Undetected abulic state after anterior communicating artery aneurysm surgery under motor evoked potential (MEP) and somatosensory evoked potential (SEP) monitoring

Intraoperative neurophysiologic monitoring (IONM), including somatosensory evoked potential (SEP), and transcranial electric motor (MEP), had been utilized during brain or spine surgery to identify neurologic deficits. But some deficits, such as abulia, could not be detected through routine IONM. MEP SEP might monitor non-motor sensory lesions surgery. We experienced a 72-year-old case with an anterior communicating aneurysm who abulia after even though IONM was performed. There no abnormality on clipping surgery, but she turned into abulic state. This alerts us the possibility that failure occur despite standard procedures using SEP.