contrast with previous literature [19], we observed that FAS was not present in our patient while singing (Online resource 2). Functional MRI studies described activation in the fronto-parietal areas and cerebellum during singing tasks [57, 58]. This finding corroborates the hypothesis, which attributes an important role to the cerebellum in modulation of patterns of speech in FAS patients with lesions in the left precentral cortex. Finally, nowadays, many people have bi- or multi-language history, thus arising difficulties in meeting Whitaker’s criteria. This issue arises important limitations on the application of criteria for FAS diagnosis. Most of the people, learning new languages, tend to retain their native accent, which may cause alteration of prosody [59], so FAS might only be due to pathological language mixing and clinicians should be aware of this aspect. Clinicians should be aware that FAS could appear after recovery from aphasic acute phase of a stroke. In these patients, a complete and systematic neurological evaluation should be performed in order to achieve the correct diagnosis and to obtain the best outcome. The present case adds further evidence to the role of the left primary motor cortex, especially in the modulation of prosody, although future research is needed to clarify the neurological, linguistic, and cognitive basis of FAS. Contributors VD, FD, AMP D, and MVD provided clinical care to the patient. VD and AMP D drafted the first version of the manuscript, and all authors contributed to and have approved the final version of the manuscript. Compliance with ethical standards Conflict of interest The authors declare that they have no conflict of interest. Ethical standards All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. Informant consent Obtained. References 1. 2. 3. 4. Conclusion In conclusion, foreign accent syndrome is a rare motor speech disorder, often related to cerebrovascular accidents involving critical regions in the dominant hemisphere. Although many cases have been described, FAS remains a poorly understood condition. FAS can be the only sign of stroke or more often occurs in association with neurological signs and symptoms. In our patient, FAS was induced by interruption of cortical-subcortical pathways that connect the precentral and premotor areas to the Blanguage network.^ Lesions affecting regions that are critical for speech production may disrupt neural processes involved in the production of accent features. As a result of impaired speech regulation, other nodes of the motor speech network provide compensation by increasing their activities. 5. 6. 7. 8. 9. 10. Marie P (1907) Présentation de malades atteints d’anarthrie par lésion de l’hémisphere gauche du cerveau. Bull Mem Soc Med Hop Paris 1:158–160 Pick A (1919) Über Änderungen des Sprachcharakters als Begleiterscheinung aphasischer Störungen. Z Ges Neurol Psychiat 45:230–241 Whitaker H (1982) Levels of impairment in disorders of speech. In: Malatesha RN, Hartlage LC (eds) Neuronsycbology and Cognition, vol 1. Nijhoff, The Hague Keulen S, Marien P, van Dun K et al (2017) The posterior fossa and foreign accent syndrome: report of two new cases and review of the literature. Cerebellum. 16:772–785 Luzzi S, Viticchi G, Piccirilli M et al (2008) Foreign accent syndrome as the initial sign of primary progressive aphasia. J Neurol Neurosurg Psychiatry 79(1):79–81 Chanson JB, Kremer S, Blanc F et al (2008) Foreign accent syndrome as a first sign of multiple sclerosis. Mult Scler 2009 15: 1123–1125 Abel TJ, Hebb AO, Silbergeld DL (2009) Cortical stimulation mapping in a patient with foreign accent syndrome: case report. Clin Neurol Neurosurg 111:97–101 Lázaro-Perlado F, Mentxaka-Solozabal O, Marín-DiazGuardamino E et al (2013) Trastorno obsesivocompulsivo con tics motores y verbales, trastorno de acumulación y síndrome del acento extranjero sin afasia: comunicación de un caso y revisión bibliográfica. Revista de la Asociación Española de Neuropsiquiatría 33(120):713–736 Lee O, Ludwig L, Davenport R, et al (2016) Functional foreign accent syndrome. Pract Neurol Edwards RJ, Patel NK, Pople IK (2005) Foreign accent following brain injury: syndrome or epiphenomenon? Eur Neurol 53:87–91 Neurol Sci 11. 12. 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 25. 26. 27. 28. 29. 30. 31. 32. 33. 34. 35. Mariën P, Keulen S, Verhoeven J (2019) Neurological aspects of foreign accent syndrome in stroke patients. J Commun Disord 77: 94–113 Mazzocchi F, Vignolo LA (1979) Localization of lesions in aphasia: clinical-CT scan correlations in stroke patients. Cortex 15(4):627– 653 Demartini B, Goeta D, Gambini O (2019) A case of foreign accent syndrome in a patient affected by a complex functional movement disorder. Neurol Sci Damasio AR, Damasio H, Rizzo M et al (1982) Aphasia with nonhemorrhagic lesions in the basal ganglia and internal capsule. Arch Neurol 39(1):15–20 Graff-Radford NR, Cooper WE, Colsher PL et al (1986) An unlearned foreign ‘accent’ in a patient with aphasia. Brain Lang 28(1): 86–94 Blumstein SE, Alexander MP, Ryalls JH et al (1987) On the nature of the foreign accent syndrome: a case study. Brain Lang 31:215– 244 Ardila A, Roselli M, Ardila O (1988) Foreign accent: an epiphenomenon? Aphasiology 2:493–499 Gurd JM, Bessell NJ, Raw B et al (1988) A case of foreign accent syndrome, with follow-up clinical, neuropsychological and phonetic descriptions. Neuropsychologia 26:237–251 Berthier ML, Ruiz A, Massone MI et al (1991) Foreign accent syndrome: behavioural and anatomical findings in recovered and non-recovered patients. Aphasiology 5:129–147 Ingram JCL, McCormack PF, Kennedy M (1992) Phonetic analysis of a case of foreign accent syndrome. J Phon 20:457–474 Seliger GM, Abrams G, Horton A (1992) Irish brogue after stroke. Stroke J Cereb Circ 23:1655–1656 Takayama Y, Sugishita M, Kido T et al (1993) A case of foreign accent syndrome without aphasia caused by a lesion of the left precentral gyrus. Neurology 43:1361–1363 Kurowski KM, Blumstein SE, Alexander M (1996) The foreign accent syndrome: a reconsideration. Brain Lang 54:1–25 Gurd JM, Coleman JS, Costello A et al (2001) Organic or functional? A new case of foreign accent syndrome. Cortex 37:715–718 Hall DA, Anderson CA, Filley CM et al (eds) (2003) A French accent after corpus callosum infarct. Neurology 60(9):1551–1552 Avila C, González J, Parcet M-A et al (2004) Selective alteration of native, but not second language articulation in a patient with foreign accent syndrome. Neuroreport 14:2267–2270 Coughlan T, Lawson S, O’Neill D (2004) French without tears Foreign accent syndrome. J R Soc Med 97:242–243 Fridriksson J, Ryalls J, Rorden C et al (2005) Brain damage and cortical compensation in foreign accent syndrome. Neurocase 11: 319–324 Ryalls J, Whiteside J (2006) An atypical case of foreign accent syndrome. Clin Linguist Phon 20:157–162 Kwon M, Kim JS (2006) Change in dialect after stroke: a variant of foreign accent syndrome. Eur Neurol 56:249–252 Varley R, Whiteside S, Hammill C et al (2006) Phases in speech encoding and foreign accent syndrome. J Neurolinguistics 19:356– 369 Scott SK, Clegg F, Rudge P et al (2006) Foreign accent syndrome, speech rhythm and the functional neuronatomy of speech production. J Neurolinguistics 19:370–384 Mariën P, Verhoeven J (2007) Cerebellar involvement in motor speech planning: some further evidence from foreign accent syndrome. Folia Phoniatr Logop 59:210–217 Naidoo R, Warriner EM, Oczkowski WJ et al (2008) A case of foreign accent syndrome resulting in regional dialect. Can J Neurol Sci 35:360–365 Cohen DA, Kurowski K, Steven MS et al (2009) Paradoxical facilitation: the resolution of foreign accent syndrome after cerebellar stroke. Neurology 73:566–567 36. 37. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. 48. 49. 50. 51. 52. 53. 54. 55. 56. 57. 58. Bhandari HS (2011) Transient foreign accent syndrome. BMJ Case Rep bcr0720114466 Dankovičová J, Hunt C (2011) Perception of foreign accent syndrome speech and its relation to segmental characteristics. Clin Linguist Phonet 25:85–120 Karanasios P, Loukopoulou P, Zampakis P et al (2011) Foreign accent syndrome caused by a left temporal–parietal ischaemic stroke. Acta Neuropsychiatrica 23(5):249–251 Levy ES, Goral M, Castelluccio De Diesbach C et al (2011) Stronger accent following a stroke: the case of a trilingual with aphasia. Clin Linguist Phonet 25:815–830 Nishida K, Yamamoto R, Nakamura M et al (2011) Foreign accent syndrome associated with left frontal infarction in a corrected righthander. Koujinoukinou Kenkyu 31(2):205–211 Roy J-P, Macoir J, Martel-Sauvage V et al (2012) Two Frenchspeaking cases of foreign accent syndrome: an acoustic-phonetic analysis. Clin Linguist Phonet 26:934–945 Moreno-Torres I, Berthier ML, del Mar Cid M et al (2013) Foreign accent syndrome: a multimodal evaluation in the search of neuroscience-driven treatments. Neuropsychologia 51(3):520–537 Tran AX, Mills LD (2013) A case of foreign accent syndrome. J Emerg Med 45(1):26–29, 2013 Sakurai Y, Itoh K, Sai K et al (2015) Impaired laryngeal voice production in a patient with foreign accent syndrome. Neurocase 21:289–298 Azuar C, Leger A, Arbizu C et al (2013) The aphasia rapid test: an NIHSS-like aphasia test. J Neurol 260(8):2110–2117 Goldstein LB, Samsa GP (1997) Reliability of the National Institutes of Health Stroke Scale. Extension to non-neurologists in the context of a clinical trial. Stroke 28(2):307–310 Toni D, Mangiafico S, Agostoni E et al (2015) Intravenous thrombolysis and intra-arterial interventions in acute ischemic stroke: Italian Stroke Organisation (ISO)-SPREAD guidelines. Int J Stroke 10(7):1119–1129 Luzzatti C, Willmes K, de Blaser R (1996) Aachener Aphasie Test (AAT), Versione Italiana, 2nd edn. Organizzazioni speciali, Firenze Munson PD, Heilman B (2005) Foreign accent syndrome: anatomic, pathophysiologic and psychosocial considerations. South Dakota J Med 58:187–189 Riecker A, Mathiak K, Wildgruber D et al (2005) fMRI reveals two distinct cerebral networks subserving speech motor control. Neurology 64:700–706 Bohland JW, Guenther FH (2006) An fMRI investigation of syllable sequence production. Neuroimage. 32:821–841 Alexander MP (1989) Clinical–anatomical correlations of aphasia following predominantly subcortical lesions. In: Boller F, Grafman J (eds) Handbook of Neuropsychology, vol 2. Elsevier Science, Amsterdam, pp 47–66 Berthier ML, Dávila G, Moreno-Torres I et al (2015) Loss of regional accent after damage to the speech production network. Front Hum Neurosci 9:610 Schiff HB, Alexander MP, Naeser MA et al (1983) Aphemia: clinical-anatomic correlations. Arch Neurol 40:720–727 Christoph DH, de Freitas GR, dos Santos DP et al (2004) Different perceived foreign accents in one patient after prerolandic hematoma. Eur Neurol 52(4):198–201 Mattioli F (2019) The clinical management and rehabilitation of post stroke aphasia in Italy: evidences from the literature and clinical experience. Neurol Sci Riecker A, Ackermann H, Wildgruber D et al (2000) Opposite hemispheric lateralization effects during speaking and singing at motor cortex, insula and cerebellum. Neuroreport 11(9):1997–2000 Mavridis IN, Pyrgelis ES (2016) Brain activation during singing: Bclef de sol activation^ is the Bconcert^ of the human brain. Med Probl Perform Art 31(1):45–50 Neurol Sci 59. Perecman E (1989) Language processing in the bilingual: evidence from language mixing. In: Hyltenstam K, Obler L (eds) Bilingualism across the lifespan. Cambridge University Press, Cambridge, pp 227–244 Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.