Aphasia in left-handers

BRAIN

AND

LANGUAGE

38,

233-252 (I!%@

Aphasia in Left-Handers Comparison

of Aphasia Profiles and Language in Non-Right-Handed and Matched Right-Handed Patients

Recovery

ANNA BASSO,* MARIO FARABOLA,? MARIA PIA GRASSI,$ MARCELLA LAIACONA,* AND M. ESTERZANOBIO* *Clinic

for

Nervous

Diseases, Milan University, TNeuroradiology Maggiore, Milan, and SNeurological Department, L. Sacco (Vialba) Hospital, Milan

Service,

Ospedale

The present retrospective analysis reports two studies. In Study 1, clinical aspects of aphasia are compared in right-handed (RH) and non-right-handed (NRH) patients; in Study 2, recovery from aphasia is compared in RH and NRH aphasic patients with a minimum of 5 months of daily language rehabilitation. From a continuous series of 1200 brain-damaged subjects, 24 NRH patients with a vascular lesion documented by computerized tomography were selected. In 19 cases the lesion was in the left hemisphere and in 5 cases in the right hemisphere. For 14 NRH patients, a RH subject with similar lesion, matched for age, education, length of illness, etiology (ischemic vs. hemorrhagic), and, when possible, sex was found. Presence and type of aphasia were compared in the two patients of the same pair and were found similar except for Pair 14: the RH subject had global aphasia and the NRH had conduction-like aphasia. Fifteen NRH patients were rehabilitated and reexamined at least 5 months after the first examination. Recovery of the 12 patients with a left-hemisphere lesion was compared with recovery of a group of RH subjects and no significant differences were found. Recovery of the three patients with right-hemisphere lesions is described. It is concluded that differences in type of aphasia and recovery between RHs and NRHs have been overemphasized in the past and must be reconsidered. o IEJO Academic

Press. Inc.

Soon after Broca (186.5) suggested that left-handers (LH) have righthemisphere dominance for language, cases of aphasia following lesion This research was supported by a grant from CNR. We are grateful to Dr. Guido Gainotti for his helpful comments and to Dr. Claudio Luzzatti who kindly assisted us with the drawings of the maps. Send reprint requests to Anna Basso, Istituto di Clinica Neurologica, Via F. Sforza 35, 20122 Milan, Italy. 233 0093-934x/90 $3 .oo Copyright D 19% by Academic Press, Inc. All rights of reproduction in any form reserved.

234

BASSO

ET AL.

of the hemisphere ipsilateral to the preferred hand were published. As these are rare among right-handed (RH) but much more common in LH subjects, the functional organization of the brain in LHs cannot simply be the mirror image of that found in RHs. The study of functional organization in LHs is complicated by the indeterminateness of the concept of left-handedness. In a review of approximately 50 studies Hecaen and Ajuriaguerra (1963) found that the reported incidence of left-handedness can vary as much as from 1 to 30%, but that in the majority of studies the reported incidence ranged from 4 to 10%. These differences may be partly due to different populations (according to sex, for example) having different incidence of lefthandedness. More important, however, is the fact that handedness was evaluated by different methods and that different criteria for considering a hand as dominant were adopted. If the criterion is very strict and allows identification of strong RHs only, the remaining population forms a dishomogeneous group comprising rare strong LH subjects and subjects with varying degrees of left-handedness. Most of the studies of the relationship between handedness and aphasia have studied such heterogeneous subjects that are better qualified as non-right-handers (NRH). Many studies have been devoted to clarifying the incidence of language disorders in NRH. Goodglass and Quadfasel (1954) considered 123 (13 personal cases and 110 from the literature) NRH patients and found that 87% of the left-hemisphere damaged and 81% of right-hemisphere damaged patients were aphasic. Incidence of aphasia after right-hemisphere lesions was distinctly lower in subsequent studies. Data from sodium amytal studies (Milner, Branch, & Rasmussen, 1964; Kimura, 1983) suggest that speech is represented in the left hemisphere in approximately 70% of NRHs, and bilaterally or in the right hemisphere in the remaining 30%. In NRHs with familial sinistrality (FS), a right-hemisphere lesion gives rise to aphasic disturbances more frequently than in NRHs without FS (Hecaen & Sauguet, 1971; Hecaen, De Agostini, & Monzon-Montes, 1981). In summary, in NRHs, left-hemisphere dominance for language is much more common than the opposite, even though a right-hemisphere lesion with aphasia is not an infrequent finding, and particularly so in NRHs with FS. Much less is known about the possible qualitative differences in the clinical aspects of aphasia in RH and NRH subjects but clinicians generally assume that the clinical aspects of aphasia in NRHs are different from those in RHs. This problem has been directly confronted in two studies. In a retrospective study, Gloning, Gloning, Haub, and Quatember (1969) compared 57 RH and 57 NRH (32 with a right-hemisphere lesion and 25 with a left-hemisphere lesion) patients with almost identical cerebral lesions verified by autopsy. For each verbal behavior considered, they compared the number of pairs in which NRH subjects did

APHASIA

IN

LEFT-HANDERS

235

better than RH subjects with the number of pairs in which the reverse situation occurred. They did not find any difference in tasks such as comprehension, expressive language, confrontation naming, writing, reading, or calculation between the two groups of patients with lefthemisphere lesions. However, in pairs with right-hemisphere lesions, many more NRHs were more severely impaired in all these tasks. Hecaen and Sauguet (1971; the data of the Hecaen & Ajuriaguerra’s study of 1963 are included in the more general and later study by Hecaen and Sauguet) compared the frequency of occurrence of language and other higher nervous function disorders according to the hemisphere involved, in RH and NRH subjects. They came to the conclusion that, with an important exception, the patterns of disorganization of language and praxic and gnosic functions are very similar in RHs and NRHs with lefthemisphere damage. The exception concerned the observation that NRHs were less frequently impaired in comprehension and writing but were more likely to present with spatial reading deficits. As expected, NRHs with right-hemisphere damage were more likely to present with impaired language and constructive apraxia than RHs; the latter, in turn, more frequently had dressing apraxia. The comparison between NRHs with left- and NRHs with right-hemisphere damage did not yield any striking differences: disturbances of calculation, reading textual material, and writing complex sentences were more frequent in the left-hemisphere damaged group; constructional apraxia and unilateral spatial agnosia were more frequent in the right-hemisphere group. Results of these studies do not support the idea that cerebral representation of language is different in RHs and NRHs with left-hemisphere lesion but they did not take into consideration all the factors supposed to affect type of aphasia, such as age and sex. Another aspect of aphasia in NRHs, which has been considered in the literature, is recovery. Some authors have proposed that NRHs recover more rapidly than RHs from aphasia. Subirana (1958) and Luria (1970) found a higher proportion of strong RHs in a group of nonrecovered aphasic patients than in a group of recovered aphasic patients. Moreover, according to Luria (1970) recovery from aphasia is more frequent among patients with FS. Better prognosis for NRH aphasic patients is not, however, supported by the data of Newcombe and Ratcliff (1973) from a study of war traumas. The present retrospective analysis reports two studies. In Study 1, clinical aspects of aphasia and occurrence of acalculia, apraxia, and position preference (i.e., response preference to alternatives on either the left or right side of a display) are compared in RHs and NRHs matched for location of lesion and other variables influencing type of aphasia such as etiology, age, education, and length of illness. In Study 2, recovery of production and comprehension of oral and written language

236

BASSO ET AL.

is compared in RHs and NRHs with a minimum of 5 months of daily language rehabilitation. Cerebral dominance for language has not been studied because of preselection of patients referred at the Aphasia Unit. While acute patients are hospitalized in the neurological wards and undergo a neuropsychological evaluation independently of presence of aphasia, chronic patients are referred to the Aphasia Unit only if they are aphasic. STUDY 1 Materials and Methods Subjects From a continuous series of 1200 subjects referred to the Aphasia Unit of the Clinic for Nervous Diseases of Milan University between November 1979 and May 1987 we selected all patients conforming to the following criteria: (I) non-right-handedness according to the Edinburgh Inventory (Oldfield, 1971) (maximum score, 6 of 10 items executed with the right hand); (2) a minimum of 3 years of schooling; (3) no previous lesion of the central nervous system; (4) a right or left vascular lesion ascertained by CT scan; (5) a full neuropsychological examination performed after at least 15 days postonset. Twenty-four patients fulfilled these conditions: 19 with left- and 5 with right-hemisphere lesions. For each of these patients we selected from the whole sample of 1200 patients one RH patient who could be matched for age (k 10 years), sex, years of schooling (? 5 years), etiology (ischemic or hemorrhagic), length of illness (criteria were strict for acute patients and looser for chronic patients), and location of lesion. When this was not possible, sex was not considered. We succeeded in matching 14 NRH patients (1 with right- and 13 with left-hemisphere lesions) with comparable RH patients. In four pairs the lesions were subcortical: In Pairs 1 and 7 the lesion was in the caudate nucleus and anterior limb of the internal capsule; in Pair 8 in the putamen and caudate nucleus; and in Pair 13 in the posterior white matter. Mappings of the 10 cortico-subcortical lesions (Pairs 2, 3, 4, 5, 6, 9, 10, 11, 12, 14) are shown in Figs. 1 through 10.

Tests and Procedures Subjects had been examined with the following tests. Aphasia resring. A Standard Language Examination (Basso, Capitani, & Vignolo, 1979) which was used in our Aphasia Unit. The type of aphasia (fluent/nonBuent) was judged

NRH 2

RH 2

FIG. I. Mappings of lesions in Pair 2 patients. Diagonal lines sloping downward right to left: lesion seated deeper than 5 mm from the surface of the radiographic picture; lines sloping downward left to right: lesion depth less than 5 mm from the surface of the radiographic picture; cross-hatch lines indicate that the lesion is both deep and superficial.

APHASIA IN LEFT-HANDERS

NRH 3

237

RH 3

FIG. 2. Mappings of lesions in Pair 3 patients. Basal ganglia are also involved.

NRH 4

RH 4

FIG. 3. Mappings of lesions in Pair 4 patients.

NRH 5

RH 5

FIG. 4. Mappings of lesions in Pair 5 patients.

NRH 6

RH 6

FIG. 5. Mappings of lesions in Pair 6 patients. Deep structures are also involved.

238

BASSO ET AL.

NRH 9

RH 9

FIG. 6. Mappings of lesions in Pair 9 patients.

NRH

10

RH 10

FIG. 7. Mappings of lesions in Pair 10 patients. Deep structures are also involved.

NRH 11

RH 11

FIG. 8. Mappings of lesions in Pair I1 patients.

NRH 12

RH 12

FIG. 9. Mappings of lesions in Pair 12 patients.

APHASIA

IN LEFT-HANDERS

239

RH 14

NRH 14

F1c.10. Mappings of lesions in Pair 14 patients. Lenticular

nucleus is also involved.

from speech production during extended conversation and in the telling of an event. The features of speech production taken into account were melodic line, phrase length, and articulatory difficulty (Goodglass & Kaplan, 1983). For each of the four verbal modalities taken into account in the recovery study (oral production, oral comprehension, reading, and writing), there were two different sets of tests; in one set of tests, single word processing tasks were used, and in the other sentences. The first set of tests consisted of oral confrontation naming, pointing to command, word recognition, and written confrontation naming of 20 pictures of common objects. Scoring for each item in a test ranged from 0 to 2, for a maximum score of 40. Oral and written sentence comprehension was explored by asking the patient to carry out 10 simple commands. In these tests too, scoring for each item ranged from 0 to 2, for a maximum score of 20. In oral description, the patient was asked to describe as accurately as possible how he would shave (if a man) or how she would cook spaghetti (if a woman). Performance was scored as follows: 0 for no production, 1 for poor production, 2 for sufficient production, and 3 for good production. In the description writing task, the patient was asked to write a letter to a relative or a friend. Performance was scored in the same manner as for oral expression. In each modality, compound scores ranged from 0 (no communication) to 4 (very good communication). Progress of 1 point on such a scale corresponds to a clinically relevant recovery. Token test. A shortened version of the Token Test was administered (De Renzi & Faglioni, 1978) with 36 items and a cut-off score for normals of 29 correct responses. We considered pathologic a score of 28 or less. Oral apraxia (OA). OA was evaluated with a IO-item test requiring the execution of movements of the buccofacial apparatus (De Renzi, Pieczuro, & Vignolo, 1966). Cut-off score: 16 out of a maximum of 20. Ideomotor apruxia (MA). IMA was evaluated with a test consisting of 24 movements of the whole arm or fingers, single or in sequences, meaningful or meaningless, which the patient has to imitate with the hand ipsilateral to the lesion (De Renzi, Motti, & Nichelli, 1980). Cut-off score: 53/74 (De Renzi, Faglioni, & Sorgato, 1982). Apraxia of use (AU). AU was evaluated with a seven-item test requiring the use of seven different objects (De Renzi, Pieczuro, & Vignolo, 1968). Cut-off score: 14/14. Constructional apraxia (CA). CA was evaluated by asking the patient to reproduce IO geometric figures (Arrigoni & De Renzi, 1964). Cut-off score: 15/20. Acalculia. Patients were asked to execute simple written mathematical additions, subtractions, divisions, and multiplications (Basso & Capitani, 1979). Cut-off score: 74/101.

Results Disorders of Language

The data for the 14 NRH patients and their RH controls are shown in Table 1. The matched pairs of patients can be grouped into three

NRH RH

,

M M

75

66

54 56

M M

NRH RH

51

6

7

10

42

M M

NRH RH

5

8 13

5 8

13 13

56 64

M hi

12

17

10

5

10

6

10

6

10

4

10

2

9

13

NRH RN

38

5

17

4

M

NRH*

39 49

2

10

5

Ed. lnv.

1

H H H H H H 1 I

-

-

+ -

-

1

-

-

I I

I I

f -

+

I/H

Fam. Sin.

273 302

163 143

17 19

149 123

235

253

23 40

362 192

On-Ex (days)

AND NEUROPSYCHOLOGICAL

10

48

M M

NRH RH

59 61

School

M

M F

NRH RH

Age

RH

3

2

1

Sex

Pair

ANAMNESTIC

FTP and deep shuttures lesion Head caudate nucleus and ALIC

Small T operculum

Small, head caudate nucleus and ALIC Mainly anterior, perisylvian lesion Mainly anterior, perisylvian lesion and basal ganglia T and angular gyrus

Site of lesion

Aphasia type

(mild

Mild Wemicke Nonaphasic

Global Global

Wemick Wemicke

Wemicke Wemicke

Broca (mild agrammatism) Broca

Agraphia Agraphia Broca)

25 30

12 8

6 3

13 6

19

23

28 21

32 29

12 20

18

1

18 12

18 20

4

12

17 14

18 19

OA

(16)

Tr

64

58

7 49

68 58

64

61

57

64

65 70

71 69

153)

IMA

PATIENTS

(29)

AND THE 14 PAIRED RH

Nonaphasic Border line (rare WFD)

TABLE 1 DATA OF THE 14 NRH

14 14

14 13

14 14

14 14

14

14

14 14

14 14

(14)

AU

CA

I2 17

8 I9

17 6

17 20

18

19

17 20

20 18

(15)

AC

98

68

unt unt

38 54

84 23

32 62

57

101

(74)

M M

F F

NRH RH

NRH RH

‘*

I3

76

85

72 82

57 Sl

72 71

3

6

6 5

5 8

13 I3

5 5

17 17

5 5

10

5

2 10

I IO

3 IO

-

+

+ -

-

-

+ -

-

2 10

2 10

+ -

4 10

1

1

I I

H H

I I

I I

I I

I I

44

69

22 19

256 147

I8 15

600 440

16 23

813 520

Note. School, years of schooling; Ed. Inv, Edinburgh Inventory; lesion; On-Ex, onset-exam; TT, Token Test; OA, oral apraxia; acaluculia; M, male; F, female; + , present; - , absent; F, frontal; PLIC, posterior limb of internal capsule; PVWM, periventricular

RH

M M

F

I1

NRH

M

NRH RH

lo

14

5-l

M M

NRH RH

48

31 31

F F

NRH RH

9

56 66

F M

NRH RH

8

Fluent (unclassified) Global

Nonaphasic Conduction

Wemicke Conduction (dysgraphia) Unclassified Wernicke

Global Mixednonfluent

Broca Mixednonfluent

Broca Broca

7

I7

32 25

3 8

unt. 23

unt. I2

21 13

24 17

6

8

19 5

4 9

18 16

II

67 49

12 15

14 14

14 I4

29

60

66 50

44 40

31 35

9

12

14 14

14

I4

13 IO

untestable 60 14

66 53

4 12

9

8

16 10

13

II

17 8

15

I7 16

I1 17

13

43

17 unt

unt

22

17 10

unt 43

65 unt

71 51

Fam. Sin., familial sinistrality; 1, ischemic; H, hemorrhagic; *right-hemisphere IMA, ideomotor apraxia; AU. apraxia of use; CA, constructive apraxia; AC, T, temporal; P, parietal; 0, occipital; ALIC, anterior limb of internal capsule; white matter; WFD, word finding difficulty: unt, untestable

Subcortical lesion involving ALIC, putamen and caudate nucleus Large, mainly anterior, perisylvian lesion Large subcortical lesion extending to TP cortex Small TPO junction lesion Large anterior T and TPO junction lesion Small postPVWM lesion Large FTP and lenticular lesion

E

g z

2

s 3 6

2

z z

>

242

BASSO

ET AL.

subgroups according to the degree of similarity between patients of the same pair. Group I. In the first group (Pairs 1 to 6), there are only minor differences in type and severity of aphasia between patients of the same pair. In Pair 1, the NRH patient was nonaphasic when we first saw him 1 year postonset, but he reported having been aphasic during the first month or so. At the time of examination he had a pathological score only in a verbal fluency test with phonemic cues. His control RH patient was not matched for sex. She had some very rare word-finding difficulties and also reported that language was not as easy as before and for that reason she did not like to speak. Pair 2 patients were agraphic, and the RH patient more severely so. Speech output of the NRH patient was fluent, with some rare phonemic errors; for the RH patient it was very slightly slowed and monotonous. Oral comprehension, as measured by the Token Test, was border-line in the NRH patient and mildly impaired in the RH patient who was classified as a mild Broca’s aphasic. Broca’s aphasia was present in Pair 3 patients. Speech output was laborious for both, and the NRH patient (with right-hemisphere lesion) omitted some verbs. He was 8 months postonset when we first saw him. His wife reported that he had been more severely agrammatic but that he had partially recovered. The RH patient did not show any sign of agrammatism when we first examined him and it is not known whether he had ever been agrammatic. When seen at another hospital 3 months postonset, his speech output was scanty and laborious and too severely impaired to show agrammatism. He still was slightly more impaired overall than the NRH patient when we examined him. Patients of Pairs 4 and 5 had Wernicke’s aphasia. Oral production of the Pair 4 patients was jargon-like and the only apparent difference between the two patients was a slightly greater degree of severity, particularly in written language, in the RH patient. In the NRH patient of Pair 5, oral and written output were somewhat repetitive and rather scarce, in contrast to abundant oral and written output in the RH patient, who also had frequent verbal paraphasias. Comprehension was severely impaired in both. In Pair 6, both patients had global aphasia. Comprehension was slightly less impaired in the NRH patient and speech output in the RH patient, who could emit some recognizable words in a confrontation naming task. Group 2. In this second group of patients (Pairs 7 to 12) differences among patients of the same Pair were more marked, particularly the severity of the disorder, but the types of aphasia were not dissimilar. In Pair 7, the NRH had fluent speech output which was sufficiently informative; he had some word-finding difficulties, a mild impairment of comprehension, and dysgraphia and had been classified as mild Wer-

APHASIA

IN LEFT-HANDERS

243

nicke’s aphasic. The RH patient was nonaphasic when we first saw him 10 months postonset but he reported having had mild difficulties in the first month. Pair 8 patients were not matched for sex. They had Broca’s aphasia of approximately the same severity but some aspects of the disorder were different: The NRH patient had severe articulatory difficulties, with written confrontation naming preserved better (1.5 of 20 correct answers) than oral confrontation naming (2 of 20) and the reverse was true for the RH patient (2 of 20 vs. 13 of 20). Pair 9 patients also had nonfluent aphasia. The NRH patient’s speech output was slowed, with slight articulatory difficulties, and her comprehension was slightly impaired. Oral and written output were totally impossible for the RH patient, who was more severely impaired in general than the NRH patient. She had been classified as mixed nonfluent and the NRH as a Broca’s aphasic. The opposite was true in Pair 10, with the NRH patient much more severely impaired. He had a global aphasia with no speech output; most of the tests could not be given because the patient did not understand what he was requested to do. The RH patient had mixed nonfluent aphasia, with relatively preserved clinical comprehension and speech output restricted to some isolated syllables. In Pair 11, the NRH patient (a male) had severe Wernicke’s aphasia and the RH (a female) had conduction aphasia with severe dysgraphia. Spontaneous speech production, however, was very similar: abundant with phonemic errors in both patients and frequent cliches in the NRH. In confrontation naming, word-finding difficulties were frequent in both patients and phonemic errors in the RH patient. In the last pair of this group (Pair 12), the difference was not one of severity of the disorder but of quality of speech output. Both patients had severe aphasia. Speech output of the NRH patient was rather scarce, with frequent perseveration of the same nonword (“petro”) and some other expressions fluently uttered. Speech output of the RH patient was more abundant and varied, with cliches. Comprehension was severely impaired in both. The RH patient had been classified as a Wernicke’s aphasic and the NRH was considered unclassifiable because of the contrast between scarce and repetitive output, preservation of melodic line, and ease of articulation with occasional long uninterrupted runs of words. Group 3. The two members of the Pairs 13 and 14 presented with largely different clinical pictures. The NRH patient in Pair 13 had no language disorders and aphasia had never been noted in her medical files. The RH patient had definitely impaired language, with a full-blown conduction aphasia. Her aphasic disturbances were distinctly more severe than those of RH 1 and NRH 7, whose matched patients also were nonaphasic. In Pair 14, the NRH’s aphasia was conduction-like, with fluent and

244

BASSO ET AL.

abundant output, relatively spared comprehension, and repetition disproportionately severely impaired. We, however, did not classify this patient as a conduction aphasic because of the characteristics of his speech which, even though abundant and apparently easily articulated, were made up only of frequently repeated syllables interspersed rarely with some words (“nothing,” “ this one”). He was, however, classified as a conduction aphasic on second examination. The RH patient had global aphasia. He had no speech output and comprehension was more severely impaired than in the NRH patient. Apraxia, Acalculia, and Neglect The frequencies of occurrence of OA, IMA, AU, and CA were compared in the 13 NRH patients with left-hemisphere lesion and in their controls (see Table 2) and the differences were never found to be statistically significant. Acalculia was the most frequent deficit. Only 3 NRH and 2 RH patients scored above the cut-off score. As for the apraxias, frequency of occurrence was not statistically different in the 13 NRH and in the 13 matched RH patients with left-hemisphere lesions (see Table 2). Formal tests of neglect were not given, but clues for its presence can be derived from the patients’ performance on the CA test and behavior in the PM test that requires scanning an array of three horizontally arranged stimuli. For each patient we computed the number of responses given to stimuli lying to the right, middle, or left of the patient. Position preference was defined on the basis of a significant difference in number of responses given to the left or right with respect to chance, ascertained through x2 analysis. Two NRH patients did not understand the task and were not given the PM test. Position preference was noted in three NRH patients with left-hemisphere lesions. The NRH of Pair 6 chose only 2 items on his right and 12 on his left (x2(1) = 8.04, p < .Ol) and in the CA test omitted to copy one figure on the right of an array of three figures. The NRH of Pair 12 chose only 4 items on his right and 18 on his left (x2(1) = 8.33, p < .Ol). A third patient, the NRH of Pair 8, had TABLE FREQUENCIES

2

OF OCCURRENCE OF NEUROPSYCHOLOGICAL DISORDERS IN NRH WITH HEMISPHERE LESION (n = 13) AND MATCHED RH CONTROLS

RH

X2

df

P

7

8 6 3 6 12

0.16 6.65 0 0.16 0.295

1 1 1

IIS

4 3 5

NRH Oral apraxia Ideomotor apraxia Apraxia of use Constructional apraxia Acalculia

LEFT

10

1 1

ns ns ns ns

APHASIA

IN LEFT-HANDERS

245

a position preference on the ipsilesional side (4 responses on her left and 13 on her right; x*(l) = 5.42, p < .025). Position preference was also present in four RH controls. The incidence of position preference was not significantly different in NRH and RH patients (x’(l) < 1, ns). STUDY 2 Materials and Methods Subjects From the original group of 24 NRH patients we selected the 15 rehabilitated patients (3 with right- and 12 with left-hemisphere lesion) who had had a second language examination; 9 of these were included in the previous group and 6 were patients for whom comparable RH subjects had not been found. In Table 3, data from the first and second examinations are reported. Recovery could not be studied in nonrehabilitated patients, as in our group only two nonrehabilitated NRH subjects had a second examination. From the original series of 1200 patients we also selected all the patients presenting with the same characteristics as NRHs except for hand preference (minimum score on the Edinburgh Inventory, 9 of 10 items executed with the right hand) (Oldfield, 1971) who had had a second examination at least 5 months after the first and had undergone rehabilitation between the first and second examinations. There were 157 such subjects.

Tests and Procedures The same tests and procedures as those reported for Study 1 were used.

Results Patients were classified as improved when they made a minimum of 1 point of progress on the compound scale, ranging for each modality studied from 0 (no communication) to 4 (very good communication) at the second examination, over their scores on the first examination. For each modality, patients scoring 4 at first examination were excluded from study of recovery in that modality. The numbers of NRH rehabilitated patients with left-hemisphere lesion and RH patients recovered in each modality were compared. Differences were never significant: x’(l) = < 1 for oral production, oral and reading comprehension, and = 1, ns for spontaneous writing. The same was true for recovery in the Token Test: NRH and RH patients at first examination had the same mean score (NRH = 13.6; RH = 13.8). On second examination, comprehension evaluated with Token Test had improved in both groups but not differently: NRH = 19.2, RH = 20.2. The three NRH patients with right-hemisphere lesion were not included in the preceding comparison, as side of lesion can itself be an important factor of recovery. All three patients had improved by the second examination but none totally recovered. Patient 13 (Table 3) had Wernicke’s aphasia 1 month postonset with verbal paraphasias and frequent wordfinding difficulties and mildly impaired comprehension (TT = 26). Six months later, verbal paraphasias had disappeared and word-finding dif-

Sex

M

M

M

M

F

F

M

M

M

Case

1

2

3

4

5

6

7

8

9

85

57

72

31

56

54

42

56

39

Age

6

5

13

17

5

5

7

13

17

Ed. Inv

Fam. Sin.

AND NEUROPSYCHOLOGICAL

School

ANAMNESTIC

I/H

TABLE

3

FTP and deep structures lesion Subcortical lesion involving AL IC, putamen and caudate nucleus Large, mainly anterior, perisylvian lesion Small TPO junction lesion Large anterior T and TPO junction lesion Large FTP and lenticular lesion

Small T operculum

Mainly anterior, perisylvian lesion T and angular gyrus

Site of lesion

69

256

18

16

813

163

17

149

23

On-Ex

Aphasia We

Broca 179 Nonaphasic Wernicke 272 Wernicke Unclassified 450 Wemicke Fluent 397 (unclassified) Conduction

12 16 18 17 4 6 8 10

21

17 20 18 18 18 20 I 5 4 7

OA (16)

54

67 71 31 58 44 45 60

65 72 61 66 68 70 7 24 66 59

IMA (53)

14

14 14 13 14 14 13 12

14 14 14 14 14 14 14 10 14 14

AU (14)

NRH PATIENTS

21 29 unt 9 3 16 17

28 32 13 16 6 13 12 11 24 22

‘IT (29)

OF THE 15 REEXAMINED

Agraphia 208 Mild agraphia Wernicke 360 Wernicke Wernicke 340 Wernicke Global 103 Global Broca 330 Broca

V-2” Ex

(days)

DATA AT FIRST AND SECOND EXAMINATION

65 % 17 58 22 18 43 61

13

32 93 84 97 38 66 unt unt 71 %

AC (74)

17 20 17 15 11 12 8

17 19 17 19 17 19 8 11 11 15

CA (15)

M

M

F

M

M

11

12

13*

14*

15*

42

64

47

70

54

59

5

13

8

13

6

8

2

2

6

-

-

+

H Large FTP lesion extending to deep structures

I Small posterior TP lesion H Small posterior T and trigonal lesion I Large TP lesion

H Large deep structures lesion

I TPO junction lesion

172

43

34

20

98

II5

1900

390

184

573

528

960

Mild alexia + agraphia Mild alexia Mixed-non fluent Broca Unclassified Mild agraphia Wernicke Amnestic Transc. Sensory Wemicke Mixed non fluent Broca (aggrammatism) 23

II 24

17 8 17 26 29 7

28 14

30

17

14 12

12 II 18 18 20 12

20 10

19

25

48 24

65 57 67 68 71 44

62 62

64

14

14 6

14 14 14 14 14 14

14 14

14

8

15 4

16 10 18 18 18 14

19 20

20

35

41 40

55 42 87 72 87 15

101 47

61

Nofe. School, years of schooling; Ed. Inv., Edinburgh Inventory; Fam. Sin., familial sinistrality; I, ischemic; H, hemorragic; On-Ex, onsetexam; I”-2” Ex, first-second exam; *=right hemisphere lesion; TT, Token Test; OA, oral apraxis; IMA, ideomotor apraxia; AU, apraxia of use; CA, constructive apraxia; AC, acalculia; M, male; F, female; +, present; - , absent; F, frontal; T, temporal; P, parietal; 0, occipital; unt, untestable.

M

10

248

BASSO

ET AL.

ficulties were much less frequent but still clearly present. Comprehension was scored as nonpathologic on the Token Test (TT = 29). Patient 14 (Table 3) had transcortical sensory aphasia on first examination, with frequent verbal paraphasias, and was classified as Wemicke aphasic 1 year later on second examination since his comprehension had slightly improved (from 7 to 11 on the Token Test). Patient 15 (Table 3) had a mixed nonfluent aphasia on first examination: his speech output was scarce and made up almost exclusively of cliches devoid of any communicative value; his oral and written comprehension on the Standard Language Examination was definitely impaired but he scored 24 on the Token Test. A second examination was performed 5 years later. His speech output was still scarce and clearly agrammatic but more informative. Comprehension on the Token Test (TT = 23) was unchanged but he performed better on the oral and written comprehension tasks of the Standard Language Examination. He had undergone rehabilitation in the first year or so after the first examination and his wife reported that his language had improved in the first months and then reached a plateau. DISCUSSION

Occurrence

of Apraxia,

Acalculia,

and Neglect

Our data on the frequency of calculation disturbances are in agreement with previous results of HCcaen and Sauguet (1971), who found that disturbances of calculation were equally frequent in NRH and RH patients with left-side lesions. According to these authors, ideomotor praxic symptoms were less frequent and constructive apraxia was more frequent in NRHs than in RHs. In our sample the pattern of disorganization of praxis was indistinguishable between NRH and RH patients with leftside lesions. Position preference did not distinguish between RH and NRH with left-hemisphere lesions. Unilateral spatial neglect (ULN) was not examined specifically and the presence of position preference cannot simply be equated to ULN. However, inasmuch as position preference indicates some form of ULN (Costa, Vaughan, Horwitz, & Ritter, 1969) it was equally present in our left-hemisphere damaged patients with either left or right handedness. ULN has been reported after left-hemisphere lesions (see Ogden 1987, for a review) and also at least two paradoxical cases of ULN on the ipsilesional side have been reported (Costa et al., 1969; Damasio, Damasio, & Chang Chui, 1980). We are not in a position to investigate in depth the relationship between ULN and left-hemisphere lesion, but all that matters for our present purpose is the fact that position preference was not differently present in NRHs and RHs. Recovery It was difficult to find a theoretically correct comparison for studying recovery in NRH. If patients are matched on the basis of lesion site, as

APHASIA

IN LEFT-HANDERS

249

we did in our study on clinical aspects of aphasia, there is no guarantee that the resulting patient pairs will also match in terms of type and severity of aphasia. (However, our data now indicate that the differences may not be so important as previously thought.) If, on the contrary, patients with similar aphasic impairment are compared, these may have lesions in different locations. Type (Kertesz & McCabe, 1977) and severity of aphasia (Basso et al., 1979) and location of lesion (Mohr, Pessin, Finkelstein, Funkestein, Duncan, & Davies, 1978; Brunner, Kornhuber, Seemuller, Surger, & Wallesch, 1982; Ludlow, Rosemberg, Fair, Buck, Schesselman & Salazar, 1986; Naeser, Helm-Estabrooks, Haas, Auerbath, & Srinivasan, 1987) all have been reported to affect recovery, and therefore these comparisons are not defendable on theoretical grounds. We ended up comparing recovery of NRH patients with recovery of a matchable group of RH patients. Right hemisphere. Only three NRH patients (13, 14, 15) with righthemisphere lesions were rehabilitated and given second examinations. They all improved but in no case was improvement striking. Patient 13 had never been severely impaired and 7 months postonset had normal comprehension on the Token Test, with word-finding difficulties in spontaneous speech and in confrontation naming. Patient 14 still had severe Wernicke’s aphasia 14 months postonset and patient 15 was clinically agrammatic 5 years postonset. It is not possible to know whether recovery would have been exactly the same in RH patients with a lefthemisphere lesion, but it is not obvious that they would have improved less. Left-hemisphere lesion. Recovery of the NRHs as a group is not different from recovery of a group of standard RHs, contrary to the reports of Luria (1970) and Subirana (1958). Although we cannot have statistical confidence in our data due to the small number of patients with FS, in our sample FS does not seem to have played an important role in recovery. Of the five patients with FS reexamined, only one (12) had made a remarkable improvement. Aphasia

Profiles

Right-hemisphere lesion. In our group, right-hemisphere lesions are rare and only for one patient (Pair 3) could we find an appropriate RH control; the two patients had very similar language disturbances. Left-hemisphere lesion. In five pairs (1,2,4,5,6) only minor differences of no clinical importance were found. In five more pairs there was a clear difference in the severity of the disorder but not of type of aphasia: three NRH patients (7,10,11) and two RH patients (9,13) were more impaired than their matched patients. The difference was most striking in Pair 13 where the NRH was nonaphasic and the RH patient had conduction aphasia. However, in this case (as well as in the NRH patient

250

BASSO

ET AL.

of Pair 1) this result can be simply explained by right-hemisphere dominance for language in the NRH patient. An opposite dissociation between oral and written production was found in patients of Pair 8, and a difference in the quality of speech output in Pairs 12 and 14. In Pair 12, speech output was more abundant and varied in the RH patient; in Pair 14 the RH patient had no speech output and the NRH had fluent and abundant production. Our data do not permit us to draw any firm conclusions about patients with right-hemisphere lesion, since we had only one such patient for whom we found a comparable RH patient and three who were rehabilitated and had a second examination. Generalizations from such a small number of subjects are not possible but our patients do not differ much from standard RHs. As for NRHs with left-hemisphere lesion, our data are not in accord with the idea that language is more bilaterally represented in NRHs, as this would predict better recovery. Some of our patients seen years after the first examination still had aphasia, severe in some cases. Our results do not confirm this even for the so-called familial group for which bilaterality of representation for language has been considered the rule (Hecaen & Sauguet, 1971). Nor do the data confirm the hypothesis of a different or less-marked intrahemispheric localization for language, since the same type of aphasia was generally found in both RHs and NRHs matched patients. The only striking exception being Pair 14. Previous studies (Gloning et al., 1969; Hecaen & Sauguet, 1971) also reported a similar pattern of disorganization of language for RHs and NRHs with left-hemisphere damage. Our evidence, however, is more compelling as we controlled the site of lesion and most of the factors known to influence type and severity of aphasia. The lesions were not exactly the same in the two patients of a pair and it could be the case that differences between RHs and NRHs in the aphasia profiles are to be explained by differences in Iesion location. It seems, however, more plausible that importance of left-handedness for the functional organization of the brain has been overemphasized in the past. Strong left-handedness is rare and in our study, as well as in previous studies (Gloning et al., 1969; Hecaen & Sauguet, 1971; Newcombe & Ratcliff, 1973), not all of the subjects were strong LHs and this could have reduced the effect of left-handedness. However, when strength of left-handedness has been studied (Hecaen & Sauguet, 1971; Newcombe & Ratcliff, 1973), it was not found to be related to functional hemispheric organization. In this research we considered handedness to be a unidimensional trait which forms a continuous distribution, as is generally assumed. However, if this is not the case and there are independent dimensions of hand preference (Healey, Liederman, & Geschwind, 1986), these would have

APHASIA

251

IN LEFT-HANDERS

to be taken into account when looking for regularities haviors in NRHs with hemispheric damage.

of impaired

be-

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