A study of acupuncture in Asian patients: clinical aspects and effects on cortical excitability

OBJECTIVE

To determine the effect of acupuncture on the phosphene threshold, by transcranial magnetic stimulation (TMS), and the clinical effect of acupuncture on headache frequency, duration and severity.

METHODS

Twenty-one patients (16 women; mean age 46 years; range 23-61 years, 17 Chinese, 2 Malays, 2 Indians) underwent 10 acupuncture sessions scheduled twice a week for 5 weeks. The lowest TMS intensity to elicit phosphene perception is defined as the phosphene threshold. TMS was performed before the first and last sessions, and at 2 months' follow-up.

RESULTS

Acupuncture resulted in reduction of headache frequency, duration and severity over the course of treatment. However, this was not accompanied by a corresponding increase in the phosphene threshold over a similar time course. The baseline threshold before acupuncture treatment had no predictive value for outcome of treatment.

CONCLUSIONS

Although acupuncture was effective in treating migraine, the use of occipital cortex excitability as an adjunctive parameter to evaluate treatment response was not suitable. The relief of migraine with acupuncture may be related to separate neural pathways independent of occipital or visual processes in the human brain.

A pilot study of topiramate dosages for migraine prophylaxis in an Asian population

Topiramate is known to be efficacious in migraine prophylaxis, but its optimal dose has not been systematically studied in the Asian population. Here, we show that a fixed low dose of topiramate 25 mg/day is efficacious in migraine prophylaxis and also attest to advantages in terms of medication cost savings and more favourable side effect profile.

Clinical correlates of phosphene perception in migraine without aura: An Asian study

INTRODUCTION

Although controversy exists with regard to the presence of hypoexcitability versus hyperexcitability of the visual cortex in migraine patients, there remain a group who do not perceive phosphenes (P-). However, its clinical implications have not been systematically addressed. In this study, we hypothesize that P- patients classified as migraine without aura (MO) have distinct clinical features.

METHODS

Twenty-nine Asian MO patients (7 men; mean age: 44; median: 45; range: 25 to 65) were consecutively entered into the study. Visual cortex transcranial magnetic stimulation (TMS) was performed in the migraine interictum.

RESULTS

Of the 19 patients, 19 (66%) were able to perceive phosphenes (P+), while 10 (34%) were not able to after repeated TMS (P-). P- patients had significantly higher headache frequency (p=0.008) and pain score (p=0.002) compared with P+ patients. In addition, there was significant positive correlation of phosphene threshold with pain score (r=0.52, p=0.02) in P+ patients. There was no significant difference between P+ and P- patients in terms of age (t-test, p=0.6).

CONCLUSIONS

Our study is inkeeping with the hypothesis that interictal visual cortex excitability is reduced in relation to the severity of migraine in Asian MO patients, and lack of phosphene perception may be related to significantly elevated thresholds beyond the output of TMS stimulators.

Clinical features of childhood onset essential tremor

Childhood onset essential tremor (ET) is uncommon. It is not clear as to whether ethnicity-specific differences may influence the phenotypic features. To determine the frequency and clinical characteristics of childhood ET in a tertiary referral center. In a prospective evaluation of 120 consecutive ET patients in a movement disorders clinic, we found a 15.5% (19) frequency of childhood onset ET patients. The mean age of onset and mean age was 10.8 +/- 4.1 (6-16) years and 25.7 +/- 15.0 (16-73) years consisting of 73.6% (14/19) men and 26.4% (5/19) women. A positive family history of ET was present in 11 of 19 (52.6%). Presence of a head tremor was observed in 2/19 (10.5%). We highlighted a relatively high frequency (15,5%) of childhood ET in our Asian cohort. In addition, we drew attention to the male preponderance and the low frequency of head tremor in childhood ET corroborating study findings in white ET patients. These observations appear to transcend ethnic and cultural differences and lend further support that gender difference may play a role in the pathogenesis and expression of ET.

Knowledge about the genetics of essential tremor in patients and their relatives

In a face-to-face questionnaire-based survey involving a total of 111 essential tremor (ET) patients and their relatives, we demonstrated a general lack of genetic insight amongst our study subjects. There was no significant correlation between genetic knowledge of ET and age, level of education, disease duration or severity. A proactive effort is needed to encourage physicians managing ET patients to incorporate genetic information and education into their practice.

Non-motor manifestations in essential tremor: use of a validated instrument to evaluate a wide spectrum of symptoms

INTRODUCTION

Recent studies suggest an association between non-motor symptoms and essential tremor (ET). Few studies have assessed psychological symptoms in ET. These studies were limited to western white populations and utilized scales that were specific to only one or two psychiatric domains. By contrast, the Symptom Checklist-90R (SCL-90R) is a validated clinical scale to screen for symptoms related to a spectrum of nine different psychological domains.

OBJECTIVE

To determine whether a wide spectrum of non-motor manifestations is associated with ET in patients in an Asian cohort.

METHODS

Consecutive ET patients and a group of control subjects were evaluated using the SCL-90R, which is comprised of items in nine major symptom dimensions and three global indices, including the positive symptom distress index.

RESULTS

ET patients (N = 84) and controls (N = 78) were similar in age (50.0+/-18.0 vs 46.0+/-14.4 years), gender and other demographic variables. ET patients had higher scores in three of nine major symptom dimensions: anxiety, phobic anxiety (p < 0.0005) and psychoticism (p = 0.005). In multivariate analysis, the anxiety (p < 0.0005) and the positive symptom distress index scores (p < 0.0005) were greater in ET patients compared to controls after adjusting for sex, age, marital status and educational level. The severity, but not duration of ET was correlated with the severity of anxiety symptoms.

CONCLUSIONS

Utilizing the SCL-90R, we highlighted that ET patients reported more non-motor symptoms than healthy controls. The more frequent occurrence of anxiety symptoms in our Asian cohort extends the observation that such non-motor manifestations should be considered in the clinical management of ET.

Restless legs symptoms in thyroid disorders

Dopaminergic dysfunction is associated with thyroid disorders and restless legs syndrome (RLS). In a 'face-to-face' interview, we evaluated for RLS using the diagnostic criteria of the International Restless Legs Syndrome Study Group (IRLSSG) in patients diagnosed biochemically with either hyper- or hypothyroidism, and in controls without thyroid disorders. Amongst 146 consecutive patients with biochemically confirmed thyroid disorders, none satisfied all the IRLSSG criteria of RLS, similar to the control population (0.2%, 1/434). However, we found 8.2% (12/146) with RLS-like symptoms (satisfied the first 3 IRLSSG criteria) compared to 0.9% (4/434) in the controls (p < 0.0001). Four (33.3%) of these patients reported complete resolution of these symptoms after treatment for their thyroid condition. In conclusion, while RLS-like symptoms were observed in some patients with thyroid disorders, our study demonstrates no significant difference of RLS prevalence between patients with thyroid disorders and euthyroid controls.

Dose-dependent protective effect of coffee, tea, and smoking in Parkinson's disease: a study in ethnic Chinese

INTRODUCTION

Few studies have examined the relationship of coffee and tea in Parkinson's disease (PD). The potential protective effect of coffee intake and risk of PD has not been studied in a Chinese population. There is a high prevalence of caffeine takers among Chinese in our population.

OBJECTIVE

We undertook a case control study to examine the relationship between coffee and tea drinking, cigarette smoking, and other enviromental factors and risk of PD among ethnic Chinese in our population.

METHODS AND RESULTS

300 PD and 500 population controls were initially screened. Two hundred case control pairs matched for age, gender, and race were finally included in the analysis. Univariate analysis revealed significant association of PD with coffee drinking (p<0.0005), tea drinking (p=0.019), alcohol drinking (p=0.001), cigarette smoking (p<0.0005), and exposure to heavy metals (p=0.006). Conditional logistic regression analysis demonstrated that amount of coffee drunk (OR 0.787, 95%CI 0.664-0.932, p=0.006), amount of tea drunk (OR 0.724, 95%CI 0.559-0.937, p=0.014), number of cigarettes smoked (OR 0.384, 95%CI 0.204-0.722, p=0.003), history of heavy metal and toxin exposure (OR 11.837, 95%CI 1.075-130.366, p=0.044), and heart disease (OR 5.518, 95%CI 1.377-22.116, p=0.016) to be significant factors associated with PD. One unit of coffee and tea (3 cups/day for 10 years) would lead to a 22% and 28% risk reduction of PD. One unit of cigarette smoke (3 packs/day for 10 years) reduced the risk of PD by 62%.

CONCLUSIONS

We demonstrated a dose-dependent protective effect of PD in coffee and tea drinkers and smokers in an ethnic Chinese population. A history of exposure to heavy metals increased the risk of PD, supporting the multifactorial etiologies of the disease.

Monoamine oxidase B polymorphism, cigarette smoking and risk of Parkinson's disease: a study in an Asian population

Cigarette smoking is associated with reduced monoamine oxidase B (MAO B) activity. Polymorphisms of the MAO B gene may modify the relationship between smoking and Parkinson's Disease (PD). We examined the association of MAO B intron 13 G/A polymorphism and risk of PD, and the modulation of the polymorphism on smoking and PD in an Asian study population in Singapore. Two hundred and thirty PD patients (mean age 66.0 +/- 9.4 years, 63% men) and 241 age, gender, and race matched controls (mean age 64 +/- 9.2 years, 58.9% males) were studied. The frequency of G and A alleles in PD and controls was; 66/315 (21.0%) vs. 73/340 (21.5%) and 249/315 (79.0%) vs. 267/340 (78.5%). For women, the genotype frequency in PD and controls was; GG: 7/85 (8.2%) vs. 8/99 (8.1%); GA: 25/85 (29.4%) vs. 27/99 (27.3%); AA: 53/85 (62.4%) vs. 64/99 (64.6%). For men, allele frequency in PD and controls was; A: 118/145 (81.4%) vs. 112/142 (78.9%) and G: 27/145 (18.6%) vs. 30/142 (21.1%). The allele and genotype frequencies were not significantly different between young and late onset PD. The frequency of "ever" smokers in PD and controls was 31/230 (13.5%) vs. 52/241 (21.6%), P = 0.02. A stepwise logistic regression analysis did not reveal any interaction of smoking and the G allele and risk of PD. The MAO B G/A genotype frequency in our Asian population was quite different from Caucasians suggesting that ethnicity specific effects need to be considered in evaluating gene-environmental interaction.

Exploring the relationship between forced maximal flow at functional residual capacity and parameters of forced expiration from raised lung volume in healthy infants

The raised volume rapid thoraco-abdominal compression technique (RVRTC) is being increasingly used to assess airway function in infants, but as yet no consensus exists regarding the equipment, methods, or analysis of recorded data. The aim of this study was to explore the relationship between maximal flow at functional residual capacity (V'(maxFRC)) and parameters derived from raised lung volumes, and to address analytical aspects of the latter technique in an attempt to assist with future standardization initiatives. Forced vital capacity (FVC) from lung volume raised to 3 kPa, timed forced expiratory volumes (FEV(t)), and forced expiratory flow parameters at different percentages of expired FVC (FEF(%)) were measured in 98 healthy infants (1-69 weeks of age). V'(maxFRC) using the tidal rapid thoraco-abdominal compression (RTC) technique was also measured. The within-subject relationships and within-subject variability of the various parameters were assessed. Duration of forced expiration was < 0.5 sec in 5 infants, meaning that FEV(0.3) and FEV(0.4) were the only timed volume parameters that could be calculated in all infants during the first months of life, and even when it could be calculated, FEV(0.5) approached FVC in many of these infants. It is recommended that FEV(0.4) be routinely reported in infants less than 3 months of age. Contrary to previous reports, within subject variability of V'(maxFRC) was less than that of FEF(75) (mean CV = 6.3% and 8.9%, respectively).A more standardized protocol when analyzing data from the RVRTC would facilitate comparisons of results between centers in the future.

Restless legs syndrome in Parkinson's disease

INTRODUCTION

Recent clinical and functional imaging data suggest impaired central dopaminergic transmission in restless legs syndrome (RLS). As RLS responds to dopaminergic medications, an etiologic link between RLS and Parkinson's disease (PD) has been proposed. However, few studies have examined this association.

OBJECTIVE

To investigate the prevalence of RLS amongst PD outpatient population.

METHOD

The prevalence of RLS was determined by the diagnostic criteria of the International Restless Legs Syndrome Study Group (IRLSSG). Consecutive PD patients (n=125) were prospectively evaluated in our clinic.

RESULTS

There were 77 (61.6%) males and 48 (38.4%) females with a mean age of 65.1+/-9.3 (SD) years (range 34-83), and mean age of onset of disease at 59.6 years+/-10.7 (SD) years (range 30-81). Nineteen (15.2%) patients had motor restlessness. Of these, one (0.8%) patient had RLS-like symptoms closely correlated to wearing "off" effect of levodopa. None of the patients satisfied the IRLSSG diagnostic criteria of RLS. This was not significantly different compared to the 0.6% and 0.1% RLS prevalence in our general population and clinic population.

CONCLUSIONS

Our study demonstrates that motor restlessness was present in 15.2% of our PD patients. However, prevalence of RLS in our PD patients was not significantly different from our general population or clinic population, suggesting that these two diseases may not share the same pathophysiologic mechanism.

Evaluation of somnolence in Parkinson's disease: comparison with age- and sex-matched controls

The authors found a significantly higher prevalence of daytime somnolence in 201 patients with PD compared with 214 age- and sex-matched healthy control subjects (Epworth Sleepiness Scale score 5.6 vs 4.6). The prevalence of "sleep attacks" (SA) was about seven times higher in patients with PD than in control subjects (13.9% vs 1.9%; p < 0.0005). Multivariate analysis demonstrated that a higher dose of levodopa and longer duration of disease significantly predicted for SA in patients with PD. Epworth Sleepiness Scale scores of > or =10 had 71.4% sensitivity and 88.4% specificity for SA.

Influence of jacket placement on respiratory compliance during raised lung volume measurements in infants

SUMMARY. Recent introduction of the raised lung volume rapid thoraco-abdominal compression (RVRTC) technique for measuring forced expiratory maneuvers in infants provides the potential opportunity to assess respiratory mechanics simultaneously by using multiple linear regression (MLR) of the relaxed breaths preceding jacket inflation to force expiration. This study was undertaken to investigate whether data obtained from raised lung volume are influenced by placement of the rapid thoraco-abdominal compression (RTC) squeeze jacket. Paired measurements of tidal volume (V(T)) and respiratory rate (RR) during tidal breathing, and of inflation volume (V(inf)), respiratory system compliance (C(rs)), and resistance (R(rs)) during passive lung inflations were made in 60 (30 male) healthy term infants with and without a fastened, but uninflated RTC jacket in place. Jacket placement was associated with a significant reduction (P < 0.0001) in weight-corrected V(inf) [-1.86 (95% confidence interval, -2.46, -1.27) mL.kg(-1)] and C(rs) [-0.77 (-1.04, -0.49) mL.kPa(-1).kg(-1)]. This represented a reduction in weight-corrected C(rs) from 9.00 to 8.24 mL.kPa(-1).kg(-1), with the fall being >10% in 42% of infants studied. There was no significant change in R(rs) or weight-corrected V(T). If passive respiratory mechanics are to be measured during raised lung volume maneuvers, they should be performed prior to the jacket being fastened, unless considerable care is taken with each infant to ensure that the jacket does not restrict chest wall movement during maximum inflation.