Herald Facial Numbness

Abstract

Three unusual patients who developed subacute facial numbness as the heralding symptom of an expanding tumor that involved the trigeminal nerve fibers are reported. The first patient had clinical and electrophysiological evidence of an isolated mental neuropathy as a result of metastatic lesions with bone destruction from a renal cell carcinoma. The second patient had a sensorimotor trigeminal neuropathy caused by a direct compression of the semilunar ganglion by a cavernous hemangioma of Meckel’s cave. The last patient experienced facial numbness as the unusual presenting manifestation of a primary brainstem lymphoma. Patients 1 and 3 died a few weeks after the admission, whereas patient 2 poorly recovered. Despite the availability of new techniques for early diagnosis, this report demonstrates how difficult it can initially be to differentiate a ‘benign’ trigeminal neuropathy from serious conditions and underscores the poor prognosis of fifth nerve fibers involvement by an expanding mass. Early referral with clinical and electrophysiological evaluation appears to be of crucial importance.

Numbness matters: A clinical review of trigeminal neuropathy

“…Intracranial involvement of the trigeminal pathways by tumor may occur at various anatomical levels including the brainstem, prepontine cistern, cerebellopontine angle (CPA), trigeminal ganglion, and cavernous sinus. When brainstem tumors cause TNO, it almost always occurs in association with other neurological signs and symptoms, although a single patient with isolated facial numbness who was later found to have a primary brainstem lymphoma has been reported (43). Notably, this patient was initially dismissed as having an ‘idiopathic trigeminal neuropathy' after a plain head CT was read as normal, but then later re-presented with multiple cranial neuropathies.…”

“…Vascular malformations have been reported to cause TNO, including cavernous hemangioma at Meckel's cave (43). Cavernous hemangiomas may occur along the entire course of the trigeminal nerve, including extension extra-cranially (59).…”

Numb chin syndrome: an ominous clinical sign

“…There are several hypotheses to explain the sensory defect, the most widely accepted being nerve compression by mandibular bone metastasis. 2,3 Other hypotheses include perineural invasion of the trigeminal nerve and its branches, 11 spread to the central nervous system, 3 intracranial involvement due to metastasis to the base of skull 12 and leptomeningeal seeding. 13 Numb chin syndrome in the context of metastatic disease is a serious diagnosis with a poor prognosis.…”

Trigeminal neuropathy

“…Despite availability of the most recent early diagnostic techniques, it is difficult to differentiate ‘benign’ TN from ‘malignant’ tumor‐associated presentations. Early clinical and radiological evaluation is of crucial importance (Kuntner et al , 1992). In the event of sensory defects in the territory of the trigeminal nerve, the presence of a primary tumor or of metastatic relapse of malignant disease at some point along the trigeminal trajectory must be discarded (Vadell et al , 1989).…”