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Ling-Ling Chan

Publications and source records attributed to Ling-Ling Chan.

12 recordsLinked to original sources
PubMed2006

Isolated facial myorhythmia.

Myorhythmia, characterized by relatively rhythmic and regular 1- to 3-Hz muscle contractions, may involve isolated limbs or in combination with other various body regions. Isolated facial myorhythmia is rare. We highlight the clinical and electrophysiologic features of a unique case of isolated facial myorhythmia. Extensive investigations did not reveal any conclusive secondary causes. Dopaminergic dysfunction could be one of the etio-pathologic factors. However, the pathological basis why the facial region was selectively involved in our patient is unclear. Early recognition of the symptoms and signs would facilitate investigations for an underlying cause.

Aged↗
PubMed2005

Behind the facial twitch: depressive symptoms in hemifacial spasm.

BACKGROUND: Depression impairs psychosocial and occupational functioning and contributes to significant morbidity and mortality. Hemifacial spasm (HFS) causes social embarrassment and visual and verbal disability. OBJECTIVE: We examined; (1) the prevalence and predictive factors of depressive symptoms (Becks Depression Inventory (BDI) and clinical assessment) in HFS and (2) the sensitivity and specificity of BDI as a screening and diagnostic tool in HFS. METHODS: A large cohort of HFS patients in a movement disorders clinic was clinically evaluated and the BDI self-administered by patients. Univariate analysis and multivariate logistic regression were undertaken to investigate the effect of age, gender, body-mass index, duration and severity of HFS on the outcome of BDI score. ROC (receiver operating characteristics) analysis was utilized to evaluate the sensitivity and specificity and discriminative property of the scale. RESULTS: There were 90 HFS patients with a mean age of 54.4+11.1 (35-79) years, comprising of 58.9% women and with a mean severity HFS score of 2.9+0.8 (range 1-4). The mean BDI score was higher in depressed HFS than in non-depressed HFS (19.7+6.7 vs 4.2+4.9, p<0.0001). Female gender and a younger age were risk factors (p=0.07). In the multivariate analysis, the severity of HFS was an independent predictor of BDI scores (p<0.0001). The AUC was 97.1% suggesting excellent discriminative property of BDI. For cut-off score of 12/13, the sensitivity was 93.3%, specificity 94.7%, Positive Predictive Value 77.8% and Negative Predictive Value 98.6%. CONCLUSIONS: The prevalence of depressive disorder in HFS was 16.7%, with younger women at greater risk. The severity of HFS was positively correlated with the severity of depressive symptoms. The BDI can be a complimentary screening and/or diagnostic instrument for depressive disorder in HFS. Early diagnosis of at-risk patients will prevent unnecessary morbidity and mortality.

Adult↗
PubMed2004

Severe bruxism following basal ganglia infarcts: insights into pathophysiology.

Bruxism characterized by clenching and grinding of teeth can lead to toothwear, headaches and depression. While bruxism has been associated with a number of neurological diseases, it has not been highlighted following cerebral infarction. An elderly man presented with an acute onset of tooth grinding and jaw clenching associated with dysarthria. His bruxism was worse during the day and resolved during sleep. He had frequent jaw aches, headaches and swallowing difficulty. Examination demonstrated the presence of dysarthria with jaw clenching and tooth grinding, producing persistent high pitch and loud squeaky sounds. A magnetic resonance imaging and angiography examination revealed a recent infarct in the right thalamus. In addition, chronic lacunar infarcts were present in the bilateral caudate nuclei with severe basilar artery stenosis. He was successfully treated with botulinum toxin. We discuss the pathophysiologic mechanisms of bruxism associated with basal ganglia infarcts. Dysfunction of the efferent and/or afferent thalamic or striatopallidal tracts may play a role in bruxism. Early recognition of bruxism following stroke could reduce unnecessary suffering since the condition can be effectively treated.

Basal Ganglia Cerebrovascular Disease↗
PubMed2003

Vascular parkinsonism in moyamoya: microvascular biopsy and imaging correlates.

We highlight the first case to our knowledge of vascular parkinsonism with angiographic moyamoya and functional imaging correlates. In addition, transmission electron microscopy of the cutaneous vasculature revealed the mean smooth muscle cell layer of the terminal arterioles to be significantly higher compared with ischemic stroke patients classified by vascular risk factors. Smooth muscle cell thickness was also greater in those with small vessel and large vessel strokes compared with cardioembolic strokes. The marked cutaneous arteriolar smooth muscle cell hypertrophy may be a useful surrogate marker for those at risk of developing angiographic moyamoya.

Arterioles↗
PubMedDate not supplied

Is your interventional radiology service ready for SARS?: The Singapore experience.

The recent epidemic of severe acute respiratory syndrome caught many by surprise. Hitherto, infection control has not been in the forefront of radiological practice. Many interventional radiology (IR) services are therefore not equipped to deal with such a disease. In this review, we share our experience from the interventional radiologist's perspective, report on the acute measures instituted within our departments and explore the long-term effects of such a disease on the practice of IR.

Humans↗
PubMedDate not supplied

Use of reconstructed, non-orthogonal plane, high-resolution computed tomography of the temporal bone in the planning of temporal bone surgery.

OBJECTIVES: To demonstrate the utility of high-resolution computed tomography (HRCT) reconstructed in non-orthogonal planes in the planning of temporal bone surgery. STUDY DESIGN: Qualitative and quantitative comparison of in vivo anatomic measurements between orthogonal and non-orthogonal plane reformatted HRCT of the temporal bone. METHODS: HRCT data of 10 normal temporal bones were reconstructed two-dimensionally in two non-orthogonal planes. Parallel to the plane defined by the superior semicircular canal (defined as transverse) as well as perpendicular to the plane defined by the superior semicircular canal (defined as longitudinal). This was done using commercially available software. Sixteen surgically important relationships between neural, vascular and/or bony structures were measured and analyzed. RESULTS: Quantitatively, wide variations were obtained in the measurements obtained from images of both non-orthogonal planar orientations. These variations were not age or sex dependent. Qualitatively, the images obtained highlight the anatomy of the temporal bone and skull base as it will be encountered during otologic surgery, since the surgical visual axis is along the long axis of the temporal bone. CONCLUSIONS: The reformatted images in non-orthogonal planes were superior to the axial and coronal series because they condensed critical relationships into a single perspective which promoted an intuitive understanding of the surgical approach. These reconstructed images show wide differences in quantitative measurements between surgically relevant landmarks. The protocol can be easily implemented in the clinical setting and is a potentially valuable educational tool. We recommend that non-orthogonal reconstructed images be routinely included with orthogonal temporal bone HRCT scans.

Adult↗