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Y Y Sitoh

Publications and source records attributed to Y Y Sitoh.

At least 37 records · Page 2Linked to original sources
PubMed2003

Bedside clinical methods useful as screening test for aspiration in elderly patients with recent and previous strokes.

INTRODUCTION: This study was undertaken to ascertain the usefulness of clinical screening tools for dysphagia in a heterogeneous group of older stroke patients. The usefulness of bedside clinical assessment tools for detecting dysphagia on different consistencies of feeds was also studied. MATERIALS AND METHODS: Fifty patients referred to a speech therapist for the assessment of possible dysphagia were recruited. The clinical tools studied included the water swallow test, the oxygen desaturation test and the combination of both tests (termed "clinical aspiration test"). The outcomes of the clinical assessments were compared with a fibreoptic endoscopic examination of swallowing (FEES) conducted at the same sitting. Fifty patients underwent an examination of their ability to swallow 50 mL of water in 10-mL aliquots. They underwent a FEES with different food consistencies by a speech therapist and oxygen saturation with pulse oximetry was monitored during the procedure. Oxygen desaturation of more than 2% was considered to be clinically significant. RESULTS: The water swallow test had a sensitivity of 79.4% and specificity of 62.5% for the detection of aspiration, with a positive predictive value (PPV) of 81.8% and a negative predictive value (NPV) of 58.8%. The oxygen desaturation test had a sensitivity of 55.9% and a specificity of 100% with PPV of 100% and NPV of 51.6%. When both tests were combined, a sensitivity of 94.1% and a specificity of 62.5% was attained, with PPV of 84.2% and NPV of 83.3%. Using the clinical assessment test, we were able to pick up 3 aspirators who would otherwise have been missed if they were assessed with the water swallow test using thin fluids alone. CONCLUSION: Simple clinical assessment tools can be used to screen for dysphagia in a heterogeneous group of older patients with stroke disease, and clinical testing using feeds of different consistencies should be considered.

Aged↗
PubMed2003

Rising signal intensity observed in extra-axial brain tumours - a potential pitfall in perfusion MR imaging.

OBJECTIVE: Dynamic perfusion magnetic resonance (MR) techniques may be used to track the susceptibility effects of gadolinium contrast material as it passes through the brain. We describe three intracranial tumours that showed progressively rising signal intensity above the baseline during first-pass contrast-enhanced echo-planar imaging (EPI) MR imaging. METHODS: Multiphase acquisition using single-shot EPI was performed during rapid bolus contrast injection. Ten studies, using either spin-echo or gradient-echo EPI sequences, were carried out in eight patients with intracranial tumours. Time-signal intensity graphs and regional cerebral blood volume (rCBV) were reviewed. RESULTS: In seven studies, the signal intensity within the tumour showed initial signal drop and quick recovery to baseline and increased rCBV. Three studies revealed progressively rising signal intensity. These patients were all imaged using a spin-echo EPI method and subsequent histology revealed meningioma, hemangiopericytoma and pinealblastoma. CONCLUSION: Dynamic perfusion MR methods may be used to study intracranial tumours. However, in short relaxation time spin-echo EPI, the T1- effect of gadolinium becomes noticeable during the first-pass acquisition in extra-axial tumours that lack a well-developed blood-brain barrier. Careful selection of patients and pulse sequence is essential to avoid this potential pitfall.

Adult↗
PubMed2002

Quantitative ultrasound of the calcaneus and falls risk in the institutionalized elderly: sex differences and relationship to vitamin D status.

Very frail older people constitute an increasing proportion of aging populations and are likely to contribute substantially to costs due to osteoporosis. Quantitative ultrasound (QUS) of the calcaneus is potentially a simple method for assessing fracture risk in frail elderly, but there have been few studies of male/female differences in QUS or its relationship to falls risk or vitamin D status, which is often subnormal in this population. We studied QUS, falls risk and serum 25(OH)-vitamin D in subjects living in institutional aged care facilities (hostels or nursing homes). The study sample comprised 294 men (mean age 81.2 years, range 65-102 years) and 899 women (mean age 86.7 years, range 65-104 years). Broadband ultrasound attenuation (BUA) and velocity of sound (VOS) were higher in men than women by approximately 30% and 2% respectively ( p<0.0001) and this difference was maintained at all ages. Serum 25(OH)D levels were higher in men than women ( p<0.001) but vitamin D deficiency was very common in both sexes and serum 25(OH)D was not associated with QUS in either sex. There was no significant decline in BUA or VOS with age in men; however, for women BUA declined by 2.8-4.7% per decade and VOS by 1% per decade (both p<0.001). Mean BUA T-scores were -1.55 and -2.48 at age 90 years in men and women. Quadriceps strength and weight but not serum 25(OH)D were significantly associated with BUA. These data suggest only minor loss occurs at the calcaneal site in BUA and VOS with very old age in either sex.

Accidental Falls↗
PubMed2002

MRI findings in osmotic myelinolysis.

OBJECTIVES: Osmotic myelinolysis is a distinctive clinical syndrome with characteristic CT and MR features. This study was undertaken to determine the MR appearance of these lesions on T1 and T2-weighted, and diffusion-weighted imaging (DWI) sequences with apparent diffusion coefficient (ADC) mapping. MATERIALS AND METHODS: We describe six patients who presented with deranged serum sodium levels and subsequently developed osmotic myelinolysis. CT and MRI scans were retrospectively reviewed, including the advanced functional MR sequence of DWI with ADC mapping. RESULTS: Both cerebral white matter and pontine lesions were typically hypo and hyper-intense on T1 and T2W sequences respectively. Lesions were mildly hyperintense on isotropic DWI images with elevation of the ADC. CONCLUSION: MRI is superior to CT in depicting lesions in osmotic myelinolysis. DWI with ADC mapping suggests that osmotic myelinolysis is not simply a demyelinating disorder but has similarities to multiple sclerosis.

Adult↗
PubMed2001

Clinics in diagnostic imaging (58). Chronic cerebral paragonimiasis.

A 36-year-old Korean man presented with a history of epilepsy. MR imaging of the brain revealed multiple conglomerated round nodules that were hypointense on both T1-and-T2 weighted images. These were located at the left temporal and occipital lobes and had surrounding encephalomalacia. CT scan confirmed the presence of large calcified nodules in the corresponding regions. These imaging findings were typical of chronic cerebral paragonimiasis. The clinical, CT and MR features of cerebral paragonimiasis are reviewed.

Adult↗
PubMed2001

Concurrent myelitis and Guillain-Barré syndrome after varicella infection.

Myelitis and Guillain-Barré syndrome occurring concurrently after varicella infection is very rare. A 34-year-old man presented with progressive flaccid tetraparesis, facial palsy, respiratory failure, sensory loss and urinary incontinence one week after varicella infection. Clinical, imaging and electrodiagnostic studies supported the diagnosis of myelitis and Guillain-Barré syndrome. He improved with intravenous acyclovir and gammaglobulin.

Acyclovir↗
PubMed2000

Nipah viral encephalitis or Japanese encephalitis? MR findings in a new zoonotic disease.

BACKGROUND AND PURPOSE: An epidemic of suspected Japanese encephalitis occurred in Malaysia in 1998-1999 among pig farmers. In neighboring Singapore, an outbreak occurred among pig slaughterhouse workers. It was subsequently established that the causative agent in the outbreak was not the Japanese encephalitis virus but a previously unknown Hendra-like paramyxovirus named Nipah virus. METHODS: The brain MR images of eight patients with Nipah virus infection were reviewed. All patients tested negative for acute Japanese encephalitis virus. Seven patients had contrast-enhanced studies and six had diffusion-weighted examinations. RESULTS: All patients had multiple small bilateral foci of T2 prolongation within the subcortical and deep white matter. The periventricular region and corpus callosum were also involved. In addition to white matter disease, five patients had cortical lesions, three had brain stem involvement, and a single thalamic lesion was detected in one patient. All lesions were less than 1 cm in maximum diameter. In five patients, diffusion-weighted images showed increased signal. Four patients had leptomeningeal enhancement and four had enhancement of parenchymal lesions. CONCLUSION: The brain MR findings in patients infected with the newly discovered Nipah paramyxovirus are different from those of patients with Japanese encephalitis. In a zoonotic epidemic, this striking difference in the appearance and distribution of lesions is useful in differentiating these diseases. Diffusion-weighted imaging was advantageous in increasing lesion conspicuity.

Abattoirs↗
PubMed2000

Stereotactic brain biopsies in AIDS patients--early local experience.

AIM: To assess the usefulness of stereotactic brain biopsies in AIDS patients with cerebral lesions in Singapore. METHODS: A total of 10 patients with AIDS and cerebral lesions underwent stereotactic brain biopsies in the Department of Neurosurgery, Tan Tock Seng Hospital (TTSH) between September 1997 and September 1998. The patients were referred from the Communicable Diseases Centre (CDC), TTSH. These patients either failed a trial of therapy for toxoplasmosis encephalitis (TE) or had CT/MRI scans which did not suggest TE. Four were CT-guided and six were MRI-guided stereotactic biopsies. The Radionics Cosman-Robert-Wells (CRW) stereotactic apparatus was used for all cases. RESULTS: The male to female ratio was 9:1. Histological diagnosis from biopsy was lymphoma (5), metastatic adenocarcinoma (1), TE (1), abscess (1), encephalitis (1) and granulomatous tissue (1-presumed tuberculosis). CONCLUSION: The early experience is that stereotactic brain biopsy is useful in patients with AIDS and cerebral lesions. The etiology is confirmed in the majority of cases and impacts on management decisions and prognostication.

Acquired Immunodeficiency Syndrome↗
PubMed2000

Bedside assessment of swallowing: a useful screening tool for dysphagia in an acute geriatric ward.

AIM: Dysphagia is common in the elderly and is associated with increased morbidity and mortality. We undertook a prospective study to determine the usefulness of a simple bedside swallowing test in terms of (1) detecting previously undiagnosed dysphagia, (2) agreement of the doctor's assessment with that of the speech therapist, (3) impact on subsequent feeding modality, (4) predicting risk of subsequent pneumonia. METHOD: Patients in an acute geriatric ward who had no contra-indications to oral feeding were subjected to a bedside swallowing assessment by a geriatrician within 24 hours of admission. All patients found to be dysphagic were subsequently re-assessed by a speech therapist within 48 hours. In addition, every fifth patient deemed to have normal swallowing by the doctor was assessed by the speech therapist. RESULTS: Sixty-five patients were studied. The doctor's assessment was in very good agreement with the assessment of the speech therapist (kappa = 0.87). Patients found to have dysphagia using the doctor's assessment protocol had an increased risk of developing pneumonia during their hospitalization (relative risk R.R.: 9.9 confidence interval C.I.: 1.2-81.2). Cough on swallowing and delayed swallowing were both found to be associated with an increased risk of developing pneumonia during the period of hospitalization (R.R.: 4.2, C.I.: 1.2-14.4; R.R.: 5.3, C.I.: 1.1-26.3 respectively). CONCLUSION: A simple bedside swallowing test can be used as an effective screening tool in detecting hitherto undiagnosed dysphagia. The validity of this tool in the diagnosis of aspiration requires further investigation.

Acute Disease↗
PubMed1999

Meningoencephalitis caused by a novel paramyxovirus: an advanced MRI case report in an emerging disease.

Eleven abattoir workers in Singapore were infected in March 1999 by an outbreak caused by the Nipah virus. This newly discovered, Hendra-like paramyxovirus causes acute infection of the CNS. We present the magnetic resonance imaging (MRI) and proton magnetic resonance spectroscopy (MRS) findings in a patient suffering from acute meningoencephalitis. Multiple small white matter lesions were detected on diffusion-weighted imaging (DWI) and T2-weighted images. There were no abnormalities detected on MRS. We believe this to be the first reported MRI findings in this novel zoonotic viral disease.

Abattoirs↗
PubMed1999

Planning of skull base surgery in the virtual workbench: clinical experiences.

Based on the KRDL Virtual Workbench, we present a neurosurgical planning system called VIVIAN (Virtual Intracranial Visualization And Navigation). This VR environment allows for fast and intuitive interaction with three-dimensional multimodal (MRI, MRA, MRV, CT) patient specific data-sets. The user reaches behind a mirror into a 3D workspace where the 3D data is surrounded by interactive virtual tools-racks. Tumors, blood vessels, cranial nerves and surgically relevant parts of the brain are segmented by interactive control of density transfer-functions or by manual outlining and tracing tools. A neurosurgical procedure is planned by using various visualization and measurement tools and the system allows for the simulation of bone drilling and tissue removal. We have planned 16 cases which required tumor surgery at the cranial base. VIVIAN provided an efficient and comprehensive way to understand pre-operatively the complexity of anatomical and pathological relationships. The ideal craniotomy and the extent of the required skull base exposure could be specified accurately.

Computer Simulation↗
PubMed1999

Swallowing impairment and feeding dependency in the hospitalised elderly.

A prospective study was carried out to determine the prevalence of swallowing impairment and feeding dependency in an acute geriatric medicine unit in Singapore and the co-morbidity associated with it. A total of 211 patients were assessed over a 3-month period. Only 7.1% of patients gave a history of swallowing impairment prior to hospitalisation. We found that 29.4% of patients on admission and 28.2% on discharge had swallowing impairment, with a mortality of 8.1%. The prevalence of feeding dependency, as defined by the need for feeding assistance or tube feeding, was 26.5% before admission and 27.8% on discharge. The mode of feeding between the time of admission and discharge was changed in 14.9% of patients in response to the evolving medical condition. Swallowing impairment was significantly associated with the presence of dehydration (RR = 2.82, CI = 1.74-4.57), chest infection on admission (RR = 2.85, CI = 1.85-4.41), development of nosocomial chest infection (RR = 6.75, CI = 2.60-17.5), discharge to institutional care (RR = 2.8, CI = 1.51-3.47) and increased mortality (RR = 3.77, CI = 1.45-9.70). We concluded that swallowing impairment and feeding dependency are common in the elderly admitted to an acute geriatric unit. As elderly patients seldom inform clinicians of any underlying swallowing impairment and in view of the increased morbidity and mortality associated with this disability, it is important to screen for swallowing impairment. The high prevalence of feeding dependency adds to the burden of care in the ill elderly.

Aged↗
PubMed1998

Haematuria clinic--a preliminary audit and considerations for a one-stop assessment centre.

AIM: To audit and study the practicality of an integrated Haematuria Clinic as a one-stop assessment centre for the investigations of patients presenting with haematuria. METHODS: A weekly clinic was organised to facilitate consultation, intravenous urogram and flexible cystoscopy for patients with haematuria. A protocol was set up and data on symptoms, types of haematuria, results of the investigations and outcomes were collected. RESULTS: About half of all the patients seen in this clinic were found to harbour urological lesions; of which urolithiasis (20.4%) and urological malignancies (14.2%) were the most common lesions identified. Transitional cell carcinoma of the bladder was the most common malignancy diagnosed (8%). Significantly, 2 of 9 (22.2%) bladder cancers were found on cystoscopy and missed on the cystogram phase of the intravenous urogram. Ten urological lesions would have been missed if cystoscopies were not performed. Conversely, in 14 patients, cystoscopy could be avoided because their intravenous urograms identified lesions sufficiently to allow for definitive treatment. CONCLUSIONS: The need and types of investigation for patients with haematuria are evolving. We recommend intravenous urogram and flexible cystoscopy as the standard investigations and caution against ignoring microscopic haematuria. These assessments can be organised into an integrated clinic improving deliverance of clinical care; which may result in better patient compliance for investigations and earlier detection and treatment of urological lesions presenting as haematuria.

Adult↗
PubMed1998

Spiral computed tomography demonstration of active haemorrhage in blunt abdominal trauma.

In blunt abdominal trauma, patients may still be actively bleeding despite being physiologically stable. Fast computed tomography scanning permits the detection of active haemorrhage by localising the site of extravasation of contrast enhanced blood. Though a specific sign of active bleeding, particularly arterial haemorrhage, it is insensitive to the slow, continuous venous oozing associated with retroperitoneal and pelvic skeletal injuries. However, its presence will have a critical influence on further surgical intervention. The imaging features of this uncommon entity are demonstrated in our case report.

Abdominal Injuries↗
PubMed1997

The limbic system. An overview of the anatomy and its development.

The limbic system has a pivotal role in attention, memory, and the emotions. The limbic lobe comprises four C-shaped arches stretching from the medial surface of the frontal lobe to the temporal pole. The anatomic relationships are elegantly demonstrated by MR imaging. This article provides an overview of the development and complex anatomy of the limbic system.

Amygdala↗