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

Area of Science:

• Neurosurgery
• Pain Medicine
• Neurology

Background:

• Chronic headache is a frequent complication following craniotomy.
• Neuropathic pain subtypes, including scar neuroma pain and occipital neuralgia, are common but poorly quantified.
• This study aims to estimate the prevalence and characterize post-craniotomy neuropathic pain phenotypes.

Purpose of the Study:

• To estimate the prevalence of chronic neuropathic cranial pain after craniotomy.
• To describe the characteristics and phenotypes of post-craniotomy neuropathic pain.
• To identify common management strategies for these pain conditions.

Main Methods:

• Retrospective review of 5624 adult craniotomy patients.
• Identification of patients referred to a multidisciplinary pain clinic (n=272).
• Classification of neuropathic pain into occipital neuralgia-like, supraorbital/supratrochlear neuralgia-like, and scar-site phenotypes based on documented features.

Main Results:

• Probable neuropathic cranial pain was identified in 111 cases (2% of the cohort).
• Occipital neuralgia-like pain was the dominant phenotype, followed by supraorbital/supratrochlear neuralgia-like pain.
• Scar-site pain frequently coexisted, suggesting an overlapping spectrum. Median time to pain referral was 12-18 months post-surgery.

Conclusions:

• A significant subset of post-craniotomy patients develops chronic neuropathic cranial pain with distinct regional features.
• The study likely underestimates the true incidence, as it focuses on refractory cases referred to a pain clinic.
• Recognition, prospective study, and targeted prevention strategies are crucial for managing this patient subgroup.