Original Article

Prakash, Bhardwaj AK, Devi MN, Sridevi NS, Rao PK, Singh G
Correspondence: Dr Prakash, prakashrinku@rediffmail.com

ABSTRACT
Introduction The sciatic nerve is the largest nerve, with a long course in the inferior extremity. Its division into the tibial and common peroneal nerves can occur at any level from the sacral plexus to the inferior part of the popliteal space. These anatomical variations may contribute to clinical conditions such as piriformis syndrome, sciatica and coccygodynia.
Methods This study was performed on cadavers in order to study the level of sciatic nerve division. The inferior extremities of 43 cadavers were classified into six groups depending on the level of sciatic nerve division in the gluteal region, the upper, middle and lower parts of the back of the thigh, and the popliteal fossa.
Results The highest incidence of sciatic nerve division (40.7 percent) was observed in the lower part of the posterior compartment of the thigh. In 34.9 percent of the specimens, the sciatic nerve was divided into tibial and common peroneal nerves in the popliteal fossa. 16.3 percent of extremities showed sciatic nerve division proximal to its entrance in the gluteal region.
Conclusion In sciatic nerve neuropathies, the extent of neurological deficits depends on the level of sciatic nerve division. Sciatic nerve division into tibial and common peroneal components at a higher level can result in the involvement of only one out of the two divisions from sciatic neuropathy. It can also result in a failure of the sciatic nerve block while performing popliteal block anaesthesia.

Keywords: anatomy, cadaver, common peroneal nerve, sciatic nerve, tibial nerve
Singapore Med J 2010; 51(9): 721-723

Ko KF
Correspondence: Dr Ko Kwai-fu, kokwaifu@yahoo.com.hk

ABSTRACT
Introduction The role of evoked potential (EP) in evaluating multiple sclerosis (MS) has changed with the advent of magnetic resonance (MR) imaging. Given the possibly varied nature and distribution of pathologic lesions in Asian MS, this study compared the diagnostic usefulness of EPs to that of MR imaging among Chinese subjects.
Methods This was a retrospective study of MS patients treated at the Kwong Wah Hospital, Hong Kong, between June 2004 and June 2009. The visual (VEPs), brainstem auditory (BAEPs), somatosensory (SEPs) and trigeminal (TSEPs) EPs were compared with MR imaging for correlation and usefulness using the chi-square test. Sensitivities and specificities were calculated.
Results The results showed that abnormalities were detected in the three modalities of EP among the 17 patients studied (VEP 82 percent, median and tibial SEP 65 percent, BAEP 47 percent). Compared with MR imaging, VEP was far more useful at detecting optic nerve lesions, while SEP was less sensitive at detecting cord lesions. BAEP was able to localise lesions along the auditory pathways at a rate that was almost similar to that of MR imaging (non-inferiority). Both TSEP and MR imaging for trigeminal nerves were negative in the two patients with trigeminal neuralgia. In some instances, EPs yielded abnormalities that were undetected by conventional MR imaging, and the sensitivity increased with the number of EP modalities.
Conclusion EP may be considered in clinical situations in which MR imaging is negative or cannot be performed. They may also be performed when evaluating treatment response, long-term prognosis and nonspecific changes on MR imaging.

Keywords: Chinese, comparative study, evoked potentials, MR imaging, multiple sclerosis
Singapore Med J 2010; 51(9): 716-720

Chin LF, Lim WS, Kong KH
Correspondence: Ms Chin Lay Fong, lay_fong_chin@ttsh.com.sg

ABSTRACT
Introduction The aim of this study was to determine whether robotic-assisted locomotor training, a new clinical service introduced at the Tan Tock Seng Hospital (TTSH) Rehabilitation Centre, Singapore is effective at improving the ability to transfer and the ambulatory status of patients with an acquired brain injury.
Methods This was a retrospective review of data collected from patients with an acquired brain injury, before and after robotic-assisted locomotor training from September 2008 to May 2009. The primary outcome measures used were the functional independence measure (FIM) for transfer and ambulation, and the Rivermead Motor Assessment (RMA) gross function subscale. The secondary outcome measures used were the Motricity Index (MI) and Modified Ashworth Scale of the lower limb. Statistical analysis was performed on this data to evaluate whether robotic-assisted locomotor training was effective at improving the functional mobility of these patients.
Results Significant improvement was observed in the scores of FIM transfer (p is less than 0.05), FIM ambulation (p is less than 0.05) and RMA (p is less than 0.05) after robotic-assisted locomotor training. Significant improvements in the MI of hip flexion (p is less than 0.05), knee extension (p is less than 0.05) and ankle dorsiflexion (p is less than 0.05) post training have also been noted.
Conclusion Robotic-assisted locomotor training was found to be effective at improving the transfer, ambulation and functional mobility of patients with an acquired brain injury.

Keywords: acquired brain injury, locomotion, robotic, training, transfer
Singapore Med J 2010; 51(9): 709-715

Saw A, Sallehuddin AY, Chuah UC, Ismail MS, Yoga R, Hossain MG
Correspondence: Prof Saw Aik, sawaik@hotmail.com

ABSTRACT
Introduction The pattern of fracture, including the anatomical location and age distribution, may differ among urban and rural populations due to various factors such as the inhabitants’ occupation and living environment.
Methods This was a retrospective multicentre study involving two urban and three rural hospitals in Malaysia. The demographic data and anatomical location of fracture of patients admitted in 2007 were collected for analysis.
Results A total of 7,973 patients were admitted for fractures between January and December 2007. The femur was the commonest fracture site that required admission in the urban population (21.9 percent), followed by the tibia-fibula (18.7 percent), while the radius-ulna was the commonest site among the rural population (22.0 percent), followed by the tibia-fibula (19.4 percent). The rates of head and pelvic fractures were comparatively higher in the urban population, while hand fractures were more common in the rural population. The higher rate of femur fracture in the urban group, especially among the elderly, may be due to the higher incidence of osteoporosis or a higher proportion of older people in the population.
Conclusion The anatomical locations of common fractures differed between the urban and rural populations. A higher rate of upper limb fractures was observed in the rural areas, while femur fractures in the elderly was the main cause of fracture admission in the urban areas. The relatively high rate of hand fractures in the rural areas, especially among children and young adults, may require further investigation.

Keywords: bone fractures, developing countries, rural population, urban population
Singapore Med J 2010; 51(9): 702-708

Hendricks MS, Chin H, Loh SF
Correspondence: Dr Marianne Sybille Hendricks, mariannehendricksemail@gmail.com

ABSTRACT
Introduction Women with a single ovary present a unique problem in assisted reproductive techniques. The aim of our study was to compare the ovarian response and pregnancy rates of women with one ovary and those with two ovaries in assisted reproduction.
Methods A total of 18 consecutive women with a single ovary (n is 22 cycles) were identified. The control group included 44 women with two ovaries and mechanical infertility, who were selected as frequency-matched samples (2:1) to meet the distribution of age at treatment and race in the single ovary group. All patients underwent controlled ovarian hyperstimulation treatment via the long down-regulation protocol using a gonadotropin-releasing hormone agonist. Standard procedures were carried out for gamete-embryo handling, and embryo transfer was performed using a soft catheter on day two in all cases. The luteal phase was supported by progesterone or Pregnyl after oocyte pick-up.
Results The duration of stimulation (11.3 +/- 1.7 versus 10.1 +/- 1.4 days) and the total follicle stimulating hormone (FSH) consumption (3906.8 +/- 1860.6 mIU/ml versus 2900.0 +/- 1440.0 mIU/ml) were significantly higher, and the mean number of oocytes (10.8 +/- 4.5 versus 16.8 +/- 10.9) and metaphase II oocytes collected (9.5 +/- 4.5 versus 13.3 +/- 7.7) were significantly lower in the single ovary group (p is less than 0.05). The clinical pregnancy rates (31.8 percent versus 43.2 percent) were comparable between the two groups.
Conclusion Although women with a single ovary required significantly higher doses of FSH and a longer duration of stimulation, as well as produced less oocytes, their clinical pregnancy rates were comparable to those of women with two ovaries in assisted reproduction.

Keywords: gonadotrophin-releasing hormone agonist, in vitro fertilisation, outcome, single ovary
Singapore Med J 2010; 51(9): 698-701

Boonsarngsuk V, Raweelert P, Sukprapruet A, Chaiprasithikul R, Kiatboonsri S
Correspondence: Dr Viboon Boonsarngsuk, bss-vb@hotmail.com

ABSTRACT
Introduction In day-to-day bronchoscopic practice, no guidance is available to pinpoint the precise location of pulmonary nodules or masses, especially in developing countries. This results in a large number of non-diagnostic testings. The present study aimed to determine the predictors of diagnostic yield in bronchoscopy without guidance and develop a model to predict the decision to perform this procedure.
Methods A retrospective study was conducted on 330 patients with pulmonary nodules or masses without any sign of atelectasis on chest radiographs, who underwent diagnostic bronchoscopy without guidance between June 2004 and May 2008. The patient characteristics, as well as radiological and bronchoscopic findings were included in the analysis of factors affecting the diagnostic yield.
Results The overall diagnostic yield of bronchoscopy was 55.8 percent. The tumour size, endobronchial visibility and the characteristics of endobronchial abnormalities were predictors of higher diagnostic yield. The prediction model was developed from the data that can be recognised before bronchoscopy. Bronchoscopy provided the diagnosis in 66.4 percent of the patients who had a tumour size of 4 cm or larger.
Conclusion The diagnostic yield of bronchoscopy without guidance was influenced by the size of the lesion, the endobronchial visibility and the characteristics of endobronchial abnormalities. Computed tomography (CT) of the chest should be performed to evaluate airway involvement. If the lesion is less than 4 cm in diameter and there is a negative CT illustration of airway involvement, flexible bronchoscopy with guidance should be considered.

Keywords: diagnostic yield, flexible bronchoscopy, guidance, pulmonary nodule
Singapore Med J 2010; 51(8): 660-665

Meric M, Sayan M, Dundar D, Willke A
Correspondence: Dr Meliha Meric, drmelihameric@gmail.com

ABSTRACT
Introduction Tularaemia is an important zoonotic disease that leads to outbreaks. This study aimed to compare the epidemiological characteristics of two tularaemia outbreaks that occurred in the Sakarya region of Turkey, analyse the risk factors for the development of outbreaks and identify Francisella (F.) tularensis in the water samples.
Methods Two tularaemia outbreaks occurred in the Kocadongel village in 2005 and 2006. A field investigation and a case-control study with 47 cases and 47 healthy households were performed during the second outbreak. Clinical samples from the patients and filtrated water samples were analysed for F. tularensis via real-time polymerase chain reaction.
Results From the two outbreaks, a total of 58 patients were diagnosed with oropharyngeal tularaemia based on their clinical and serological results. Both outbreaks occurred between the months of January and April, and the number of patients peaked in February. Logistic regression analysis revealed that the consumption of natural spring water was the only significant risk factor for tularaemia infection (odds ratio 3.5, confidence interval 1.23–10.07). F. tularensis was detected in eight clinical samples and in the filtrated natural spring water.
Conclusion This study is the first report of tularaemia from this region. The results show that both tularaemia outbreaks were related to the consumption of untreated natural spring water. To prevent waterborne tularaemia, community water supplies should be treated and checked periodically.

Keywords: Francisella tularensis, outbreaks, polymerase chain reaction, risk factors, tularaemia
Singapore Med J 2010; 51(8): 655-659

Wong MTC, Ng KH, Lim JF, Ooi BS, Tang CL, Eu KW
Correspondence: Prof Eu Kong Weng, eu.kong.weng@sgh.com.sg

ABSTRACT
Introduction Evidence from randomised controlled trials has shown that laparoscopic colon and rectal cancer resection not only confers short-term benefits but also does not differ considerably in terms of its long-term oncological outcomes, as compared with open surgery.
Methods All laparoscopic colon and rectal resections performed between January 2005 and December 2007 were included. Patient records were reviewed from a prospective database and the relevant clinical data was obtained, with a subgroup analysis of cancer procedures performed.
Results 418 patients (247 male), median age 63 years (range 24 to 88), underwent laparoscopic resection of the colon and rectum. The median Body Mass Index (BMI) was 22.5 (range 13.5 to 39.3). The majority of the procedures were performed for malignant disease (81.3 percent) and the most common procedure was anterior resection (79.4 percent). The median duration of surgery was 135 minutes (range 65 to 330), with conversions to open surgery in 44 patients (10.5 percent). Complications occurred in 78 patients (18.7 percent), including anastomotic leaks in five (1.20 percent). The median length of hospital stay was five days (range 3 to 90) and the median follow-up was 19 months (range 1 to 46). In the 340 patients with malignant disease, the median number of lymph nodes harvested was 13 (range 5 to 48), and at the latest review, 230 patients (67.6 percent) were disease-free, with locoregional recurrence in 2.9 percent and systemic recurrence in 10 percent.
Conclusion To date, this is the largest series of laparoscopic colorectal resections reported locally, and our results show that it is safe, feasible and produces favourable results.

Keywords: benign, colon, laparoscopic, malignant, minimally invasive, rectum
Singapore Med J 2010; 51(8): 650-654

Shiva F, Ghotbi F, Yavari SF
Correspondence: Dr Farideh Shiva, shivahfa@yahoo.com

ABSTRACT
Introduction A study was conducted to define the pattern of baby walker usage and the rate of walker-related injuries in infants, as well as to determine the effects of baby walkers on the start of independent walking among infants.
Methods Families of infants aged six months to two years who presented at health facility clinics in 2007 and 2008 were enrolled in the study. The study team interviewed the primary caregiver and documented the relevant data on a pre-designed questionnaire. The data of users of baby walkers was compared with that of non-users.
Results Walkers were used by 54.5 percent of 414 infants. Their use was significantly higher in one-child families (p-value is 0.009) and in those with higher parental education levels (p-value is less than 0.001). 78.6 percent of users and 85 percent of non-users were walking by 12 months of age (p-value is 0.283); no significant difference was observed between the two groups in terms of the age at which the infants starting walking (p-value is 0.401). 76.8 percent of parents of users versus 8.2 percent of parents of non-users believed that walkers promote early walking (p-value is less than 0.001). 44.7 percent of parents of users knew that walkers can be hazardous, as compared to 22.3 percent of parents of non-users. No serious injury was reported, but 14.1 percent of infants sustained trivial walker-associated injuries.
Conclusion Baby walkers do not hasten independent walking and may be associated with injuries. However, it was noted that knowledge of the associated hazards has not deterred parents from using baby walkers for their infants.

Keywords: baby walkers, infants, injury, walking
Singapore Med J 2010; 51(8): 645-649

Gharehbaghi MM, Hosseinpour SS
Correspondence: Dr Mostafa Gharehbaghi Manizheh, gharehbaghimm@yahoo.com

ABSTRACT
Introduction Exchange transfusion is performed using many different combinations of blood components. No single component is unequivocally the best. The purpose of this study was to determine the efficacy and adverse events of exchange transfusion (ECT) with whole blood and reconstituted blood in neonatal hyperbilirubinaemia.
Methods The medical charts of all neonates who had undergone ECT over a two-year period were retrospectively reviewed. The demographic features, causes of jaundice, details of the exchange method and ECT-related adverse events of the infants were recorded. A total of 107 ECT procedures were performed in 92 neonates during the study period. The neonates were categorised into those who received whole blood (n is 38) and those who received reconstituted blood (n is 54) for ECT.
Results There was no significant difference in the demographic characteristics and causes of jaundice between the two groups. ABO blood group incompatibility was the most common cause of hyperbilirubinaemia in both groups. The mean pre-ECT haematocrit of exchange transfused patients with whole blood and reconstituted blood was compatible. Although the mean post-ECT haematocrit in the reconstituted group was higher (39.74 +/- 5.65 versus 38.21 +/- 3.59), this difference was not significant (p is 0.15). The mean post-ECT platelet count was 59,000 +/- 29,400 and 73,000 +/- 21,300 in patients who underwent ECT with reconstituted and whole blood, respectively. A similar number of patients in both groups experienced hypocalcaemia and thrombocytopaenia after ECT. No case of ECT-related mortality was observed.
Conclusion ECT with either reconstituted or fresh whole blood is an efficient and safe method for reducing hyperbilirubinaemia.

Keywords: exchange transfusion, fresh citrated whole blood, neonatal hyperbilirubinaemia, reconstituted blood
Singapore Med J 2010; 51(8): 641-644