Tongue somatosensory evoked potentials in multiple sclerosis

Objective: Th e aim of this study was to determine the effi cacy of tongue somatosensory evoked potentials (tSSEP) in the evaluation of brainstem involvement in patients with multiple sclerosis (MS). Methods: tSSEP was performed in ten healthy volunteers and 29 patients with fi rst clinical episode of a demyelinating event suggestive of MS. Th e data obtained were compared between the two groups and tSSEP fi ndings of MS patients were correlated with their clinical and magnetic resonance imaging (MRI) data. Results: Multiple sclerosis patients had statistically signifi cant prolongation of N1, P1 and N2 latencies on the left side compared with healthy controls (17.8±3.5 vs. 15.2±1.3, p=0.004; 23.9±3.3 vs. 20.8±1.0, p<0.001; 29.9±4.2 vs. 26.7±2, p=0.01, respectively) and of P1 and N2 on the right side (23.8±3.5 vs. 20.8±1.3, p=0.04; 30.3±3.8 vs. 27.3±1.9, p=0.01, respectively). Out of the 29 MS patients, eight (28%) had clinically evident involvement of the brainstem and 19 (66%) had brainstem lesions demonstrated on brain MRI. Th ere were 19 MS patients with prolonged latencies of tSSEP on either side with no clinical signs of brainstem dysfunction and this diff erence was statistically signifi cant (p<0.0001). Although tSSEP detected brainstem lesions in a higher percentage than MRI, it was not statistically signifi cant (p=0.18). Conclusion: Th is study conducted on a larger number of MS patients confi rmed the usefulness of tSSEP in the evaluation of aff erent trigeminal pathways in MS.