Development of Tactile Allodynia Immediately After Spinal Anesthesia.

Dear Editor,The mechanisms of allodynia are ascribed to crosstalk and impaired inhibitory interneurons ⇓. A-beta fibers are indirectly linked to lamina I output neurons via a polysynaptic pathway, and this link is normally repressed by inhibitory interneurons. If these inhibitory interneurons are impaired, allodynia can develop. Lowered nociceptive threshold, phenotypic switch and reorganization of dorsal horn are also mechanisms of allodynia ⇓. Concern over exacerbation of pre-existing neurologic disease after spinal anesthesia has been recognized for some time ⇓. However, there are few case reports of paradoxical response immediately after spinal anesthesia in the operating room. Kato et al. have reported a case that a burning abdominal pain appeared in a patient with complex regional pain syndrome after spinal anesthesia prior to a cesarean section ⇓. We experienced a patient who complained of sudden tactile allodynia immediately after spinal anesthesia despite spinal blockade.A 20-year-old male patient was scheduled for arthroscopic meniscus repair of both knees under spinal anesthesia. He had a history of previous arthroscopic meniscectomy of both knees 5 years prior due to a fall during wrestling training. He had been experiencing dysesthesia and mild allodynia in both knees when he stretched or scratched his knees since the operation. …