Original Article

Tay LB, Urkude R, Verma KK
Correspondence: Dr Kamal K Verma, kamal_verma@nni.com.sg

ABSTRACT
Introduction Carpal tunnel syndrome (CTS ) is the most common entrapment neuropathy seen in our neurodiagnostic laboratory referrals. We describe the clinical profile, and outcome in patients with electrophysiological diagnosis of CTS seen in our centre over a six month period.
Methods A retrospective study was carried out and included 134 consecutive patients with CTS referred to the Neurodiagnostic Laboratory, National Neuroscience Institute, from October 2003 to March 2004, for the confirmatory testing. Severity grade was assigned following American Association of Electrodiagnostic Medicine criteria of CTS.
Results The majority of patients were female (81.3 percent) with mean age of presentation being 53.6 years. Chinese women constitute the majority racial group. Paraesthesia (70.1 percent) and numbness (19.4 percent) were the presenting sensory symptoms. In the nerve conduction study, 108 patients had bilateral CTS with 35 having unilateral symptoms. Dominant hand involvement was present in 92.3 percent. Overall, 40.3 percent had mild, 46.3 percent had moderate and 13.4 percent had severe CTS, with median duration of symptoms of two, four and 12 months, respectively. Follow-up data were available for 115 patients. 27 patients with surgical treatment showed resolution or improvement in 53.3 percent with moderate CTS, and 83.3 percent with severe CTS, at three-month follow-up. 14 patients turned up for six-month follow-up and 92.9 percent showed improvement in symptoms. 88 patients were managed conservatively; symptoms were unchanged or worsened in 80.6 percent with mild CTS, 65.9 percent with moderate CTS, and 62.5 percent with severe CTS at three-month follow-up. Of the 54 patients who turned up for six-month follow-up, the clinical symptom remain unchanged or worsened in 68.5 percent.
Conclusion The severity of CTS is associated with longer duration of symptoms. Sensory symptoms and dominant hand involvement is more common. There is a high default rate in the clinical follow-up. Early surgical intervention results in either resolution or improvement in symptoms, whereas conservative management does not affect the natural history with symptoms that persisted or worsened with time.

Keywords: carpal tunnel syndrome, electrodiagnosis, entrapment neuropathy, nerve conduction, neuropathy
Singapore Med J 2006; 47(12): 1049-1052

Bhat RA, Kushtagi P
Correspondence: Prof Pralhad Kushtagi, pralhadkushtagi@hotmail.com

ABSTRACT
Introduction The duration of human pregnancy is arbitrarily taken as 280 days (40 weeks). Foetuses are considered to be at high risk once pregnancy goes beyond the expected date of confinement. This study was carried out with the aim of determining the mean gestation age of low-risk pregnancies that went into spontaneous labour and the incidence of adverse outcomes in relation to gestation.
Methods Low-risk singleton pregnancies admitted in spontaneous labour at a single community hospital in the Udupi district of Karnataka in South India, from December 2002 to December 2003, were analysed for mean gestational age at the onset of spontaneous labour and rates of perinatal complications by gestational age.
Results Among the 1,094 women who went into spontaneous labour, the mean gestational age was 272.1 +/- 9 days. A significantly increased incidence of meconium-stained amniotic fluid beyond 39 weeks of gestation was observed. 783 of 1,094 women (80 percent) had delivered during the period of 261-280 days of pregnancy (period of one standard deviation around the mean gestational age at delivery). There was significant increase in perinatal morbidity indicators and mortality rates once the pregnancy carried beyond 280 days.
Conclusion Mean gestational age at the onset of labour for women native to the area of study was 272 days (standard deviation 9 days). Pregnancies beyond a duration of 280 days showed significantly increased perinatal morbidity. It is suggested that there is a need for determining the length of gestation and to compile gestation-wise incidence of meconium-stained amniotic fluid as an indicator of foetal maturity or the undisclosed risk factor, in addition to other neonatal morbidity indicators for different populations.

Keywords: human pregnancy, low-risk pregnancy, meconium-stained amniotic fluid, perinatal morbidity, pregnancy duration
Singapore Med J 2006; 47(12): 1044-1048

Manoharan S, Kavitha K, Senthil N, Renju GL
Correspondence: Dr S Manoharan, manshisak@yahoo.com

ABSTRACT
Introduction Oral cancer is the fifth most frequent cancer worldwide and India has recorded the highest incidence (40-50 percent) of oral malignancy. Clerodendron inerme is used by Indian traditional practitioners for the treatment of various ailments, including cancer. Our aim was to investigate the chemopreventive potential of the aqueous leaf extract of Clerodendron inerme (CiAet) in 7,12-dimethylbenz(a) anthracene (DMBA)-induced hamster buccal pouch carcinogenesis.
Methods We developed oral squamous cell carcinoma in the buccal pouch of male Syrian golden hamsters by painting them with 0.5% DMBA in liquid paraffin thrice a week for 14 weeks. The tumour incidence, tumour volume and tumour burden that were formed in the hamster buccal pouches were determined.
Results Oral administration of CiAet at a dose of 500 mg/kg body weight to DMBA-painted animals on days alternate to DMBA painting for 14 weeks significantly prevented the tumour incidence, tumour volume and tumour burden. CiAet also exerts potent antilipidperoxidative effect and improved the antioxidant defence system in DMBA-painted animals. The chemopreventive efficacy of CiAet was evident by inhibition of tumour formation (80%) in DMBA-painted animals.
Conclusion The chemopreventive potential of CiAet is probably due to its antilipidperoxidative effect or the presence of some potent bioactive chemopreventive principles in the leaves of Clerodendron inerme.

Keywords: antioxidants, chemoprevention, Clerodendron inerme, hamster buccal pouch, lipid peroxidation, oral carcinogenesis
Singapore Med J 2006; 47(12): 1038-1043

Agarwal R, Srinivas R, Aggarwal AN, Gupta D
Correspondence: Dr Ritesh Agarwal, riteshpgi@gmail.com; ritesh@indiachest.org

ABSTRACT
Introduction Paraquat poisoning is an uncommon entity in India. We report our experience of managing five patients with paraquat poisoning using immunosuppressive therapy.
Methods Retrospective analysis of 84 patients admitted with a diagnosis of poisoning over the last eight years was performed. The data were presented in a descriptive fashion.
Results Five (5.9 percent) out of the 84 patients were admitted with a diagnosis of paraquat poisoning. All patients were mechanically ventilated. All patients had hepatic failure with median peak bilirubin being 22.1 +/- 15.1 mg/dL (range 8.4-45.5). Four of the five patients had renal failure (median peak creatinine 3.8 +/- 1.5 mg/dL; range 3.4-11.1) requiring renal replacement therapy. All patients were treated with intravenous methylprednisolone 15 mg/kg/day for three consecutive days and intravenous cyclophosphamide 10 mg/kg/ day for two consecutive days, followed by intravenous dexamethasone 4 mg thrice a day until recovery or death. Two out of the five patients survived. Three died because of severe acute respiratory distress syndrome and multiorgan dysfunction syndrome.
Conclusion Paraquat poisoning is an uncommon entity in India, and is associated with a high mortality rate. There is a potential role for immunosuppressive therapy in patients with moderate to severe poisoning.

Keywords: cyclophosphamide, immunosuppression, methylprednisolone, paraquat, poisoning
Singapore Med J 2006; 47(12): 1033-1037

Karatas AD, Aygun D, Baydin A
Correspondence: Dr Aydin Deniz Karatas, aydindeniz75@gmail.com

ABSTRACT
Introduction Organochloride insecticides are chlorinated cyclic hydrocarbons having molecular weights in the range of 300-550 Da. Case series of endosulfan poisoning are extremely rare in the literature. We report 23 cases of endosulfan poisoning.
Methods This retrospective study enrolled patients with endosulfan poisoning presenting to our emergency department from January to December 2005. The data were collected from clinical records and laboratory files.
Results On admission, initial symptoms were nausea and vomiting in 17 patients (73.9 percent), seizures in five patients (21.7 percent), and dizziness in one patient (4.3 percent). Symptoms began within one hour after ingestion in 12 patients (52.2 percent), in the second hour in nine patients (39.1 percent), and in the third hour in two patients (8.7 percent). Seizure types were generalised tonic-clonic in 16 patients (84.2 percent), and focal seizures in three patients (15.8 percent). 19 patients were observed for one day, two patients were observed for two days, and one patient was followed-up for ten days in the emergency department. One patient was transferred for liver transplantation on the fifth day to another centre. All patients were treated symptomatically by intravenous diazepam for controlling seizures.
Conclusion Endosulfan poisoning can be suspected in the presence of primary central nervous system manifestations including seizures, with or without clinical or laboratory evidence of other organ dysfunction such as liver failure.

Keywords: central nervous system disorders, endosulfan poisoning, insecticide ingestion, organochloride insecticide, poisoning
Singapore Med J 2006; 47(12): 1030-1032

Tan KH, Lai FO, Hwang NC
Correspondence: Dr Kian-Hian Tan, tankianhian@gmail.com

ABSTRACT
Introduction Physio Flow is a non-invasive impedance cardiograph device that measures cardiac output. Recommended electrode placements involve six electrodes, including two near the xiphisternum (Z3 and Z4/ ECG3/neutral). This study aims to evaluate if changing the positions of these two leads to the left fourth and fifth intercostal spaces along the mid-axillary line results in a change in the cardiac output measurement.
Methods This was a prospective, controlled, crossover, paired study of 30 patients where electrodes were placed in the recommended positions and cardiac output (CO1) obtained after two minutes. The second cardiac output (CO2) was then obtained with the electrodes Z3 and Z4/ECG3/neutral repositioned at the left mid-axillary line at the fourth and fifth intercostal spaces. The final step involved switching the Z3 and Z4/ECG3/neutral leads back to the recommended position and the cardiac output (CO3) was measured.
Results The average of the initial and third readings (COave) was compared with the measured CO2 and analysed. The regression equation was: CO at the proposed site (CO2) = COave at the recommended site + 0.058. The paired samples correlation was 0.995. Within the 95 percent limits of agreement, the bias with CO measured at the proposed site of electrode placement was 0.046 L/min with the limits at -0.24 L/min and 0.34 L/min. The mean difference was 0.86% of the average CO.
Conclusion A small positive bias was demonstrated when Physio Flow measurements were taken with the leads Z3 and Z4/ECG3/neutral placed in the mid-axillary line fourth and fifth intercostal spaces.

Keywords: electrode placements, impedance, non-invasive cardiac output monitoring, Physio Flow®
Singapore Med J 2006; 47(11): 967-970

Afifi M
Correspondence: Dr Mustafa Afifi, afifidr@yahoo.co.uk

ABSTRACT
Introduction The study aimed to investigate the association of health practices and depressive symptoms among high school adolescents in a national representative sample of 5,409 students in Oman.
Methods Depressive symptoms were screened in 2004 through the application of the self-report 27-item Child Depression Inventory. Health practices scale comprised a simple sum of five healthy practices, namely: sleeping seven to eight hours at night, having breakfast daily, not eating between meals, not smoking the month prior to the study, and doing physical activities more than once per week apart from attending physical education classes in school.
Results Sequential logistic regression models were run to test for the change in the odds-ratio (OR) of having depressive illness with a one point increase in the healthy practices scale, after adjustment for other risk factors of depression. Health practices remained having a significant protective effect on depression (OR is 0.72, 95 percent confidence interval is 0.64-0.80) even after adjustment to other significant covariates in the last model, such as history of chronic medical or mental illness diagnosed by a doctor, high scoring in chance health locus of control (HLC), low scoring in internal HLC, poor relationships with social contacts, and physical abuse during childhood or adolescence.
Conclusion Findings support the protective effects of positive health practices on adolescents' depression.

Keywords: adolescents, depression, health practices
Singapore Med J 2006; 47(11): 960-966

Mahendran R, Vaingankar JA, Mythily S, Cai YM
Correspondence: Dr Rathi Mahendran, rathi_mahendran@imh.com.sg

ABSTRACT
Introduction Co-sleeping or bed-sharing is a common practice that has been little researched. While often viewed as being "cultural" in nature, there is a suggestion that it may be a parental response to sleep problems. Some studies link co-sleeping with behavioural and temperamental difficulties. The objectives of the current study were to determine the prevalence of co-sleeping and how they relate to sleeping problems among a cohort of children and adolescents seen in a child guidance clinic.
Methods Parents or guardians of all new patients seen at the child guidance clinic were asked to complete a questionnaire upon their consent to participate in the study. The questionnaire included socio-demographical data and frequency of sleep problems in the past six months. A list of nine common sleep problems was included.
Results The prevalence of co-sleeping was found to be 72.7 percent. The children who co-sleep were significantly younger and there was a decrease in the practice with increasing age. Sleep starts and nightmares were significantly more among those sleeping alone.
Conclusion Co-sleeping was not associated with significant sleep problems in our cohort. Co-sleeping may have been initiated in response to an existing sleep problem but eventually resolved the problem. If co-sleeping is not permitted, the sleep problem could be compounded, giving rise to a higher prevalence of sleep starts and nightmares among those in our cohort who slept alone.

Keywords: adolescents, bed-sharing, child guidance, co-sleeping, sleep problems
Singapore Med J 2006; 47(11): 957-959

Sia AT, Lim Y, Ocampo CE
Correspondence: Dr Alex Sia, athsia@kkh.com.sg

ABSTRACT
Introduction The need for individualisation of analgesic therapy in labour cannot be overemphasised. We have devised a programme, based on a novel clinical algorithm, that converts a continuous infusion pump into a patient-controlled epidural analgesia (PCEA) pump that is responsive to the patient's needs by varying its rate of infusion.
Methods In this double-blinded, controlled trial, 40 American Society of Anesthesiologists 1 patients were recruited to receive either a continuous infusion of 10 ml/hour (Continuous Epidural Infusion [CEI], n=20) or the computer-integrated (CI) regimen (CI-PCEA, n=20) to maintain epidural analgesia after successful induction of combined spinal analgesia during early labour. The proportion of patients who had delivered without a requirement for analgesic supplementation was the primary outcome measure.
Results There was a significant difference in the incidence of breakthrough pain, i.e. the primary outcome measure (two in CI-PCEA versus eight in the CEI group, p-value is 0.027). There was a trend towards a longer duration before analgesic supplementation of analgesia was required after its induction with CI-PCEA than CEI (p-value is 0.06). We could not detect a difference in the total hourly consumption of epidural analgesics between the two groups.
Conclusion Our study also showed that with the CI-PCEA programme, we were able to convert an ordinary infusion pump to one which analyses the patients' needs in the previous hour (based on analgesic demands) and automatically adjusts the basal infusion accordingly. CI-PCEA reduced the incidence of breakthrough pain without the evidence of increasing drug consumption when compared with CEI.

Keywords: computer integration, labour analgesia, patient-controlled epidural analgesia
Singapore Med J 2006; 47(11): 951-956

Udayakumar N, Chandrasekaran M, Rasheed MH, Suresh RV, Sivaprakash S
Correspondence: Dr Navaneethan Udayakumar, udhaykumar81@yahoo.co.in

ABSTRACT
Introduction This project aimed to study the incidence and profile of bone involvement in thyrotoxicosis patients by dual energy X-ray absorptiometry (DEXA) scan and the effect of treatment on the bone mineral density (BMD).
Methods A total of 50 young patients with a mean age of 29.4 years, diagnosed to have thyrotoxicosis clinically and proven by thyroid function tests, were included in this prospective three-year study conducted at the Madras Medical College and Government General Hospital in Chennai, India. Patients were enrolled if they had bone pain or had elevation of serum alkaline phosphatase. All these patients had a baseline BMD measurement by DEXA scans in the region of the lumbar vertebrae before treatment and the T-score was computed. All other secondary causes of low BMD, like primary hyperparathyroidism, long-term steroid intake, vitamin D deficiency, was ruled out. After definitive management of hyperthyroidism by anti-thyroid drugs and surgery, all the patients with bone involvement had a repeat DEXA scan after one year and the T-score was computed.
Results Out of 50 patients, 46 had bone involvement (92 percent). Based on the World Health Organisation classification, 16 (32 percent) had osteopenia and 30 patients (60 percent) had osteoporosis. After control of thyrotoxicosis, the mean bone mass increased from 0.729 g/sq cm to 0.773 g/sq cm, a statistically significant increase of 0.044 g/sq cm (p-value is less than 0.001) after one year, compared to age- and sex-matched controls. The mean percentage of the bone mass compared to the peak BMD increased from 70.2 percent to 74.2 percent after treatment, an increase of four percent (p-value is less than 0.001). The mean percentage of the bone mass compared to the age-matched BMD increased from 71.2 percent to 75.2 percent after treatment, an increase of four percent (p-value is less than 0.001), all of which were statistically significant.
Conclusion Metabolic bone disease should be looked for in all thyrotoxic patients, especially patients complaining of bone pain and those with elevated bone enzymes. DEXA scans offer a convenient, reliable and noninvasive modality for diagnosis and monitoring therapy.

Keywords: bone mineral density, dual energy x-ray absorptiometry, metabolic bone disease, osteoporosis, thyrotoxicosis
Singapore Med J 2006; 47(11): 947-950