Electrophysiological assessment in patients with Möbius syndrome and clumsiness

The authors studied the nature of clumsiness in Möbius syndrome in terms of motor or sensory deficits, and sought to clarify the pathophysiological mechanism of the syndrome. Standardized electrophysiologic studies were conducted, with special emphasis on the long motor and sensory tracts and peripheral nerves, in seven Möbius patients with clumsiness, of whom six participated in MRI studies; five of them showing brainstem hypoplasia. All performed motor-evoked potentials were normal. In all patients, normal somatosensory-evoked potentials were recorded and peripheral nerve conduction assessment revealed no abnormalities. The electrophysiologic data indicate that the traversing motor and sensory tracts through the brainstem, and the peripheral nerves are not affected in Möbius syndrome.