Oxcarbazepine in glossopharyngeal neuralgia: Clinical response and effect on serum lipids

Hepatitis C-related cryoglobulinemic neuropathy: potential role of oxcarbazepine for pain control

BACKGROUND

Peripheral neuropathy is one most common, limiting and invalidating neurological symptom in subjects with hepatitis C virus and mixed cryoglobulinemia. Notably, the medical therapy proposed to eradicate HCV, can frequently exacerbate the painful neuropathy. Therefore, neuropathy therapies are insufficient and inadequate, and comprise immunosuppressive drugs, such as steroid or cyclosporine, intravenous immunoglobulin or plasma exchange. These have shown variable success in case reports, with a presumably temporary effect, but with major side effects.

METHODS

We assessed the effects of oxcarbazepine treatment in 67 cases of cryoglobulinemia related neuropathy, who did not respond to either steroid or Gabapentin, or Pregabalin. Oxcarbazepine was chosen based on the promising preliminary results.

RESULTS

Patients treated with Oxcarbazepine showed a rapid, discrete and persistent relief of polyneuropathic signs, without consistent side effects, and with a limited interaction with concomitant drugs.

CONCLUSIONS

These data favor the use of oxcarbazepine as a useful tool in the management of neuropathic pain associated with Hepatitis-C cryoglobulin neuropathy.

Current neurosurgical management of glossopharyngeal neuralgia and technical nuances for microvascular decompression surgery

Glossopharyngeal neuralgia (GPN) is an uncommon facial pain syndrome often misdiagnosed as trigeminal neuralgia. The rarity of this condition and its overlap with other cranial nerve hyperactivity syndromes often leads to a significant delay in diagnosis. The surgical procedures with the highest rates of pain relief for GPN are rhizotomy and microvascular decompression (MVD) of cranial nerves IX and X. Neurovascular conflict at the level of the root exit zone of these cranial nerves is believed to be the cause of this pain syndrome in most cases. Vagus nerve rhizotomy is usually reserved for cases in which vascular conflict is not evident. A review of the literature reveals that although the addition of cranial nerve X rhizotomy may improve the chances of long-term pain control, this maneuver also increases the risk of permanent dysphagia and vocal cord paralysis. The risks of this procedure have to be carefully weighed against its benefits. Based on the authors' experience, careful patient selection with a thorough exploratory operation most often leads to identification of the site of vascular conflict, obviating the need for cranial nerve X rhizotomy.

Analgesic efficacy and safety of medical therapy alone vs combined medical therapy and extraoral glossopharyngeal nerve block in glossopharyngeal neuralgia

OBJECTIVE

The aim of this study is to compare medical therapy alone and medical therapy with add on extraoral glossopharyngeal nerve block in terms of analgesic efficacy and hemodynamic safety in patients with glossopharyngeal neuralgia (GPN). As GPN is a rare disease, our secondary targets were to review the demographic profile of the disease, clinical profile, and any associations with the disease.

DESIGN

This was a randomized, prospective, active-controlled, parallel group study conducted from 2007 to 2009 to determine the safety and efficacy of extraoral glossopharyngeal nerve block in GPN and compare it with pharmacological intervention. After institutional ethics committee approval and patient's consent, GPN patients were randomly allocated into two groups. Group A (N = 15) received standard medical therapy (gabapentin 300 mg, tramadol 50 mg TDS, methylcobalamin 500 μgm PO) and group B (N = 15) patients received extraoral glossopharyngeal nerve block together with standard medical therapy. Patients were analyzed for analgesic outcome using numerical pain scale (NPS) and brief pain inventory (BPI) assessing both analgesic effect and degree of interference in quality of life (QOL) during 3-month follow-up. They were also evaluated for any significant hemodynamic alterations.

RESULTS

Over the follow-up of 90 days, the mean NPS in group A decreased from 6 ± 2 to 3 ± 2 and in group B from 5 ± 1 to 2 ± 2. From the mean NPS scores, it can be interpreted that both the modalities were effective clinically in treating GPN. However, NPS scores were statistically similar by the end of 90 days. Improvement from baseline in BPI measurement of QOL (mood, interpersonal relationship, and emotion) was earlier in group B (1, 2, and 1 months, respectively) compared with group A (2, 3, and 2 months, respectively). However, there were no significant hemodynamic adverse outcomes after administration of the block.

CONCLUSION

This study found that patients in both the groups had significantly lower pain intensities, improved pain relief, and reduced pain interference with QOL, which was especially evident on fourth visit (2 months) after the initiation of treatment regimen. Both were safe and well tolerated. The study advocates rational polypharmacy approach (oral and block) in difficult to treat painful conditions. Further controlled trials are warranted to further define the impact of such a combination therapy.

Medical management of trigeminal neuropathic pains

IMPORTANCE OF THE FIELD

Although trigeminal neuralgia has traditionally been considered the prime neuralgic condition in the face region, other forms of neuropathic pain are now being more frequently recognized and require recognition and a different management approach.

AREAS COVERED IN THIS REVIEW

This review principally covers medical management of trigeminal neuralgia; but also included is glossopharyngeal neuralgia, trigeminal neuropathic pain (atypical odontalgia) and burning mouth syndrome. Systematic reviews and guidelines will be discussed.

WHAT THE READER WILL GAIN

An update will be provided of drug therapy for these relatively rare facial pains.

TAKE HOME MESSAGE

Trigeminal neuralgia continues to be best managed using anticonvulsant drugs, the primary ones being carbamazepine and oxcarbazepine; baclofen may be helpful and, of the newly emerging drugs, pregabalin has potential. Glossopharyngeal neuralgia remains managed in the same way as trigeminal neuralgia. Trigeminal neuropathic pain is probably best managed according to guidelines used for the management of neuropathic pain, which include the use of tricyclic antidepressants, gabapentin, pregabalin, duloxetine, venalafaxine and topical lidocaine. Burning mouth syndrome is a neuropathic pain managed initially with topical clonazepam and then with other neuropathic drugs. Patients need to be involved in their management.