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Europa Medicophysica 2002 December;38(4):203-213

Copyright © 2002 EDIZIONI MINERVA MEDICA

language: English

Language disorders following lesions to the thalamus and basal ganglia

Fabbro F. ^{1, 2}, Vorano L. ³, Fabbro S. ², Tavano A. ^{1, 2}

¹ Neurolinguistics Unit IRCCS E. Medea, Polo del Friuli Venezia Giulia San Vito al Tagliamento, Italy 2 Division of Physiology Faculty of Education Sciences University of Udine, Udine (Italy) 3 Rehabilitation Medicine Department Physical Medicine and Rehabilitation Institute, Udine (Italy)

We ­present a ­review of ­the lit­er­a­ture on sub­cor­ti­cal apha­sia ­and a fol­low up ­study of ­5 cas­es of sub­cor­ti­cal apha­sia in bilin­gual ­patients. Two cas­es ­involve dam­age to tha­lam­ic ­nuclei, ­while ­the remain­ing 3 main­ly ­involve dam­age to ­the cau­date nucle­us ­and ­the puta­men. Results sug­gest ­that ­the thal­a­mus ­and ­basal gan­glia of ­the ­left hem­is­fere ­may be ­involved in ­some lan­guage func­tions. The ­types of def­i­cits ­showed by tha­lam­ic ­patients impli­cate ­the thal­a­mus in ­voice ­and ­speech pro­duc­tion, sen­tence con­struc­tion ­and lex­i­cal ­access (Cases 1 ­and 2). Patterns of lan­guage recov­ery in ­these bilin­gual ­patients ­vary ­from dif­fe­ren­tial recov­ery (Case 1) to par­allel recov­ery (Case 2). Language dis­or­ders fol­low­ing ­lesions to ­the ­basal gan­glia (espe­cial­ly ­the ­head of ­the cau­date nucle­us ­and ­the puta­men) ­may pro­duce ­severe def­i­cits in com­pre­hen­sion, ­due to impair­ment of mor­pho­log­i­cal ­and syn­tac­tic lev­els (Case 3, ­which ­involved ­also a ­lesion to ­the ­left inter­nal cap­sule). However, mild­er lin­guis­tic def­i­cits ­are ­present ­with a ­main ­lesion to ­the puta­men (Case 4) or an iso­lat­ed ­lesion to ­the ­head of ­the cau­date nucle­us (Case 5). The pat­tern of lan­guage recov­ery ­was par­allel in Cases 3 ­and 5, ­but par­a­dox­i­cal in Case 4, ­where ­the ­patient recov­ered to a great­er ­extent a lan­guage (L2) ­she ­did ­not ­use ­for com­mu­ni­ca­tion. The lin­guis­tic def­i­cits ­observed in ­these ­patients ­are in ­line ­with ­the hypoth­e­sis ­that ­some spe­cif­ic sub­cor­ti­cal struc­tures (thal­a­mus ­and ­basal gan­glia) sub­serve ­some lan­guage func­tions. Therefore, ­these sub­cor­ti­cal struc­tures ­are like­ly to be ­involved in ­the reg­u­la­tion of ­the pho­nem­ic, syn­tac­tic ­and lex­i­cal ­chunks pro­cessed in ­the cere­bral cor­tex.