{'fraction_non_alphanumeric': 0.02247191011235955, 'fraction_numerical': 0.0012484394506866417, 'mean_word_length': 5.416, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Loss of cortical evoked responses due to intracranial gas during posterior fossa craniectomy in the seated position.

Sensory evoked responses (SERs) are frequently monitored to assess the integrity of neural pathways at risk for injury during surgical procedures. To be clinically useful, intraoperative SERs must not only be sufficiently sensitive to detect early injury but should also spare the operating team frequent disruptive false alarms. Because concern has been raised over the occurrence of "false positive" results, i.e., loss of the evoked response waveform in the absence of neurologic injury (1), we call attention to a previously unreported artifactual cause for the loss of the cortical somatosensory evoked potential (SSEP) during posterior fossa craniectomy in the seated position.