Three-dimensional CT angiography for the surgical management of the vertebral artery-posterior inferior cerebellar artery aneurysms.

BACKGROUND: Surgery of vertebral artery-posterior inferior cerebellar artery (VA-PICA) aneurysms is not easy because there is a close anatomical relationship between aneurysms and the surrounding neurovascular structures, and bony structures in the lateral foramen magnum. The preoperative evaluation for a circumstantial comprehension of anatomical relationships is very important for the surgical treatment of the VA-PICA aneurysms. Our experience in using three-dimensional CT angiography (3D-CTA) for the surgical management of VA-PICA aneurysms is herein reported. METHODS AND FINDINGS: We successfully performed neck clipping in 5 cases of VA-PICA aneurysm using 3D-CTA. On 3D reconstructed images, we could see the characteristics of the aneurysms such as their relationships to the jugular tubercle and hypoglossal canal, the projecting direction of the dome, and the configuration of the neck in each case. 3D-CTA also provided a clear surgical view as well as the relationships of the aneurysms to the VA and origin of the PICA. Based on such information, we selected the most appropriate surgical approach among the transcondylar fossa approach, the transcondylar approach, or the far lateral approach with a C1 laminectomy. CONCLUSIONS: Since 3D-CTA demonstrates the surgical anatomy of VA-PICA aneurysms in detail, it is very useful for helping surgeons to select the optimal approach.

Neuroendoscopic third ventriculostomy in a patient with occluded foramen of Monro: a case report.

We treated recurrent hydrocephalus in a previously shunted patient by neuroendoscopic third ventriculostomy. A tear was noted in the septum pellucidum. As the foramen of Monro was found to be occluded, we first fenestrated the floor of the lateral ventricle and then performed third ventriculostomy through the fenestration. A tough membrane believed to be Liliequist's membrane isolated the space immediately beneath floor of the third ventricle from the cistern below. Cerebrospinal fluid pulsation appeared after fenestration of this membrane. These obstructions presumably resulted from congenital and/or inflammatory causes. In cases such as this, successful neuroendoscopic third ventriculostomy presents a challenge to surgical judgment.

Office blood pressure variability as a predictor of acute myocardial infarction in elderly patients receiving antihypertensive therapy.

Larger variability of office blood pressure (BP) was reportedly associated with a higher risk of stroke or mortality from all causes. In the present study, we focused on the relationship of variability of office BP and occurrence of acute myocardial infarction (MI). We registered 139 patients receiving antihypertensive therapy for more than 1 year who experienced first-ever episode of MI at the age of 60 years or over. At least two sex- and age-matched (+/- 5 years) control patients were registered for every MI patient. Average systolic and diastolic BP during the 12-month period prior to the occurrence of MI, or the time of registration in the case of control patients, was similar in both patient groups. The office BP variability was evaluated by calculating the variation coefficient (VC) of BP. VC of diastolic BP was significantly higher in the MI patients (10.0 +/- 4.0%) compared with the control patients (8.8 +/- 3.4%). VC of systolic BP was not different between the MI and the control patients. Multiple logistic analysis revealed the relationship of the VC for office diastolic BP to the occurrence of MI was significant after adjustment for BP level, age, gender, body mass index, serum total cholesterol concentrations, diabetes mellitus, and current smoking. In conclusion, larger long-term variability of office diastolic BP during antihypertensive therapy is a predictor of MI.

Evidence for high incidence of end-stage renal disease in patients after stroke and acute myocardial infarction at age 60 or younger.

The impact of stroke and acute myocardial infarction (AMI) on the incidence of end-stage renal disease (ESRD) is unknown. Two community-based registries, one of patients with stroke or AMI and another of patients with ESRD who undergo dialysis, are available in Okinawa, Japan. Whether survivors after stroke and AMI who were registered from April 1988 through March 1991 entered an ESRD dialysis program by the end of December 1999 was determined. Among 4,556 patients (3,809 patients with stroke, 747 patients with AMI) who survived at least 28 days after the event onset, 44 patients (36 patients, stroke; 8 patients, AMI) entered an ESRD dialysis program during the study period. The 10-year cumulative incidence of ESRD was approximately 2.0% in those who survived stroke or AMI. The observed-expected ratio was 4.1 in men (P < 0.01) and 5.8 in women (P < 0.01) aged 30 to 59 years and 0.8 in men (not significant) and 0.4 in women (not significant) 60 years and older. The present results confirm that survivors after stroke or AMI have a greater incidence of ESRD than those in the general population, in particular, those who had stroke or AMI at 60 years or younger.

Hypotensive and sedative effects of clonidine injected into the rostral ventrolateral medulla of conscious rats.

We examined the effects of clonidine injected unilaterally into the rostral ventrolateral medulla (RVLM) of conscious, unrestrained rats. We also examined whether the local alpha(2)-adrenoceptor mechanism contributed to the action of clonidine injected into the RVLM. Injection of clonidine but not vehicle solution significantly decreased the mean arterial pressure (MAP), heart rate (HR), and renal sympathetic nerve activity (RSNA) in conscious, unrestrained rats as well as in propofol-anesthetized rats. The frequency of natural behavior was significantly lower after clonidine injection than after vehicle injection. The depressor and sympathoinhibitory responses were significantly larger in the propofol-anesthetized rats than in the conscious rats. Coinjection of a selective alpha(2)-adrenoceptor antagonist, 2-methoxyidazoxan, with clonidine into the RVLM significantly attenuated the depressor, bradycardiac, sympathoinhibitory, and sedative effects of clonidine injected alone. In conclusion, clonidine injected into the RVLM decreased MAP, HR, and RSNA and caused sedation in conscious, unrestrained rats. The action of clonidine in the RVLM was at least partly mediated by alpha(2)-adrenoceptor mechanisms.

Office blood pressure variability as a predictor of brain infarction in elderly hypertensive patients.

Large 24-h blood pressure (BP) variability and an excessive drop in BP during nighttime are associated with a higher risk of cardiovascular events. Data are lacking regarding the prognostic significance of variability in BP measured during office visits. We analyzed the relationship between office BP variability and the risk of brain infarction in elderly patients receiving antihypertensive therapy. Patients who experienced their first-ever stroke at the age of 60 years or over were registered in the study. At least 2 sex- and age-matched control patients were registered for each case patient. Office BP at each clinic visit and known cardiovascular risk factors were recorded. The BP variability was defined as the variation coefficient (VC) of office BP. In this report, we analyze the data of brain infarction patients. The VC of both systolic and diastolic BPs was significantly higher in the brain infarction patients than in the control patients. Higher office BP variability was associated with a higher risk of brain infarction after adjustment for BP level and other confounding factors. Regarding diastolic BP, the association of brain infarction with the maximal value for the difference of office BPs taken at any consecutive two visits (Max-deltaBP) or the difference between the highest and lowest values of office BP (BP-range) recorded during a 1-year period prior to the event was also significant. In conclusion, a retrospective case-control study suggested that office BP variability was an independent predictor of brain infarction. Either the Max-deltaBP or the BP-range may be surrogate indices of diastolic BP variability.

Cardiovascular and sympathetic effects of L-glutamate and glycine injected into the rostral ventrolateral medulla of conscious rats.

The aim of the present study was to examine the effects of L-glutamate and glycine microinjected into the rostral ventrolateral medulla (RVLM) in conscious unrestrained rats. Microinjection of 2 nmol of L-glutamate increased the mean arterial pressure (MAP) and renal sympathetic nerve activity (RSNA) in the conscious rats. The RSNA responses were significantly larger in the conscious rats than in anesthetized rats, while the magnitude of the pressor responses was similar in conscious and urethane-anesthetized rats. L-Glutamate injection significantly decreased heart rate in the conscious rats, whereas it increased the heart rate slightly but not significantly in the anesthetized rats. Microinjection of 100 nmol of glycine into the RVLM of conscious rat decreased MAP and RSNA. In 2 of the 6 rats examined, the depressor and sympathoinhibitory responses were preceded by a few seconds of a pressor and sympathoexcitatory phase. The decreases of RSNA in response to glycine injection were significantly larger in the conscious rats than in the anesthetized rats, whereas the magnitude of the depressor responses was similar in the two groups of rats. Heart rate decreased in response to glycine injection into the RVLM in the conscious and the anesthetized rats. In conclusion, in conscious unrestrained rats, as well as in urethane-anesthetized rats, L-glutamate acts as a sympathoexcitatory agent and glycine acts as a sympathoinhibitory agent in the RVLM. The sympathetic responses to these amino acids are larger in conscious rats than in anesthetized rats.

Spinal intradural perimedullary arteriovenous fistula with varix in infant.

A rare occurrence of type IV spinal arteriovenous malformation (intradural perimedullary arteriovenous fistula) is described in an 18-month-old boy initially misdiagnosed with Guillain-Barré syndrome. An intramedullary mixed-intensity mass lesion at Th1 was demonstrated by magnetic resonance imaging together with flow voids over the dorsal aspect of the swollen spinal cord. Angiography demonstrated an intradural perimedullary arteriovenous fistula including an intraparenchymal vascular pocket. After partial embolisation of the posterior spinal arteries through the left intercostal-radicular artery, the arteriovenous fistula was removed completely together with an organised haematoma. The fistula directly opened into a vascular pocket, which was confirmed pathologically to be a varix. The postoperative course was uneventful, and the patient resumed ambulation within 4 months. The case, subclassifiable as a type IVb spinal perimedullary AVF, was unique given its location and the patient's age at presentation.

Control of blood pressure and lifestyle-related risk factors in elderly Japanese hypertensive subjects.

The aim of this study was to analyze the treatment of elderly hypertensive patients by Japanese physicians specializing in hypertension. We enrolled 939 patients with hypertension who were treated in the outpatient clinics of 11 hospitals in 1995; 793 of these patients (388 men and 405 women; mean age, 66.6+/-9.0 years) received follow-up examinations in 1996, and the data on these patients was used for the present analysis. Blood pressure (BP), body mass index, lifestyle, and laboratory data were analyzed in all patients. The average BP was 143+/-16/81+/-10 mmHg in 1995 and 142+/-15/80+/-10 mmHg in 1996. The patients whose baseline BP was at the level of Grade 2 or 3 in the WHO-ISH classification (n=117) were characterized by a higher women-to-men ratio, higher age, a higher serum total cholesterol concentration, and higher QRS voltage. In these patients, from 1995 to 1996, the average BP significantly decreased, whereas fasting plasma glucose, serum total cholesterol and serum creatinine concentrations showed only negligible changes. In 220 patients (28%), BP was <140/<90 mmHg at both the initial and the follow-up examinations, whereas 351 patients (44%) were hypertensive in both 1995 and 1996. Thirty-three percent of the patients were smokers. More smokers than nonsmokers had had prior cardiovascular events, diabetes mellitus, or overt proteinuria. In conclusion, the average BP level among the patients treated by Japanese physicians specializing in hypertension was somewhat higher than that recommended by WHO-ISH Guidelines (1999). Patient education to control lifestyle-related risk factors, particularly to stop smoking, should be emphasized.

Non-corresponding effects of an angiotensin-converting enzyme inhibitor on cardiac and vascular hypertrophy in spontaneously hypertensive rats.

Angiotensin-converting enzyme inhibitors (ACEIs) may have different effects on cardiac hypertrophy than on vascular hypertrophy. Arginine vasopressin (AVP) may promote cardiac hypertrophy. Our aims were (1) to simultaneously examine the chronic effects of ACEIs on hypertrophy of the heart and hypertrophy of the coronary and renal interlobular arteries, and (2) to clarify the relation between AVP concentration (AVPC) and cardiac hypertrophy. ACEI (delapril: 30 mg/kg/day) or vehicle (5% arabic gum) was administered in a preventive (4 to 28 weeks of age) or a therapeutic (12-24 weeks of age) protocol in spontaneously hypertensive rats. In both protocols, delapril produced a slight but significant decrease in systolic blood pressure. In the therapeutic protocol, the weight of the left ventricle (mean+/-SE) was lower (p<0.05) in the ACEI group (64+/-2 mg/100 g body weight) than in the control group (69+/-1 mg/100 g body weight). Plasma renin activity was significantly higher in the ACEI group than in the control group in both the preventive (p <0.01) and therapeutic (p<0.01) protocols. In the therapeutic protocol, AVPC was significantly (p<0.05) lower in the ACEI group than in the control group. AVPC was significantly (p=0.02, r=0.46) correlated with the weight of the left ventricle in the therapeutic protocol. For both protocols, no differences were noted between the ACEI and control groups in the vascular hypertrophy of the coronary and renal interlobular arteries. We conclude that (1) the preventive or therapeutic effect of ACEIs on hypertrophy may not be the same in the heart as in the coronary and renal arteries; and (2) AVP was significantly correlated with the left ventricular weight. This indicates that AVP could play a role in the etiology of cardiac hypertrophy in SHR.

Hemorrhagic subdural effusion complicating an endoscopic III ventriculostomy.

Subdural effusion, a common postoperative complication of extracranial shunting for hydrocephalus, is usually caused by excessive drainage of cerebrospinal fluid. Subdural effusion is thought to occur less frequently after a neuroendoscopic III ventriculostomy, and no reported cases have been symptomatic. We encountered a symptomatic subdural effusion with a component of hemorrhage 5 days after the latter procedure was performed to treat massive hydrocephalus in a 2-year-old boy.

Incidence and long-term prognosis of initial stroke and acute myocardial infarction in Okinawa, Japan.

We performed a cross-sectional survey of the incidence of stroke and acute myocardial infarction (AMI) in Okinawa, Japan, with a census population of about 1.2 million. A total of 3,644 cases of first-ever stroke and 898 cases of initial AMI were detected. The age-adjusted annual incidence rate of stroke was 105 per 100,000 of the standard population of Japan based on census population taken in 1985, and that of AMI was 26 per 100,000. The case-fatality rate of stroke within 28 days of onset was 12.8%, and that of AMI was 22.2%. Of the stroke cases, 51.4% were diagnosed as brain infarctions, 38.7% as brain hemorrhages, and 9.3% as subarachnoid hemorrhages. The diagnoses of stroke subtypes were confirmed by computed tomography or magnetic resonance imaging in 98.4% of all stroke cases. The long-term prognosis of patients with stroke and AMI was studied by examining their 10-yr survival rates (follow-up rate 89.8%). The cumulative survival rate was 38.2% in brain infarction cases, 40.4% in brain hemorrhage cases, and 38.2% in AMI cases. The 50% reduction of survival had occurred at 2,880 days after onset in brain infarction cases, at 2,764 days in brain hemorrhage cases, and at 2,658 days in AMI cases. In Okinawa, the incidence rate of AMI was still considerably lower than that in the Western population, and the rate of stroke was similar to that in the Western population. The ten-year survival rates were quite similar in AMI and stroke, and both were unexpectedly high.

Comparison of the effect of blood pressure on the development of stroke, acute myocardial infarction, and end-stage renal disease.

Hypertension is a known risk factor for cardiovascular disease, but few epidemiological studies have examined simultaneously the effect of baseline blood pressure on the development of stroke, acute myocardial infarction (AMI), and end-stage renal disease (ESRD). In 1983, a large, community-based mass screening covered about 14% of the adult population in Okinawa, Japan. The total number of people screened was 107,192 (51,122 men, 56,070 women). We had access to two independent registries of end-organ damage: the Co-operative Study Group of Morbidity and Mortality of Cardiovascular Diseases in Okinawa (COSMO) registry for stroke and AMI, and the Okinawa Dialysis Study (OKIDS) registry for ESRD. The total number of people registered was 4,756 with stroke, 1,059 with AMI, and 641 with ESRD during the study period from April 1, 1988, to March 31, 1991. By using the name, sex, birth date, and ZIP code of registrants, we identified those registrants who were screened in 1983 and had developed stroke, AMI, or ESRD. Hypertension was defined as systolic blood pressure (SBP) of 140 mmHg or higher or diastolic blood pressure (DBP) of 90 mmHg or higher. Other readings were regarded as normotensive. The prevalence of hypertension was 35.8% (N=37,299). The cumulative incidence of stroke, AMI, and ESRD was 154, 21, and 19 subjects among those with SBP < or = 119 mmHg, and 1933, 315, and 71 subjects among those with SBP > or = 160 mmHg. Similarly, the incidence of stroke, AMI, and ESRD was 234, 44, and 25 subjects among those with DBP < or = 69 mmHg and 1980, 381, and 364 subjects among those with DBP > or = 110 mmHg. Hypertension was prevalent in the adult population in Okinawa, Japan, and was a significant predictor of stroke, AMI, and ESRD. However, the effect of blood pressure on target organs differed and was more evident in those with stroke than in those with AMI and ESRD.

Factors related to impairment of activities of daily living.

OBJECTIVE: We examined the factors related to the impairment of activities of daily living (ADL). METHODS: ADL was evaluated by using ADL-20, which consists of 20 items from 4 major categories of activities; mobility, self-care, instrumental, and communication. The patients' gender, birth date, clinical diagnosis, past history, life styles, physical findings, laboratory data, and details of therapy were also recorded. Patients A total of 1,163 outpatients aged 50 years or older were included. Data from 1,093 patients were analyzed. RESULTS: We divided the subjects into two groups; Group I having full marks of ADL-20 (n=582) and group II exhibiting an impairment of ADL (n=511). Multiple logistic analysis revealed that in both sexes age and stroke were common independent factors related to the impairment of ADL. Other factors associated with impairment of ADL were smoking in men and presence of proteinuria in women. The presence of hyperlipidemia was associated with preservation of the ADL in women. CONCLUSION: The results demonstrated significant associations of smoking in men and the presence of proteinuria in women with the impairment of ADL in elderly Japanese outpatients. There appears to be a sex difference in the risk factors of impairment of ADL.

Divergent effects of beta-blocker therapy on self-estimated and objectively scored activities of daily living.

To identify factors that influence changes in the activities of daily living (ADL) assessed by a standardized scoring system, ADL-20, and factors affecting the self-estimate of the changes in ADL, we conducted a 1-yr follow-up study of 1,163 outpatients aged 50 yr or older. The follow-up rate was 83.1%. A decrease in the ADL score was associated with advancing age and a lower prescription rate of beta-blockers. Analysis of the modalities of ADL revealed an association between a decreasing mobility score and a lower prescription rate of beta-blockers. In patients with impaired ADL at the time of enrollment, worsening of the ADL score was also associated with a lower baseline ADL score and a history of cardiovascular events. The prescription rate of diuretics was lower in patients who exhibited an improvement in ADL score. There was a considerable dissociation between the self-estimate of changes in ADL and the actual change in ADL-20 score. In more than 60% of patients with impaired baseline ADL, the self-estimate of changes was worse than the actual change in the ADL score. The "worse-than-actual" self-estimate of changes in ADL was associated with a higher prescription rate of beta-blockers. Thus, a history of cardiovascular events accelerates the aging-related deterioration of ADL. The use of a beta-blocker may worsen the self-estimate of the changes in ADL, while the actual ADL is preserved or slightly improved during beta-blocker therapy.

Serial MRI of cerebral infarcts before and after removal of an atrial myxoma.

We describe a cerebral infarct caused by atrial myxoma. A 30-year-old woman with an atrial myxoma presented with a right hemisensory deficit. MRI carried out before and after removal of the myxoma, showed multiple small bilateral white-matter infarcts which increased in number up to the surgery. A lesion in the left thalamus, which enlarged and showed contrast enhancement 4 months before surgery, resembled an old cerebral infarct by the time the myxoma was removed. The number of lesions stopped increasing after surgery. We suggest that atrial myxomas should be removed even in asymptomatic patients, to prevent cerebral infarcts due to embolism of tumour or thrombus.

Sudden death in the general population in Okinawa: incidence and causes of death.

Sudden unexpected death is generally considered to be caused by acute myocardial infarction and/or arrhythmia. To document the incidence and causes of sudden death in Japan, where the incidence of myocardial infarction is low, the present study examined death certificates, hospital records, the forensic medical records, and the police records of residents of the southern part of Okinawa island who died at the age of 20-74 years during a 3-year period from January 1, 1992 to December 31, 1994. Sudden death was defined as death within 24 h from the onset of unexpected symptoms. The study documented 126 (87 men and 39 women) sudden deaths. The crude incidence rate was 0.37/1,000 person per year (0.51 in men and 0.23 in women). According to the death certificates, 78 cases died of heart diseases. However, the cause of death could be determined by examination of all available records in only 64 cases: myocardial infarction in 10, non-ischemic heart diseases in 13, and stroke in 23 cases. Even when the analysis was limited to the cases who died within 1 h from the onset of symptoms, heart disease was the cause of death in only 22% of the cases while the cause of death could not be determined in 53% of the cases. Only 13% of those diagnosed as heart diseases on the death certificate were verified. The agreement rate between the diagnosis reached by the re-evaluation of the records and that on the death certificate was 82% for stroke and 33% for other diseases. In Okinawa, Japan, the frequencies of heart disease and stroke as the cause of sudden death may be similar. Except for stroke, the diagnosis appearing on the death certificate has substantial inaccuracy.

Low serum cholesterol as a risk factor for hemorrhagic stroke in men: a community-based mass screening in Okinawa, Japan.

The relation between the level of total serum cholesterol and stroke is controversial. The relation between serum total cholesterol and subtypes of stroke was examined in the participants of a community-based mass screening program in Okinawa, Japan. A total of 38,053 subjects, whose serum level of cholesterol had been determined during a mass screening carried out in 1983, were examined to see whether they had experienced stroke during a 3-year period from 1988 to 1991. Of them, 315 subjects aged 33-93 years (174 men, 141 women) had had a stroke during that period. The types of stroke were cerebral infarction in 164, cerebral hemorrhage in 111, subarachnoid hemorrhage in 19, and others in 21. In men, the odds ratio of cerebral hemorrhage was 0.71 (95% confidence interval, 0.55-0.95), and the odds ratio of cerebral hemorrhage associated with serum level of cholesterol < or =167 mg/dl, 168-191 mg/dl, 192-217mg/dl, and > or =218mg/dl were 1.00 (reference), 0.70 (0.38-1.30), 0.77 (0.55-1.08), 0.73 (0.56-0.96), respectively. Lower serum cholesterol was an independent predictor of cerebral hemorrhage in men.

[Clinical experience of image-guided neurosurgery with a frameless navigation system (StealthStation)].

We have applied the frameless navigation system (StealthStation) to various neurosurgical procedures to examine its usefulness. The system consists of a UNIX based workstation that creates triplanar and 3-dimensional images; an infrared optical digitizer with camera array; a reference-light-emitting diode (LED) array (e.g., reference array); and pointer probe modified by the addition of LEDs. This system was used to assist in placing a minimal skin incision and craniotomy in 4 cases, to determine the tumor/brain interface in 2 cases, to target the subcortical lesion in one case, and to correlate bony structure with a skull base tumor in 3 cases. The combined use with magnetic source imaging of the somatosensory cortex allowed a fast orientation of eloquent areas in 2 cases with peri-Rolandic tumor. This system, thus, was proved to be a useful adjunct to open-tumor biopsy or resection.

[Carbamazepine induced hyponatremia].

Carbamazepine (CBZ) is a drug which can induce the syndrome of inappropriate antidiuretic hormone (SIADH). Until 1980's, there were reports regarding CBZ-induced SIADH, but it is rarely reported these days. We here report two cases of CBZ-induced SIADH. Hyponatremia in these cases was rapidly improved by withdrawal of administration of CBZ. According to the previous reports, the rate of hyponatremia in patients receiving CBZ is not small. It ranges from 48% to 31%. As CBZ is frequently used for patients with epilepsy and neuralgia, not only their blood CBZ concentration but also their serum Na level should be monitored.