Lhermitte sign and urinary retention: atypical presentation of oxaliplatin neurotoxicity in four patients.

Background: Regimens combining oxaliplatin with fluorouracil and folinic acid are standard therapeutic options for patients with metastatic colorectal carcinoma. Oxaliplatin has a good safety profile, although it is responsible for dose-limiting neurotoxicity typically consisting of two distinct clusters of symptoms. Cold-induced distal paresthesiae occur during or shortly after infusion in most patients and are usually transient and mild. A persistent sensory peripheral neuropathy may develop with prolonged treatment, eventually causing superficial and deep sensory loss, sensory ataxia and functional impairment.

Methods: The authors report four cases of atypical neurotoxicity induced by oxaliplatin in patients treated for metastatic colorectal carcinoma. Two patients were male and two were female, with an age range of 52-59 years.

Results: Three patients experienced Lhermitte sign and two experienced urinary retention. In all cases, the cumulative dose of oxaliplatin was higher than 1000 mg (range, 1248-2040 mg). Brain and spinal magnetic resonance imaging was performed in two patients and was normal. Somatosensory evoked potentials were recorded in two patients and suggested cervical dorsal column dysfunction. Symptoms resolved a few weeks after discontinuation of oxaliplatin.

Conclusions: Lhermitte sign may be induced via a neurotoxic effect on the ascending axons of these T-shaped neurons. An atonic bladder may be the result of damage to the sensory portion of the sacral reflex arc, either in the dorsal roots, as for example in diabetic neuropathy, or in the posterior columns, as in tabes dorsalis. Alternatively, it may result from a paralysis of the parasympathetic fibers that control the bladder musculature. It is unclear at present whether the micturition difficulties observed in patients in the current series are due to sensory neuropathy or to autonomic neuropathy, event if the former hypothesis seems more likely, as autonomic neuropathy has not been previously observed with oxaliplatin, and its association with cisplatin is exceedingly rare and controversial.