Neuropsychologh, Printed in Gnat Vol. 24, No. 2, pp. 241-254, Britian. 1986 0 DOES REVERSED LATERALITY REALLY DEXTRALS? A CASE STUDY 0028-3932186 $3.00+0.00 1986 Perpamon Press Ltd. EXIST IN CARMEJIJNQuB,* IRENE LITVAN and PERE VENDRELL Neurology Service, Sta Creu i Sant Pau Hospital, School of Medicine, Autonomous 1Jniversity of Barcelona, Barcelona, Spain (Accepted 19 August 1985) Abstract-We report a case of a right-handed patient who, after a massive left-hemisphere infarction, had neuropsychological disturbances compatible with a right-hemisphere lesion. This has been previously called ‘reversed laterality’. Two new aspects of this pattern are described: (1) the right hemisphere is as capable as the left in processing complex syntactic and higher psycholinguistic stimuli; (2) reversed laterality is not complete, ideomotor praxis is the only function that does not follow an inverted representation. The existence ofdifferent forms of cerebral organization in dextrals is discussed. INTRODUCTION RECENTLY TAYLOR and SOLOMON [SS] reported a case of cerebral infarct in the left hemisphere which did not result in aphasia but in visuo-spatial deficits. The patient was right-handed and CT showed the presence of a lesion involving the ‘language’ area. This unusual anatomo-functional organization was called ‘reversed laterality’. Previously a case had been reported [8] where autopsy for lung cancer also revealed destruction of Wernicke’s area without any evidence of aphasia in the patient before death. An apparent absence of language representation in the left hemisphere has also been occasionally discovered during sodium amytal injection [lo]. On the other hand, language representation in the right hemisphere in right-handed subjects has been observed on several occasions since BRAMWELL [9] introduced the term ‘crossed aphasia’ in 1899. Unfortunately, most studies of crossed aphasia focus only on the unique aspects of language impairment in these patients without assessing all neuropsychological functions [ll, 351. Crossed aphasia is not the equivalent to reversed laterality since some cases of crossed aphasia also present with visuospatial deficits [12,54]. Thus, there is evidence of two forms of atypical cerebral organization in right-handed adults, one of which is compatible with reversed laterality. This type of representation was theorized in 1966 by KREINDLER et al. [38]. In this paper we report the case of a right-handed patient with a left fronto-temporoparietal lesion whose characteristics are: absence of aphasia and presence of a neglect syndrome, visuo-spatial and visuo-constructive deficits, amusia, inattentiveness and apathy. All of these symptoms better correspond to a right-hemisphere lesion. In view of the rarity of this clinical picture of reversed laterality, we believe that it would be of interest to describe in detail the normal and impaired neuropsychological functions of this patient. In addition, the notable intellectual level of our patient has permitted us to *Address correspondence to: Dr Junque, Seccio de Neuropsicologia, Servei de Neurologia, Hospital de la Sta. Creu i Sant Pau, Avgda. St. A. M&Claret 167, 08025 Barcelona, Spain. 241 demonstrate the intactness of his psycholinguistic tasks, in contrast to the case reported by TAYLOR CASE abilities, apparent even on complicated and SOLOMON [SS]. REPORT Our patient, J.R., is a 62-yr-old male bilingual. He learned Catalan* as a first language, and was taught Spanish at about 5 yr of age. Since then he has been speaking both languages with similar use and efficiency. J.R. is college educated. a lawyer by profession without family history of sinistrality (investigated by asking the patient about the handedness ofhis relatives) and who is 100% right-handed according to the Edinburgh Handedness Inventory [44]. He had 4 yr of musical education. J.R. had a myocardial infarction when he was 43 yr old. and he had a history of chronic coronary insufficiency. Three months before being seen by the Neurology Service he presented with an auriculo-ventricular block which led to the implantation of a pacemaker. In January 1984 he was admitted to our hospital with the following reported clinical symptoms: acute right hemiplegia. left oculocephalic deviation and low level of consciousness. A neurological examination carried out the day after he was admitted showed him to be conscious; oriented to time, space and person; dysarthric, with a tendency to oculocephalic deviation to the left; right hemispatial neglect; hemiasomatognosia; right homonymous hemianopia; right facie-brachio-crural hemihypoestesia; and hemiplegia with right hyperreflexia and Babmski sign. A general medical examination did not reveal any,situs inversus. An initial CT scan revealed a massive left fronto-temporo-parietal infarct. The chmcal neuropsychological examination carried out two days post onset showed fluent language with severe dysprosodia and mild dysarthria. J.R.‘s comprehension, naming, pointing and repetition abilities-scored according to the bilingual aphasia test of our hospital-were normal. No manifestations of aphasia was seen in either of his two languages, In writing, an apraxic agraphia with macrographia was observed. In reading, the patient demonstrated right spatial alexia. Right spatial neglect was also seen on Albert’s test [l] and in another test requiring bisection of lines [32]. The reproduction of rhythm assessed by tapping was impaired and when asked to sing J.R. recited words without any accompanying melody. The general attitude of the patient was one of indifference characterized by apathy and inattentiveness. In order to identify more accurately the topology of the lesion a second CT scan of higher resolution on a fourthgeneration scanner (Somatom DR2, matrix 256 x 256) was done. Nine slides were obtained routinely at an angle of 20’ to the centro-meatal line. Results of CT show a large area of decreased density (see Fig. 1) consistent with an acute infarction, involving the left parietal lobe, two thirds of the anterior left temporal lobe, including the basal ganglia and the posterior third of the left frontal lobe. There was no mass lesion effect. As is shown, Broca’s and Wernicke’s areas of language are affected. Cerebral hemispheric asymmetries were measured from the CT scan according to the methodology of PIENIADZ and NAESER [45]. In our patient, the CT pattern of asymmetry was typical of right-handed subjects with lefthemisphere language dominance: the left occipital lobe was wider than the right occipital lobe and the right frontal lobe was wider than the left one. In most of the crossed aphasia cases measured by CT scan this asymmetry has also been found [35, 541. NEUROPSYCHOLOGICAL ASSESSMENT A more comprehensive neuropsychological assessment onset in order to study this atypical case in detail. was carried out two months post- Language The Boston Diagnostic Aphasia Examination (BDAE) [29] was given and the results may be seen in Figs 2 and 3. The rating scale profile of language functions shows normal scores with the exception of melodic line and articulation agility. In the subtest summary profile, maximum scores were observed on all subtests with the exception of average articulation and articular agility skills and those of writing and singing which are clearly deficient. The Boston Naming Test [30] was performed within normal limits (raw score = 55). Verbal comprehension examined by the shortened version of the Token Test [21] was also normal (raw score = 35). The Sentence Anagram Test [13] was completed flawlessly. The patient also solved *Catalan is a Romance language (such as Spanish, French, Italian, etc.) spoken principally in the east of Spain. KtVI KSEU LATEKALITY IN IEXTRALS? I. CT scan shows a massive acute infxction involving the left parietal lobe, IWO thirds of the anterior temporal lobe, and the posterior third of the left frontal lobe. 243 REVERSED LATERALITY IN DEXTRALS? 245 RATING SCALE PROFILE OF SPEECH CHARACTERISTICS WORD FINMNC nbmUlOMlC-iW d4lm lo flumcr FIG. 2. BDAE rating scale profile of speech characteristics, which is not typical of any aphasic disturbance. The only remarkable findings are the dysarthria and the lack of melody. without any difficulty all the items of the Active-Passive Test [19]. J.R.‘s production on the Thurstone test of verbal fluency [56] by oral modality was 58 words. Reading and oral spelling of isolated letters, syllables, words, and texts are normal. Reading comprehension of a complicated test was above average. Writing both spontaneously (see Fig. 4) and by copying was severly affected. His writing improved slightly when copying. In addition, he was able to use the typewriter effectively for linguistic expression. This apractic agraphia was accompanied in our patient by a marked constructional apraxia apparent in his drawings. Praxis Praxis was initially examined using the items contained in the BDAE supplemental subtest [29]. Ideatory praxis was normal but ideomotor praxis was impaired. For example: J.R. could fold a letter and put it inside an envelope without any difficulty, but in contrast he put three fingers on his lips to indicate silence, waved his arms vigorously to say goodbye. To supplement this examination another exhaustive procedure [40] was used which consists in 246 C. JUNQU~ et d. SUBTEST SUMMARY NAME: 3 Q FUOEILE DATE OF EXAM: 3 - a- g4 FIG. 3. Boston subtest summary profile. It shows J.R.‘s music impairment (singing and rhythm), besides the dysarthria, dysprosodia and mechanics of writing disturbance. 241 REVERSED LATERALITYIN DEXTRALS? FIG. 4. Sample of the patient’s apractic agraphia. The text was the transcription of the BDAE sentence “the quick brown fox. .“. The correct Spanish translation of this sentence is: “El ripido zorro marron salta sobre el perro perezoso”. Table 1.Results of ideomotor praxis test assessed according procedure etal.[4] (610) Symbolic (@ 10) Arms Meaningless (&IO) Symbolic (G7) Legs Meaningless W) 6(60%) 6(60%) 3(30%) 3(30%) 10(l00%) lqloo%) 3(43 %) 6(860/o) 8(100%) 8(100%) Oral Verbal Imitatory to the LEHMKUHL the carrying out of verbal instructions and imitation of 100 meaningful and nonsensical movements with the superior and inferior limbs. Since the patient was hemiplegic, bimanual requirements were eliminated. The results are presented in Table 1. Errors in symbolic praxis consisted of inadequate gestures. Surprisingly we found that meaningless gestures were performed accurately (100%) and only symbolic ones were clearly impaired, contrary to what is classically described [17]. Comprehension of praxis was also investigated [23] following the same protocol 11401.In this case, the examiner made the gestures and asked the patient to tell him what he was doing. All gestures were interpreted correctly. In summary the patient only had a clear expressive ideomotor apraxia for symbolic gestures. Visuoperceptive and visuoconstructive functions The Purdue Pegboard Test [58] was administered to evaluate dexterity of the left hand. The average score of three trials fell below the normal range for the non-dominant left hand and was similar to the average for a heterogeneous brain-damaged population [41]. Constructional praxis was assessed by the Benton Tridimensional Praxis Test [6]. The total score using the standard notation systems was 15 for the photographic presentation and 22 for the model block. Both scores fell out of the range of the control group and were indicative of a markedly impaired performance. All kinds of errors were found: omissions, additions, substitutions, angular deflection and displacements. The slowness of the patient’s C. FIG. 5. Patient’s copy and visual memory JUNQU~ reproduction figure. et al. (below) ofa modified Rey-Osterrieth complex construction was also notable: 885 set for the photographic model and 406 set for the threedimensional one. In copying Rey’s complex figure [493 J.R. achived a score of 18.5 (score 29 = percentile 10). Fig. 5 is an illustration of J.R.‘s copying that indicates the severity of his disorganization. On the Bender test [S] he also achieved a deficient performance. On the WAIS Block Design subtest [60] J.R. achived a scale score of 9, which although normal, is clearly below the expected value given his verbal IQ (VIQ see below). The Object Assembly subtest [60] revealed a markedly deficient performance (scale score = 4). REVERSED LATERALITY IN DEXTRALS? 249 Gnosis The patient performed normally on a finger gnosis examination and on left-right orientation testing following BDAE methodology [29]. Proprioception deficits precluded visuo-tactile exploration of the right hand. The results of the Poppelreuter test [47] and a test of colour recognition were normal. The examination of auditory gnosis was carried out by identification of 10 common sounds (laughter, crying, bells, engine, running water, drilling, birds singing, alarm, clock ringing, ticking of clock), all of which the patient identified correctly. Musical ability The BDAE Rhythm subtest [29] revealed a slight deficit (score = 1). On the Stamback test [52] J.R. only reproduced 14 of 21 rhythms (a performance corresponding to an age of 7 yr). His identification of well-known rhythms was normal, but J.R. was unable to reproduce them. Musical knowledge and ability was examined by an experimental test of amusia which consisted of 24 pieces of famous melodies with varying degrees of complexity. The patient first had to identify the tune and give its title and then had to hum them in unison. The identification portion of the task was performed above average compared to a non-matched control group, but reproduction in unison was severly impaired. His melodic production was inadequate for all the melodies given. When he attempted to sing famous songs, J.R. could reproduce the words but was incapable of reproducing melodies. Intelligence On the Wechsler Adult Intelligence Scale (WAIS) [60], the patient achieved a VIQ of 137 and a performance IQ (PIQ) of 82. Table 2 lists the scale scores for each of the subtest. These Table 2. Standard Scaled Scores obtained by J.R. on the WAIS Information Comprehension Arithmetic Similarities Digit Span Vocabulary Verbal 17 Digit Symbol 0 19 Picture Completion 12 13 Block Design 9 19 Picture Arrangement 8 14 Object Assembly 4 14 IQ = 137 Performance IQ = 82 Full Scale IQ = 116 results indicate that the patient has superior verbal intelligence. In contrast, the patient’s PIQ is below average and significantly inferior to his VIQ. The Digit Symbol and Object Assembly subtests were most affected with the remaining performance scale subtest scores falling in the normal range, but relatively impaired when contrasting to his verbal performance. This dramatic finding cannot be solely explained by his being functionally limited to the use of his left hand. On the Raven’s Progressive Matrices Test [48] J.R. attained a percentile score of 66 which corresponds to an IQ of 104 [60]. The different results obtained by these two intelligence tests may be explained by J.R.‘s visuo-spatial deficit [3] or his constructional apraxia [4]. Neglect may not explain the errors [ 141 since the frequency of right and left choices on the Raven’s test are similar. 250 C. JUNWJ~ et ul. The patient’s memory quotient on the Wechsler Memory Scale (WMS) [59] was 104 which is lower than expected given his WATS VIQ score. All subtests were performed within normal limits. Verbal recall on the Rey’s Auditory Verbal Learning Test [SO] was below the 10th percentile. On the recognition version ofthe Benton Visual Retention Test [7] J.R. achieved a score of 9 (very impaired) and as is shown in Fig. 4., his performance on Rey’s Visual Memory Test [49] is also impaired.. We administered a test of recognition of faces using 10 photos of famous international personalities. J.R. correctly named seven out of 10, but given the written name, he recognized 100% of the faces successfully. Pcwonality crnd emotionul hehur+our J.R. showed an apathetic and apparently hostile attitude towards his family and the medical staff. He also showed a tendency to fall asleep when he was not externally stimulated. J.R. often looked like he was confused but he had a good performance on tests of attention (WAIS Digit Span [60] and Strub and Black’s Auditory Attention Test [7]) and he was well orientated to person, space and time. Thus. J.R.‘s behavior was more characteristic of the pseudoconfusion which typically accompanies the neglect syndrome 132, 511. The patient did not show any spontaneous emotion with gesture or in speech. As a result. the examiners felt hesitant in interpreting his emotional state. In addition, the examiners couldn’t tell if the patient liked or disliked the tasks he was required to do. We can not conclude from these observations that the patient ignored his shortcomings or did not know the precision or imprecision of his responses. However, in spite of J.R.‘s motor, sensory and cognitive deficits which make him unable to rejoin the labor force. he never had a ‘catastrophic reaction’ as has been described in left iesioned patients [ZSJ. It is :;ignificant that ixj bpitc ot his postmorbid superior intellectual level, J.R.‘s degree of apathy is so seri\)us i.ht hi, family shows concern for his ‘mental balance‘. These disturbances of emotional behaviour were not reflected in the Mir;nesota hlultlphasic F’el sonality Inventory (MM PI) profiic [3 I I] as we can see in F’ig. 6. The MM PI was administered twice hccausz the patient initially classified too many statements in the “donf kno?.:.,” category indicating indecisiveness. Hut even when the MMPI was readministered and the pdticn: strongly encouraged to classify all answers as true or false. the ob:ained profjle nils remarkably similar to his earlier one. Since the patient \vas bilingual we have examined diochotic listening performance in both languages. The results revealed total right-ear extinction for both languages (the Marshall index score 1421 was - 100 for two languages). These results were expected considering J.R.‘s left temporal lobe damage [ 161. The performance of the left ear was average and similar in both languages. Reaction times to lateralized visual stimuli was measured by a microcomputer (Apple Il+).The results showed a slowed response time to stimuli in both visual fields as is commonly seen in patients with right-hemisphere lesions [27]. The patient neglected to respond to a small number of stimuli presented in his right visual hemifield which was compatible with his right homonymous hemianopia. REVERSED LATERALITY 12a4s67s90 Is*.sK rl _ HI R1t.u; _ - : (s_ - _ _s - - - : Q_ _ - p_ _ - . _ h PwlK - _ _ _ _ M a- w_ _ y)_ T & -u- lo- o- _ _ :llS - ’ - - . _ . . w- . - --jlIO _ _ - SD- - : -w- - =- - - ( _ - SS- O_-_ m- _ - - ._ . - - _ -,I?- - _ ~lr6 :__2% - -_--_-_-.-_.-_w -oIO- FIG. 6. MMPI Ma..zK Y- - W- SC’IK -1w _ _ 251 IN DEXTRALS’! . rcl. s- _ -- : : _ -2s I_ profile. The continuous line reflects the results of the first administration discontinuous line represents the results of the readministration. _-0 while the DISCUSSION We had the opportunity to examine neuropsychologically a right-handed patient with a massive lesion of the left hemisphere. Surprisingly the patient’s performance was more compatible with a lesion in the right hemisphere. His symptoms included: neglect, visuoperceptive and visuoconstructive deficits, motor amusia and disturbances in the voluntary expression of emotion. In contrast, J.R. never showed any aphasic manifestation. This unusual profile of results suggests that our patient has what might be termed ‘reversed laterality’, previously described by TAYLOR and SOLOMON [55]. We want to stress the absence of any neurolinguistic disorder despite a massive infarct in the left hemisphere. Not only was language skill intact in J.R. but he showed superior psycholinguistic abilities. It is very unusual to obtain a VIQ of 137 after an extensive left- 252 C.J~JNQU~ rt al. hemisphere lesion [41]. Moreover, unlike Taylor and Solomon’s previously described case (H.B.), J.R. did not have any difficulty on tasks requiring complex syntactic skills. H.B. was reported as having poor comprehension of passive-negative sentences. This difficulty was interpreted by TAYLOR and SOLOMON [SS] as a limitation of the right hemisphere solving complex grammatical structures, similar to that seen in cases of compensatory righthemisphere language mediation (hemispherectomized patients) [ZO]. We think that this comparison is inadequate because in contrast to left hemispherectomized patients whose right hemisphere udopts linguistic functions, in ‘reversed laterality’, the representation of language in the right hemisphere probably reflects a primary functional organization. We think that an alternative for H.B.‘s deficiencies in complex language comprehension may be his low VIQ. We have demonstrated that our patient J.R., who has a superior VIQ, perfectly solved complex syntactic tasks. Our results imply that the ‘reversed laterality’ case may process linguistic stimuli as well as a patient with an intact and typically lateralized left hemisphere, as has also been suggested in crossed aphasia cases [54, 571. Another critical finding is the persistent impairment of functions which are typically lateralized in the right hemisphere: constructional tasks such as the execution of block construction, design or copy of complex figures [24, 611, non-verbal memory [46], melody [43] and the ‘indifference reaction’ [25]. These deficits are both severe and persistent. The severity ofthese symptoms corresponds to the lesion extent observed in J.R.‘s CT scan, but not to its side. The ideomotor apraxia manifested by J.R. is a conflicting result for a ‘reversed laterality’ model. In right-handed patients, almost all cases of apraxia are from left-hemisphere lesions [26,28] and commonly are associated with aphasia. The lesion that produces either or both appears to overlap extensively [36]. In addition to this intrahemispheric dissociation, there is a interhemispheric one. In this sense, many previously reported cases of crossed aphasia in right-handed individuals show no ideomotor apraxia [l 1, 39, 541. Further evidence comes from a left-handed patient with a right-hemisphere lesion who did not develop aphasia, but did show ideomotor apraxia (33). In this patient it appeared that dominance for language lateralized in the left hemisphere, whereas ideomotor praxis was lateralized to the right. Thus, language and ideomotor praxis are not necessarily linked in a given individual and may be lateralized to opposite hemispheres. Conceivably, apraxia corresponds more closely with a hemisphere lesion opposite to the dominant hand than a lesion on the side of language dominance. Our case supports this interhemispheric dissociation. Despite the lesion size which involved classical language and praxic areas, the patient suffered ideomotor apraxia without aphasia. It is difficult to explain why the apraxia involves only symbolic gestures; recent exhaustive studies show similar impairment on meaningful and meaningless movements [22]. Unfortunately, the praxic performance of TAYLOR and SOLOMON’S [55] patient has not been reported and we can not compare their findings to ours. ‘Reversed laterality’ implies that all the specialized functions of the left hemisphere are processed by the right hemisphere and vice versa. This requirement has been met for almost all functions in both TAYLOR and SOLOMON'S [55] and our case, and also in the cases of crossed aphasia in which right-hemisphere lesions were followed by aphasia without visuospatial disturbances. We suggest that ‘reversed laterality’ is never complete. In effect, in right-handed subjects not all functions would follow a reversed pattern. Ideomotor praxis should remain lateralized in the left hemisphere, since handedness is a manifestation of contralateral cerebral dominance for that function. In a strict sense, the term ‘reversed laterality’ would only be applicable to some left- REVERSEDLATEKALITYIN DEXTRALS? 253 handers. Since in those cases, language and praxis are lateralized to right hemisphere and visuospatial functions are left-hemisphere lateralized. One patient with these characteristics has been recently reported [18]. By contrast, a complete inversion of neuropsychological functions (including praxis) has never been reported in dextrals. In summary, we suggest that there are three different possible forms of cerebral organization in right-handed adults. The typical (expected in almost all subjects) lefthemisphere representation contains those cognitive processes utilized for linguistic communication whereas the right-hemisphere contains those cognitive processes utilized for visuo-spatial functions. More atypical forms would posit inversed representation (as ours and some crossed aphasias) or overlapping representation in the same hemisphere (in other type of crossed aphasias). More exhaustive neuropsychological examinations of unusual cases are needed for definitive conclusions. Acknowledgements-We thank Drs J. Ruscalleda and A. Rovira for the helpful collaboration in the CT scan study and Dr J. Grafman for his valuable suggestions on the manuscript. In addition the authors acknowledge M. Batalla for the drawings of the Active-~Passive Test, and A. Mones for typing the manuscript. REFERENCES 1. ALBERT, M. C. A simple test of visual neglect. Neur&yy, 23, 658.-664. 1973. 2. ANGELERGUES,R., H~CAEN, H., DJINDJIAN, R. ANV JARRIE-HAZAN. N. Un cas d’aphasie croiste. Revue neural. 107, 543-545, 1962. evidence for the 3. BASSO, A., DERENZI, E.. FAGLIONI, P., SCOTTI, G. and SPINNLER, H. Neuropsychological existence of cerebra1 areas critical to the performance of intelligence tasks. Brain 96, 715-728, 1973. 4. BASSO, A., CAPITANI. E., LUZZATTI, C. and SPINNLER H. Intelligence and left hemisphere. The role of aphasia. apraxia, and size of lesion. Brain 104, 721--734, 1981. Corporation, New York, 1955. 5. BENDER, L. Visual Motor Gestalt Test. American Orthropsychiatric Constructional Prams. University of Iowa Press, Iowa City, 1973. 6. BENTON, A. L. Testof Three-Dimensionul Corporation, New York, 1974. 7. BENTON, A. L. The Revised Visual Retention Test. Psychological of Wernicke’s area without language disturbance. A fresh look at crossed aphasia. 8. BOLLER, F. Destruction Neuropsychologia 11, 243-246, 1973. 9. BRAMWELL, B. On “crossed aphasia” and the factors which go to determine whether the “leading” or “driving” speech-centres shall be located in the left or in the right hemisphere of the brain, with notes of a case of”crossed” aphasia (aphasia with right side hemiplegia) in a left-handed man. Luncet i, 1473 1479, 1X99. sodium amytal for the lateralization ofcerebral speech 10. BRANCH, C., MILNER, B. and RASMUSSEN.T. Intracarotid dominance. J. Netrrosurg. 21, 339-405, 1964. 23, 907 91 I, 1973. 11. BROWN, J. W. and WILSON, F. Crossed aphasia in a dextral. A case report. Neurology, 12. CARR, M. S.. JACOBSON, T. and BOLLER. F. Crossed aphasia: analysis of four cases. Bruin Lang. 14, 190-202. 1981. of right brain-damaged patients on a 13. CAVALLI.. M., DERENZI. E., FAGLIONI. P. and VITALB, A. Impairment linguistic cognitive task. C’orteu 17, 545 556, 19XI. 14. COS-~A.L. D.. VAUGHAN, H. G., HORWITZ, M. and RITTER. W. Patterns of behavioural deficit associated with visual spatial neglect. Cortex 5, 243 263, 1969. In Music md the Bruin, M. 15. DAMASIO. A. R. and DAMASIO. H. Musical faculty and cerebral dominance. CRIT~HLEY and R. A. HEN~~N (Editors), pp. I41 -155. Heinemann Medical Books, London. 1977. 16. DAMASIO. H. and DAMASIO. A. R. Dichotic listening patterns on conduction aphasia. Brain Lung. 10,281-286. 1980. 17. DE AJURIAGIJERRA. J., H~AEN. H. and ANGELERC~UES.R. Les apraxies. Vari&tt% cliniques et lattralization Itsionelle. Recur nrurol. 102, 566 594, 1960. 18. DELIS, D. C. and KNIC~HT.R. T. Reversed hemispheric organization in a left hander. Neurops~cl~~~logic. 21, I3 24, 1983. linguistic superiority of 19. DENNIS, M. and WHITAKER. H. A. Language adquisition following hemidecortication: the left over the right hemisphere. Brain Lung. 3, 404433. 1976. of syntax in infantile hemiplegics after cerebra1 hemidecortication: 20. DENNIS. M. and KOHN. B. Comprehension left hemisphere superiority. Bruin Lang. 3, 404-433, 1976. 21. DE RENZI. E. and FAC~LIONI.P. Normative data and screening power of a shortened version of the Token Test. C0rfe.x 14, 41~49, 1978. approach to ideomotor apraxia. 22. DE RENZI. E., MOTTI. F. and NI~HELLI. P. Imitating gestures: a quantitative Archs. Newel. 3, 6-10, 1980. 23 FEKKO. J. M.. SANTOS. M. E . CASTRO-CALDAS. A. and MAKIANO, Ci. Gesture recognilion in aphasia. J. L,/in. Neuropsychol. 2,277-292, 1980. 24 FKIEU. 1.. MATEER, C., OJEMANN, G., WOHF;S. R. and Ft.u~o, P. Orgamzatlon ofvlsuospatlal functions in human cortex. Evidence from electrical stimulation. Bruin 105, 349 371. 1982. ‘5 GAINOTTI, G. Emotional behavior and hemispheric hide of lesion. Cortex 8. 41 55. 1972. syndromes in animals and man. Rruin 88, 237 294; 5X5 644, 1965. 76 GESCHWIND, N. Disconnexion Rrhaldi~Ltrron. Life Science 21 GIANUTSOS, R. and KLITZNER, C. Hundhook of Computrr Proymms,/i~- C’,qniriw Association, New York, 1981. of gesture and pantomime in aphasia. Brain 86, 703 720, 1963. 28 GOODGLASS,H. and KAPLAN. E. Disturbance 29. GOODC;LASS.H. and KA~L.AK, E. The Asses.smenf of .Iphasiu und Relaferl Disorders. Lea & Febiger, Phdadelphia. 1983. 1983. 30 GCMID~;LASS.H. and KAPLAPC.E. Thr Bmtm :Vuminy Tcpsr.Lea & Febiger, Philadelphia, 31 HATHAWAY, S. R. and MCKINLEY. J. C. 7%~~Minnrsotu Mulriphasic P~,rsclnulity Im~mtory. Psychological Corporation. New York, 1951. 32 HEILMAN. K. M. Neglect and Related Disorders. In C‘!iniud Neurop.r~~lrolr,y!, K. M. H~ILMA~‘ and E. VAI.ENSTTIN(Editors), pp 275~-276: 294 296. Oxford University Press. New York, 1979. 33. HEII.MAN, K. M.. COYLE. J. M.. GIINYF, E. F and GTSCHM’INL), N. Apraxia and agraphia in a left hander. Bruin 96, ?I 28, 1973. 34 HENDERSON,V. W., NAESEK. M. A. and C~I~JI, II. C. Cerebral asymmetries evaluated by computed tomography in crossed aphasia. Neuroloyy 33, 104, 1983. 35. JOANIXTTE.Y.. P~JEL, M., N~SPOULOUS. J. L. R~\sc.oL, A. and Roc~j L.t~ror!~s. A. Aphasia croisPe chez les droitiers. Revue de la littrature. Revue rrrurol. 138, 575~-586, 1982. 36. KEKTESZ, A.. FEKKO. J. M. and %EwaN, C. M. Apraxia and aphasia: the functional anatomical basis for their dissociation. Neurdoy~ 34, 40 47, 1984. 37. KERTESZ, A. and FEKRO.J. M. Lesion size and localization in ideomotor apraxla. Bruirl 107, 931 ~933. 1984 38. KREINDLER. A., FRADIS, A. and SEVASTOPOL,N. La rkpartition des dominances hCmisph&riques, NeuropsychoIoyicc, 4, 143-149, 1966. analysis of a case of crossed aphasia’ 39. LARRABEE. G J., KANE. R. L. and RC~GERS,J. A. Neuropsychological implications for reversed laterality. J. ciin. Neurops,yrhol, 4, 131-142, 1982. apraxia and aphasia. An examination of types and 40. LEHMKIJHL, G., POECK. K. and WILLMES, K. Ideomotor manifestations of apraxic symptoms. ,~reurops~choloyicl 21, 199~ 212, 1983. Assessment. Oxford University Press, New York, 1983. 41. LEZAK. M. D. Nelrropsy~holoyica( Neeurops~~chologia 13,3 15-322, 1975. 42. MARSHALL. J. C., CAPLAN, D. and HOLMES,J. M. The measure oflaterality. 6, l9l43 MILNEK, B. Visual recognition and recall after right temporal lobe excision in man. Nerrropsycholoyia 209. 1968. the Edinburgh Inventory. Neuropsychologicl 9, 44 OLDFIELD. R. C. The assessment and analysis of handedness: 97 113, 1971. 45. PIENIALX. J. M. and NA~SEK. M. A. Computed tomographic scan cerebral asymmetries and morphologic braIn a.\ymmetries. Archs. Net&. 4, 403 409. 1983. apraxia associated with lateral cerebral 46. PIERCY. M.. H~CAIX. H. and Dr: AJI:K:AC~UEKKA.J. Constructional lesions. Left and right sided casts compared. Brulri 83, X5-242. 1960. ITIX. W. Die Ps)‘d~iscl:en J;‘hiicieiqumgiw Dun-h Kopfischuss im Krir~qc 19 I4 I9 16. Verlag Van Leopold 47. PCJP~‘ELRI.I Voss. Leipzig. I9 I 7. Progwawr Motr-ic,es. A. K. Lewis. London. 1960. 48. RAVI,N, J. C Gu& /(I use rhe Stmdwd ~‘mnpluur.~. Lcs edItIons du Centrc 49 RFY. A. TL’s~dr C‘opic>t’t JL. Raprmhution de A4krmure de Fi~qures Gom&riqur.\ de PsychologIc Appliyu&, Porls. I Y5Y. dc France. Paris, 1Yh4. 50. RI:>. A. Z,‘rurrme,z Ciriq:rr e,l Pv~clrol~vqir. Pl-cszs IJnlversltalres confusional states in patient5 Rith right hemisphere infarctions. 51. SC’HIDLIy, J W ,lnd MhssIN~;, R. D. A&ted Slrokc 15, X83 885, I983 b,/ &;uamt~n Pricoltigico de/ Nifio, R. ZA~ZO (Editor). pp. 52. STAMBACR, M. Tres pruebas de ritmo. In M<~nucilI)L(~LI 162 279. Fundamentos. Madrid. 1976. 1:. A. I)avia, Philadelphia. 1977. 5.:. SIKI.II. R. L. and BL.A~~, F. W The ;Lf~w?u/ S’t~us Ewr~inrilir~rt UI Yrurvloy~. 54. SWFI-.I. E. W. S.. PANIS. W. and LIIVINE, D. N. Crossed Wernicke‘s aphasia. Nrurolo