Sandy Wai Lam

Prince of Wales Hospital, Hong Kong, Chiu-lung, Kowloon City, Hong Kong

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Publications (14)27.92 Total impact

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    ABSTRACT: Cognitive deficits commonly occur after aneurysmal subarachnoid hemorrhage (aSAH) and clinical understanding is important for treatment and rehabilitation. Delayed cerebral infarction was shown to be related to poor outcome. Data on delayed cerebral infarction-related cognitive impairment were lacking.
    Acta neurochirurgica. Supplement 01/2015; 120:303-6. · 1.79 Impact Factor
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    ABSTRACT: Although aneurysmal subarachnoid hemorrhage (aSAH) accounts for only 3-5% of all strokes, a high degree of morbidity has been reported in this relatively young subset of patients. Neuropsychiatric disturbance has often been neglected in these reports. We aimed to investigate the pattern and pathological factors of chronic neuropsychiatric disturbance in aSAH patients. This cross-sectional observational four-center study was carried out in Hong Kong. Neuropsychiatric outcome (Neuropsychiatric Inventory Chinese Version [CNPI]) assessments were conducted cross-sectionally 1-4years after ictus. Pathological factors considered were early brain injury as assessed by admission World Federation of Neurosurgical Societies grade, aneurysm treatment (clipping versus coiling), delayed cerebral infarction, and chronic hydrocephalus. One hundred and three aSAH patients' spouses or caregivers completed the CNPI. Forty-two (41%) patients were reported to have one or more domain(s) of neuropsychiatric disturbance. Common neuropsychiatric disturbance domains included agitation/aggression, depression, apathy/indifference, irritability/lability, and appetite/eating disturbance. Chronic neuropsychiatric disturbance was associated with presence of chronic hydrocephalus. A subscore consisting of the five commonly affected domains seems to be a suitable tool for aSAH patients and should be further validated and replicated in future studies.
    Journal of Clinical Neuroscience 06/2014; · 1.32 Impact Factor
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    ABSTRACT: After aneurysmal subarachnoid hemorrhage (aSAH), cognitive impairment, even mild and relatively isolated, can be devastating, especially in working-age persons. The Montreal Cognitive Assessment (MoCA) is accepted as a valid screening tool for mild cognitive impairment due to cerebral ischaemia. Whether MoCA is independently associated with excellent outcome [a score of 0 on the modified Rankin Scale (mRS) or 18/18 on the Lawton Instrumental Activities of Daily Living (IADL) scale] 1 year after aSAH was assessed. Hong Kong Chinese aSAH patients were assessed prospectively by means of the MoCA, Mini-Mental State Examination (MMSE), mRS and IADL scale at 1 year. This multicenter prospective observational study is registered at ClinicalTrials.gov of the US National Institutes of Health (NCT01038193). In all, 194 patients completed the assessments at 1 year. After adjustment for age, both excellent IADL and mRS outcomes were associated with MoCA (OR 1.2, 95% CI 1.1-1.3, P < 0.001, and OR 1.1, 95% CI 1.0-1.2, P = 0.001, respectively). MoCA-assessed cognitive function is an important determinant for excellent outcomes after aSAH.
    European Journal of Neurology 01/2014; · 3.85 Impact Factor
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    ABSTRACT: Although aneurysmal subarachnoid hemorrhage (aSAH) accounts for only 3–5% of all strokes, a high degree of morbidity has been reported in this relatively young subset of patients. Neuropsychiatric disturbance has often been neglected in these reports. We aimed to investigate the pattern and pathological factors of chronic neuropsychiatric disturbance in aSAH patients. This cross-sectional observational four-center study was carried out in Hong Kong. Neuropsychiatric outcome (Neuropsychiatric Inventory Chinese Version [CNPI]) assessments were conducted cross-sectionally 1–4 years after ictus. Pathological factors considered were early brain injury as assessed by admission World Federation of Neurosurgical Societies grade, aneurysm treatment (clipping versus coiling), delayed cerebral infarction, and chronic hydrocephalus. One hundred and three aSAH patients’ spouses or caregivers completed the CNPI. Forty-two (41%) patients were reported to have one or more domain(s) of neuropsychiatric disturbance. Common neuropsychiatric disturbance domains included agitation/aggression, depression, apathy/indifference, irritability/lability, and appetite/eating disturbance. Chronic neuropsychiatric disturbance was associated with presence of chronic hydrocephalus. A subscore consisting of the five commonly affected domains seems to be a suitable tool for aSAH patients and should be further validated and replicated in future studies.
    Journal of Clinical Neuroscience. 01/2014;
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    ABSTRACT: The Quality of Life after Brain Injury Overall Scale (QOLIBRI-OS) is a recently developed instrument that provides a brief summary measure of health-related quality of life (HRQoL) in domains typically affected by brain injury. This study examined the application of the six item QOLIBRI-OS in patients after aneurysmal subarachnoid hemorrhage (aSAH). Hong Kong Chinese aSAH patients were evaluated prospectively within the chronic phase of 1year after aSAH in this multi-center observational study. Cronbach's α was 0.88, and correlations were satisfactory for all six items. QOLIBRI-OS demonstrated good criterion validity with other 1year outcome assessments. In conclusion, QOLIBRI-OS can be used as a brief index for disease-specific HRQoL assessment after aSAH. Further validation in another population of aSAH patients is recommended.
    Journal of Clinical Neuroscience 11/2013; · 1.32 Impact Factor
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    ABSTRACT: The identification of aneurysmal subarachnoid hemorrhage (aSAH) patients with a decrease in health-related quality of life (HRQOL) is challenging. Stroke-Specific Quality of Life (SS-QOL) Scale is one of the commonest disease-specific quality of life measures initially developed and validated for ischemic stroke patients. A disadvantage is subject burden and a short form is more practical to use in clinical and research setting. This study aimed to develop a short form (12-item) of a Chinese version of Stroke-Specific Quality of Life Scale for aSAH (SSQOL-a) for clinical and research applications. We carried out a prospective observational assessor-blinded multi-center study in Hong Kong. The study was registered at ClinicalTrials.gov of the U.S. National Institutes of Health (NCT01038193), and was approved by hospital ethics committees. One hundred and eighty-six aSAH patients were recruited over a 30month period during admission. One hundred (54%) aSAH patients completed the 12-month assessment battery and were included into the current study. The total score, physical component score, and psychosocial score of the 12-item Chinese version showed satisfactory internal consistency and explained high percentages of variance of the full Chinese version (92% to 96%). The 12-item Chinese version showed significant correlations with neurological, functional, generic quality of life, psychiatric, and cognitive outcome measures at 12months. Chinese version calculated physical subscore had better discrimination in detecting complete recovery than the Dutch version calculated physical subscore in our Chinese population. The 12-item Chinese version of SSQOL-a has a satisfactory internal consistency and criterion validity for SAH patients at 12month assessments.
    Journal of the neurological sciences 10/2013; · 2.32 Impact Factor
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    ABSTRACT: Recent clinical research into aneurysmal subarachnoid hemorrhage (aSAH) has confirmed the long-term effect of cognitive dysfunction on functional outcomes. We hypothesized that early cognitive impairment was a marker of permanent brain injury and hence predicted long-term functional outcome. Hong Kong Chinese patients with aneurysmal subarachnoid hemorrhage were evaluated prospectively by means of the Montreal Cognitive Assessment (MoCA) in the subacute phase (2-4 weeks after aSAH) and by neuropsychological evaluation of functional outcomes in the chronic phase (1 year after aSAH). This multi-center prospective observational study is registered at ClinicalTrials.gov of the US National Institutes of Health (NCT01038193). One hundred and eight patients completed both the subacute and chronic phase assessments. Cognitive dysfunction in the subacute phase independently correlated with functional outcomes at 1 year, after adjusting for age, admission clinical condition, treatment modality, motor score, and mobility in the subacute phase, but the positive predictive values remained low. MoCA-assessed cognitive impairment in the subacute phase cannot accurately predict functional outcomes at 1 year. Future study should focus on understanding the relative importance of different components of early cognitive impairment.
    Translational Stroke Research 09/2013;
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    ABSTRACT: Cognitive deficits are common after aneurysmal subarachnoid haemorrhage (aSAH), and clinical evaluation is important for their management. Our hypothesis was that the Montreal Cognitive Assessment (MoCa) is superior to the Mini-Mental State Examination (MMSE) in screening for cognitive domain deficit in aSAH patients. We carried out a prospective observational and diagnostic accuracy study on Hong Kong aSAH patients aged 21 to 75 years who had been admitted within 96 hours of ictus. The domain-specific neuropsychological assessment battery, the MoCA and MMSE were administered 2-4 weeks and 1 year after ictus. A cognitive domain deficit was defined as a cognitive domain z score <-1.65 (below the fifth percentile). Cognitive impairment was defined as two or more cognitive domain deficits. The study is registered at ClinicalTrials.gov of the US National Institutes of Health (NCT01038193). Both the MoCA and the MMSE were successful in differentiating between patients with and without cognitive domain deficits and cognitive impairment at both assessment periods. At 1 year post-ictus, the MoCA produced higher area under the curve scores for cognitive impairment than the MMSE (MoCA, 0.92; 95% CI, 0.83 to 0.97 versus MMSE, 0.77; 95% CI, 0.66 to 0.83, p = 0.009). Cognitive domain deficits and cognitive impairment in patients with aSAH can be screened with the MoCA in both the subacute and chronic phases.
    PLoS ONE 04/2013; 8(4):e59946. · 3.53 Impact Factor
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    ABSTRACT: Background and primary objective: In recent years, the Montreal Cognitive Assessment (MoCA) has been developed to assess patients with ischemic stroke. However, it has not been validated for use on traumatic brain injury patients with intracranial haemorrhage (tICH). The aim was to evaluate the psychometric properties of the MoCA (MoCA) in such patients. Research design and method: A cross-sectional observational study was carried out on 40 controls and 48 tICH patients recruited in Hong Kong. Concurrent validity was assessed by a comprehensive battery of neuropsychological tests and the Mini-Mental State Examination (MMSE). Criterion validity was assessed by the differentiation of tICH patients from controls. Main outcome and results: In tICH patients, cognitive z-scores (β = 0.579; p < 0.001) and MMSE (β = 0.366, p = 0.012) significantly correlated with performance in the MoCA after adjustment for age, gender and total score for the Geriatric Depressive Scale. For the differentiation of tICH patients from controls, analysis of receiver operating characteristics curves in the MoCA revealed an optimal balance of sensitivity and specificity at 25/26 with an area under the curve of 0.704 (p = 0.001). MoCA is applicable to and significantly correlated with excellent neurological outcomes in tICH patients. Conclusions: MoCA is a useful and psychometrically valid tool for the assessment of gross cognitive function in tICH patients.
    Brain Injury 03/2013; · 1.51 Impact Factor
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    ABSTRACT: Identification of patients with aneurysmal subarachnoid haemorrhage (aSAH) with cognitive impairment is important for patient management (medical treatment, cognitive rehabilitation and social arrangements). The Montreal Cognitive Assessment (MoCA) is currently recommended over the Mini-Mental State Examination (MMSE) by the US National Institute of Neurological Disorder, in the chronic post-stroke setting. We hypothesised that the MoCA has a better correlation with functional outcome at 3 months than the MMSE. We carried out a prospective observational study in Hong Kong over a 2 year period, recruiting patients aged 21-75 years with aSAH admitted within 96 h of ictus. The assessments included the modified Rankin Scale, Lawton Instrumental Activity of Daily Living (IADL), Short Form-36, MoCA and MMSE at 3 months after ictus. Analyses were carried out to compare MoCA with MMSE. 90 patients completed the 3 month assessments. Cognitive impairment (MoCA <26) was determined in 73% of patients at 3 months. Delayed cerebral infarction explained the 31-38% variance in cognitive outcomes (MMSE and MoCA) at 3 months. MoCA demonstrated good discrimination of favourable neurological and IADL outcomes similar to the MMSE in receiver operating characteristics curve analyses. MoCA defined cognitive impairment was common at 3 months after aSAH and MoCA correlated with functional outcomes similar, but not superior, to the MMSE. The study is registered at ClinicalTrials.gov of the US National Institutes of Health (NCT01038193).
    Journal of neurology, neurosurgery, and psychiatry 07/2012; 83(11):1112-7. · 4.87 Impact Factor
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    ABSTRACT: The identification of aneurysmal subarachnoid hemorrhage (aSAH) patients with a decrease in health-related quality of life (HRQOL) is challenging. Failure of clinical trials has been partially attributed to lack of sensitivity in outcome measures. Stroke-specific Quality of Life (SS-QOL) is a disease-specific HRQOL tool widely applied in ischemic stroke researches, but not in aSAH. This study aimed to validate a Chinese version of SSQOL (SS-QOL-CH) for aSAH patients and proposed summary scores for clinical application. We carried out a prospective observational assessor-blinded multi-center study in Hong Kong. One hundred and four Chinese adults were recruited into the current study, and assessments of the outcome of aSAH patients were made 3months after ictus. Internal consistency was good and supported convergent validity for 12 domains of the SS-QOL-CH, with Cronbach's α coefficients ranging from 0.73 to 0.98. Principal component analyses suggested a two-component solution to explain a total of 65% variance. The two-component solution showed no significant floor or ceiling effects in our aSAH population. Validity of the criteria for the physical and psychosocial subtotal scores showed relevant and distinct correlations with other outcome measures. Dichotomization of physical and psychosocial subtotal scores is valid and can simplify applications of the scale.
    Journal of the neurological sciences 07/2012; 320(1-2):97-101. · 2.32 Impact Factor
  • ANZ Journal of Surgery 06/2012; 82(6):476. · 1.50 Impact Factor
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    ABSTRACT: Cognition had recently been suggested as a supplement to traditional measures of neurological outcome. However, no data were available in the literature on long-term cognitive outcomes in patients with traumatic subarachnoid hemorrhage (tSAH). We explored the long-term cognitive profiles of patients with tSAH who had returned to the community, and the risk factors associated with this event. Patients with tSAH were contacted to obtain their consent to participate in the study of cognitive profiles and outcome. Forty-seven (42%) of 111 eligible patients completed all the assessments. Time from ictus to assessment ranged from 3 to 5 years. No difference in patient characteristics was observed between those who participated and those who did not. In patients with tSAH who had returned to the community, domain deficits and cognitive impairment were correlated with the extended Glasgow outcome scale (GOS-E), and were predicted by age and Glasgow coma scale (GCS) on admission. The accuracies of classifications were 79% and 81%, respectively. The number of domain deficits was also correlated with GOS-E, and was predicted by age, GCS on admission, and the extent of tSAH, with a total R (2) value of 50%. Long-term cognitive dysfunction is common after tSAH. In addition to GCS on admission and follow-up GOS-E, the extent of tSAH is an independent risk factor for the number of cognitive domain deficits that occur.
    Acta Neurochirurgica 01/2012; 154(1):105-11; discussion 111. · 1.79 Impact Factor
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    ABSTRACT: Dear editor, We recently reported the clinical outcome of traumatic acute subdural hematoma in Hong Kong [1], and we supplemented our work in collaboration with students from the faculty of social science on the impacts on the quality of life of these patients and their next-of-kins. Quality of life was measured with the Chinese version of short form-36 (SF-36) [2]. The phone interviews were carried out after sessions of training and practice by two university undergraduates (BL and SS). Quality of life assessment was omitted if the patient is unable to follow commands or unable to comprehend or answer the questions properly. Patient’s next-of-kin was also interviewed for the questionnaire. The results of the questionnaires were compared with age- and sex-matched Hong Kong population
    Acta Neurochirurgica 11/2010; 153(1):107-8. · 1.79 Impact Factor