[Preliminary report of botulinum toxin type A injection at trigger point for treatment of trigeminal neuralgia: experiences of 16 cases]

PURPOSE

To investigate the effects of injection of botulium toxin type A at trigger point for treatment of patients with primary trigeminal neuralgia.

METHODS

Sixteen patients with primary Trigeminal Neuralgia were treated with injection of botulium toxin type A. Visual analog scores(VAS) at 1 week, 2 weeks, 1 month, 3 months and 6 months after treatment and Barrow Neurological Institute (BNI) pain evaluation criteria were utilized to measure the degree of pain. The data was analyzed with SPSS 10.0 software package.

RESULTS

The VAS score was 9.12±0.65 before botulium toxin type A injection while the scores were 2.8±1.36, 2.2±1.26, 1.3±1.45, 1.3±1.45 and 1.2±2.52 at 1 week, 2 weeks, 1 month,3 months and 6 months after treatment. There was significant difference in VAS compared with before treatment. VAS score was lower and stable at 1 month, 3 months and 6 months after treatment, but no significant difference was found at 1-week and 2-week after treatment. BNI evaluation results showed good therapeutic effect 1 week after treatment, while the best therapeutic effect was noted 1-3 months after treatment. 6 months later, 1 patient had recurrence and 11 patients had complete relief of pain.

CONCLUSIONS

Botulium toxin type A injection is an effective way for treatment of patients with primary trigeminal neuralgia.

Neurosarcoidosis presenting as trigeminal nevralgia: a case report and review of the literature

Sarcoidosis is a granulomatous disease that can present systemically, but primarily has pulmonary manifestations. It is reported across all races, but has a higher incidence among African Americans. Neurological involvement in sarcoidosis is rare, with cranial nerve seven being the most commonly reported neurological finding. Trigeminal neuralgia, as presented in this case, is very rare. A 38-year-old African American female, with history of refractory trigeminal neuralgia, cutaneous sarcoidosis, and an extensive psychiatric history, presented to the hospital for fifth cranial nerve decompression. She had failed medical therapy and gamma knife therapy. Prior to surgery, magnetic resonance imaging (MRI) revealed a mass of 1.5 cm x 0.6 cm x 1.1 cm in the left Meckel's cave, which, when compared with prior imaging, was not present. A partial craniotomy was done to excise the mass. Frozen pathological sections showed granulomatous inflammation consistent with sarcoidosis. Stains for acid fast bacilli and fungi remained negative. Quantiferon Gold and HIV serum studies were negative. High resolution computed tomography (CT) scan the chest showed patchy infiltrates in the lungs that presented as chronic interstitial lung disease. The patient's neurological symptoms resolved after surgical resection. She was dismissed home on a tapering dose of dexamethasone and follow-up with a rheumatologist. This case illustrates that when a patient with sarcoidosis presents with neurological symptoms, neurosarcoid should be considered. Most cases are diagnosed during autopsies. Recognizing and correctly diagnosing neurosarcoid leads to proper treatment and decreased morbidity in patients.

[Treatment of primary trigeminal neuralgia with radiofrequency thermocoagulation: report of 648 consecutive cases]

PURPOSE

To analyze the clinical efficacy of radiofrequency thermocoagulation in the treatment of idiopathic trigeminal neuralgia, and discuss the method, skill of radiofrequency thermocoagulation and complications.

METHODS

648 patients with idiopathic trigeminal neuralgia , who were treated by radiofrequency thermocoagulation via foramen infraorbitale approach, lateral approach, anterior approach and other approach from July 2001 to March 2011 in our hospital, were observed and the clinical efficacy was evaluated.

RESULTS

After the first treatment of the 648 patients, the rate of pain control was 98.3% via foramen infraorbitale approach, 91.0% via lateral approach and 95.5% via former approach. The overall response rate was 96.0%. 395 patients were followed up from 6 months to 2 years. The recurrent rate within one year was 9.6%, 20.5% within two years. Good response was achieved after re-treatment with radiofrequency thermocoagulation in recurrent patients.

CONCLUSIONS

The clinical efficacy of radiofrequency thermocoagulation in the treatment of idiopathic trigeminal neuralgia is good and reliable. The operation is simple, the indication is wide, and the complication is fewer. CT location can improve the accuracy of puncture, and reduce complications.

[Change of calcium channel alpha-2-delta-1 subunit expression levels in trigeminal neuralgia rats]

OBJECTIVE

To determine the expression levels of calcium channel alpha-2-delta-1 (Cavalpha2delta-1) subunit in trigeminal ganglia (TG) and trigeminal spinal subnucleus caudalis C1-C2 spinal cervical dorsal horn(Vc/C2) after infraorbital nerve (ION) ligation injury in relation to the development of neuropathic nociception.

METHODS

Twelve male SD rats were divided into two groups randomly, with 6 rats for each. In the ligation group, the ION was ligated by chromic gut loosely. In the sham operation group, the ION was exposed under same procedure but not ligated. The behavioral tests were conducted before 1 d and after 3, 6, 9, 12, 15 d with calibrated von Frey filaments. Cavalpha2delta-1 protein levels in TG and Vc/C2 were measured with Western blots 15 days after surgery.

RESULTS

Compared with the sham operation group, changes of allodynia to mechanical stimulation on the territory of ligated ION were found from the 9th to 15th day after operation in the ligation group (P<0.05). The expression levels of Cavalpha2delta-1 in TG and Vc/ C2 after ION ligation injury upregulated significantly (P<0.01).

CONCLUSION

The expression levels of Cavalpha2delta-1 in TG and Vc/C2 after ION ligation injury were upregulated and it may contribute to the pathogenesis of neuropathic nociception.

Nociceptin/orphanin FQ modulates cortical activity and trigeminal nociception

BACKGROUND

Alterations in the levels of nociceptin/orphanin FQ (N/OFQ) have been reported in patients with primary headaches, including migraines and cluster headaches. These clinical observations suggest that N/OFQ is involved in the pathogenesis of primary headaches.

OBJECTIVES

The present study was conducted to determine the role of N/OFQ in the control of trigeminal nociception and cortical excitation.

METHODS

Cortical spreading depression (CSD) was elicited in Wistar rats by cortical application of potassium chloride, and electrocorticograms were recorded. N/OFQ was administered via an intracisternal injection. The presence of CSD-evoked trigeminal nociception was determined with Fos and transient receptor potential vanilloid 1 (TRPV1) immunoreactivity.

RESULTS

Nociceptin/orphanin FQ produced a biphasic effect on CSD generation, characterized by an initial attenuation followed by delayed potentiation. The amplitude of CSD waves were lower in the initial period but increased in the later period. The total number of CSD waves recorded in 1 hour was greater in the N/OFQ-treated group. Exposure to N/OFQ significantly increased the number of Fos-immunoreactive cells in the trigeminal nucleus caudalis and the number of TRPV1-immunoreactive cells in the trigeminal ganglia, indicating the enhancement of trigeminal nociception.

CONCLUSION

These results indicate that N/OFQ can lead to biphasic effect characterized by an initial inhibition, and delay potentiation that eventually intensify CSD-evoked trigeminal nociception.

[Expression and activity of Cdk5/p35 in a rat model of trigeminal neuropathic pain]

PURPOSE

To test the hypothesis that Cdk5/p35 plays important roles during trigeminal neuropathic pain.

METHODS

Trigeminal neuralgia rat model was established with a chronic constriction injury (CCI) of the infraorbital branch of the trigeminal nerve (ION). The change of Cdk5 activity, expression of Cdk5 and p35 in Vc after CCI-ION were studied by Western blot, immunoprecipitation and Kinase assay. Statistical analysis was performed using SPSS13.0 software package.

RESULTS

Western blot showed CCI-ION induced a time-dependent upregulation of p35 primarily within the ipsilateral superficial laminae of Vc (day 1:1.23±0.15, day 3:1.36±0.12, day 7:1.62±0.17, day 14:1.83±0.16). In contrast, the expression of Cdk5 was constant during day 1-14 in Vc after CCI-ION. Cdk5 activity on day 14 in Vc after CCI-ION (115.5 Kcpm) was 6 times as that on day 1 in Vc after CCI-ION (19.0 Kcpm). The difference was significant (P<0.01).

CONCLUSIONS

The results suggest that cdk5/p35 may plays important roles on synaptic reorganization of Vc after CCI-ION, expression of p35 may be a novel regulatory mechanism to control cdk5 activity in Vc after CCI-ION.

Surgical treatment of cranial neuralgias

The most common types of cranial neuralgias amenable to surgical therapeutic options are trigeminal neuralgia and glossopharyngeal neuralgia, the former having an approximate incidence of 5/100000 cases per year and the latter of 0.05/100000 cases per year. Surgical therapy of these pathological conditions encompasses several strategies, going from ablative procedures to neurovascular decompression, to radiosurgery. The choice of the most appropriate surgical option (which must be taken into account when all conservative treatments have proven to be unsuccessful) has to take into account many factors, the most important ones being neuroradiological evidence of a neurovascular conflict, severity of symptoms, the age and clinical history of the patient, and the patient's overall medical condition. In this chapter we report our experience with the treatment of trigeminal and glossopharyngeal neuralgia, describing the surgical procedures performed and reviewing the most recent aspects on this subject in the past literature.

Cranial neuralgias

After a description of the anatomical-functional organization of the human trigeminal system, this chapter discusses the diagnostic and therapeutic options for trigeminal neuralgia (TN). In about 15% of patients who present with the clinical picture of typical TN, this is secondary to a major neurological disease, i.e., benign tumors of the cerebellopontine angle or multiple sclerosis. Some clinical criteria that were used to distinguish between classic and symptomatic TN, such as age at onset, involvement of the ophthalmic division, and responsiveness to medical treatment, are no longer considered reliable. It is recommended that all patients undergo magnetic resonance imaging (MRI) or trigeminal reflex recording. Carbamazepine (CBZ) and oxcarbazepine (OXC) are the first-choice medical treatments. Although other drugs may be effective, these are indicated when the patient cannot reach the therapeutic dosage of CBZ/OXC because of adverse events. Patients unresponsive to CBZ/OXC should be made aware of the available surgical interventions. Surgical procedures (including percutaneous lesions to the ganglion/root, microvascular decompression (MVD) in the posterior fossa, and gamma knife radiosurgery) are extremely efficacious with relatively few complications: each procedure has some advantage and disadvantage with respect to the other. Only MVD is a non-destructive procedure. This chapter also describes management of glossopharyngeal neuralgia, which is often misdiagnosed, and some other chronic pain conditions mediated by the trigeminal system, such as ophthalmic postherpetic neuralgia (PHN).

[Connection of trigeminal nerve and facial nerve branches and its clinical significance]

In recent years, many anatomical researches have showed that there are common and extensive connections between the trigeminal nerve and the facial nerve.They are briefly outlined as follows: (1) The infraorbital nerve communicates with buccal branch of the facial nerve. (2) The auriculotemporal nerve of the trigeminal nerve communicates with the buccal, zygomatic,temporal branches and the upper divisions of the facial nerve. (3) The supraorbital nerve communicates with the zygomatic and temporal branches of the facial nerve. (4) The mental nerve communicates with the marginal mandibular branch of the facial nerve. (5) The buccinator nerve communicates with the zygomatic, buccal and marginal mandibular branches. These communications between the trigeminal nerve and facial nerve are probably related to several clinical signs, for example,some trigeminal neuralgia patients are complicated by facial spasm, some patients appeared spontaneous partial functional recovery of mimetic muscles following surgical resection of a considerable segment of the facial nerve (including a portion of its main trunk and the peripheral plexus), etc. The purpose of this article was to review the anatomical features and clinical significance of the communications between the trigeminal nerve and the facial nerve.

[The neuromuscular toxicity and clinical application of adriamycin]

Adriamycin (doxorubicin) is commonly used in the treatment of malignant tumours. In recent years,retrograde adriamycin sensory ganglionectomy has been used in treatment of trigeminal neuralgia and has obtained good therapeutic effect. The mechanism of action, particularly, of the toxic effects with different medication methods and choice of doses for muscle cells and nerve cells is still unclear. This article reviewed the mechanism and feature of the toxicity of adriamycin effects on these cells and its advance in experimental study. The damage of adriamycin was highly selective and self-limited. The different effects of adriamycin with different administration routes and doses is also described. Adriamycin shows great potentiality in treatment of trigeminal neuralgia, facial spasm and some other neuromuscular diseases.

[Study on specific distribution of afferent fibers in trigeminal sensory root of the rat]

OBJECTIVE

To study the distribution character of the trigeminal sensory afferent fibers in rat's trigeminal sensory root (RxV) and to explore the possibility of selectively injury of the pain afferent fibers.

METHODS

The retrograde tracer fluorogold (FG) was injected into trigeminal spinal subnucleus and pontine nucleus respectively. After 7 days survival, the rats were sacrificed and the RxV was removed and sectioned. The distribution of FG at RxV was studied under fluorescent microscope and its character was analyzed.

RESULTS

After being introduced into trigeminal spinal rostral nucleus, the FG could be observed at the lateral portion on the sections of RxV. The fibers were small and concentrated. The interpolaris subnucleus and caudal subnucleus injection group also showed small and concentrated fibers in the lateral portion of RxV, but the distribution area was larger than that of the rostral subnucleus group. While being injected into trigeminal pontine nucleus, the FG positive axons could be found in the ventral, medial and central portion of the RxV cross sections. These fibers were thicker and more scattered compared to those projecting into trigeminal spinal nucleus.

CONCLUSION

The fibers relating to transporting pain sensory concentrate at a certain area of rat' s RxV, which indicate that selectively injury of the pain afferent fibers of RxV should be possible.

[Case of tsutsugamushi disease (scrub typhus) presenting with fever and pain indistinguishable from trigeminal neuralgia]

A 64-year-old man visited our clinic with a 9-day history of headache and fever. He had frequent, severe, electric shock-like pain in his left eye, forehead, and scalp. The body temperature was 37.1 degrees. Cranial nerve functions were intact. Limb weakness and stiff neck were absent. There were injection of the conjunctiva, a red rash on the trunk, and an eschar in the axilla. Abnormal laboratory findings included AST 40 IU, ALT 44 IU, CRP 16.0 mg/dl, WBC 11,090/microl, and proteinuria. CT scan was unremarkable. The cerebrospinal fluid (CSF) showed 2 polymorphs/microl, 6 lymphocytes/microl, 65 mg/dl of glucose, and 42 mg/dl of protein. A diagnosis of scrub typhus was made. Treatment with minocycline brought about prompt disappearance of the fever and dramatic clinical improvement. Increased antibody titers confirmed the diagnosis. Although almost all patients present with high fever and severe headache, only a small number of patients have CSF pleocytosis. The present case illustrates that pain in scrub typhus is, on rare occasions, indistinguishable from trigeminal neuralgia. Neurologists should have a high index of suspicion in patients with fever and headache during the epidemic season and should be familiar with the systemic symptoms and signs.

[Association of estrogen receptor gene polymorphisms and primary trigeminal neuralgia]

OBJECTIVE

To investigate the association of estrogen receptor (ER) gene polymorphism and primary trigeminal neuralgia.

METHODS

By polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), ER gene polymorphism was analyzed in 20 trigeminal neuralgia (TR) patients and 20 control individuals, and the distribution of ER genotype was compared in TR group and control group.

RESULTS

There was no significant difference in frequencies of allele and genotype in XbaI or PvuII polymorphism or XbaI with PvuII polymorphisms together between TR group and control group (P > 0.05). The genotypic distribution of Xx or PpXx in TR group was higher than control group, and it was contary to xx, ppxx or Ppxx in TR group and control group.

CONCLUSION

XbaI or PvuII polymorphism may be related to TR. Women with PpXx genotype may be a dangerous factor to primary trigeminal neuralgia.

Vascular Compression Syndrome of the Vestibular Nerve: A Critical Analysis

The rationale, indications, and surgical results of microvascular decompression for the treatment of vertigo are reviewed, and a critical analysis is made. The syndrome of disabling positional vertigo is discussed. It is concluded that (1) vascular compressive vestibular neuropathy may exist, (2) the current published diagnostic criteria for this disorder are insufficient to firmly establish the diagnosis, and (3) further work delineating this syndrome should be undertaken.