Byung Hee Lee

Cognitive dysfunction in 16 patients with carotid stenosis: detailed neuropsychological findings.

Background Impairment of cognitive function is often present in patients with carotid artery stenosis but the details of this dysfunction have rarely been reported. Our purpose was to elucidate the cognitive dysfunction in patients with unilateral severe carotid stenosis using comprehensive neuropsychological testing, and also to identify the specific underlying clinical and radiological factors. Methods We analyzed the results of neuropsychological testing, the clinical history, and MR findings in 16 consecutive patients with angiographically proven severe (70-99%) stenosis of the extra cranial internal carotid artery (ICA). Cognitive functions were examined using the Seoul Neuropsychological Screening Battery and the Neglect Battery. We excluded patients with cortical infarction and those with contra lateral ICA occlusion or severe stenosis. Results Our comprehensive neuropsychological testing revealed obvious cognitive deficits in all patients with unilateral severe ICA stenosis, the most common being frontal executive impairment. The mean cognitive score on the memory test was also significantly lower in patients with symptomatic ICA stenosis than in asymptomatic patients (29.33±10.98, mean±SD, p < 0.05). The total score on the global cognitive test was significantly lower in patients with an ischemic lesion on MRI than in no lesion patients (113.23±34.78, p < 0.05). The presence of symptoms related to the ICA stenosis was related to cognitive dysfunction even when there were no ischemic lesions on MRI. SPECT revealed ipsilateral cortical hypoperfusion in 9 of 12 patients (75%). Conclusions Cognitive deficits are common in patients with unilateral severe ICA stenosis. Our findings suggest that an additional mechanism beyond the structural lesion such as chronic hypoperfusion may affect cognitive function in patients with high-grade ICA stenosis.

Significance of Clopidogrel Resistance Related to the Stent-Assisted Angioplasty in Patients with Atherosclerotic Cerebrovascular Disease

OBJECTIVE To evaluate the prevalence and risk factors of clopidogrel resistance, and association between thromboembolic complications and clopidogrel resistance in patient with stent-assisted angioplasty for atherosclerotic cerebrovascular disease. METHODS Between September 2006 and June 2008, clopidogrel resistance test was performed on 41 patients who underwent stent-assisted angioplasty for atherosclerotic cerebrovascular disease. It was performed before drug administration and about 12 hours after drug administration (loading dose : 300 mg, maintain dose : 75 mg). Two patients were excluded, and 41 patients were included (mean : 67.59±7.10 years, age range : 41-79). Among 41 patients, 18 patients had intracranial lesions, and 23 had extracranial lesions. We evaluated the prevalence, risk factors and complications related to clopidogrel resistance. RESULTS Twenty-one patients (51.2%) showed clopidogrel resistance [intracranial : 10 patients (55.6%), extracranial : 11 patients (47.8%)] and no clopidogrel resistance was seen in 20 patients. Hypercholesterolemia was an indepedent risk factor of clopidogrel resistance. Stent-assisted angioplasty was technically successful in all patients, but acute in-stent thrombosis occurred in 5 patients with intracranial lesions (4 patients with clopidogrel resistance and 1 without clopidogrel resistance). Acute thrombi were completely lysed after intra-arterial infusion of abciximab. CONCLUSION There was relatively high prevalence of clopidogrel resistance in patients with atherosclerotic cerebrovascular disease. Hypercholesterolemia was an independent predictive factor of clopidogrel resistance. Acute in-stent thrombosis was more frequently seen in the clopidogrel resistant group. Therefore, clopidogrel resistance test should be performed to avoid thromboembolic complications related to stent-assisted angioplasty for atherosclerotic cerebrovascular disease, especially patients with hypercholeterolemia and intracranial lesion.

Endovascular Embolization of Intracranial Aneurysms Using Bare Platinum Axium™ Detachable Coils: Immediate and Short-Term Follow-up Results from a Multicenter Registry

Purpose Axium™ coils were developed to improve the durability of coil-embolized cerebral aneurysms by increasing packing density. The purpose of this prospective multicenter registry was to evaluate the safety and durability of Axium™ coils. Materials and Methods One hundred twenty-six patients with 135 aneurysms of ≤ 15 mm in size underwent coil embolization using bare platinum coils, with Axium™ coils constituting over 50% of the total coil length. Immediate and short-term follow-up results were prospectively registered and retrospectively evaluated. Results Of the 135 aneurysms (83 unruptured and 52 ruptured), immediate post-embolization angiography revealed complete occlusion in 80 aneurysms (59.3%), neck remnants in 47 (34.8%), and incomplete occlusion in 8 (5.9%). The mean packing density was 42.8% (range, 9.5 - 90%) with Axium™ coil length constituting a mean of 87.9% of total coil length. The rate of procedure-related complications was 16.3%. Procedure-related permanent morbidity and mortality rates were 3.2% and 0.8%, respectively. Follow-up catheter or MR angiography, which was available in 101 aneurysms at 6 - 15 months (mean, 7.7 months), revealed stable or improved occlusion in 95 aneurysms and worsening in 6 aneurysms (5.9%). Lower packing density (< 30%) remained the only predictor for anatomical worsening on multivariable logistic regression analysis (P < 0.05). Conclusion In this registry, Axium™ coils showed a relatively low rate of anatomical worsening on short-term follow-up imaging with an acceptable periprocedural safety profile compared to reports of other platinum coils. These results may warrant further study of long-term durability with Axium™ coils in larger populations.

Tracheal Deviation in Thy roid Lesions: Correlation with Chest Radiograph

Purpose: To evaluate the prevalence and degree of tracheal deviation seen on chest PA radiographs of thyroid lesions and to correlate these findings with their size, volume, pattern (localized or diffuse), location, and constitution . Materials and Methods: Between May 1995 and July 1998, tracheal deviation seen on chest PA radiographs was retrospectively reviewed in 179 consecutive cases in which a thyroid lesion was seen on ultrasonography and/or CT of the thyroid. The criterion of tracheal deviation was more than 3mm. Thyroid lesions were classified as diffuse or localized according to their pattern; as central, marginal or borderline on the basis of their location, and as cystic, solid or mixed, depending on their constitution. Results: Tracheal deviation was seen in 53 cases (29.6%, n=179); mean deviation was 5.6mm (3 -27 mm). Its incidence increased with lesion size (p2.8 cm in the tracheal deviation group and 1.6 1 .2 cm in the non-tracheal deviation group. Tracheal deviation was seen in 46 localized-type cases (86.8 %) and 7 diffuse-type cases (13.2 %) (p>0.05). The volume of the former type was measured and the incidence and degree of tracheal deviation was found to increase with lesion volume (p0.05). The most common location was borderline (n=30, 65.2 %), followed by central (n=12, 26.1%), and marginal (n=4, 8.7%). The most common type by constitution was solid (n=32, 69.6 %), followed by cystic (n=10, 21.7 %), and mixed type (n=4, 8.7 %) (p>0.05). Conclusion: Chest PA radiography revealed tracheal deviation of thyroid lesion in 53 cases (29.6 %). The incidence and degree of deviation increased with increasing size and volume of the lesion, but deviation did not correlate with the pattern (localized or diffuse), location or constitution of the lesion.

Diffuse Pachymeningeal Enhancement on Brain MRI: Spontaneous Intracranial Hypotension and Head Trauma

Purpose: We evaluated the MRI finding of pachymeningeal enhancement in patients with intracranial hypotension and head trauma with particular attention to differential findings and change in follow-up study, and in order to support the knowledge about the pathophysiology of d ural enhancement. Materials and Methods : The findings of enhanced brain MRI offifteen patients who showed diffuse pachymeningeal enhancement were retrospectively examined. Seven of fifteen patients were finally diagnosed as spontaneous intracranial hypotension (SIH) . Eight of fifteen patients had a recent history of head trauma. We analyzed the shape, thickness , continuity and extent of dural enhancement , and the others concerned with positive MR findings. We also analyzed findings suggested displacement of brain parenchymadisplacement of the iter and cerebellar tonsil, and f1attening of the anterior aspect of the pons. Four of seven patients with SIH and four of eight patients with head trauma, underwent fl이low-up MRI. In the follow-up study, the presence of resolving pachymeningeal enhancement and symptom improvement was investigated. Results : In all cases of SIH, the dura showed diffuse, even 3 (1 mm thick, global and contiguous enhancement along both cerebral convexities, both tentoria, and the falx. Displacement of the iter was noted in six cases and f1attening of the anterior aspect of the pons in five. Displacement of the cerebellar tonsil was noted in one case. Five of seven cases showed small amount of subdural f1uid collection. In all èases ofhead trauma, the dura was enhanced diffusely and asymmetrically, and showed no contiguity. Its distribution was consistent with the locations of traumatic lesions. Displacement of the iter was noted in one case. In four cases of SIH, clinical symptoms had improved, and three showed complete resolution of dural enhancement, in one patient continuously showed partial dural enhancement. Four cases ofhead trauma showed complete resolution of dural enhancement. Conclusion : Reversible diffuse pachymeningeal enhancement and additional findings in brain MRI of SIH and head trauma are valuable for differenciation from other irreversible pathological conditions related to pachymeningeal enhancement and to support the knowledge about pathophysiology of dural enhancement.