Medical Necessity Determination for Intraoperative Neurophysiological Monitoring Codes
Direct Answer
Codes 95939 (MEP) and 95938 (SSEP) are medically indicated for this patient with documented cervical spondylotic myelopathy (M47.12) with myelomalacia and critical canal stenosis undergoing multilevel anterior cervical discectomy and fusion. However, codes 95955 (intraoperative EEG), 95861 (needle EMG), and 95941 (continuous remote monitoring) are NOT medically indicated for this procedure. 1, 2
Codes That ARE Medically Indicated
CPT 95939 (Motor Evoked Potentials) and 95938 (Somatosensory Evoked Potentials)
These codes meet medical necessity criteria based on the following:
The American Association of Neurological Surgeons guidelines explicitly state that IONM may be justified during cervical spine surgery when there is severe cord compression with documented myelopathy. 2 This patient has documented myelomalacia within the spinal cord and critical canal stenosis, which qualifies as severe cord compression with myelopathy.
Multimodal monitoring combining MEPs and SSEPs is the recommended approach for cervical myelopathy cases, with MEP monitoring showing greater utility than SSEP alone for detecting neurological injury during cervical decompression in myelopathic patients. 2
IONM has demonstrated 84.2% sensitivity and 93.7% specificity for detecting neurological complications in cases with severe cord compression and myelopathy. 2
The presence of myelomalacia represents a high-risk condition where IONM has demonstrated clinical utility in detecting neurological complications and potentially improving outcomes. 2
Codes That Are NOT Medically Indicated
CPT 95955 (Intraoperative EEG)
This code is NOT medically indicated because:
EEG monitoring during cervical spine surgery lacks evidence of clinical benefit and is considered unproven according to evidence-based guidelines. 1
Intraoperative EEG is only considered medically necessary for monitoring cerebral function during carotid artery surgery, intracranial vascular surgical procedures, or parietal tumor resection near eloquent cortex - none of which apply to this anterior cervical spine procedure. 1
CPT 95861 (Needle Electromyography)
This code is NOT medically indicated because:
EMG monitoring during spinal surgery lacks sufficient evidence that this technique provides useful information to the surgeon for assessing nerve root decompression or detecting nerve root irritation. 3
While needle EMG may be justified for detecting C5 nerve root injury in specific high-risk scenarios, 1 the documentation does not indicate specific C5 nerve root monitoring was performed or that there was a particular C5 palsy risk that would justify this separate code.
CPT 95941 (Continuous Remote Monitoring)
This code is NOT medically indicated because:
- The operative note indicates the monitoring was performed during a single surgical case, not remote monitoring of multiple cases or from outside the operating room. The technical report shows standard intraoperative monitoring during one procedure, which is already captured by codes 95938 and 95939.
Critical Clinical Context Supporting This Decision
Why This Case Qualifies for IONM (95938 and 95939)
The patient has documented myelomalacia within the spinal cord, which represents actual spinal cord injury/damage, not just compression. 2
Critical canal stenosis with large disc protrusions at three levels (C4-5, C5-6, C6-7) with severe foraminal stenosis creates a high-risk surgical scenario. 2
The procedure involved multilevel decompression (C4-7) with both fusion and arthroplasty, increasing the complexity and risk of neurological injury. 4
Important Limitations and Caveats
C5 nerve root palsy may occur without intraoperative monitoring changes, as postoperative segmental C5 palsy can develop without detectable intraoperative nerve injury. 2
Intraoperative evoked potential worsening is not specific and may not represent clinical worsening - both false positives and false negatives have been reported. 2
IONM cannot prevent all neurological injuries, but provides additional safety monitoring in high-risk cases with documented myelopathy. 1
Comparison to Cases Where IONM Would NOT Be Indicated
In contrast, IONM would NOT be medically necessary for:
ACDF procedures in patients with cervical stenosis and radiculopathy WITHOUT myelopathy, tumor, trauma, or significant deformity. 1 This patient clearly has documented myelopathy with myelomalacia, distinguishing this case from routine radiculopathy cases.
Lower lumbar procedures below L1-L2 where the spinal cord has already terminated. 3 This cervical case involves direct spinal cord risk.
Final Recommendation Summary
Approve: CPT 95939 and 95938 - These meet medical necessity based on documented cervical spondylotic myelopathy with myelomalacia and critical canal stenosis per American Association of Neurological Surgeons guidelines. 2
Deny: CPT 95955,95861, and 95941 - These lack evidence-based support for this specific procedure and clinical scenario. 1, 3