J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.51.3.367 on 1 March 1988. Downloaded from Journal of Neurology, Neurosurgery, and Psychiatry 1988;51:367-373 On the neurolinguistic nature of language abnormalities in Huntington's disease CLAUS-W. WALLESCH, ROSE A FEHRENBACH From the Departments ofNeurology, University ofFreiburg and University of Ulm, Federal Republic of Germany SUMMARY Spontaneous language of 18 patients suffering from Huntington's disease and 15 dys- arthric controls suffering from Friedreich's ataxia were investigated. In addition, language functions in various modalities were assessed with the Aachen Aphasia Test (AAT). The Huntington patients exhibited deficits in the syntactical complexity of spontaneous speech and in the Token Test, con- frontation naming, and language comprehension subtests of the AAT, which are interpreted as resulting from their dementia. Errors affecting word access mechanisms and production of syn- tactical structures as such were not encountered. A participation of the basal ganglia not only in artic- striatum,8 whereas at least "the early brunt of Hunt- Protected by copyright. ulatory motor but also in language functions has ington's disease" seems to fall of the caudate repeatedly been proposed (for a review, see ref 1), and nucleus,9 thus rather affecting the "complex" than the aphasia with vascular lesions of the left caudate and "motor" loop.'0 lenticular nuclei has been reported in a number of The main reason for our decision to investigate cases.2 5 language functions in Huntington's chorea was that If, however, the basal ganglia were indeed crucial in basal ganglia diseases lead to dysarthria in most language production, as has been stated by Brunner cases, the consequences of which upon language et al,2 then degenerative diseases should also result in production have to be taken into account. The effects language deficits, and, ifthey were involved in linguis- upon communication of mainly hyperkinetic dys- tic processes, their chronic pathology should lead to arthria in Huntington's disease and of cerebellar dys- abnormalities of phonological, lexical and/or syn- arthria in Friedreich's ataxia are quite similar (for a tactical aspects. If, on the other hand, only motor6 or detailed description of these dysarthnas, see ref 11). motor and behavioural7 aspects of the use of lan- Both are chronic, inherited diseases which lead to a guage were concerned, these linguistic features should slowly progressive motor speech impairment. Other adapt in a rule-governed and systematic way to the than in Huntington's disease, impairments of higher nonlinguistic impairment. mental functions in Friedreich's ataxia are only mild http://jnnp.bmj.com/ The aim of the present study was to analyse the and seem to affect almost exclusively nonverbal linguistic aspects of verbal behaviour in chronic basal aspects. 12 13 Deficits of language functions other than ganglia disease. Although Parkinson's disease proba- the consequences of dysarthria4 have not been bly constitutes a more exact model of chronic basal reported in Friedreich's ataxia. ganglia pathology,8 we chose to investigate the effects The pathology in Huntington's disease is not of Huntington's disease upon language behaviour. It confined to the basal ganglia, but also involves the has been pointed out that Parkinsonian patients may cerebral cortex. Therefore, deficits found in Hunt- suffer from a rather selective functional striatal ington patients cannot be unequivocally related to on September 26, 2021 by guest. dopamine deficit confined to the putaminal motor striatal dysfunction. On the other hand, if certain lin- guistic processes were found to be spared in Hunt- ington's disease, these may be considered as rather independent of basal ganglia functions. In a recent Address for reprint requests: Dr C W Wallesch, Department of review of the literature7 it has indeed been proposed Neurology, Hansastr. 9, D-7800 Freiburg FRG. that linguistic functions proper such as word form Received 19 May 1987 and in revised form 14 October 1987. access and production of sentence frames are not Accepted 19 October 1987 affected by basal ganglia disease. 367 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.51.3.367 on 1 March 1988. Downloaded from 368 Wallesch, Fehrenbach Patients propositionally relevant linguistic units and was not redundant. The parameter words/UI therefore gives an Eighteen patients suffering from Huntington's disease (nine estimate of the density of information contained in a male, nine female; mean age 41-8 yr (SD 9 1); mean age at message. manifestation 35 8 yr (SD 7 7) were included. The diagnosis perseverative errors: Any repetitions of productions (pho- was made on the basis of the clinical findings and the family nemes, words, phrase fragments and phrases) were included. history. Five patients were still at work, five lived in phonemic paraphasias psychiatric institutions, one in a home for aged and disabled semantic paraphasias persons, and the others within their families. Eleven patients neologisms received regular medication with tiapride-HCl and four a stereotypies neuroleptic drug in addition. On the basis of the Shoulson- (for definitions ofparaphasias, neologisms, and stereotypies, Fahn rating scale15 10 patients were rated as early Hunt- see Huber et al."9 ington's disease (scores 1-2, mean age 37-2 yr, SD 59) and t-icht nntientq qq qrIvqnrPdf tqrnre 7.-I mi-nn :nai 217-f vr SD9-4. (B) Syntactical structure The Friiedreich patients consisted of 15 subjects (four sentences: A sentence was defined as a linguistically inde- female, 11 male; mean age 42-4 yr (SD 11-6); mean duration pendent structure without syntactical relations with a super- of illness 2!3-4 yr (SD 18-8)). The diagnosis was made on the ordinate form. basis of cllinical 16-18 subordinate clauses criteria and positive family history. discontinuedsentences: sentences broken off and remaining Eight patients were still employed, two ofthese in a sheltered rammatinued incomplete workshop. All patients lived with their families. Patients grammatically incomplete with a visujal acuity of less than 0-5 had been excluded. agrammatical errors: defined as missing syntactical ele- ments Methods paragrammatical errors: defined as erroneous or incongru- ous syntactical elements. Language,assessment consisted of a detailed linguistic anal- For an analysis of grammatical complexity of sentence ysis of spcrntaneous language productions in an interview productions an immediate constituent analysis was per-Protected by copyright. concerning the topics of the course of illness, personal, fam- formed.1 This type of analysis is based on the assumption that sentences are ily and professional history and of the Aachen Aphasia number of hierarchicalhierarchicallylevels necessaryorganisedto derivestructures.the surfaceThe Test. 19 20 1 completely structure of the sentence was scored (fig). Subordinate clau- ses were analysed as separate sentences. (1) LINGU ISTIC ANALYSIS (2)THE AACHEN APHASIA TEST20 (AAT) The follow were included: The Aachen Aphasia Test19 was specifically constructed iing parameters for the assessment of aphasic patients. On the basis of this (A) Phonoological and semantic structure test patients with language abnormalities can be discrimi- syllables nated from normals, but whether the language deficit is words: w4ord classes (nouns, full verbs, auxiliary verbs, aphasic in nature or not cannot be decided without further modal verbs, adjectives, participles, adverbs, pronouns, information. prepo:sitions, conjunctions, articles) The AAT consists of an analysis of the patients spontane- pauses: A rpause was required to exceed 2 seconds and not to ous language productions (the levels of communicative be situated at phrase boundaries. behaviour, articulation and prosody, automatised language, units of in]o'ormation (UI): A UI was defined as a word or semantic, phonologic, and syntactic structure which are group of words necessary for the message contained in scored on scales of 0-5), the Token Test in the version of a state ment-.enwhichwiccouldoudnototbbe subdividedsbdvieditosmllrinto smaller Orgass,22 repetition of phonemes, words and sentences, http://jnnp.bmj.com/ written language (reading aloud and writing and word and sentence assembly to dictation), confrontation naming (including description of action pictures) and a multiple Levels Sentence choice task for comprehension of spoken and written lan- guage. The scores can be transformed into percentile ranks and scores. Noun phrase Verbphrase Thus, two quite different approaches towards assessment II /' \\ ~ / ~\ of linguistic performance were employed. The linguistic Article Noun Verb Object analysis of spontaneous speech aims at a description of the on September 26, 2021 by guest. / \ use of language within the context ofactual communication, III Article Noun whereas in the AAT aspects of language behaviour are iso- lated by the introduction of artificial situations such as con- frontation naming and repetition. As the deficits resulting The girl buys a dress from various language disorders affect the use of language in The sente?nce is organised in three levels spontaneous speech and in formal test situations quite differently, inclusion of both types ofassessment was consid- Fig Examiple ofimmediate constituent analysis. ered imperative for the analysis of linguistic functions the The sentenc7e is organised in three levels. present study aimed at. J Neurol Neurosurg