Doug Hyun Han

Aplasia of the internal carotid artery.

Summary. Background: The majority of previous reports on this rare agenesis of the internal carotid artery (ICA) have been limited to reporting upon its association with other congenital anomalies case by case. In order to collectively summarize this congenital anomaly of ICA, we have reviewed nine cases of ICA aplasia and their associated abnormalities. Method: Nine cases of ICA aplasia were reviewed. The diagnosis of aplasia or agenesis of the ICA was based on angiographic findings and the presence of an absent or hypoplastic bony carotid canal by temporal bone computed tomography (TBCT). Their presumable embryological aetiologies, initial presenting symptoms, unusual collateral circulations, as demonstrated by angiographies, and various associated anomalies are reviewed. Findings: The initial presentations were; subarachnoid haemorrhage in three patients, headache in one patient and ischemic symptoms and signs in three patients. The remaining two cases were found incidentally during angiography for other diseases. Collateral circulations to the middle cerebral artery ipsilateral to the ICA aplasia were via posterior communicating artery (P-com) or anterior communicating artery (A-com). On TBCT, all cases but one demonstrated agenesis of the bony carotid canal and the remaining case showed a hypoplastic canal. Cerebral aneurysms were found in six patients, four with A-com aneurysm, one with a basilar bifurcation aneurysm, and one with both a right P-com and a left cavernous ICA aneurysm; two incidentally found cases had no aneurysm. Other associated abnormalities were found in four cases; one case of hypoplasia of the common carotid artery (CCA) with an arachnoid cyst at the temporal pole, one case of abnormal origin of the right CCA from the aorta and the right subclavian artery from the descending aorta, one case of congenital temporomandibular joint (TMJ) ankylosis, and one case of nasopharyngeal angiofibroma with atresia of the upper basilar artery. Except for the atresia of the upper basilar artery, all such abnormalities were found on the same side as the ICA aplasia. Interpretation: Agenesis or aplasia of ICA may be entirely harmless. However, associated conditions such as cerebral aneurysm or abnormal collateral channels should alert clinicians to the possibility of deterioration to life-threatening conditions, such as subarachnoid haemorrhage or irreversible ischemia. Other associated anomalies are commonly depicted on the same side as the ICA aplasia and may also give rise to issues of clinical importance.

Embolization of wide-necked aneurysms with using three or more microcatheters

SummaryBackground. A new and relatively simple endovascular technique, in which more than three microcatheters are used for endovascular treatment of cerebral aneurysms for the first time, is described. Method. Eight patients with wide necked aneurysms were successfully treated with detachable coils using the multiple microcatheter technique. Three patients presented with subarachnoid haemorrhage and five were unruptured. The aneurysm locations were superior hypophyseal artery (2), posterior communicating artery (2), middle cerebral artery bifurcation (1), distal anterior cerebral artery (1), basilar artery (1) and vertebral artery (1). The average neck size was 7.4 ± 2.8 mm (3.5–12 mm), average width of the aneurysms was 10.6 ± 5.7 mm (6.2–23 mm) and depth was 8.9 ± 5.8 mm (3–22 mm). Three microcatheters (7 patients) and four microcatheters (1 patient) were introduced and used for coil delivery. Three or four coils were deployed and intermingled to stabilize the whole coil mass as well as to occupy the aneurysmal sac. When a relatively stable coil frame was formed, one coil was detached and subsequent coils were inserted. After the coil mass became more stable, other coils were also detached and all microcatheters were used for subsequent coil deployment. Findings. All aneurysms were successfully treated without complications. Postemboilzation angiograms showed no contrast filling in 5 cases (100% occlusion) and a very small residual neck in 3 cases. There was no procedure related complication. Conclusion. The multiple microcatheter technique can be one technical option for the endovascular treatment of wide necked aneurysms.

Clinical analysis of vertebrobasilar dissection

SummaryBackground. The natural history of vertebrobasilar artery dissection (VAD) is not fully known. The purpose of this study was to review the clinical outcome of the patients with VAD, then to propose an appropriate management strategy for VAD.Method. From 1992 to 2004, 35 VAD patients admitted to our institutes were retrospectively reviewed. There were 28 men and 7 women, whose age ranged from 4 to 67 years with a mean age of 44 years. Angiography was assessed to document the shape, and location of the dissecting aneurysm with respect to the posterior inferior cerebellar artery (PICA). A modified Rankin score was assigned for functional outcome. The functional outcome scores were analyzed according to the patient’s age, gender, hypertension history, the pattern of initial manifestation, angiographic shape of VAD, angiographic location of VAD, treatment modality.Findings. There was no statistically significant difference between the functional outcome with age, gender, trauma history and past medical history of hypertension. Of 35 patients, 22 presented with SAH, 11 with ischemic symptoms and 2 were incidentally detected. The patients without SAH had a better functional outcome than those with SAH (p = 0.029). There was statistical significance between Hunt–Hess (H–H) grade and clinical outcome (p = 0.032). The shape and location of VAD was not significantly related to the functional outcome (p = 0.294, 0.840). But all the cases of rebleeding and mortality (except one case with initially poor H–H grade) developed exclusively in patients with aneurysms. There was no statistically significant correlation between the treatment modality and the outcome (p = 0.691).Conclusion. The VAD patients with SAH would be recommended to be managed by either surgical or endovascular treatment, but those without SAH, could be managed conservatively with antiplatelet therapy and/or anticoagulation.

Association between Urine Phthalate Levels and Poor Attentional Performance in Children with Attention-Deficit Hyperactivity Disorder with Evidence of Dopamine Gene-Phthalate Interaction

Although there is some evidence supporting the existence of an association between prenatal maternal or postnatal child’s urine phthalate metabolite concentrations and poor attentional performances, the interaction between urine phthalate metabolite levels and genetic variation for neuropsychological deficit of attention-deficit hyperactivity disorder (ADHD) has not been examined. The aim of this study was to determine whether phthalate metabolites in urine are associated with poor neuropsychological performance in children with ADHD, and whether such association is affected by genotype-phthalate interaction. A cross-sectional examination of urine phthalate metabolite concentrations and the continuous performance test (CPT) were performed in 179 Korean children with ADHD recruited from department of psychiatry of university hospital. Correlations between urine phthalate metabolite concentrations and the CPT scores were investigated, and the interaction of phthalate metabolite levels with the selected polymorphisms at major candidate genes for ADHD, namely dopamine receptor D4 (DRD4), dopamine transporter, α-2A-adrenergic receptor, and norepinephrine transporter genes. For the subjects with the DRD4 4/4 genotype, there were significant associations of the urine phthalate metabolite concentrations with the number of omission errors, the number of commission errors, and the response time variability scores on the CPT. However, for the subjects without the DRD4 4/4 genotype, no significant associations were found. The results of this study suggest a possible association between phthalate metabolite concentrations and poor attentional performances of ADHD as well as a genetic influence on this association. Further prospective and epigenetic studies are needed to investigate causality and pathophysiological mechanisms.