Tongue deviation in acute ischaemic stroke: A study of supranuclear twelfth cranial nerve palsy in 300 stroke patients

It is generally believed that the supranuclear innervation of the hypogloss al nucleus is bilateral and symmetrical. The aim of this work is to study t he frequency and clinical characteristics of supranuclear tongue palsy in u nilateral stroke. 300 patients with acute unilateral ischaemic motor stroke s (excluding those in the lower brainstem) and an equal number of normal co ntrols were studied for the presence of tongue deviation in a standardised manner. 29% of stroke patients and 5% of controls had tongue deviation (p<0 .00001). Deviation was always to the side of the limb weakness. In patients with a history of stroke, it occurred more frequently in those with previo us stroke on the contralateral side. Tongue deviation was most common in pa tients with clinical features of the nonlacunar stroke subtype (56%) or in those with cortical or large subcortical infarctions on brain CT scan (55 a nd 45%, respectively). All tongue deviations were associated with supranucl ear 7th nerve palsy. Dysphagia and dysarthria occurred in 43 and 90% of pat ients with tongue deviation. Weakness of the arm was significantly associat ed with presence of tongue deviation. Tongue deviation in unilateral stroke most likely results from asymmetrical supranuclear control of the 12th cra nial nerve in many individuals. The finding that it occurs relatively commo nly in large (non-lacunar) infarcts and its association with dysphagia may have clinical utility, Copyright (C) 2000 S. Karger AG. Basel.