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Jiann-Der Lee

Publications and source records attributed to Jiann-Der Lee.

4 recordsLinked to original sources
PubMed2007

Carotid ultrasound criteria for detecting intracranial carotid stenosis.

BACKGROUND/AIMS: This study attempted to establish carotid ultrasound criteria for identifying stenosis of the intracranial internal carotid artery (ICA) and middle cerebral artery (MCA). METHODS: Two hundred and fifty-five patients were enrolled. Ultrasound measurements for common carotid artery (CCA) and ICA were as follows: flow volume (FV), peak systolic velocity (PSV), end-diastolic velocity (EDV), pulsatility index (PI) and resistance index (RI). The sensitivity and specificity of the ultrasound criteria for determining intracranial ICA or MCA>or=50% stenosis were calculated. RESULTS: The criteria identified for detecting intracranial ICA>or=50% stenosis were ICA FV<159 ml/min, ICA PSV<33 cm/s and CCA PSV<42 cm/s. When ICA PSV<33 cm/s was combined with CCA PSV<42 cm/s, sensitivity increased to 82%, with 91% specificity. The criteria identified for detecting MCA>or=50% stenosis were CCA FV<285 ml/min, ICA FV<179 ml/min, ICA PSV<33 cm/s, >35% reduction in FV in the CCA, >40% reduction in FV in ICA, and >35% reduction in PSV in ICA. When these criteria were combined, sensitivity increased to 69%, with 85% specificity. CONCLUSION: This study demonstrated that ultrasound criteria are sensitive and specific for detecting intracranial ICA and MCA significant obstruction.

Angiography↗
PubMed2006

Massive pontine hemorrhagic transformation associated with an anticoagulant for basilar artery occlusion.

Symptomatic hemorrhagic transformation is common in supratentorial and cerebellar infarction, but is rare in brainstem infarction. It is seldom reported in basilar artery occlusion. Although early arterial recanalization by thrombolytic agent has became the new trend of treatment, for some neurologists anticoagulant is still a conventional alternative treatment of basilar artery occlusion, especially in longer-existing ischemic deficits. We report a case of massive pontine hemorrhage associated with enoxaparin (low-molecular-weight heparin) treatment for basilar artery occlusion. On the basis of the clinical information and neuroimaging, an embolism was the most likely cause of stroke. The case presented herein adds massive pontine hemorrhagic transformation to the list of possible complications of anticoagulants for basilar artery occlusion. Apart from no evidence-based benefit in treatment of basilar artery occlusion, anticoagulant may contribute to devastating hemorrhagic transformation.

Aged↗
PubMed2005

Pallidotomy effect on the cortical excitability in patients with severe Parkinson's disease.

Surgical lesions in the medial pallidum have been shown to ameliorate motor deficits in patients with Parkinson's disease (PD). It is believed that interruption of the pallidothalamocortical projections to the motor cortex is required for the satisfactory results. In this report, we adopt cortico-cortical inhibition as the tool to assess the pallidotomy effect on cortical excitability in PD. Interstimulus interval between 1 and 15 msec were investigated. The average peak-to-peak amplitude was measured and calculated at each delay. A total of 8 patients (M:F = 4:4) 54.9 years of age (SD = 9.6) and 10 controls were recruited for the study. In the controls, the inhibitory phenomenon was observed from the 1-msec to the 4-msec delay points and the maximal inhibition was at the 3-msec delay point (33.69% +/- 6.50% of the control response). Mild facilitation was noticed since the 5-msec delay point and thereafter. In patients before operation, a similar trend of inhibition was also observed in the initial 4 msec with the maximal inhibition also at the 3-msec delay point (64.66 +/- 6.77% of the control response). In the postoperative group, the short interstimulus interval inhibition can no longer be observed and the conditioned response was 95.06 +/- 23.68% of the control at the 3-msec delay point. The suppression was gone at and after the 7-msec delay point. Results of repeated-measures analysis of variance show a significant difference among the controls and PD patients before and 3 months after pallidotomy (F = 3.40, P = 0.05). Post hoc examination revealed a significant difference between the controls and PD patients 3 months after pallidotomy at the 3-msec delay point (P = 0.004). However, no correlation was observed between the 3-msec inhibition and the Unified Parkinson's Disease Rating Scale Motor score or the dyskinesia score. The results suggest that pallidotomy can modulate the cortical inhibitory circuitry in patients with PD.

Adult↗