Neurology International 2012; volume 4:e6

Thalamic semantic paralexia mented with only mild slowing in her (family corroboration). Cerebrovascular risk Correspondence: Michael Hoffmann, Stroke factors included a significant smoking history Center, James A. Haley VA Hospital, 13000 Bruce Michael Hoffmann and on investigation hyperhomocyteinemia B Downs Blvd, Tampa, FL, 33612, USA. Department of Neurology, Stroke Center, (15.6 mmol/L). Within 4 days, the reading dif- Tel. +1.813.9722000-7633 - Fax: +1.813.9785995. James A. Haley VA Hospital, Tampa and ficulty had normalized but she remained with E-mail: [email protected] University of Central Florida, Orlando, mild speech dysfluency, right hand ideomotor Key words: thalamic stroke, paralexia. FL, USA apraxia and developed a Dejerine Roussey or post stroke thalamic pain syndrome. Received for publication: 19 August 2011. Revision received: 15 February 2012. Neuroimaging Accepted for publication: 23 February 2012. Abstract Multimodality magnetic resonance imaging This work is licensed under a Creative Commons Investigations revealed a left lateral posterior Attribution NonCommercial 3.0 License (CC BY- Alexia may be divided into different sub- thalamic infarct, well circumscribed on T2 NC 3.0). types, with semantic paralexia being particu- weighted and diffusion weighted imaging larly rare. A 57 year old woman with a discreet without other parenchymal lesion ©Copyright M. Hoffmann , 2012 left thalamic stroke and semantic paralexia is (Figure 1). Magnetic resonance angiography Licensee PAGEPress, Italy described. Language evalution with the Boston revealed a left internal carotid artery stenosis Neurology International 2012; 4:e6 Diagnostic Battery confirmed the graded 50-74% and basilar artery fenestration. doi:10.4081/ni.2012.e6 semantic paralexia (deep alexia). Multimo - dality magnetic resonance imaging brain scan- Cognitive testing ning excluded other cerebral lesions. A good In view of the isolated reading impairment, recovery sequences for covert white matter recovery ensued. additional psychometric examination was per- lesions and gradient echo sequences to formed on day 3 after the stroke onset, with exclude minor hemorrhagic lesions, implicat- The Boston Diagnostic Aphasia Examination ed theonly thalamic lesion alone as the critical lesion in the syndrome described. Although not Introduction (Third Edition - short form).7 In addition, the test for semantic paralexia prone words were a routine stroke investigative tool, functional tested with the standard version of the Boston magnetic imaging (f-MRI) would have been an The acquired alexias may be categorized Diagnostic Aphasia Examination (versionuse III) important additional neuroimaging modality to into posterior, anterior, central and deep alexi- (Table 1). In comparison to normative data, 1 as. Analagous to semantic paraphasias, notable deficiencies were noted only in speech semantic paralexias constitute the substitu- Table 1. Boston diagnostic aphasia test - fluency, articulation, oral word and sentence version III. tion of content related words during reading. reading, picture word matching and writing. Unlike the analogous subcortical Subtests % such as thalamic aphasia, subcortical syn- Fluency dromes of alexia have rarely been described.2-5 Phrase length 30 This report depicts a patient with thalamic Discussion Melodic line 60 alexia with features of deep alexia (or paralex- Grammatical form 70 Conversation expository speech 100 ia), the latter which has not been described The commonly referred to syndromic classi- after review of the English based literature. Auditory comprehension fication of Benson and Geschwind of posterior Basic word discrimination 100 alexia (alexia without ), central alex- Commands 100 ia (alexia with agraphia), anterior alexia Complex ideational material 100 Case Report (alexia in association with expressive dyspha- Articulation (agility) 70 sia) and deep (primarily semantic Recitation (automatized sequences) 100 paralexia disorder) aptly describes most Repetition Index patient Non-commercialacquired reading deficiencies.1 Alexia second- Words 60 A 57 year old white, right handed, English ary to isolated thalamic lesion has not been Sentences 100 speaking woman with 13 years of education, reported other than in combination with left Naming presented to our stroke center with mild right occipital lesions, the latter lesions the usual Responsive naming 100 sided numbness and weakness (graded +4/5 focus.8,9 Semantic paralexia due to thalamic Boston naming test 100 Special categories 100 lesions has not been reported previously with Medical Research Council grading scale) with Paraphasia 100 the family reporting transient confused con- neuroanatomical lesions mostly referred to as Reading large perisylvian10-12 and even right hemi- versation and speech difficulty. The clinical Matching case and scripts 100 evaluation at our center encompasses a cogni- sphere lesions implicated.13 Similar to subcor- Number matching 100 tive screening evaluation in all patients fol- tical aphasias, the subcortical (thalamic) alex- Picture word matching 40 lowed by psychometric assessment in selected ia reported here is characterized by atypical Oral word reading 40 patients described in detail elsewhere.6 No alexia syndrome components. These include Oral sentence reading 80 dysnomia was documented. Specifically visual relatively mild deficit, transience, a mixture of Oral sentence comprehension 100 acuity and visual fields were normal and there syndromic components with rapid recovery.1 Sentence/paragraph 100 Comprehension 100 was no object , dyschromatopsia, The lack of hemispheric lesions on magnetic Wiriting , finger agnosia, right left disorien- resonance imaging using standard T2 weight- Form 20 tation, or hemineglect syndrome. The substitu- ed images diffusion weighted imaging for Letter choice 40 tion of semantically related words was docu- infarct exclusion, fluid attenuation inversion Motor facility 40

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Alexia without agraphia associated with spleniogeniculate infarction. Neurology 1991;41:587-8. 6. Hoffmann M. Higher cortical function deficits after stroke: an analysis of 1000 patients from a dedicated cognitive stroke registry. Neurorehabil Neural Repair 2001;15:113-27. 7. Goodlglass H, Kaplan E, Barresi B. Boston diagnostic aphasia examination (third edition). Philadelphia: Lipincott Williams and Wilkins; 2001. 8. Michel F, Schott M, Boucher M, Kopp N. Anatomical and clinical correlations in a case of alexia without agraphia. Rev Neurol 1979;135:347-64. 9. Araki S, Kawamura M, Isono O, et al. Reading and writing in cases of Localized infarction of the left anterior . No To Shinkei 1990;42:65-72. Figure 1. Left thalamic infarct depicted on diffusion weighted and T2 weighted magnetic 10. Marin OSM. CAT scans of five deep dyslex- resonance scan (arrows). ic patients. In: Coltheart M, Patterson K, Marshall JC. Deep Dyslexia. London: Routledge and Kegan Paul; 1980. pp 407- 411. assess whether the right hemisphere had or Philadelphia: FA Davis Company; 1983. pp 11.only Marshall JC, Newcombe F. Synctatic and had not played a role. However, the rapidity of 193-238. semantic errors in paralexia. Neuropsy - recovery precluded functional magnetic imag- 2. Tamhankar MA, Coslett HB, Fisher MJ, et chologia 1966;4:169-76. ing, that may have helped ascertain whether al. Alexia without agraphia followign biop- 12. Marshall JC, Newcombe F. Patterns of right hemisphere linguistic processing was sy of a left thalamic tumor. Pediatruse Neurol paralexia - a psycholinguistic approach. J operative, the contemporary hypothesis of 2004;30:140-2. Psychol Res 1973;2:175-99. semantic paralexia.14 3. Maeshima S, Osawa A, Sujino K, et al. 13. Henderson VW, Alexander MP, Naeser MA. Pure alexia caused by separate lesions of Right thalamic injury, impaired visuospa- the splenium and optic radiation. J Neurol tial perception and alexia. Neurology 2011;258:223-6. 1982;32:235-40. References 4. Crosson B. Subcortical mechanisms in 14. Goodglass H, Lindfield KC, Alexander MP. language: lexical-semantic mechanisms Semantic capacities of the right hemi- 1. Benson DF, Geschwind N. Aphasia and and the thalamus. Brain Cogn sphere as seen in two cases of pure word related disorders: a clinical approach. In: 1999;40:414-38. blindness. J Psycholinguist Res 2000;29: Mesulam MM. Behavioral Neurology. 5. Stommel EW, Friedman RJ, Reeves AG. 399-422.

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