Hiroki Tomita

Chronological changes of perihematomal edema of human intracerebral hematoma

Recent investigations have indicated the importance of secondary brain damage in the pathophysiology of intracerebral hemorrhage (ICH), which includes ischemic brain damage and edema formation around a hematoma. The purpose of the current study is to investigate chronological changes of perihematomal edema in patients with human ICH and also the correlation between volume of perihematomal edema and neurological status. Fourteen patients with medium-sized putaminal hemorrhage (29.4 +/- 13.2 ml) without hematoma enlargement were included in this study. To investigate chronological changes of perihematomal edema, we performed CT scans prospectively on the day of hemorrhage and repeated them on days 1, 3, 7, 14, and 28. We evaluated the patients neurologically using the NIH stroke scale on the day a CT scan was performed. The volume of perihematomal edema in human ICH increased rapidly three days after hemorrhage and the score on the NIH stroke scale showed a deterioration. The volume of perihematomal edema then increased slowly until day 14 after hemorrhage, and decreased thereafter. Despite progression of perihematomal edema, the score on the NIH stroke scale improved gradually after day 3.

High Colloid Oncotic Therapy for Brain Edema with Cerebral Hemorrhage

We examined the effectiveness of high colloid oncotic pressure (COP) therapy to suppress and/or reduce brain edema associated with putaminal hemorrhage of patients whose clinical grades were grade 3 or 4a classified according to the Japanese neurological grading for putaminal hemorrhage. In the treated group of 11 patients, 25% albumin solution was intravenously administered (50-100 ml/day) with additional use of furosemide (20-40 mg/day) following hematoma removal. The serum COP was maintained at 25-30 mmHg for 2 weeks. In the untreated group of 11 patients, the COP therapy was not applied following hematoma removal. The serum COP was 20-25 mmHg for 2 weeks thereafter. During the 2-week observation period, serum osmolality, electrolyte, and hematocrit levels did not significantly differ between the two groups. The midline structure shift on CT of the treated group was 4.5 mm, which was significantly smaller than that of the untreated group (p < 0.05). The numbers of patients either in the vegetative state or death were 0 and 3, respectively, in the treated and the untreated groups. We concluded that high COP therapy for 2 weeks following hematoma removal was effective to suppress and/or reduce brain edema associated with putaminal hemorrhage, and that this therapy could be continued for 2 weeks without systemic complications.

Peritumoral Edema in Meningioma: a Contrast Enhanced CT Study

The propagation of extravasated contrast medium around 6 supratentorial meningiomas with peritumoral white matter of low density (PWL) of Lanksch II-III was investigated by repeated CT scanning at 4 h intervals, following a 1 h drip infusion of 200 ml of Iopamidol. The volume of the expanding peritumoral contrast enhancement was calculated according to a method previously described. By calculating the increase in volume from the first to the second scan, and from the second to third, we derived the rate of edema formation as well as the resolution rate of edema in the PWL. The surface area of the entire tumor (TS) and area of tumor surface facing the PWL (LS) were calculated by summating the surface areas of all CT slices, each area of which was derived from the measured length of the entire circumference of the tumor and circumference of the tumor facing the PWL, respectively, multiplied by the slice thickness of 0.5 cm. The volume of PWL, edema formation rate of entire tumor, and tumor volume x LS/TS were well correlated with each other. We concluded that the severity of peritumoral edema in meningiomas depends on the size of the tumor and the extent of tumor surface contact with the PWL.

Cerebral Changes during Recirculation Following Temporary Ischemia in Mongolian Gerbils

Studies on cerebral changes during recirculation after temporary ischemic insult were carried out in the Mongolian Gerbil which frequently shows anomaly of the circle of Willis. In this animal, occlusion of one side of the common carotid artery resulted in a large focal ischemia of the ipsilateral hemisphere in about 30%. Animals susceptive to ischemia could be selected by neurological symptoms observed soon after the carotid occlusion. Following temporary ischemia of 15, 30 mins., 1 hr., 3, 6 and 9 hrs., the cerebral circulation was resumed by releasing the carotid occlusion for different time lengths. A multidisciplinary and comparative approach which included a) histopathological study, b) morphological assessment on Blood-Brain Barrier (BBB) damage by Evans Blue for protein leakage and on edema, c) morphological evaluation of “no-reflow phenomenon” by injection of carbon black, d) contact autoradiographic assays on regional cerebral blood flow (rCBF) with 14C-antipyrine was made. 1. The histopathological change is related to the duration of ischemia and recirculation. The ischemic lesion appears to progress (or mature) after re-establishment of the circulation. The rate of “maturation” is related to the intensity of the ischemic insult, i.e. the shorter the occlusion time, the later the onset of tissue damage. Neuronal recovery was suggested by time course histological study. 2. The incidence and time of appearance of the BBB lesions following recirculation is related directly to the duration of the ischemic insult. When the duration of ischemia was 30 mins., BBB damage was demonstrated in 50% of animals only at 20 hours after re-establishment of the circulation. On the other hand, BBB damage was always seen in all animals at one hour after recirculation, when the duration of ischemia was 6 hours. 3. Although the duration of “no-reflow phenomenon” relates to the length of ischemia, the phenomenon is transient and lasts about 10 minutes in animals suffering from temporary ischemia up to 6 hours. 4. Following cerebral ischemia for one hour, bi-phasic, reactive hyperemia which includes oligemic phase in between was observed. Later hyperemia associates una voce with the appearance of severe tissue damage, which progressed continuously following release of carotid occlusion. The breakdown of BBB accompanied both severe tissue damage and local increase of rCBF. The histopathological changes as well as BBB damage for protein tracer appears and progresses concurrently after recirculation. Increased rCBF (luxury perfusion) was always noted when the tissue damage was severe.

Correlation between cerebral blood flow values obtained by Xenon/CT and Kety‐Schmidt (N2O) methods

The means of the cerebral blood flow (CBF) values obtained by the stable xenon enhanced CT (Xe/CT) method using two different CT scanners were compared with the global CBF value obtained by the Kety‐Schmidt (N2O) method as a reference. Xe/CT CBF values were obtained using a GE CT9200 (31 patients, 2 flow maps, 120 kV, absorption constant of 0.040) as well as a GE ProSeed Accell (38 patients, 4 flow maps, 80 kV, absorption constant of 0.028). The protocol of inhalation in the Xe/XT method consisted of 4 min wash‐in and 4‐min wash‐out of 35% stable xenon. In the Kety‐Schmidt method, 15% N2O gas was inhaled for 10 min. The N2O content of blood samples was measured using a van Slyke‐Neill blood gas analyzer. We corrected all obtained CBF values for a PaCO2 of 34 mmHg (CBF34).

Atrophy and maldevelopment of the ipsilateral cerebral hemisphere after acute subdural hematoma in infants

Among nine infants aged less than 4 years with acute subdural hematoma admitted between 1980 and 1991, five required evacuation of a hematoma. Eight of them survived longer than 1 month and the remaining patient who had a hematoma removal died 3 days postoperatively. The four infants who required evacuation of a hematoma and survived longer than 1 month had prolonged hemispheric swelling ipsilateral to the hematoma lasting for 2 weeks postoperatively. Intracranial pressure was higher than 25 mm Hg during this period. Diffuse high density was observed in the affected hemisphere in one patient 12 days after injury, which was assumed to be hemorrhagic infarction. Subsequently, these four infants developed atrophy of the cerebral hemisphere ipsilateral to the hematoma. The pathophysiology of the atrophy of the cerebral hemisphere ipsilateral to the acute subdural hematoma is discussed.

Correlations between Cognitive Impairments and Employment Status in Patients with Diffuse Axonal Injury.

Patients with diffuse axonal injury (DAI) may initially present with prominent physical impairments, but their cognitive dysfunctions are more persistent and are attributable to later unemployment. In this study, we analyzed how the findings of early and delayed neuropsychological assessments correlated with employment outcome of patients with DAI. A total of 56 patients with DAI without motor or visual dysfunction were included in this study. The neuropsychological battery consisted of the Wechsler Adult Intelligent Scale - Revised (WAIS-R), Wechsler Memory Scale - Revised (WMS-R), Trail Making Test (TMT), Wisconsin Card Sorting Test (WCST), and Word Fluency Test (WFT). This battery of tests was administered twice in early stage after injury and in later stage. The results of all of the neuropsychological tests improved significantly (P <0.001) between the early and later assessments. All scores other than TMT part A and B improved to the normal range (Z-score ≥ 2). The patient characteristics (age, gender, initial Glasgow Coma Scale, and duration of posttraumatic amnesia) had no relationship to the outcome. The results of TMT part B, however, were significantly correlated with employment outcome in both the early and later assessments (P = 0.01, 0.04). Given that TMT evaluates visual attention, we surmise that a lack of attention may be the core symptom of the cognitive deficit and cause the re-employment failure in patients with DAI. TMT part B in both early and later assessments has the potential to accurately predict chronic functional outcome.

Efficacy of the American Heart Association/American Stroke Association guidelines for ultra-early, intentional antihypertensive therapy in intracerebral hemorrhage

Whether the intentional antihypertensive therapy recommended by the American Heart Association/American Stroke Association (AHA/ASA) guidelines has clinical benefit for patients who have acute spontaneous intracerebral hemorrhage (ICH) has yet to be proven. We retrospectively reviewed the clinical charts of 175 patients with putaminal or thalamic ICH with acute hypertension to examine the correlation between the efficacy of antihypertensive therapy within 3 hours of onset, hematoma expansion (HE) after hospitalization and clinical outcome. The aim of the antihypertensive therapy was to achieve and maintain a systolic blood pressure of 120 mm Hg to 160 mm Hg until the second CT scan. The mean arterial pressure (MAP) after admission was the average MAP values measured every hour for the first 3 hours of hospitalization or until the second CT scan, if this was performed within the same timeframe. Thirty-two (18.3%) patients were found to have HE. Prior to the second CT scan, antihypertensive medications were administered to all patients without any major complications. A multiple logistic regression analysis revealed that a MAP of >110 mm Hg after admission was the only variable independently associated with HE (odds ratio [OR] = 3.455; 95% confidence interval [CI] = 1.510-8.412; p = 0.004). Modified Rankin Scale scores of < or = 3 on day 30 were significantly more common in those patients without HE (p = 0.002). Our findings suggest that there are clinical benefits, by the prevention of subsequent HE, in maintaining a MAP level lower than that recommended by the AHA/ASA (110 mm Hg) after hospitalization for patients who have ICH.

Coil Embolization for Ruptured Cerebral Aneurysms of 2×3 mm Diameter

Small ruptured cerebral aneurysms, such as those of 2×3 mm diameter, are considered to be difficult to embolize by detachable coils because of the risk of procedural perforation of the aneurysms. We have treated these small aneurysms and report the techniques and pitfalls of these embolizations. Twenty-four patients with ruptured cerebral aneurysms of 2×3 mm diameter were intended for treatment by coil embolization. Before coil embolization, three-dimensional digital subtraction angiography was performed, and the simulation of the volume embolization ratio (VER) was performed in all patients, except for the first basilar artery aneurysm patient. The tip of the microcatheter was steam-shaped several times and was placed on the neck of the aneurysm. A balloon neck remodeling technique was used for two aneurysms. GDC 10 softs and soft SRs were used for the first ten aneurysms, and Ultrasofts were used for the last eleven aneurysms. Out of twenty-four aneurysm embolizations, we aborted the procedure in three cases, because of a failure in catheterization; we performed clipping surgery for these cases. For the first case of a basilar tip aneurysm, the aneurysm was perforated, due to the use of too long a coil and the insertion of the tip of the microcatheter into the aneurysmal dome. Minor infarction occurred in one patient. The mean VER was 33.9%, and two aneurysms recanalized, and out of these one needed a second embolization. Six months postoperatively, 81% of patients had made in a good recovery or had a moderate disability. We recommend the following techniques to embolize aneurysms of 2×3 mm diameter: the tip of the microcatheter should be stabilized on the aneurysmal neck by steam shaping of the microcatheter, GDC 10 soft and Ultrasoft should be selected for use, and the simulation of the VER should be performed before embolization to select coils of a suitable length.

Neuropsychological recovery in pediatric patients with acute subdural hematoma treated with mild hypothermia therapy : Report of two cases

In Case 1, an 11-year-old boy fell and struck the occipital part of his head. He was admitted to our hospital with a Glasgow Coma Score (GCS) of 4, and both pupils were dilated. Computed tomography (CT) showed a right acute subdural hematoma (ASDH), necessitating an emergency decompressive craniectomy and hematoma removal. In Case 2, a 6-yearold girl was admitted with severe head injuries caused by a traffic accident. Her GCS was 5 (El VI M3) and both pupils were dilated. Emergency CT showed a left ASDH and acute brain swelling, necessitating a decompressive craniectomy and hematoma removal. These two children were both treated with mild hypothermia after the evacuation of ASDH. Neuropsychological examinations were conducted 6 months and 1 year after injury. The Wechsler Intelligence Scale for Children, third edition (WISC-III), and the social maturity scale were used to score their total intellects and social behaviors. The results showed that mild hypothermia could be a beneficial therapy in preserving neuropsychological function in pediatric patients suffering from severe head injuries.