This case report describes the clinical course, evaluation, and diagnosis of post-surgical inflammatory sciatic neuropathy, in a patient without any known risk factors. As is common in the setting of postoperative neuropathy, this patient experienced evolving symptoms, multi-disciplinary consultations, a broad differential diagnosis, and a variety of therapies for pain management. His final diagnosis of post-surgical inflammatory neuropathy was ultimately supported by imaging studies and the exclusion of other etiologies, as there are no known markers for this condition. His course improved with conservative management, but consideration for immunosuppressive treatment may have been given to a more severe or worsening clinical course.

The incidence of post-surgical inflammatory neuropathy is unclear, and it may be under-appreciated (Staff NP et al. 2010). The cause of this condition is likely multifactorial, and given its heterogeneous presentation in prior case reports, it may encompass multiple different entities. It is thought to be an immunological response to stress, such as surgery. Based on a retrospective study (Staff NP et al. 2010), additional possible risk factors may include diabetes mellitus, tobacco use, cancer, and infection; in this case, the patient did not have any of these suggested risk factors. Given the rarity of this condition, more case reports and studies would be useful to further elucidate predisposing factors. This condition should be included in the differential diagnosis for post-surgical neuropathy, particularly when there is no clear mechanical insult to explain the neuropathy.

Evaluation of postoperative nerve injury includes neurological consultation, as well as consideration of ancillary testing (Fig. 3). Electrophysiological studies can be useful for defining the type of neuropathy. MR imaging can help to identify areas of nerve injury. Nerve biopsy is less often considered, but it can show lymphocyte-mediated inflammation (as opposed to macrophage infiltration, which is seen in axonal degeneration related to mechanical insult) (Staff NP et al. 2010; Rattananan et al. 2014; Ahn et al. 2011).

Evaluation modalities for postoperative neuropathy

The optimal treatment and management of inflammatory neuropathy is yet to be determined. Some cases have improved with conservative management, as with this patient. Other cases of inflammatory neuropathy have improved with immunotherapy, including intravenous immunoglobulin and steroids (such as methylprednisolone and prednisone) (Staff NP et al. 2010; Rattananan et al. 2014; Ahn et al. 2011; Cetiz 2017; Warner and Warner 2014; Laughlin et al. 2014). Although this treatment has only been reported in retrospective studies and case reports, it does suggest that early consideration and prompt diagnosis of this entity is important so that suppression of the immune response can be considered. For this reason, it is important for anesthesiologists and surgeons to be aware of this condition when confronted with a case of post-surgical neuropathy. Future prospective studies would be helpful to demonstrate the true incidence of post-surgical inflammatory neuropathy, predisposing risk factors, effectiveness of immunotherapy, and prophylactic role of steroids pre- or intra-operatively.