Michael Mu-Huo Teng

Cubital tunnel syndrome : Diagnosis by high-resolution ultrasonography

The purpose of this study was to evaluate the morphologic changes in the ulnar nerve in cubital tunnel syndrome with high‐resolution ultrasonography. The mean values of the short axis (cm) x long axis (cm) at the arm, epicondyle, and forearm levels were 0.057 +/‐ 0.01, 0.068 +/‐ 0.019, and 0.062 +/‐ 0.01 in control group; 0.069 +/‐ 0.04, 0.139 +/‐ 0.06, and 0.066 +/‐ 0.023 in the symptomatic side in patients with cubital tunnel syndrome; and 0.063 +/‐ 0.029, 0.068 +/‐ 0.029, and 0.057 +/‐ 0.012 in the normal side in patients with cubital tunnel syndrome. No significant difference was found in the area (short axis x long axis) of the ulnar nerve at the arm, epicondyle and forearm levels between the left and right ulnar nerve in the control group and between the control group and the normal side in symptomatic patients. However, the mean value of the area of the ulnar nerve at the epicondyle level in symptomatic patients was significantly larger than that of the control group and that of the contralateral side in patients, and the P value was less than 0.001. High resolution ultrasonography can detect morphologic changes in the ulnar nerve accurately, and it could therefore be useful as a screening and even follow‐up modality in patients with cubital tunnel syndrome.

Outcomes of Thrombolytic Therapy for Acute Ischemic Stroke in Chinese Patients The Taiwan Thrombolytic Therapy for Acute Ischemic Stroke (TTT-AIS) Study

Background and Purpose— The safety and efficacy of alteplase for ischemic stroke has not been examined in Chinese patients. We assessed the safety and efficacy of alteplase for acute ischemic stroke in daily clinical practice in Taiwan. Methods— A prospective, multicenter, observational study was conducted in Taiwan from December 2004 to July 2008. Eligible patients (241) receiving alteplase were recruited and divided into 2 groups: standard dose (0.90±0.02 mg/kg, n=125) and lower dose (0.72±0.07 mg/kg, n=116). Primary outcome measures were safety: symptomatic intracerebral hemorrhage and death within 3 months. The secondary outcome measure was efficacy a modified Rankin scale of 0 to 2 after 3 months. Results— The standard-dose group had higher rates of symptomatic intracerebral hemorrhage using National Institute of Neurological Diseases and Stroke, European Cooperative Acute Stroke Study, and Safe Implementation of Thrombolysis in Stroke-Monitoring Study definitions (10.4% versus 5.2%, 8.0% versus 2.6%, and 5.6% versus 1.7%, respectively) and mortality within 3 months (12.8% versus 6.9%), twice that of the lower-dose group. This pattern was more prominent in older patients. Significantly higher rates of symptomatic intracerebral hemorrhage per European Cooperative Acute Stroke Study (15.4% versus 3.3%, P=0.0257) and mortality (21.1% versus 5.0%, P=0.0099) and significantly lower independence rate (32.6% versus 53.6%, P=0.0311) were observed among patients ≥70 years old receiving the standard dose than those receiving the lower dose. Conclusions— This study suggests that the standard dose of 0.9 mg/kg alteplase may not be optimal for treating aged Chinese patients. However, the dose of recombinant tissue plasminogen activator for ischemic stroke in Chinese patients should be based on more broad and convincing evidences and randomized trials of lower versus higher doses are needed.

Evaluation of ocular arterial changes in glaucoma with color Doppler ultrasonography.

The purpose of this study was to evaluate hemodynamic changes of the retrobulbar vasculature caused by different intraocular pressures with color Doppler ultrasonography. Fifty normal eyes in 25 patients, 13 patients with normal tension glaucoma, and 19 patients with acute glaucoma and increased intraocular pressure (greater than 30 mm Hg) were enrolled in this study. In 15 of 19 patients with acute glaucoma patients, follow‐up color Doppler ultrasonography was also undertaken after laser peripheral iridectomy when the intraocular pressure had returned to normal. The peak systolic velocity, end diastolic velocity, resistive index, time average maximum velocity, and pulsatility index were compared in different vessels, including the central retinal artery, lateral posterior ciliary artery, medial posterior ciliary artery, and ophthalmic artery in each orbit. The peak systolic velocity, end diastolic velocity, and time average maximum velocity of the central retinal artery were significantly lower (P<0.01) in acute glaucoma patients than in the control group. The resistive index and pulsatility index of the central retinal artery were significantly higher (P<0.01) in acute glaucoma patients than in the control group. The end diastolic velocity of the lateral and medial posterior ciliary arteries was significantly lower in patients with acute glaucoma than in the control group, and the resistive index and pulsatility index of both of these arteries were significantly higher (P<0.001) in patients with acute glaucoma than in the control group. However, no statistical significantly differences were found in the peak systolic velocity or time average maximum velocity in either of the posterior ciliary arteries; similarly, no statistically significant differences were noted in any of the parameters in the ophthalmic artery between the control group and the group with acute glaucoma. The pulsatility index of the central retinal artery and of the lateral and medial posterior ciliary arteries was significantly lower (P<0.01) in acute glaucoma patients after laser therapy than in acute glaucoma patients before laser therapy. The resistive index of both posterior ciliary arteries was also significantly lower (P<0.004) in acute glaucoma patients after laser therapy than before laser therapy. All parameters for all vessels examined among the normal subjects, the patients with normal tension glaucoma, and the patients with acute glaucoma after laser therapy when the intraocular pressure had returned to normal showed no statistically significant differences. Color Doppler ultrasonography is a good modality for both imaging and studying the hemodynamics of the perioptic nerve vessels.

CT of Globe Rupture: Analysis and Frequency of Findings

OBJECTIVEnThe objective of our study was to evaluate the CT characteristics of globe rupture.nnnMATERIALS AND METHODSnThe medical records of patients seen in the emergency department with blunt, penetrating, or explosive orbit injury were retrospectively reviewed. A total of 75 patients (76 injured globes) were included (56 males and 19 females; average age, 45.1 years; age range, 5-95 years). CT examinations were reviewed by two experienced radiologists without knowledge of ophthalmologic findings, original orbital CT images, or surgical outcomes.nnnRESULTSnOf the 76 globe injuries, 33 (43%) were ruptured and 43 (57%) were nonruptured. There were significant differences between the ruptured and nonruptured globes with respect to intraocular hemorrhage, lens dislocation and destruction, an intraocular foreign body, intraocular gas, anterior chamber depth (ACD), and globe deformity and wall irregularity (p < 0.05). There was good interrater agreement between the two radiologists (kappa value range, 0.63-0.96). The average sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and accuracy of CT for the detection of globe rupture based on readings by two radiologists were 76%, 85%, 80%, 82%, and 81%, respectively.nnnCONCLUSIONnAlthough CT is extremely useful in the evaluation of ocular trauma, it should not be solely relied on for the diagnosis of globe rupture because of the potentially catastrophic consequences of an undiagnosed injury. A difference in ACD can be diagnostic of globe rupture.

Verifying complete obliteration of carotid artery-cavernous sinus fistula: role of color Doppler ultrasonography.

The purpose of this study was to evaluate the role of color Doppler ultrasonography in verifying obliteration of carotid artery‐cavernous sinus fistula before and after therapeutic embolization or gamma knife radiosurgery. Before treatment, carotid artery‐cavernous sinus fistula showed the following data on color Doppler ultrasonography: (1) increased blood flow in the common carotid artery (220 to 1264 ml/min with mean+/‐SD of 728+/‐378 ml/min); internal carotid artery (435 to 1097 ml/min with mean+/‐SD of 834+/‐216 ml/min) in fistulas of the direct type; and external carotid artery (85 to 257 ml/min with mean+/‐SD of 170+/‐75 ml/min) in fistulas of the indirect type in comparison to the contralateral side; (2) reverse pulsatile flow or spiculated wave form with turbulent flow in the engorged superior ophthalmic vein on the lesion side in all patients. All of the above abnormal hemodynamic changes became normal in six patients immediately after first embolization, in two patients with balloon embolization combined with subsequent direct embolization by direct puncture through the superior orbital fissure or internal carotid artery embolization, and in five patients after gamma knife radiosurgery at 4, 4, 8, 9, and 9 months, respectively. Color Doppler ultrasonography might be a good modality in long‐term follow‐up of carotid artery‐cavernous sinus fistula after gamma knife radiosurgery and embolization.

Toward the Era of a One-Stop Imaging Service Using an Angiography Suite for Neurovascular Disorders

Transportation of patients requiring multiple diagnostic and imaging-guided therapeutic modalities is unavoidable in current radiological practice. This clinical scenario causes time delays and increased risk in the management of stroke and other neurovascular emergencies. Since the emergence of flat-detector technology in imaging practice in recent decades, studies have proven that flat-detector X-ray angiography in conjunction with contrast medium injection and specialized reconstruction algorithms can provide not only high-quality and high-resolution CT-like images but also functional information. This improvement in imaging technology allows quantitative assessment of intracranial hemodynamics and, subsequently in the same imaging session, provides treatment guidance for patients with neurovascular disorders by using only a flat-detector angiographic suite—a so-called one-stop quantitative imaging service (OSIS). In this paper, we review the recent developments in the field of flat-detector imaging and share our experience of applying this technology in neurovascular disorders such as acute ischemic stroke, cerebral aneurysm, and stenoocclusive carotid diseases.

In-room assessment of cerebral blood volume for guidance during intra-arterial thrombolytic therapy.

In acute ischemic stroke, the ability to estimate the penumbra and infarction core ratio helps to triage those who will potentially benefit from thrombolytic therapies. Flat-panel post-contrast DynaCT imaging can provide both vasculature and parenchymal blood volume within the angio room to monitor hemodynamic changes during the endovascular procedures. We report on an 80-year-old woman who suffered from an acute occlusion of the right distal cervical internal carotid artery. She was transferred to the angio room where in-room post-contrast flat-panel DynaCT imaging (syngo Neuro PBV IR) was performed to access the ischemic tissue, followed by successful mechanical thrombolytic therapy.

Transarterial Embolization of Traumatic Carotid-cavernous Fistulae by Gugliemi Detachable Coils: A Seven-year Experience

We report our experience with transarterial embolization of traumatic carotid-cavernous fistulae (TCCFs) by using Gugliemi detachable coil (GDC). From 2000 to 2007 at our institution, 11 patients with 12 TCCFs underwent transarterial GDC embolization because of failure to occlude fistulae by detachable balloon with preservation of the parent artery. The cause of the failure to occlude the fistula by detachable balloon was small fistula tract (n=9) and/or tortuous parent artery (n=3) or repeated balloon puncture by bony fragment (n=1). All TCCFs were successfully occluded by a single session transarterial GDC embolization. The average number of coils were eight (range, two-16) with an average length of 104 cm (range, 12–283 cm). No statistically significant procedure-related neurological complication or recurrent TCCF was observed in any of the patients. Transarterial GDC embolization is a useful method in the treatment of TCCFs, particularly in those TCCFs with small fistula tract or small CS.

Preliminary efficacy report of a novel thrombolytic agent for acute ischaemic stroke within a 5-hour window.

AbstractBackground: Adopting thrombolytic therapy with tissue plasminogen activator (tPA) in clinical practice presents many challenges. One major factor is the restrictive time window of 0–3 hours after symptom onset, for the commencement of treatment.n Objective: To test the efficacy of a newly developed plasminogen activator (human tissue urokinase type plasminogen activator [HTUPA]) for the treatment of acute ischaemic stroke within 5 hours of symptom onset.n Design: An open-label, dose escalation trial. The initial dose was 0.3 mg/kg and could be increased or decreased depending on tolerability.n Setting: Three teaching hospitals in Taiwan.n Participants: Thirty-three patients who presented with National Institute of Health Stroke Scale (NIHSS) scores of between 9 and 20, who had evidence of ischaemic stroke confirmed by CT.n Main outcomes measures: Efficacy was assessed by the NIHSS, the Modified Rankin Scale (MRS), the Barthel Index and the Glasgow Outcome Scale. Preliminary efficacy endpoints included major neurological improvement at 24 hours and favourable outcome at 90 days after administration of HTUPA.n Results: Of the 33 patients who received HTUPA, 29 received 0.3 mg/kg, 3 received 0.35 mg/kg and 1 received 0.4 mg/kg. Major neurological improvement, defined as improvement of ≥4 points on the NIHSS 24 hours after treatment, was observed in 45% of all patients treated (15/33) and in 48% (14/29) of those treated with 0.3 mg/kg. Ninety days after symptom onset, in those who received HTUPA 0.3 mg/kg, the proportion of patients with a favourable outcome was 34% on the NIHSS (≤1), 45% on the MRS (0 or 1), 41% on the Barthel Index (≥95) and 45% on the Glasgow Outcome Scale (1). Eighty six percent of the patients treated with 0.3 mg/kg within 0–3 hours of symptom onset reached scores of 0–1 on both the NIHSS and the MRS.n Conclusions: Approximately 50% of patients treated with HTUPA 0.3 mg/kg within a 5-hour window after symptom onset experienced major neurological improvement within 24 hours of drug administration. Thrombolytic agents, in this case HTUPA, may be suitable for Taiwanese or Asian patients with acute ischaemic stroke who meet the inclusion criteria.

Impact of carotid stenting in dizzy patients with carotid stenosis.

Background Little is known about the impact of severe carotid stenosis on health‐related quality of life (HRQoL). The aim of this study was to assess the effects of carotid stenting (CAS) on HRQoL in dizzy patients with carotid stenosis. Methods Patients with symptomatic (≥60%) or asymptomatic (≥80%) severe carotid stenosis and who complained of dizziness and received CAS were recruited. Two HRQoL questionnaires—a generic survey, the 36‐item Short‐Form Health Survey and a disease‐specific instrument, the Dizziness Handicap Inventory—served as outcome measures. Patients were followed 1 week prior to CAS and 6 months postprocedurally. Results CAS was performed in 178 consecutive patients, 61 of whom complained of dizziness. Forty‐one patients (67.2%, 34 male; mean age, 73.3 ± 10.5 years; range, 47–87 years) completed the study. Twenty asymptomatic volunteers (17 male; mean age, 70.3 ± 9.3 years; range, 54–84 years) served as normal controls. Compared to controls, patients tallied lower scores in the overall total and three subscales (physical, functional, and emotional) of the Dizziness Handicap Inventory (p < 0.01). Similar findings were noted in seven out of eight domains of the 36‐item Short‐Form Health Survey score. After 6 months, CAS resulted in significantly improved HRQoL (role physical, bodily pain, general health, social function, and role emotional) in these patients. Conclusion CAS resulted in improved HRQoL in patients with severe carotid stenosis who experienced dizziness.