Neuropathic Cranial Pain Phenotypes After Craniotomy: A Large, Single-Center Retrospective Cohort Study

Background and Objectives: Chronic headache after craniotomy is common and may include neuropathic subtypes (scar neuroma pain, occipital neuralgia). However, no large series has quantified these phenotypes. We conducted a single-center retrospective review (n = 5624 adult craniotomy patients) to estimate the prevalence of post-craniotomy neuropathic pain and to describe its characteristics. Materials and Methods: Institutional records were screened to identify craniotomy patients referred to a multidisciplinary pain clinic (n = 272). Eligible cases were reviewed in tiers: (1) exclusion of primary headache and noncranial pain; (2) identification of "probable neuropathic cranial pain" based on documented neuropathic features (lancinating/scalp pain, trigger tenderness, dermatomal distribution); and (3) subgroup categorization into occipital neuralgia-like, supraorbital/supratrochlear neuralgia-like, and scar-site neuropathic pain phenotypes. The supraorbital/supratrochlear subgroup was defined by frontal or frontotemporal postoperative pain in the supraorbital region, local tenderness or Tinel-like hypersensitivity over the supraorbital/supratrochlear course, and/or response to supraorbital-supratrochlear nerve block. Data extracted included demographics, timing (surgery to pain referral), pain characteristics, and treatments (blocks, radiofrequency, medications). Results: Of 5624 craniotomy patients, 272 (4.8%) had pain clinic encounters. The initial review identified 124 cases with chronic post-craniotomy headache requiring follow-up; after detailed chart classification, probable neuropathic cranial pain was present in 111 cases (2% of the cohort). Among the 111 probable neuropathic cranial pain cases, the dominant regional phenotype was occipital neuralgia-like pain. In addition, eight patients (7.2%) demonstrated a supraorbital/supratrochlear neuralgia-like phenotype, predominantly after frontal or frontotemporal craniotomies. Scar-site neuropathic pain frequently coexisted with both regional phenotypes, supporting a partially overlapping spectrum rather than mutually exclusive categories. The median time from surgery to pain referral was several months (≈12-18 months). Management commonly included occipital nerve blocks (±steroid); some patients received pulsed radiofrequency ablation of the occipital nerves, and most were trialed on neuropathic analgesics (gabapentinoids, SNRIs, etc., according to neuropathic pain guidelines). Conclusions: A clinically meaningful subset of post-craniotomy patients develops chronic neuropathic cranial pain, most commonly with occipital, supraorbital/supratrochlear, or scar-related features. Because most postoperative headaches are managed through neurosurgical follow-up and improve without pain clinic referral, the present cohort likely underestimates the true burden of neuropathic post-craniotomy pain while enriching for its most refractory neuralgic presentations. This is nevertheless the subgroup that must be recognized, discussed with patients, studied prospectively, and targeted in future prevention strategies.