Isolated dysarthria due to hypoglossal palsy caused by supratentorial ischemic stroke: Radiological and electropsyological analysis

Abstract

Objectives: Isolated dysarthria caused by stroke is a rare condition and generally seen in infratentorial lesions, especially in cerebellar lesions. Isolated dysarthria associated with supratentorial ischemic lesions are also very rare and, these conditions were shown in only a few cases. In this study, six patients characterized by IHP due to supratentorial ischemic lesions are presented.

Patients and methods: Physical examinations of patients were done by two different neurologists. The risk factors for stroke were determined. Localisations of lesions were identified by using magnetic resonance images(MRI). Corticolingual tract affection without sensorial and other corticospinal tract involvement was confirmed using Somatosensory evoked potentials(SEPs) and Transcranial Magnetic Stimulation(TMS).

Results: Unilateral lingual paresis was detected in all of the patients. The lesions were demonstrated on MRI slices. All lesions were on the same localization. The affection of the corticolingual tract without any other motor and sensory tract involvement was proven electrophysiologically.

Conclusion: Corticospinal and corticobulbar fibers are very close to each other. Therefore common involvement is expected in cerebrovascular diseases. However, six patients with IHP caused by supratentorial ischemic lesions were reported in this study. Thus, a possible map of the corticolingual tract was drawn.

Keywords: Corticolingual tract; Isolated central hypoglossal palsy; Lacunar stroke; Motor evoked potential.