Hypoglossal neuritis with associated lingual hemiplegia secondary to guttural pouch mycosis.

G uttura l pou ch mycosis In the hor se is a pseudo-membran ous inflammat ion of the di vertieula of the Eustac hian tub es usually caused by Aspergillus species.J.9 Inflammatory changes mostly occur in the dorsal part of the caudo medial co m partme nt of the gutt ural pouch. Th ey frequently ero de the intern al caro tid art ery,"? which passes with the superio r cerv ical ganglion, vaga l, and intern al carotid nerves' caudally along the med ial co mpartme nt. Erosio n of the condylar artcry and cere bral vein, branches of occi pita l artery and vein, may occu r when inflam ma tion is localized dor sally in the ca udomed ial com par tme nt ." Inflammatory processes in the lat eral co mpartme nt can lead to erosion of the maxillary artery: a branch of the externa l carotid artery . Thus, the most freq uen t clinica l sign of gutt ural pouch mycosis is uni lateral epistaxis.' Othe r co mp lications of th is mycoti c infection arc inflam ma tion of the atlanto-occipita l joint ,' > encepha litis ,' and ostei tis of adjacent bones and path ologic fractures of the proximal end of the hyoid bon e.' Ne uro logic com plica tions of gutt ura l pouch mycoses include laryngeal hemiplegia,' ca used by unilateral dener vati on at roph y of the largyngeal mu scles due to degenerati ve lesions o f the vagal nerve. '·J Phar yngeal paralysis also ca n be caused by m ycoti c inflammation of glosso pharyngeal and spina l accesso ry nerves becaus e they pass along the lateral compartment of the gutt ural pouch .' Clinical signs referabl e to the sym pathetic nervous system lesions such as Horn er 's syndrom e, shive ring, swea ting, and colic arc attri buted to invo lvement of the superior cerv ical ganglion.' > Un ilat eral facia l paralysis in connection with erosion of the facial nerve as it passes along the dor sal sur face of the lat eral com partment of the gutt ura l pouch also has been docum ent ed .' > Two cases of dysph agia in the hor se du e to unilateral lingua l hemi plegia are descr ibed . T his conditio n is du e to hypoglossal neuriti s seco nda ry to the guttural pouch mycosis and represent s a previ ou sly unreport ed complication of guttur al pouch mycosi s. Th e first horse, a 12-yearold Standardbred geld ing, had