Morphometric Study of the Anterior Thalamoperforating Arteries

OBJECTIVE: To evaluate the morphometry of the anterior thalamoperforating arteries (ATPA). METHODS: A microanatomical study was performed in 79 specimens from 42 formalin-fixed adult cadaver brains. The origins of the ATPAs were divided into anterior, middle, and posterior segments according to the crowding pattern. The morphometry of the ATPAs, including the premammillary artery (PMA), were examined under a surgical microscope. RESULTS: The anterior and middle segments of the ATPAs arose at mean intervals of 1.75+/-1.62 mm and 5.86+/-2.05 mm from the internal carotid artery (ICA), and the interval between these segments was a mean of 3.17+/-1.64 mm. The posterior segment arose at a mean interval of 2.43+/-1.46 mm from the posterior cerebral artery (PCA), and the interval between the middle and posterior segments was a mean of 3.45+/-1.39 mm. The mean numbers of perforators were 2.66+/-1.19, 3.03+/-1.84, and 1.67+/-0.98 in the anterior, middle, and posterior segments, respectively. The PMA originated from the middle segment in 66% of cases. A perforator-free zone was located >2 mm from the ICA in 30.4% and >2 mm from the PCA in 67.1% of cases. CONCLUSION: Most perforators arose from the anterior and middle segments, within the anterior two-thirds of the posterior communicating artery (PCoA). The safest perforator-free zone was located closest to the PCA. These anatomical findings may be helpful to verify safety when treating lesions around the PCoA and in the interpeduncular fossa.

Results of Isotope Cisternography in 175 Patients with a Suspected Hydrocephalus / 대한신경손상학회지

OBJECTIVE: Normal pressure hydrocephalus (NPH) is a syndrome characterized by gait disturbance, memory impairment and urinary incontinence. The isotope cisternography (ICG) became less useful because of low accuracy and complications. We tried to evaluate the safety and value of the ICG. METHODS: We retrospectively collected data on ICG of 175 consecutive patients with a suspected hydrocephalus. We classified the ICG into four types by the ventricular reflux and circulation time. The ventricular size was measured by Evans index and the width of the third ventricle. RESULTS: There were three complications including one case of paraplegia. Type 4 was the most common type, observed in 53%. Type 3 (33%), type 2 (7%), and type 1 (7%) were observed less often. Type 4 was more common in patients with large ventricles. Types of the ICG were not related to the causes of hydrocephalus, gender, or age of the patients. Shunting was more frequently performed in type 4 (71%), compared to type 1 (17%), type 2 (33%), and type 3 (46%). Surgery was more common when the cause was vascular. After the shunt surgery, 33.0% were graded as the improved. Although there were some improvements even in the not-improved patients, they still needed many helps. The improvement was related to the preoperative state. CONCLUSION: ICG may bring a serious complication, however the incidence is very low. Although the predictability of response rate on the shunting is doubtful, ICG is a cheap and useful tool to select surgical candidates in NPH.

A Design for Evaluation of the Trauma Apportionment in Cerebral Infarction after Trauma

OBJECTIVE: Posttraumatic cerebral infarction (CI) is a well-known complication of traumatic brain injury (TBI). However, the causation and apportionment of trauma in patients with CI after TBI is not easy. There is a scoring method, so-called trauma apportionment score (TAS) for CI, consisted with the age, the interval, and the severity of the TBI. We evaluated the reliability of this score. METHODS: We selected two typical cases of traumatic CI. We also selected consecutive 50 patients due to spontaneous CI. We calculated TAS in both patients with traumatic and spontaneous CI. To enhance the reliability, we revised TAS (rTAS) adding three more items, such as systemic illness, bad health habits, and doctor's opinion. We also calculated rTAS in the same patients. RESULTS: Even in 50 patients with spontaneous CI, the TAS was 4 in 44 patients, and 5 in 6 patients. TAS could not assess the apportionment of trauma efficiently. We recalculated the rTAS in the same patients. The rTAS was not more than 11 in more than 70% of the spontaneous CI. Compared to TAS, rTAS definitely enhanced the discriminating ability. However, there were still significant overlapping areas. CONCLUSION: TAS alone is insufficient to differentiate the cause or apportionment of trauma in some obscure cases of CI. Although the rTAS may enhance the reliability, it also should be used with cautions.

Multiple Episodes of Hemorrhage Identified in MRI of Chronic Subdural Hematomas / 대한신경손상학회지

OBJECTIVE: Septa within the hematoma cavity are common, especially in the mixed density chronic subdural hematomas (CSHs). Although CT remains the diagnosis of choice, MRI is superior to detect the membranes in CSHs. We could obtain MRIs in 64 patients with CSH. We examined the value of MRI to understand the history of CSH. METHODS: We retrospectively examined the medical records and MRIs of 64 consecutive patients. MRI was selected to find any organic causes of neurologic symptoms. We classified the CSHs into septated or non-septated group, since classification of the septa was frequently obscure. RESULTS: Septa were identified by MRI in 43 patients (67%). They were more common in the over 70-years-old group. Unknown causes were more common in the septated group, which implies they might suffer from multiple traumas. The signal intensity of the CSH was variable. The methods of treatment were different between two groups. Surgery was more common in the septated group (p=0.021). Surgery was performed in 57 patients (89%). Burr-hole drainage was successful in 55 patients, even in the septated group. CONCLUSION: Septa within the hematoma cavity may be related to the multiple episodes of head trauma. Repeated trauma may cause acute bleedings over the CSHs, which is one of the pathogenic mechanisms of hematoma enlargement. MRI could show the history of CSH.

Morphometric Study of Hypoglossal Nerve and Facial Nerve on the Submandibular Region in Korean

OBJECTIVE: This study was performed to determine the anatomical landmarks and optimal dissection points of the facial nerve (FN) and the hypoglossal nerve (HGN) in the submandibular region to provide guidance for hypoglossal-facial nerve anastomosis (HFNA). METHODS: Twenty-nine specimens were obtained from 15 formalin-fixed adult cadavers. Distances were measured based on the mastoid process tip (MPT), common carotid artery bifurcation (CCAB), and the digastric muscle posterior belly (DMPB). RESULTS: The shortest distance from the MPT to the stylomastoid foramen was 14.1+/-2.9 mm. The distance from the MPT to the FN origin was 8.6+/-2.8 mm anteriorly and 5.9+/-2.8 mm superiorly. The distance from the CCAB to the crossing point of the HGN and the internal carotid artery was 18.5+/-6.7 mm, and that to the crossing point of the HGN and the external carotid artery was 15.1+/-5.7 mm. The distance from the CCAB to the HGN bifurcation was 26.6+/-7.5 mm. The distance from the digastric groove to the HGN, which was found under the DMPB, was about 35.8+/-5.7 mm. The distance from the digastric groove to the HGN, which was found under the DMPB, corresponded to about 65.5% of the whole length of the DMPB. CONCLUSION: This study provides useful information regarding the morphometric anatomy of the submandibular region, and the presented morphological data on the nerves and surrounding structures will aid in understanding the anatomical structures more accurately to prevent complications of HFNA.

Clinical Significance of Routine Cerebral Angiography after Cerebral Aneurysm Surgery

OBJECTIVE: To identify the clinical significance of routine postoperative angiography, the incidence of residual aneurysms after clipping and the risk factors related to the occurrence of residual aneurysm are investigated. METHODS: Of 255 patients who underwent aneurysm clipping between 1999 and 2002, ninety one patients underwent routine angiography after aneurysm clipping by one surgeon. There were 104 aneurysms in these 91 patients. Postoperative angiography were reviewed. RESULTS: Of the 104 aneurysms, 9 (8.7%) had aneurysmal remnant on postoperative angiography. Incomplete clipping was intentionally performed in 4 aneurysms more than 10mm in size and in one basilar tip aneurysm. The remaining 4 aneurysms had unexpected remnant of sac, which was anterior choroidal artery aneurysm in 1 and anterior communicating artery aneurysms projecting superiorly or posterior-superiorly in 3. Thus, the true incidence of residual aneurysm was 3.8% (4/104 aneurysms). Logistic regression analysis showed the size of aneurysm as the only risk factor of residual aneurysm. Occlusion or narrowing of major artery was noted in 4.8%. Even though we had re-adjusted the clip in two cases because of parent arterial narrowing on postoperative angiography, two patients died due to cerebral infarction. CONCLUSION: Routine postoperative angiography has little clinical significance in view of the incidence and management of the residual aneurysm or major arterial narrowing/occlusion. Postoperative angiography seems to be necessary in limited patients after aneurysm surgery.

Pituitary Macroincidentaloma - Report of 3 Cases -

With improvements in diagnostic imaging techniques for the brain, pituitary tumors without neurological signs or symptoms have occasionally been found. To evaluate therapeutic strategy for incidentally found pituitary tumors ("pituitary incidentaloma"), we analyzed the result of magnetic resonance imaging findings and of ophthalmological and endocrinological studies in 3 cases with follow up. Incidentally found functioning tumors were excluded. All of 3 cases is greater than 10mm in tumor size("pituitary macroincidentaloma"). The follow-up period was 49 months, 16 months and 6 months(mean, 25.3 months) in each case. There was no evidence of tumor enlargement, endocrinological problems and visual field defect during follow-up period. Patients with pituitary incidentalomas usually follow a benign course and neurosurgical intervention is not initially required in the management even those greater than 10mm in diameter. Observation over time may be good approach to the patient with a pituitary macroincidentaloma to avoid the unnecessary risk for surgery in a patients with a stable mass.