Lhermitte's sign is a sudden electric shock-like sensation shooting down to the spine and/or extremities triggered by neck flexion. It is classically seen in multiple sclerosis, but also reported in several conditions including spinal cord tumors, transverse myelitis, subacute combined degeneration, radiation myelopathy and cervical spondylosis. Lhermitte's sign in cancer patients can be associated with radiotherapy and chemotherapy, with cisplatin being the most common causative agent. We report an extremely rare case of isolated oxaliplatin-induced Lhermitte's sign in a rectal cancer patient.

A 54-year-old Caucasian man was diagnosed with T3 N2 M0 moderately differentiated rectal adenocarcinoma and underwent low anterior resection of the rectum after the diagnosis.  Chemotherapy with 8 cycles of Oxaliplatin, Fluorouracil and Leucovorin was initiated one month after the surgery.  During the last cycle, he started to feel electric shock-like pain in both feet upon neck flexion, consistent with Lhermitte's sign, while he denied having any symptoms of distal sensory polyneuropathy due to Oxaliplatin. Spinal cord injury was ruled out by whole spine MRI. He continued to have Lhermitte's sign 3 months after discontinuation of chemotherapy. Pregabalin was started at 75mg/day and increased gradually to 225mg/day. Significant improvement of symptoms was noted after one month.

Neurotoxicity especially cumulative, dose-dependent peripheral sensory polyneuropathy is commonly seen in platinum-based chemotherapy, but Lhermitte sign is very rare. To best of our knowledge, only 13 cases of Oxaliplatin induced Lhermitte’s sign has been reported in patients with diagnosis of colorectal cancer in English literature. Most of these cases were previously diagnosed with oxaliplatin induced dose-dependent sensory polyneuropathy upon presentation of Lhermitte’s sign. We report a rare case of isolated oxaliplatin-induced Lhermitte's sign with no other sensory symptoms in a patient with rectal adenocarcinoma.