Intrathecal steroid therapy for postherpetic neuralgia: a review.

Two recent publications advocated intrathecal injection of methylprednisolone acetate for postherpetic neuralgia. Conceptually, these therapeutic trials were based on the failed assumption that chronic inflammation persists in dorsal root ganglia even after the lesions of acute zoster have healed. Constructionally, these publications can be criticized on numerous grounds: cranial zoster was excluded, follow up periods were too short, dangers or reactivating the varicella virus were ignored, no methylprednisolone acetate-only group was included, pharmacological dangers of intrathecal lidocaine were overlooked. In addition to these basic conceptual deficiencies, multiple dangers of intrathecal methylprednisolone (therapeutically and by accidental injection) are manifest in a literature dating back over two decades in which several hundred serious complications are described. In summary, all rational evidence indicates that this treatment should not be prescribed.