Lexical Errors in Narrative Discourse of A Bilingual Subcortical

Aphasic

Sudheer Bhan *, Sonal V Chitnis**

Hyderabad Central University, India*, Yashoda Hospitals, Hyderabad, India**.

ABSTRACT

Subcortical Aphasia is defined as a language disorder associated with damage to

subcortical brain structures such as basal ganglia, thalamus, and deep white matter pathways.

It is predominantly seen in ischemic strokes patients. Clinical picture of subcortical aphasia is

of great interest to researchers as it varies according to lesion site and is also difficult to

categorize into fluent or nonfluent categories due to its typical speech & language features.

Many studies have focused light on role of subcortical structures in language processing.

Present study analyses lexical errors in narrative discourse of a bilingual (Telugu-English)

speaking subcortical aphasic, following an acute subcortical ischemic stroke. She was

assessed on Western Aphasia Battery (Kertesz 1985, translated Telugu version) and

Addenbrooke’s Cognition examination revised (ACE-R 2007-Telugu version). Results

showed frequent semantic and phonemic paraphasias. Patient reflected a typical subcortical

aphasic syndrome presenting both fluent and nonfluent characteristics of aphasia. In naming

verbs of motion, patient had dynamic misnaming. Empty speech, circumlocution,groping

behavior, semantic confusion, and neologism were also observed.

Lexical Errors in Narrative Discourse of A Bilingual Subcortical Aphasic

INTRODUCTION

Bilingualism or the alternate use of two or more languages is an integral part of

globalization and social mobility. Mcnamara(1967a) proposes a minimal competence in one

or more of the four language skills ,i.e. listening ,comprehension, speaking ,reading ,writing

in a language other than mother tongue. Whether Bilinguals two languages are organized

partly in common areas and partly in specific and separate areas of the brain is not

completely proved. However, some studies have found that bilinguals have areas where

stimulation could interrupt naming in a first language ,a second language or both (Ojemann

and Whitaker,1978) This lends support to the view that each language is processed by

partially overlapping areas.

Paradis(1994) postulated that the mother tongue or L1 and L2 of a bilingual may

rely upon different memory systems. Mother tongue relies upon implicit memory or

procedural memory, which is related to automatic processes, completed within nominal

awareness, whereas L2 depends upon explicit memory or declarative memory, which

involves controlled processes carried out at conscious level. While, implicit memory heavily

relies on subcortical structures like the basal ganglia , the cerebellum as well as left frontal

lobe. Explicit memory relies mainly on widely distributed cortical network (including

bilateral temporal lobe structures). As these memory systems employ different cerebral

pathways, Bilingual’s L1 or L2 may be selectively affected by different pathologies. This

results in different types of recovery patterns in Aphasics.

Aphasia has been classically considered a consequence of cortical lesions. However,

neuroimaging techniques in monolinguals and bilinguals have revealed that aphasia may also

occur after lesions confined to Thalamus, the Basal ganglia or paraventricular white matter.

Such aphasias are known as subcortical aphasia. While, subcortical aphasia in monolinguals

is well known, only few cases of bilingual subcortical aphasia have been reported. Hence,

present study on Lexical errors in Narrative Discourse in Bilingual Aphasic in Indian Context

is relevant.

Subcortical aphasia due to Thalamic lesions is known as thalamic aphasia. This

Syndrome shares some features with Transcortical sensory and tanscortical motor aphasia. A

relatively fluent output with semantic paraphasias and word finding deficits, intact repetition

abilities and spared auditory comprehension are the main features of Thalamic aphasia.

Subcortical aphasia following basal ganglia damage is often characterized by expressive

and Lexico-semantic impairment generally consisting of nonfluent output with semantic and

verbal paraphasias. It is caused by hemorrhages and infarctions. However, pure Subcortical

Aphasias have been rarely reported. Most of the Subcortical Aphasias result from subcortical

as well as cortical region network(e.g. disruption of fronto-Thalamic network). But, lesions

in cortical regions are not usually visible in case of subcortical Aphasia through neuro-

imaging techniques. Present Subject had a left basalganglionic infarct with C.V.A.

The subcortical aphasias can be classified into 3 types:-

1) Aphasia with white matter pathway damage

2) Straiatocapsular aphasia

3) Thalamic aphasia.

Subcortical aphasics might show specific fluent or nonfluent feature. Anterior

subcortical aphasias evolve into motor aphasia, whereas posterior lesions evolve into fluent

aphasias. (Nasar et al., 1982) Repetitions are relatively preserved in subcortical aphasics

(Andrew 2003) Initiation of speech is main problem in subcortical aphasia. Fabbro et al.,

(2001) have reported that lesion in loop of caudate nucleus, globus pallidus, anterior nuclei

anterior with cingulam cause difficulty in initiation of speech.

The introduction of advanced neuroradiological investigation methods for lesion

localization in vivo, including computed tomography and more recently magnetic resonance

imaging (MRI), SPECT, PET have led to an increasing number of reports in the literature of

aphasia following apparently purely subcortical lesions involving the striato-capsular region

and/or thalamus. Consequently, in recent years, there has been growing acceptance of a role

for subcortical structures such as the globus pallidus and thalamus in language processing.

Many lesional studies have reported language disorders following damage of the basal

ganglia in the dominant hemisphere, in particular

speech apraxia and dysarthria after lesion of

the lentiform nucleus and speech perseveration after caudate lesions. Most of these injuries,

especially stroke, involve not only the striatum, but also the surrounding areas such as the

capsulo-thalamic structures. Subcortical aphasia is also evident in patients with Parkinson’s

disease, Huntington’s disease, etc.

REVIEW OF LITERATURE

Alexander (1987) studied 19 subcortical aphasics. He observed that lesions in the

putamen or head of caudate nucleus did not produce language disturbances. They just caused

mild word finding difficulty. Lesions in posterior putamen resulted in hypophonia. Lesion

in caudate nucleus, putamen and anterior limb of internal capsule resulted in anterior

subcortical aphasia. Lesion in white matter of periventricular region or genu of the internal

capsule resulted in dysarthria. Fluent aphasia, neologism, impaired comprehension were

found when there was lesion in basal ganglia converging on the temporal isthemus. Lesions

in insula, internal capsule resulted in fluent aphasia, mild word finding difficulty and

phonemic paraphasia.

Longworth C E. et al (2001) studied the rule governed language use among

subcortical aphasics with Parkinson’s disease and Huntigton’s disease. He reported small

number of repetition, substitution and regularization errors (dug-digged). Mild Parkinson’s

disease patients made relatively few errors - stached – satched- where phonology of the verb

was distorted. Moderate Parkinson’s disease patients had correctly inflected phonological

distortion and lexical intrusion errors for novel words. Mild Huntington’s disease had only

over application of the - ed inflections. Moderate Huntington’s disease group made relatively

few regularization errors and no multiply suffixed errors in their first responses. Results

concluded that subcortical aphasics with basal ganglia dysfunction have intact automatic

processing of syntax in language comprehension into the morpho-syntactic domain.

Metter et al., (1988) focused on subcortical aphasia and role of basal ganglia in

language. Their evidence was derived from CT scan, PET studies on stroke patients.

Interesting findings were that fluency deficits were associated with basal ganglia, thalamus,

internal capsule with deficits in phrase length, variety of grammatical constructions, as well

as presence of jargon, word finding difficulty and circumlocution.

Demeurisse.G (1995) studied the contribution of functional imaging techniques in

subcortical aphasia. He found that sufficient cortical dysfunction gives rise to language

disorders. He also reported evidence of Hypophonia ( loss of volume), reduced verbal output,

jargon speech and phonological disorders.

Mega, Michel et al. (1997) studied 14 patients with aphasia after subcortical lesions

and controlled for duration, general anatomic site of lesions (capsulostriatal only), and

etiology. They found the clinical profiles of the patients were quite similar, varying in

severity in rough proportion to lesion size and varying in quality in proportion to anterior

paraventricular extent. Large lesions were associated with impaired "executive" and

"generative" language functions.

Gurd, J.M. and Bannford, J.M. (1997) studied the cognitive impairment in two

women subcortical aphasics. Both had circumscribed infarcts to the basal ganglia and

internal capsule. The lesion in case 1 extended into the head of the caudate nucleus, whereas

in case 2, it did not. Cognitive recovery was more rapid and complete in the second case,

despite persistent impairment of the right hand. Both cases showed reduced blood flow in the

left basal ganglia and fronto temporal regions at 6 months post onset.

Nadeu, Stephen E & Crosson, B. (1997) in their review of earlier studies found no

aphasia in 17 cases with dominant hemisphere straito capsuler infarction. They came across

almost all patterns of language impairment in 33 reported cases of straito capsular infarction.

It provides strong evidence against a major direct role of the basal ganglia in language and

against disconnection or diachisis as mechanism of non thalamic subcortical aphasia. They

also found that cases of C.V.A leading to straito capsular infarction strongly suggest that

associated linguistic deficits are predominantly related to sustained cortical hypoperfusion

and infarction not visible on structural imaging studies. Thalamic disconnection due to

straito-capsular infarcts with extension to the temporal stem and putamenal hemorrhages may

also contribute to language deficits in some cases. Disruption in attention gating in the

pulvinar and lateral posterior nuclei resulting from such lesions may impair selection of

specific neuronal networks in the projection field of these nuclei that serve as the substance

for lexical semantic function.

Demonet, Jean Fracois et al( 1991) assessed regional cerebral blood flow( r CBF) in

14 subcortical aphasics and 23 normal volunteers. In the subcortical aphasic group, the

severity aphasia score was correlated with rCBF ratios in three left cortical regions and in a

right posterior temporal region. Phonological disorders were associated with a hypoperfusion

in both left and right posterior temporal regions. The rCBF in these homologous regions were

highly correlated and this correlation was more marked in the subcortical patient group than

in the normal group. The study proposes that compensatory neural machanisms in these

interconnected homologous areas account for preserved comprehension capacities in many

cases of subcortical aphasia, especially the thalamic cases.

Aglioti, S et al (1996) reported neuropsychological and neurolinguistic features of a

bilingual subcortical aphasia involving the left basal ganglia. A linguistic deficit in mother

tongue production has been observed in spontaneous speech and in cross-language

translational tasks which require automatized motor and cognitive performance respectively.

She had more difficulties while translating into her second language. The study reflects the

role of basal ganglia in automatized motor and cognitive performance.

RELEVANCE OF STUDY

Since there are very few studies carried out on subcortical aphasia in India in general

and in Telugu language in particular. Hence present study – a single case study will shed

more light on lexical errors in subcortical aphasia in Telugu-English biligual at narrative

discourse level.

OBJECTIVES OF STUDY

To study the lexical error patterns in the narrative discourse of Telugu-English

subcortical aphasic.

METHODOLOGY:-

Subject - M, a 67 yr old is a right handed Telugu English bilingual woman. She was

found unconscious in bathroom following cerebro-vascular stroke. She was shifted to NIMS

hospitals, Hyderabad . Neurological examination revealed disorientation, loss of speech and

complete right sided hemiplegia with facial deviation. M had always been healthy,. She was

a social worker with graduate level education . She was proficient in both Telugu and

English languages. She had no H/o diabetes, hypertension, CVA. She regained her

consciousness after 2 hrs in hospital. During hospitalization, the patient manifested

hypersomnia, disorientation in time and space, mental slowness and loss of speech and

memory. She was severely nonfluent and could answer in just yes or no.

MRI revealed left basalganglionic infarct with CVA.

EEG showed generalized slowing of electrical activity.

After 4 days, patient became stable, oriented and thus discharged. Later she was

shifted to Nursing Home, Hyderabad for further rehabilitative measures. Memory, speech

and language deficits were still persistent. She had good comprehension, but verbal

expression was impaired. She was referred for speech therapy after 15days post stroke .

Speech and language evaluation findings 15 days post stroke :

WAB (Western Aphasia Battery): -

Spontaneous speech- 6/20

(Information Content-3, fluency-3- low volume jargon, mumbling, empty speech and certain

times automatic sentences e.g. “what’s that, don’t know”

Comprehension-58/60

Repitition-74/100

Naming-14/100

Speech was hypophonic. Max phonation duration was 4 sec. AMR (alternate motor rate)-

5syllables per second .SMR (Sequential motor rate)-2sec. Perseverations and phoneme

reversal pattern were predominantly observed in her speech.

ACE-R (Addenbrooke’s cognition examination) revealed impaired attention, concentration,

impaired working memory with short term memory deficits, very poor verbal fluency.

Reading was relatively preserved .

Orientation:- 4/10

Registration: - 3/3

Memory recall:- 0/3

Attention & concentration: - 1/5

Anterograde memory: - 2/7

Retrograde memory: - 2/4

Verbal fluency:- Letter fluency- 1/7

Fluency for generating names of animals:- 1/7

3stage command:- 2/3

Reading: - 1/1

Writing: - 0/1

Language: - Naming: 4/12

Comprehension:- 4/4

Repetition: - 2/2

Reading: - ½

Visuospatial skills: clock = 2

Pentagon= 1

Visuoperceptual skills: 4/4

Delayed recall: 0/7

Recognition:- 2/7

MMSE~ 14/30

ACE-R ~36/10

RESULTS AND DISCUSSION

Following are the error patterns seen in the language of Bilingual (Telugu + English)

subcortical Aphasic

Phonemic paraphasias

1./Pasapu/ - /parapu/

(“turmeric”)

2. /tala/ - / talapu/

‘head’ ‘lock’

3. /bred/ - /bed/

‘bread’

4. Ceyi – teyi

‘hand’

5. WƆts – WƆk

‘watch’

6. Kʌtʌpa – kʌdʌpʌ

7. Pustakam – u: stakam

‘book’

8. /Pilichkuntaru/ – /tilichikuntaru/

‘to inhale/ blow the air’

9./ kostunaru/ or /kʌt cestunaru/ – /kotcestunaru/

10. /gontu/ – /ghantamu/

‘throat’

11. /aratipandu/ – / atripandu/

‘banana’

M had several phonemic paraphasics in her speech. She substituted one phoneme for another

[1, 2, 5, 6, 8], deleted initial phonemes in a word [7], deleted one of the phonemes from a

consonant cluster [7], added an extra syllable to the target stimulus [2, 10]. Metathesis too

was seen in two instances [11]. In (10), she wanted to say Kʌnthamu; another name for

gontu, but due to articulatory difficulty, she produced ‘ghantamu”, She also blended the form

for verb ‘cut’ (koyi) in telugu with same form in English. Hence, came out with a word

kotcestunaru [9]

Neologisms

Neologisms are totally new words produced by an aphasic in response to a target stimulus.

They are not part of her native language

13. /table/- /ye sak sak/

14 . /ball/– dishti pandu ( semantic neologism)

15. /boy/ - / misen/

16. /Addʌm/ —/denti pula/

‘Mirror’

When asked to describe a picture based on Boston diagnostic aphasia examination,

she named a boy standing on a stool and trying to reach sweet box on upper shelf as misen.

She named /dishti pandu/ for ball( 14) and /ye sak sak/ for table [15] a clear example of

neologism. For /addʌm/, she named denlipula, again a neologism.(16). Later she came with

target word- table as ‘pable’ an instance of phonemic paraphasia.

Semantic paraphasias

17./ iddaru pillalu/ (two children) — /rendu pillalu/ (two children)

(animate) (inanimate)

18./ ba:tu/ (duck) --- /pilla:/ (child)

19./addʌm/ (mirror)—/pennu/ (pen)

20. /ten nunchi/---/ ten nundi/

21. /yellow/—/blu ‘blue’/

M named /rendu/ ‘two’ instead of/ iddaru/ ‘two’ however, in telugu language, iddaru ‘two’ is

used for animate objects like children, whereas /rendu/ is used only for inanimate beings

,this reflects that M is not able to differentiate between animate and inanimate terms (17)

similarly, she uttered nundi ‘from this (place)’ in place of nunci ‘from this (numeral etc). It

again reflects that she is not able to differentiate these two case relations, referring to place

and thing [20] .In (19) & (21), M named semantically unrelated paraphasia for the target

stimulus.

M named pilla( ‘child’) for batu( ‘duck’) probably, she was referring to young one of a duck,

but could not name it. However, when investigator provided a phonemic cue |d| in English,

she was able to name duck.

Dynamic misnaming

(22) gali patam egrestunnadu – gali (air) ….. ‘gali patam cestunadu’

‘(He) is flying a kite’ ‘is doing a kite’

(23) gali pilichkuntadu – gali tilicukuntadu

‘He is blowing the air’ ‘air + phonemic paraphasia

(balloon)

(24) palu pongya:i – palu khinda padipoindi

‘The milk spilt’ ‘The milk fell down’

M named first air with phonemic error in verb naming and then ‘is doing kite’ instead of

flying kite(. ) .Here, she has uttered a general verb for a specific one [22]. Similar phenomena

was seen in (23). In (24) she simplified the verb-spilling with falling down.

Empty Speech

(26) ekkada untaru miru – umm, edo untanu

“where do you live” “umm, I am somewhere”

(27) abba:yi emi chestunnadu – edo padipotuna:ru khinda

“what is the boy doing” “something is falling down”

(28) ekkad emi jaragutondi – adi adi

“What is happening here” “that that”

(29) aavida emi cestundi – edo ra:stundi, va:l amma edo

postundi

� ‘what is she doing’ ‘something (she is) applying, something she’s

Pouring ‘

When shown a B.D.A.E picture, where a boy is likely to fall down from a stool, M named

edo ‘something’ is falling down instead of evaro ‘someone’ [animate] is falling down. This

indicates that she is not able to differentiate lexemes for animate and inanimate terms (27). In

(26), instead of naming the place, where she exists, M uttered empty speech expression –e:do

‘somewhere’. In (29), where M was shown a picture revealing “a mother giving bath to a

child”, M just said that mother is applying something to the child and pouring something, but

could not name actual verb ‘bathing’ and object – soap. A similar empty speech phenomenon

was also observed in (28).

Groping behaviour

(30) Wal ekkada unnaru – pa ……… ba …. intlo unnaru

‘where do they live’

…a…………. Amerika [after priming( phonemic cue)]

(31) ivala emi tinna:ru miru – beds n a: ….. ba

‘what did you eat today’ - beds n … a: …ba

(32) din emi antaru – --------- okka … cinna illu

‘What do you call that’ – ‘one …… small house’

When investigator asked M about her children, she had severe word finding difficulty. After

great struggle, she said – ‘they are in the house’, whereas the reality is that ‘they (children)

reside in U.S.A (Amerika). However, when investigator prompted her with a phonemic cue –

a.a.., she finally named amerika [30]. She could not name completely her breakfast stuff and

had to grope about a lot. Finally, she named half way [31]. Similar behavior was seen in (32)

too. Groping behaviour is a universal phenomenon across all subcortical aphasics in their

speech. It reflects their severe word finding difficulty.

Irrelevant jargon

(33) Kichan lo unnaru, vastu tisko pote tisko potunnaru, chesko pote chesko potunnaru….

“she is in the kitchen. Having taken a thing, takes it away, having done ,doing it….”. In this

instance, M uttered a sentence, which was not relevant to the context.

Semantic confusion

(34) gajulu ekkada veskuntaru – kaluki – cetaki

‘where do you put on bangles’ ‘to feet – to hands”

(35) gajulu – golsu

‘bangles’ ‘necklace’

Instance (34) reveals that M was not able to name ‘arms’ for wearing bangles. Instead, she

named both – hands and feet., which indicates severe semantic confusion. Similarly, she

could not differentiate bangles and necklace and named later for former [35]

Circumlocution

(35) em custunaru - bel pamp undi

‘What do you see (in the picture)’ ‘There is a pump, (for filling air) in the bel’

When shown a picture, where a boy is blowing balloons, she named that there is a pump for

filling air in the balloon and named bel for baloon. Pump was not shown in the picture.

Probably, she was trying to provide function of pump for a balloon and thus circumlocuting.

(36) kurgajalu kostaru , dintoti – metiki, ceyidani ki

‘With what you cut the vegetables’ ‘ it is the one, with which we do {meti-neologism}

When asked to name with what we cut vegetables, she uttered is it the one, with which we

cut – meti.. In this instance, she named ‘doing’ instead of ‘cutting’ – a general verb for a

specific one. It is an example of dynamic misnaming. At the same time, she was unable to

name target stimulus katti ‘knife’ and provided a neologism in its place.

Repetition

(37) rayatu polani duntunadu – polani duntunadu

“The farmer is ploughing the field” “ploughing the field”

(38) atanu tiragi ravandam ledu – tiragi ravadam ledu

‘He did not return back’ ‘did not return back’

(39) merisevi anni bangaram kadu – merisevi bangaram kadu

“all that glitters is not gold” “glitters is not gold”

(40) indradhanasu - indra dhanu

M could not repeat four syllable words, as reflected in (40). She also deleted the subject,

while repeating longer sentences [37, 38, 39]. In another instance, she repeated debbai

moodu ‘seventy three’ as lekbai mudu” neologism + three”.. Hence, she produced a

neologism.

LIMITATIONS OF THE STUDY:

Since present study is a single case study based on limited narrative discourse, it doesn’t

reveal all linguistic impairments in subcortical aphasics. In future, a further study based on

several subjects and larger data can focus on the language impairment in subcortical

aphasics at a larger level. As in presented case, functional MRI, SPECT could not be done, so

mechanism of Diaschisis and cortical hypoperfusion remains questionable. Further studies

based on neuroradiological aspects will make these mechanisms clear.

CONCLUSION:-

Semantic and phonemic paraphasias were frequently observed in present study. The patient is

a typical subcortical aphasic, reflecting both nonfluent and fluent characteristics of aphasia.

In naming verbs of motion, patient had dynamic misnaming. Patient’s speech also shows

empty speech, circumlocutions, and semantic confusion. These are reflective of word finding

difficulty in her speech. The patient deleted initial subject of the sentence, while repeating

longer sentences.

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ACKNOWLEDGEMENT

We thank sincerely Dr A. Suvarna, Associate Professor, NIMS Hospital, Hyderabad, for

providing subject and also for her kind support and guidance.

We also thank Dr Jaydip Ray Choudhary, HOD Neurology, Yashoda Hospitals,Somajiguda,

Hyderabad for his valuable suggestions and inspiration.