Increased risk of trigeminal neuralgia in patients with migraine: A nationwide population-based study.

Objectives The objectives of this article are to evaluate the association between migraine and trigeminal neuralgia and to investigate the effects of age, sex, migraine subtype, and comorbid risk factors on trigeminal neuralgia development. Methods This population-based cohort study was conducted using data from Taiwan's National Health Insurance Research Database. Individuals aged ≥ 20 years with neurologist-diagnosed migraine between 2005 and 2009 were included. A non-headache age-, sex-, and propensity score-matched control cohort was selected for comparison. All participants were followed until the end of 2010, death, or the occurrence of trigeminal neuralgia. Cox proportional hazards regression was used to calculate hazard ratios (HRs) and 95% confidence intervals (CIs) for comparison of the risk of trigeminal neuralgia between groups. Results Both cohorts ( n = 137,529 each) were followed for a mean of 3.1 years. During the follow-up period, 575 patients (421,581 person-years) in the migraine cohort and 88 matched controls (438,712 person-years) were newly diagnosed with trigeminal neuralgia (incidence rates, 136.39 and 20.06/100,000 person-years, respectively). The HR for trigeminal neuralgia was 6.72 (95% CI, 5.37-8.41; p < 0.001). The association between migraine and trigeminal neuralgia remained significant in sensitivity analyses. Among migraine subtypes, patients with migraine with aura were at greater risk of trigeminal neuralgia development. No other significant interaction was identified in subgroup analyses. Conclusions Migraine is a previously unidentified risk factor for trigeminal neuralgia. The association between these conditions suggests a linked underlying mechanism, which is worthy of further exploration.

Riluzole and prognostic factors in amyotrophic lateral sclerosis long-term and short-term survival: a population-based study of 1149 cases in Taiwan.

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a rare disease in Taiwan; thus, estimation of ALS mortality is difficult. We evaluated factors associated with ALS survival in Taiwan. METHODS: The study enrolled 1149 Taiwanese with a primary diagnosis of ALS during 1999-2008. Follow-up information was available for all patients; mean (SD) duration of follow-up was 2.91 (2.62) years. Medical interventions, including noninvasive positive pressure ventilation (NIPPV), tracheotomy, gastrostomy, and riluzole, were included in time-dependent survival analysis. RESULTS: Of the 1149 ALS patients, 438 (38.12%) died during follow-up. Mortality in the first year was 16%, which was 13 times (95% CI 11.1-15.2) the age- and sex-standardized rate of the general population in Taiwan. The average annual crude mortality rate was 13.1% (person-years). Factors significantly associated with increased mortality were male sex, advanced age, rural residence, lower economic status, no tracheotomy, and no riluzole treatment. Significant predictors of long-term versus average survival were younger age at diagnosis, being a dependent or receiving social welfare, and NIPPV support. Significant predictors of short-term versus average survival were older age, being employed, no tracheotomy, and no riluzole use. CONCLUSIONS: The results support the use of riluzole to improve ALS survival. Patients who received riluzole and underwent tracheotomy had the best survival.

Efficacy, safety, and predictors of response to botulinum toxin type A in refractory chronic migraine: a retrospective study.

BACKGROUND: Due to its persistent and debilitating nature, refractory chronic migraine (RCM) can cause significant socioeconomic burden. This study retrospectively reviewed the efficacy and safety of botulinum toxin type A (BoNT-A) in the treatment of RCM. Predictors of treatment response were also investigated. METHODS: We enrolled 94 patients in this study after reviewing the records of those patients who received BoNT-A injections ≥ 75 U in our headache clinic, and who fulfilled the criteria for RCM established by Schulman et al. The outcome variables included headache frequency, migraine disability assessment score, and adverse events recorded in headache diaries. Treatment response was defined as ≥ 30% reduction in headache frequency from baseline at 12 weeks. Potential predictors of treatment response were evaluated, including patient demographics, headache directionality, ocular-type headache, medication overuse, BoNT-A dosage, body mass index, and Beck depression inventory score. RESULTS: For the 94 patients with RCM who were enrolled, their mean baseline headache frequency was 23.9 days/28 days. At 12 weeks after BoNT-A injection, the mean reduction in headache frequency was 6.5 days/28 days (p < 0.001), and the median migraine disability assessment score decreased from 60.0 to 30.0 (p < 0.001). Thirty-seven (39.4%) patients responded to treatment, and only ocular-type headache was associated with a higher response rate (ocular vs. nonocular, 54.8% vs. 31.7%; p = 0.031). The most common adverse event was lateral eyebrow elevation (19.1%), followed by neck soreness (5.3%). CONCLUSION: About 40% of patients with RCM obtained ≥ 30% reduction in headache frequency at 12 weeks after BoNT-A injection, and treatment-related adverse events were transient and acceptable. Ocular-type headache may predict treatment response.

Poor responses to interferon-beta treatment in patients with neuromyelitis optica and multiple sclerosis with long spinal cord lesions.

Interferon-beta (IFN-ß) treatment may not be effective in neuromyelitis optica (NMO). Whether the poor response to IFN-ß is related to long spinal cord lesions (LSCL) or the NMO disease entity itself is unclear. We evaluated the spinal cord involvement of patients with multiple sclerosis (MS) and NMO, as well as the response after receiving IFN-ß. Forty-nine MS and 21 NMO patients treated with IFN-ß for at least 2 years from 2002-2008 were enrolled in this study and the treatment response was analyzed 2 years post-treatment. In the study, spinal cord lesions were present in 57.1% (28/49) of the MS patients, of which 16.3% (8/49) presented spinal cord lesions longer than 3 vertebral segments (LSCL). Responses to IFN-ß treatment were seen in 69.3% (34/49) of all the MS cases, of which the appropriate response rates were 76.1% (16/21) in MS patients without spinal cord lesions and 37.5% (3/8) in patients with LSCL. Only 14.2% (3/21) of NMO patients responded to IFN-ß treatment. In conclusion, spinal cord lesion is common in MS patients in Taiwan. Both NMO and MS patients with LSCL had a poor response to IFN-ß treatment. NMO patients had a worse response to IFN-ß treatment than MS patients with LSCL, which shows that the crucial structural defect is something other than LSCL such as the elevated serum IL17 level in NMO compared to MS.

Effectiveness of botulinum toxin A in treatment of refractory erythromelalgia.

Erythromelalgia is characterized by intense burning pain, erythema, and heat in affected areas after precipitating factors such as warm temperature or stress. It is refractory to treatment in some situations. We describe a woman with adenosquamous cell carcinoma of the lung and medically refractory erythromelalgia. The symptoms of erythromelalgia presented as refractory to any medical treatment. Due to the unresponsive nature of her condition, botulinum toxin type A (onabotulinumtoxin A) was injected over both of her cheeks, periodically for six cycles. Her symptoms responded dramatically to subcutaneous and intradermal injection of botulinum toxin type A. Repetitive injection demonstrated consistent and reproducible responses, and the efficacy was maintained for approximately 1 month. No adverse effects or complications were noted. Botulinum toxin type A might be safe and effective as an alternative treatment for refractory erythromelalgia, but further large-scale studies are required.

Prominent brainstem symptoms/signs in patients with neuromyelitis optica in a Taiwanese population.

Neuromyelitis optica (NMO) is a severe demyelinating disease defined principally by its selective effect on the optic nerves and spinal cord. Contemporary diagnostic criteria require an absence of any clinical disease outside the optic nerve or spinal cord. However, we frequently encounter patients with NMO who have previously undetected symptomatic brainstem lesions. We investigated the brainstem symptoms/signs in patients with NMO and their corresponding MRI findings in a Taiwanese population. We evaluated the clinical symptoms/signs, anti-aquaporin-4 antibody titer and corresponding brain MRI of 49 patients with NMO; results were obtained from chart reviews and during clinical visits. A total of 18 (37%) patients with NMO had brainstem symptoms/signs, including diplopia (n=9, 50%), prolonged hiccup and poor appetite (n=9, 50%). For these patients, most of their brainstem events occurred during the first demyelinating attack in their NMO course. A higher percentage (77.8%) of patients with brainstem NMO had brain lesions with specific NMO patterns, including lesions involving the hypothalamus (n=6, 33.3%), midbrain or pons (n=8, 44.4%), periaqueductal regions (n=5, 27.7%), and medulla (n=10, 55.6%). Brainstem symptoms/signs and characteristic NMO imaging findings are common in Taiwanese patients with NMO, and should be considered a part of the illness in addition to optic neuritis and myelitis.

Glatiramer acetate could be a hypothetical therapeutic agent for neuromyelitis optica.

Neuromyelitis optica (NMO) is characterized by concurrence of optic neuritis and transverse myelitis, which is typically associated with a spinal cord lesion extending three or more vertebral segments. NMO is an inflammatory, demyelinating central nervous system disorder, and although it has a relapsing course in more than 90% of patients, it differs from multiple sclerosis in that it is more severe, usually spares the brain, and is associated with a longitudinally extensive lesion on spinal cord magnetic resonance imaging (MRI). Furthermore, NMO is associated with a highly specific serum marker called anti-aquaporin-4 antibody, which is believed to have a central pathogenetic role in NMO. Treatment with B-cell specific monoclonal antibody (rituximab) and plasma exchanges appears to reduce the severity and frequency of attacks in NMO, and therefore, B-cell autoimmunity as well as a humoral mechanism may be involved in the pathogenesis of NMO. Glatiramer acetate (GA; also known as Copaxone, COP-1) is a synthetic copolymer of a pool of peptides composed of random sequences of four amino acids: glutamine, lysine, alanine, and tyrosine. GA-specific T-helper 1- (Th1) and 2-type (Th2) cells produce brain-derived neurotrophic factor (BDNF), which may affect neuronal survival and myelin repair. GA treatment also leads to sustained augmentation of BDNF, neurotrophin (NT)-3, and NT-4 expression in various brain regions as demonstrated by histological analysis of immunostained brain sections and BDNF elevation after GA treatment on both protein and mRNA levels. GA-Th2 activation may also have a neuroprotective role in the course of NMO. Furthermore, B cells from GA-treated mice suppress experimental autoimmune encephalomyelitis. The pathogenesis of NMO is largely unknown. However, there is some evidence that B-cell autoimmunity, activation of eosinophils, and B-cell activating factor play important roles, based on neurotrophic factors, neuroprotection, anti-inflammation, and B-cell modulation, GA is thus a hypothetic potential treatment agent for NMO.