Idiopathic trigeminal sensory neuropathy

Idiopathic trigeminal neuropathies: a presentation of 15 cases

PURPOSE

The aim of this study is to present a clinical series of patients with trigeminal neuropathy and their treatment.

PATIENTS AND METHODS

We present a retrospective study of 15 cases of idiopathic trigeminal neuropathies, with unilateral involvement of 1 or more divisions of the trigeminal nerve. The clinical, radiologic, and laboratory data of the patients, in addition to the treatment and clinical evolution, were reviewed. The patients were followed up for a mean of 34.4 months (range, 12-120 months).

RESULTS

The study consisted of 11 women and 4 men. The numbness was predominantly located in the innervated mental area and extended in some cases to the first and second trigeminal divisions. Seven patients had slight continuous discomfort in association with the numbness, one of whom had added bouts of typical neurogenic pain. Of the 15 cases, 8 (53%) had acute idiopathic trigeminal neuropathies and fully recovered within 3 months and 7 (47%) were chronic cases, without full recovery after 3 months. Mild pain was felt by 57% of the chronic patients and 37% of the acute patients; treatment with amitriptyline achieved complete or partial improvement in over half of these patients.

CONCLUSION

Of the idiopathic trigeminal neuropathies, half were acute and half were chronic. Mild pain presented more frequently in the chronic patients and was relieved with amitriptyline.

Mental neuropathy as a manifestation associated with malignant processes: its significance in relation to patient survival

PURPOSE

Mental neuropathy (MN) is characterized by the presence of a sensory defect in the form of paresthesias or dysesthesias in the territory innervated by the mental nerve. MN may be the first manifestation of systemic cancer, a symptom of spread of an established tumor, or a sign of infiltration in an intraoral lesion. In any of these cases, the symptom is indicative of a very poor patient prognosis.

MATERIALS AND METHODS

A total of 22 cancer patients with chin paresthesia were studied. Group 1 comprised patients with chin paresthesia who had a primary tumor in some other region at a distance from the oral cavity or maxillofacial zone. Group 2 in turn comprised patients with primary malignancies of the oral and/or maxillofacial territory and who likewise presented with chin paresthesia. Data were collected relating to patient age, gender, primary intraoral lesion (location, size, histologic diagnosis), primary systemic tumor, and mean patient survival.

RESULTS

Group 1 consisted of 11 patients (8 men and 3 women), aged between 36 and 81 years (mean, 58.09 +/- 14.99 years), with different systemic cancers. The mean survival after the diagnosis of chin paresthesia was 14.8 +/- 16.5 months, and only 1 patient was still alive after 9 months. Group 2 consisted of 11 patients (8 men and 3 women), aged between 33 and 72 years (mean, 56.18 +/- 15.69 years). All presented with oral squamous cell carcinoma, with the single exception of 1 case of fibrosarcoma. In this group the mean survival of the 8 patients who died was 28.2 +/- 29.6 months. Three patients survived for a mean of 17 months.

CONCLUSIONS

Chin paresthesia is a very important prognostic symptom determining the degree of infiltration of intraoral lesions, and in some cases it may be indicative of the existence of a primary tumor (identified or otherwise), with poor short-term survival--given that 81.9% of the patients studied (18 cases) had died before a mean of 20 months. Although mean survival was shorter (14.8 months) among the patients in group 1 than in group 2 (28.2 months), the difference was not statistically significant.

Trigeminal sensory neuropathy and facial contact dermatitis due to Anthurium sp

BACKGROUND

Trigeminal sensory neuropathy (TSN) describes a heterogeneous group of disorders manifesting as facial numbness.

OBJECTIVE

We report the case of a patient who had TSN associated with contact dermatitis due to Anthurium sp.

METHOD/RESULTS

A 21-year-old female patient developed left hemifacial contact dermatitis after exposure to the anthurium plant. The patient had paresthesias and pain in the V2 and V3 divisions of the left trigeminal nerve. Eight days after its onset the dermatitis resolved, but numbness developed in the V2 and V3 divisions of the left trigeminal nerve. Cranial CT scan and MRI, as well as CSF and extensive work-up exams, were normal. After one month the symptoms disappeared completely.

CONCLUSION

Anthurium sp, an indoor ornamental plant that contains calcium oxalate crystals, and can causes contact dermatitis. To our knowledge, this is the first report associating TSN with contact dermatitis due to Anthurium sp.

Trigeminal neuropathy

Trigeminal neuropathies (TNs) are well recognized disorders characterized and manifesting as skin and mucosal numbness in the region innervated by the trigeminal nerve. Facial numbness indicates trigeminal sensory alteration affecting the trigeminal system. TNs always pose differential location difficulties as multiple diseases are capable of producing them: they can be the result of traumatism, tumors, or diseases of the connective tissue, infectious or demyelinating diseases, or may be of idiopathic origin. Their importance is explained by the fact that TN may represent the first manifestation of tumor disease, or of relapse in patients with prior neoplastic processes. As such, these manifestations are ominous, and patient life expectancy is often short. The clinical exploration reveals a loss of sensitivity in the cutaneous territory corresponding to the affected nerve, which can be partial (hypoesthesia) or complete (anesthesia). The sensory defect is occasionally associated with hyperesthesia (i.e., the patient suffers a decrease in sensory perception, but when sensation is perceived, it may cause considerable discomfort). Complementary studies are needed to establish the etiologic diagnosis, with laboratory tests to discard the possible causative diseases underlying the trigeminal neuropathy, and the opportune radiographic examinations in the form of plain X-rays or a routine cranial computed tomography scan.

Mefloquine-induced trigeminal sensory neuropathy

Trigeminal sensory neuropathy is an important finding, often indicative of trauma but sometimes related to neoplasia, infections, demyelinating conditions, connective tissue disorders, other disorders, or, occasionally, drugs. This paper reports on a patient with sudden-onset trigeminal sensory neuropathy of the lip that proved to be drug-induced, secondary to the antimalarial drug mefloquine. This appears to be the first report of sensory impairment in the orofacial region from exposure to mefloquine.

A new technique for recording sensory conduction velocity of the inferior alveolar nerve

A new electrophysiological technique for recording the sensory conduction velocity (SNCV) of the inferior alveolar nerve (IAN) is described. Bilateral orthodromic recordings were done in 21 healthy adults. The sensory responses of the IAN were obtained in all 42 nerves examined with silver wire or monopolar needle electrodes inserted beneath the zygomatic arc in front of the temporomandibular joint to a depth of 4-4.5 cm, near the oval foramen. A small bipolar surface electrode was used for stimulation at the mental foramen. In 3 subjects, the stimuli were additionally delivered via two monopolar needle electrodes to reduce the stimulus artifact. Single responses were usually sufficient for analysis, but, in some cases, averaging was adopted to improve the signal-to-noise ratio. Response latencies and amplitudes, SNCVs, and interside differences were measured, and the 97.5% upper and 2.5% lower prediction limits calculated for reference limits in clinical practice. This new technique provides a sensitive and objective diagnostic tool for the examination of IAN injuries, and may also be used for intraoperative monitoring of the IAN during mandibular surgery.

Recurrent idiopathic trigeminal sensory neuropathy

Idiopathic trigeminal neuropathy is a rare disorder characterized by transient sensory disturbances in the territory of one or more branches of the trigeminal nerve. Acute and chronic forms of the disease have been recognized, but to our knowledge no recurrent cases have been reported. Two cases of recurrent idiopathic trigeminal sensory neuropathy are reported. The patients presented sensory alterations limited to the territory of the trigeminal nerve in the absence of other clinical features. In both cases sensory disturbances began in the tongue and lips and later spread throughout the face. The whole trigeminal nerve territory was involved in the first patient, but in the second patient only the second and third trigeminal branches were affected. There was no muscle weakness or pain, and the corneal reflex was present in both patients. The first patient recovered completely after 3 months, but the symptoms recurred in a similar fashion 3 years later. In the second patient the symptoms occurred each winter for more than 10 years. The conditions in these two patients could be considered as recurrent idiopathic forms of trigeminal sensory neuropathy.