We describe a patient with sporadic amyotrophic lateral sclerosis (ALS) who showed progressive deterioration of sensory cortex excitability at the advanced stage, while using invasive ventilation. At the time of diagnosis, the patient showed enlarged N20 of the median nerve somatosensory evoked potential (SEP). Following ventilator use through tracheostomy, the patient gradually fell into a totally locked-in state for four years and the N20 showed progressive deterioration in the amplitude, which finally led to its loss. Magnetic resonance imaging (MRI) showed frontotemporal and mild parietal cortex atrophy, subcortical white matter hyperintensity and brainstem atrophy suggesting the involvement of the central sensory pathways. MRI and flash visual evoked potentials revealed that the occipital lobe was well-preserved throughout the course of the disease. This is the first case report of a physiological demonstration of multisystem neurodegeneration involving the central sensory pathway in a patient with advanced ALS and invasive ventilation use.
Keywords: Amyotrophic lateral sclerosis; MRI; somatosensory evoked potential; totally locked-in state.