E-Pearl of the Week

June 15, 2011

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June 14, 2011

Numb Chin Syndrome

Numb chin syndrome (NCS), or mental neuropathy, is a rare and potentially ominous sensory neuropathy characterized by unilateral hypoesthesia or paresthesias over the lower lip, chin and occasionally gingival mucosa. The mandibular branch (V3) of the trigeminal nerve exits the skull through the foramen ovale and divides into an anterior motor trunk and a posterior sensory trunk, the inferior alveolar nerve. It then exits the mental foramen in the mandible as the mental nerve. NCS may be a sign of occult malignancy. The most common neoplastic causes of NCS are breast cancer, and non-Hodgkin lymphoma.

References

1. Lossos A, Siegal T. Numb chin syndrome in cancer patients: etiology, response to treatment, and prognostic significance. Neurology 1992;42:1181-1184.
2. Evans RW, Kirby S, Purdy RA. Numb chin syndrome. Headache 2008 ;48:1520-1524.

Submitted by:
Yuan Fan, MD, PhD

Disclosure: Dr. Fan reports no disclosures.

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