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Positioned along the ventral surface of the pons, proximal superior cerebellar artery (SCA) aneurysms account for only 1.7% of all intracranial aneurysms [1]. Unlike more commonly encountered basilar artery aneurysms, patients often experience good outcomes when treated via endovascular coiling or surgical clipping [1,2]. These lesions frequently have a lateral projection and paucity of perforator arteries [2]. With further development of endoscopic endonasal techniques, access to this region is possible via a direct frontal exposure to the ventral brainstem, basilar artery and branching vessels. To date, there are only a limited number of reports describing an endoscopic endonasal transclival (EETC) approach for surgical clipping [3-5]. In this operative video, we detail the surgical clipping of a cerebellar arteriovenous malformation feeding vessel and an associated aneurysm using the EETC approach in a 59-year-old woman who presented with sudden onset of a severe headache. The feeding vessel and aneurysm's midline location, just below the take-off of the SCA made it a good candidate for this surgery. Major steps included in this video include 1) transsphenoidal exposure of and subsequent drilling of the clivus, 2) dural opening into the pre-pontine cistern and dissection of the aneurysm, 3) clipping of the aneurysm, and 4) multi-layered closure of the skull base defect. Overall, the patient tolerated the procedure well and was found to have no residual filling of the aneurysm or the AVM feeding vessel at 2-year follow-up. EETC is a viable surgical option for the treatment of aneurysm located along the midline of the pre-pontine cistern., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Background and Purpose: Expeditious treatment is critical in patients with aneurysmal subarachnoid hemorrhage (aSAH) due to the risk of rebleeding. This study aimed to define predictors of treatment delay among aSAH patients., Methods: A retrospective study of the Nationwide Inpatient Sample database identified patients diagnosed with SAH between 2002 and 2007. Patient's characteristics such as age, gender, race, insurance, SAH severity, treatment (coil versus clip), and other factors were studied. The Cochrane-Armitage test was used to assess delayed care trends by procedure, time of treatment, and hospital volume. Multivariate logistic regression evaluated factors associated with treatment delays., Results: A total of 38,827 patients were admitted between 2002 and 2007; 69.0% were women and 61% were white. The overall median age was 52 years. More patients underwent treatment with surgical clipping than with endovascular coiling (60.4% versus 39.6%, respectively). Overall, 74% of hospital admissions occurred on weekdays; the remaining 26% occurred on weekends. Multivariate analysis revealed that older age (odds ratio [OR]: 1.1; p = 0.0004) and surgical clipping versus endovascular coiling (OR: 1.3; p = 0.02) were independent predictors of delayed treatment (i.e., >2 days from admission). Nonwhite patients experienced greater treatment delays on weekdays compared with white patients (OR: 1.4; p = 0.01). Furthermore, patients treated in low-volume hospitals were significantly more likely to experience delays than those treated in higher volume hospitals (OR: 2.0; p = 0.007)., Conclusions: Risk factors associated with treatment delay in aSAH patients include older age, nonwhite race, surgical clipping, and admission to low surgical volume hospitals., (Georg Thieme Verlag KG Stuttgart · New York.)

While endovascular techniques play a significant and expanding role in the management of basilar trunk aneurysms, open surgical clipping remains necessary in select cases. Expanded endonasal transclival approaches offer the advantage of direct access and visualization of the midline vertebrobasilar system, benefits ideally suited to a basilar trunk aneurysm. A 59-year old woman with subarachnoid hemorrhage was found to have a ruptured basilar trunk aneurysm associated with a feeding vessel to a small cerebellar arteriovenous malformation (AVM). An expanded endoscopic endonasal transclival approach was used to successfully clip the basilar trunk aneurysm and feeding AVM vessel. The patient was subsequently discharged home without any neurological deficits. Transclival clipping of basilar trunk aneurysms is technically feasible and plays an important role in management when other strategies fail. The technical benefits of this approach include proximal and distal control of the basilar artery and improved visualization of the brainstem and perforators. Endoscopic transclival approaches should be considered in the management of complex basilar trunk aneurysms., (Copyright © 2011 Elsevier Ltd. All rights reserved.)

Object: Spontaneous intracranial hypotension (SIH) is a significant cause of new-onset daily persistent headache. A generalized connective tissue disorder also involving the intracranial arteries has been suspected in the population with SIH. Therefore, the authors reviewed angiographic studies for the presence of intracranial aneurysms in a group of patients with SIH., Methods: Magnetic resonance angiography studies of the brain were performed in 93 patients with SIH (mean age 43 years, range 14-86 years) and in 291 controls (mean age 56 years, range 28-78 years)., Results: Intracranial aneurysms were detected in 8 (8.6%) of the 93 patients with SIH (95% CI 2.9%-14.3%). This incidence was higher than in the control population (3 (1.0%) of 291 (95% CI 0%-2.2%; p = 0.0007). In 7 patients the aneurysms were incidental, and in 1 patient SIH developed 5 weeks after an aneurysmal subarachnoid hemorrhage., Conclusions: In this retrospective case-control study, the frequency of intracranial aneurysms among patients with SIH was significantly higher than in the control population.

Objective: Bicuspid aortic valve (BAV) is a common congenital heart defect affecting half to 2% of the population. A generalized connective tissue disorder also involving the intracranial arteries has been suspected in this patient population. We therefore screened a group of patients with BAV for the presence of intracranial aneurysms., Methods: Magnetic resonance angiography or CT angiography of the brain was used in 61 patients with BAV (age, 29-70 years [mean 48 years]) and in 291 controls (28-78 years [mean 56 years])., Results: Intracranial aneurysms were detected in 6 of 61 patients with BAV (9.8%; 95% confidence interval [CI] 2.4%-17.3%). This was significantly higher than in the control population (3/291 [1.1%; 95% CI 0%-2.2%]) (p = 0.0012). Female sex (p = 0.02) and advanced age (p = 0.003), risk factors for intracranial aneurysm development, were more common in the control population than among the patients with a BAV. No significant differences were detected in age, sex, smoking, arterial hypertension, alcohol use, aortic diameter, or frequency of aortic coarctation between BAV patients with and without intracranial aneurysms., Conclusion: In this case-control study, the frequency of intracranial aneurysms among our bicuspid aortic valve patient population was significantly higher than in the control population.

Spontaneous spinal CSF leaks are best known as a cause of orthostatic headache, but may also be the cause of coma. The authors encountered a unique case of a spontaneous spinal CSF leak causing coma 2 days after craniotomy for clipping of an unruptured aneurysm. This 44-year-old woman with autosomal dominant polycystic kidney disease underwent an uneventful craniotomy for an incidental anterior choroidal artery aneurysm. No intraoperative spinal CSF drainage was used. Two days after surgery the patient became comatose with a left oculomotor nerve palsy. Computed tomography scanning revealed a right extraceberal hematoma and loss of gray-white matter differentiation. The hematoma was evacuated and a diagnosis of hemodialysis disequilibrium syndrome was made. Continuous hemodialysis and hyperosmolar therapy were instituted without any improvement. The CT scans were then reinterpreted as showing sagging of the brain, and the patient was placed in the Trendelenburg position which resulted in prompt improvement in her level of consciousness. A CT myelogram demonstrated an upper thoracic CSF leak that eventually required surgical correction. The patient made a complete neurological recovery. Neurological deterioration after craniotomy may be caused by brain sagging caused by a spontaneous spinal CSF leak, similar to intracranial hypotension due to intraoperative lumbar CSF drainage.

Neurofibromatosis type 1 (NF1) is often mentioned among the heritable connective tissue disorders associated with intracranial aneurysms, but the association has not been firmly established. We therefore reviewed a contemporary series of hospitalized patients with NF1, many of whom underwent brain magnetic resonance imaging (MRI). We identified patients with NF1 who were hospitalized at Cedars-Sinai Medical Center, Los Angeles, California, between January 1, 1997 and December 31, 2001 through the hospital's centralized medical records system using DRG codes. The mean age of the 39 patients was 30.4 years, and 22 patients had undergone MRI of the brain for the evaluation of symptoms due to the presence of central or peripheral nervous system tumors. Incidental intracranial aneurysms were detected in 2 (5%) of the 39 patients. Limiting the patient population to the 22 patients who had undergone MRI examination, the detection rate was 9%. This was significantly (P < 0.005) higher than the aneurysm detection rate in a control population (0/526 [0%]) of patients hospitalized for primary or secondary brain tumors, all of whom had undergone MRI examination. Our study suggests that patients with NF1 are at an increased risk of developing intracranial aneurysms.

Objective: Ehlers-Danlos syndrome Type IV is a heritable connective tissue disorder with frequent neurovascular manifestations, such as intracranial aneurysms. Patients with this syndrome have notoriously fragile blood vessels, and the reported mortality rate for any type of vascular surgical procedure is 40%. This syndrome is rare, however, and the complication rate of aneurysm surgery may have been overestimated., Methods: We reviewed our experience with aneurysm surgery in a group of patients with Ehlers-Danlos syndrome Type IV., Results: The patient population consisted of three women and one man with a mean age of 44 years (age range, 20-57 yr). One patient, who had a ruptured anterior circulation aneurysm, died as a direct result of surgery because of marked vascular fragility. Three patients underwent successful surgery, consisting of a craniotomy and clipping of a ruptured anterior circulation aneurysm in two patients and a craniotomy and clip ligation of the parent artery in one patient with a ruptured dissecting vertebral artery aneurysm. Intraoperatively, mild vascular or connective tissue fragility was commonly observed. Postoperative complications (e.g., spontaneous pneumothorax and vertebral artery dissection) also were common but did not result in permanent morbidity., Conclusion: The risk of neurovascular surgery is high in patients with Ehlers-Danlos syndrome Type IV and intra- and postoperative complications are common. However, most patients tolerate the operation without permanent morbidity.

Objective: An excruciating headache of instantaneous onset is known as a thunderclap headache. A subarachnoid hemorrhage is the prototypical cause, but other serious disorders may also present with a thunderclap headache, including cerebral venous sinus thrombosis, carotid artery dissection, and pituitary apoplexy. We report a group of patients with thunderclap headaches as the initial manifestation of spontaneous intracranial hypotension caused by a spinal cerebrospinal fluid leak., Methods: Among 28 patients with spontaneous intracranial hypotension due to a documented spinal cerebrospinal fluid leak, four (14%) initially experienced an excruciating headaches of instantaneous onset., Results: The mean age of the four patients (two men and two women) was 35 years (range, 24-45 yr). Nuchal rigidity was present in the three patients who sought early medical attention, and they underwent emergency computed tomographic scanning, lumbar puncture, and cerebral angiography to rule out an aneurysmal subarachnoid hemorrhage. The delay between the onset of headache and diagnosis of intracranial hypotension ranged from 4 days to 5 weeks. A fourth patient did not seek medical attention until 1 month after the ictus., Conclusion: Spontaneous intracranial hypotension should be included in the differential diagnosis of thunderclap headache, even when meningismus is present.

Objective: The causes and circumstances of intracerebral hematoma after kidney transplantation have been poorly studied. No data are available on its impact on outcome after a successful renal grafting., Patients and Methods: We used the Mayo Clinic medical diagnostic index to identify the patients with a diagnosis of intracerebral hematoma among the 1573 patients who received a renal transplant at the Mayo Clinic between 1966 and 1998., Results: Ten intracranial hematomas occurred in 9 patients and were the cause of death in 6 (1%) of the 530 patients known to have died. The interval from renal transplantation to intracranial hematoma ranged from 12 to 114 months (average, 57 months). All patients with intracranial hemorrhage had poorly controlled hypertension. Intracranial hematoma was more frequently and significantly associated with autosomal dominant polycystic kidney disease (4/146 [2.7%]; P<.01) and with diabetes mellitus (3/410 [0.7%]; P<.01) than with other underlying causes of renal failure (2/1017 [0.2%])., Conclusion: In this preliminary study, the risk of cerebral hemorrhage may have increased 10-fold in patients with autosomal dominant polycystic kidney disease and 4-fold in patients with diabetes mellitus, when compared with the population of patients having other causes of renal failure. Most cerebral hemorrhages were catastrophic and fatal but appeared to be responsible for only 1% of the deaths after renal transplantation.

Object: Isolated polycystic liver disease, that is, polycystic liver disease without kidney cysts, is an entity distinct from polycystic kidney disease. It is not known whether patients with isolated polycystic liver disease are at an increased risk for developing intracranial aneurysms, similar to patients with polycystic kidney disease. The authors screened individuals for intracranial aneurysms in a family in which isolated polycystic liver disease occurred to study the relationship between these two disorders., Methods: Six siblings requested screening for intracranial aneurysms. Their father had died of a middle cerebral artery aneurysm. Isolated polycystic liver disease was found at autopsy. Their paternal aunt had died of a basilar artery aneurysm, but no autopsy had been performed in that case. Screening with magnetic resonance (MR) angiography and subsequent conventional angiography showed a 5-mm posterior communicating artery aneurysm in one sibling in whom abdominal ultrasound examination yielded normal findings and a posterior communicating artery infundibulum in another sibling in whom an ultrasound examination detected isolated polycystic liver disease. Screening did not detect aneurysms or polycystic liver disease in the other siblings. Thus, of the two patients with isolated polycystic liver disease in this family, one had a ruptured aneurysm and the other had an infundibulum., Conclusions: Findings in this family suggest an association between isolated polycystic liver disease and intracranial aneurysms. However, because of the delay in onset of the appearance of liver cysts in individuals who carry the disease gene, abdominal ultrasonography is not a useful method to exclude those family members at risk for aneurysm development.

The modern management of patients undergoing surgery for intracranial aneurysm often includes temporary periods of cerebral ischemia to minimize the risks final dissection and clipping or to allow vascular reconstruction. This article reviews the concepts of ischemic thresholds and examines the effects of the physiologic variables that may affect outcome from an ischemic episode. The protective agents presently available and the agents in development that may limit the extent of ischemic injury are reviewed extensively as well.

Intracranial aneurysms are common extrarenal manifestations of autosomal dominant polycystic kidney disease (ADPKD). Although their natural history is not completely understood, small asymptomatic intracranial aneurysms in patients with ADPKD often are not treated but are followed with serial magnetic resonance (MR) angiography. The authors report the unique case of a patient with ADPKD who bled from a previously documented asymptomatic 3-mm intracranial aneurysm. This 42-year-old man with ADPKD suffered a subarachnoid hemorrhage (SAH) from a 7-mm left pericallosal artery aneurysm. This aneurysm was clipped and the patient made an excellent recovery. An irregular asymptomatic 3-mm right middle cerebral artery (MCA) aneurysm had also been demonstrated on angiography. While the patient was considering elective surgery for the MCA aneurysm, he suffered a hemorrhage from this lesion 10 weeks after the initial SAH. The aneurysm was clipped and the patient made a satisfactory recovery (he was moderately disabled). In this report the authors indicate that small asymptomatic intracranial aneurysms are not always innocuous in patients with ADPKD, and they suggest that treatment should be strongly considered for these lesions in this group of patients when there is a history of SAH or the aneurysm is irregular in appearance. Because MR angiography studies may not adequately define the configuration of small aneurysms and irregularity may easily be missed, conventional angiography is recommended for patients with ADPKD who are found to have an intracranial aneurysm on screening with MR angiography.

This article reviews the current understanding of genetic factors involved in the development of intracranial aneurysms. Of the large number of heritable connective tissue disorders that have been associated with intracranial aneurysms, three are discussed in detail: autosomal dominant polycystic kidney disease, Ehlers-Danlos syndrome type IV, and alpha 1-antitrypsin deficiency. The author reviews the familial occurrence of intracranial aneurysms, which is found in about one-fifth of patients with aneurysm subarachnoid hemorrhage. Guidelines are provided for the evaluation of patients with familial intracranial aneurysms and screening of their relatives.

We prospectively evaluated 15 consecutive patients with spontaneous cervical artery dissections. Three patients (20%) had a heritable connective tissue disorder, each with a unique phenotype. None of these patients met the criteria of any of the named syndromes, and collagen and fibrillin analyses were normal. Heritable connective tissue disorders are common among patients with spontaneous cervical artery dissections, but, despite intensive investigations, the type of disorder usually cannot be identified. The underlying arteriopathy in cervical artery dissections is likely to be heterogeneous.

alpha 1-Antitrypsin deficiency has been associated with a variety of vascular disorders including arterial aneurysms, spontaneous extracranial arterial dissections, and arterial fibromuscular dysplasia. We determined the distribution of alpha 1-antitrypsin phenotypes in patients with intracranial arterial dissections, a rare cause of subarachnoid hemorrhage. The study population consisted of 4 consecutive patients with subarachnoid hemorrhage due to spontaneous intracranial arterial dissections. The vertebral artery was involved in 3 patients and the posterior inferior cerebellar artery in 1 patient. Three of these 4 patients were found to have a heterozygous alpha 1-antitrypsin deficiency (PiMZ or PiMS phenotypes). These data support previous studies suggesting that patients with alpha 1-antitrypsin deficiency may be at an increased risk of developing spontaneous arterial dissections.

Objective: Familial intracranial aneurysms are more common than has been appreciated, but systematic autopsy studies of affected individuals have not been reported. We reviewed the autopsy findings of a group of patients with familial aneurysms to elucidate the nature of the putative underlying arteriopathy., Methods: Using a computerized diagnostic index, we identified all patients with intracranial aneurysms in whom postmortem examination had been performed at the Mayo Clinic between January 1, 1992, and December 31, 1994. The medical records, radiographic studies, and autopsy findings of these patients were reviewed., Results: Among the 28 patients with intracranial aneurysms, 3 (11%) had one or more first-degree relatives with documented intracranial aneurysms. The mean age of the three patients (two women and one man) was 54 years. Microscopic examination of the vascular system revealed medial changes, consisting of degeneration of elastic fibers and increased ground substance, in the systemic arteries of 2 of the 3 patients with familial aneurysms but in none of the 25 patients with sporadic aneurysms. These nonspecific medial changes involved both common and extracranial internal carotid arteries in one patient and the entire aorta as well as intracranial and common carotid arteries in the other patient., Conclusion: These observations suggest that an underlying arteriopathy in patients with familial intracranial aneurysms involves the tunica media and commonly may affect systemic (extracranial) arteries.

Objective: Marfan's syndrome is a heritable connective tissue disorder that has been associated with intracranial aneurysms. However, the prevalence of intracranial aneurysms in Marfan's syndrome is unknown and pathological studies of affected vessels have not been reported. We therefore examined the neuropathological findings in a group of patients with Marfan's syndrome., Methods: We identified all patients with Marfan's syndrome in whom postmortem examination had been performed at the Mayo Clinic between 1969 and 1993., Results: Autopsy included examination of the brain in seven patients with Marfan's syndrome (five men and two women with a mean age of 28 yr). Each of two patients had one or more intracranial aneurysms. The first patient, a 32-year-old man who died as a result of aortic dissection, was observed to have an incidental saccular supraclinoid carotid artery aneurysm (7 mm). Microscopic examination of the remainder of the cerebral arteries revealed duplication and fragmentation of the internal elastic lamina. The second patient, a 20-year-old man who died as a result of a subarachnoid hemorrhage, had ruptured saccular supraclinoid carotid artery (3 mm) and anterior cerebral artery (20 mm) aneurysms as well as unruptured fusiform middle cerebral artery (18 mm) and posterior cerebral artery (13 mm) aneurysms. Microscopic examination of the cerebral arteries revealed widespread changes consisting of intimal proliferation, medial degeneration, and fragmentation of the internal elastic lamina., Conclusion: These findings confirm an association between Marfan's syndrome and intracranial aneurysms. Microscopic involvement of cerebral arteries in Marfan's syndrome may be variable, even among those with intracranial aneurysms.

The natriuretic peptide system consists of atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP). The system is implicated in the control of body fluid homeostasis, causes natriuresis and diuresis (ANP and BNP), and regulates vascular tone (CNP). A reciprocal relationship between ANP and endothelin (ET) has been suggested, and earlier studies have documented a possible role of ET in cerebral vasospasm after aneurysmal subarachnoid hemorrhage (SAH). The authors studied plasma ANP, BNP, CNP, and ET for 6 consecutive days in 13 patients with SAH by using radioimmunoassay. The median admission values for ANP were 31.5 pg/ml (range 16.8-323 pg/ml [normal 15 +/- 7 pg/ml]); for BNP, 45.3 pg/ml (range 2.2-80.2 pg/ml [normal 12 +/- 9 pg/ml]); for CNP, 7.7 pg/ml (range < 2-20 pg/ml [normal 5.2 +/- 3 pg/ml]); and for ET, 11 pg/ml (range 6.5-25.1 pg/ml [normal 7.2 +/- 4 pg/ml]). Additional increases (defined as > 100% increase on two consecutive measurements) were noted in ANP (11 patients), BNP (10 patients), and CNP (three patients), and resulted in a negative fluid balance in 10 of the 13 patients. The CNP increased in three of four patients with cerebral vasospasm and in one of nine patients without cerebral vasospasm (Fisher's exact test, p = 0.2). No major fluctuations in plasma ET were noted. In seven patients, the plasma ET level did not increase beyond 10 pg/ml during the days of measurement. In six patients, only an occasional sample showed an increase to a maximum of 25 pg/ml. Changes in BNP, ANP, and CNP were independent of each other. The authors conclude that both plasma ANP and BNP increase after SAH and often result in a negative fluid balance. Plasma ANP and BNP seem differentially regulated in the presence of SAH but not by the level of the plasma ET. The possible role of CNP as a regulatory response to cerebral vasospasm needs further exploration.

The etiology and pathogenesis of intracranial aneurysms are clearly multifactorial, with genetic factors playing an increasingly recognized role. Intracranial aneurysms have been associated with numerous heritable connective tissue disorders, which account for at least 5% of cases. Of these disorders, the most important are Ehlers-Danlos syndrome Type IV, Marfan's syndrome, neurofibromatosis Type 1, and autosomal dominant polycystic kidney disease; the association with intracranial aneurysms, however, has been firmly established only for polycystic kidney disease. Familial intracranial aneurysms are not rare but account for 7 to 20% of patients with aneurysmal subarachnoid hemorrhage and are generally not associated with any of the known heritable connective tissue disorders. First-degree relatives of patients with aneurysmal subarachnoid hemorrhage are at an approximately fourfold increased risk of suffering ruptured intracranial aneurysms, compared to the general population. Various possible modes of inheritance have been identified in families with intracranial aneurysms, suggesting genetic heterogeneity. Although the benefits have never been quantified, screening for asymptomatic intracranial aneurysms should be considered in families with two or more affected members. The yield of such a screening program may approximate 10%. Although it is unlikely that there is a single gene with major effect, much effort is currently being directed at locating intracranial aneurysm genes.

Objective: The number of patients with congenital heart disease who survive to adolescence and adulthood continues to increase. We review our experience with noninfectious intracranial aneurysms and cervicocephalic arterial dissections in patients with congenital heart disease, expanding the clinical spectrum of the cerebrovascular abnormalities that may be encountered in this group of patients., Methods: All patients with congenital heart disease and intracranial aneurysms of cervicocephalic arterial dissections, who were evaluated at the Mayo Clinic between 1969 and 1992, were identified., Results: Congenital heart disease was diagnosed in 3 (8%) of 36 children with intracranial aneurysms, in 5 (0.3%) of 1994 adults with intracranial aneurysms, in 1 (4%) of 25 children with cervicocephalic arterial dissections, and in 5 (2%) of 250 adults with cervicocephalic arterial dissections. The mean age of the 14 patients was 32 years (range, 13-58 yr). The congenital heart disorders consisted of complex cardiac anomalies in three patients (truncus arteriosus, transposition of the great arteries, and tricuspid atresia in one patient each), pulmonic valve or arterial stenosis in two patients, aortic coarctation in four patients, and bicuspid aortic valve in five patients. Only one patient had an intracranial aneurysm and coarctation of the aorta., Conclusion: Individuals with a variety of congenital heart disorders may be at an increased risk of intracranial aneurysm development and cervicocephalic arterial dissection, particularly in adolescence. The muscular arteries of the head and neck are derived from neural crest cells and the neural crest is also of major importance in early cardiac development, suggesting that an abnormality of the neural crest may be the common pathogenetic factor explaining this association.

The purpose of this study was to assess the value of magnetic resonance angiography (MRA) in the follow-up of patients with autosomal dominant polycystic kidney disease (ADPKD) and saccular intracranial aneurysms (ICA), the risk of MRA-defined growth of asymptomatic incidental ICA, and the rate of development of MRA-defined de novo ICA in these patients. Between 1989 and 1995, 15 asymptomatic incidental ICA measuring 1.5 to 6.5 mm in diameter, three symptomatic aneurysms, and one asymptomatic concurrent aneurysm were detected by MRA in this study in 18 patients from 15 families. Four-vessel cerebral angiography in the three patients with symptomatic ICA and autopsy in one patient with an asymptomatic incidental ICA did not reveal additional aneurysms undetected by MRA. Thirty MRA studies were obtained in 10 of the 15 patients with incidental ICA during a cumulative clinical follow-up of 500 months (mean, 33.3; range, 0 to 65 months). The cumulative interval between the initial and the last MRA was 306 months (mean, 30.6; range, 14 to 51 months). No change in aneurysmal size or development of de novo aneurysms was detected. Eight MRA studies were obtained in the three patients with symptomatic ICA during a cumulative clinical follow-up of 130 months (mean, 43.3; range, 23 to 64 months). The cumulative interval between the first and the last MRA was 95 months (mean, 31.7; range, 15 to 49 months). Development of de novo aneurysms was not detected. These results indicate that MRA is an appropriate technique to follow small asymptomatic incidental ICA in patients with ADPKD and that the risk for rapid growth of these aneurysms is low. Although the results of this study should be viewed as preliminary, they do not suggest a higher rate of development of de novo aneurysms or a higher frequency of multiple aneurysms in patients with ADPKD and ICA as compared with patients with sporadic ICA in the general population.

Recent studies have suggested that a deficiency of alpha 1-antitrypsin may be a genetic risk factor for the development of intracranial aneurysms and arterial fibromuscular dysplasia. The authors report a 16-year-old girl with a history of lung disease who suffered a cerebral hemorrhage due to the rupture of a giant intracranial aneurysm arising from the middle cerebral artery. This fusiform aneurysm was associated with fibromuscular dysplasia of the intimal type. She was found to have an unusual alpha 1-antitrypsin deficiency (PiMP phenotype). This case provides further evidence of an underlying arteriopathy in alpha 1-antitrypsin deficiency.

Intracranial aneurysms are uncommon in children, and their presence often leads to suspicion of a systemic connective tissue disorder. We describe the case of a young male patient with progressive hemifacial atrophy (Parry-Romberg disease) and multiple intracranial aneurysms, a previously undescribed association, and propose that a neural crest defect may be the underlying abnormality in this patient. At age 5 years, the patient was treated for a giant aneurysm of the left cavernous carotid artery with carotid ligation in the neck and a superficial temporal artery-middle cerebral artery bypass. At age 12 years, the patient was similarly treated for a giant aneurysm of the right cavernous carotid artery, which had progressed from a previously noted minute dilatation at age 5 years, with carotid ligation and a superficial temporal artery-middle cerebral artery bypass. At age 21 years, the patient was endovascularly treated for a de novo saccular aneurysm of the left posterior cerebral artery at the P1-P2 junction and a fusiform aneurysm of the distal left posterior cerebral artery. Various studies have suggested that the facial dermis, the subcutaneous tissues, and the skeleton, as well as the tunica media of the cervicocephalic arteries, all arise from neural crest cells, and a disorder of neural crest migration might explain the constellation of findings in this patient.

A deficiency of alpha 1-antitrypsin has been implicated in the development of arterial aneurysms, including intracranial aneurysms. The authors determined the prevalence of alpha 1-antitrypsin deficiency of different phenotypes in 100 consecutive patients with intracranial aneurysms and compared the distribution of alpha 1-antitrypsin phenotypes to that in the general population (904 people). The study population consisted of 44 men and 56 women with a mean age of 52 years (range 15-81 years). The heterozygous alpha 1-antitrypsin deficiency states (PiMS and PiMZ) were more common in patients (16%) than in the general population (7%), providing an odds ratio of 2.56 (95% confidence interval (CI) 1.32-4.75; p = 0.005). In addition, one patient (1%) was homozygous for the deficient allele (PiZZ) compared to an expected number of 0.015, providing an odds ratio of 67.0 (95% CI 2.0-363.3; p = 0.015). These findings lead the authors to suggest that the heterozygous and homozygous alpha 1-antitrypsin deficiency states are genetic risk factors for the development of intracranial aneurysms.

Background and Purpose: Among patients with spontaneous cervical artery dissections, the risk of recurrent arterial dissection is relatively low at 1% per year, but this risk may be higher for patients with a family history of arterial dissections. We compared the risk of a recurrent arterial dissection in patients with familial versus non familial disease., Methods: Long-term follow-up was established in 200 patients (104 women and 96 men with a mean age of 44.9 years) with spontaneous cervical artery dissections evaluated at a single institution between 1970 and 1990., Results: Among the 200 patients, 10 (5%) were identified who had a family history of spontaneous arterial dissections. In a multivariate analysis, family history was the only significant variable associated with the risk of recurrent dissection (X2=15.51; P=.0001). A recurrent arterial dissection was identified in 5 (50%) of the 10 patients with familial disease compared with 11 (5.8%) of the 190 patients with nonfamilial disease, with an estimated relative risk of 6.3 (95% confidence interval, 2.2 to 18.3; P=.0007)., Conclusions: Among patients with spontaneous cervical artery dissections, a family history of arterial dissection is an important risk factor for the development of a recurrent arterial dissection.

Autosomal dominant polycystic kidney disease (ADPKD) is a systemic disorder well known for its association with intracranial aneurysms. A series of patients with ADPKD who were screened for the presence of an intracranial aneurysm were reviewed and found to include an unexpectedly high number with intracranial arachnoid cysts. Among 247 patients with ADPKD who underwent magnetic resonance imaging (180 cases) or high-resolution contrast-enhanced computerized tomography (67 cases), there were 151 women and 96 men with a mean age of 44 years. Intracranial arachnoid cysts were found in 20 patients (8.1%) with ADPKD compared to two (0.8%) in a control group without ADPKD matched for age, sex, and method of imaging (p < 0.0001). Multiple intracranial arachnoid cysts were found in two patients. Polycystic liver disease was present in 17 (85.0%) of the 20 patients with intracranial arachnoid cysts compared to 119 (52.4%) of the 227 patients without (p < 0.004). Pineal cysts were found in two patients (0.8%) and choroid plexus cysts were found in three patients (1.2%) but this was not different from the control population. None of the intracranial cysts was symptomatic and none was treated surgically. Intracranial arachnoid cysts are a relatively frequent incidental finding in patients with ADPKD, providing further support for the systemic nature of this disease. In the authors' experience with approximately 1500 patients with ADPKD, no complication has been encountered from an intracranial arachnoid cyst, suggesting that asymptomatic intracranial arachnoid cysts in patients with ADPKD require no treatment.

The familial occurrence of intracranial aneurysms has been well described. However, intracranial aneurysms are not rare and the great majority of reported families consist of only two affected members. Therefore, the familial aggregation of intracranial aneurysms could be fortuitous. The authors investigated the familial occurrence of aneurysmal subarachnoid hemorrhage (SAH) in their community to determine whether family members of patients with a ruptured aneurysm are at an increased risk of developing an SAH. All 81 patients from Rochester, Minnesota, who suffered an SAH between 1970 and 1989 from a proven aneurysmal rupture were identified, and they or their families were contacted and a family history was obtained. The number of expected SAHs among first-degree relatives was calculated using previously established age- and sex-specific incidence rates in the community of Rochester. Of the 81 index patients, 76 had complete follow up for family history. Fifteen (20%) of these 76 patients had a first- or second-degree relative with aneurysmal SAH. The number of observed first-degree relatives with aneurysmal SAH was 11, compared to an expected number of 2.66, giving a relative risk of 4.14 (95% confidence interval 2.06-7.40; p < 0.001). In the authors' community, aneurysmal SAH was familial in one of five patients, and this familial aggregation was not fortuitous. The increase in familial risk of aneurysmal SAH is approximately fourfold among first-degree relatives.

We studied the characteristics of headaches in 161 consecutive symptomatic patients with spontaneous dissections of the internal carotid artery (n = 135) or the vertebral artery (n = 26). For patients with internal carotid artery dissection (ICAD), the mean age was 47 years and for those with vertebral artery dissection (VAD), 40.7 years. A history of migraine was present in 18% of the ICAD group and in 23% of the VAD group. Headache was reported by 68% of the patients with ICAD and by 69% of those with VAD, and, when present, it was the initial manifestation in 47% of those with ICAD and in 33% of those with VAD. Ten percent of patients with ICAD had eye, facial, or ear pain without headache. The median interval from onset of headache to development of other neurologic manifestations was 4 days for the ICAD group and 14.5 hours for the VAD group. For all dissections, headaches typically were ipsilateral to the side of dissection. In the ICAD group, headaches were limited to the anterior head in 60% of patients and were steady in 73% and pulsating in 25%. In the VAD group, headaches were distributed posteriorly in 83% of patients and were steady in 56% and pulsating in 44%. Neck pain was present in 26% of patients with ICAD (anterolateral) and in 46% of those with VAD (posterior). The median duration of the headache in patients with VAD and ICAD was 72 hours, but headaches became prolonged, persisting for months to years, in four patients with ICAD.

The first 48 hours after aneurysmal subarachnoid hemorrhage are critical in determining final outcome. However, most patients who die during this initial period are not included in hospital-based studies. We investigated the occurrence of subarachnoid hemorrhage in a population-based study to evaluate possible predictors of poor outcome. All patients diagnosed with aneurysmal subarachnoid hemorrhage between 1955 and 1984 were selected for analysis of mortality in the first 30 days using the medical record-linkage system employed for epidemiological studies in Rochester, Minnesota. One hundred and thirty-six patients were identified. The mean age of these 99 women and 37 men was 55 years. Rates for survival to 48 hours were 32% for the 19 patients with posterior circulation aneurysms, 77% for the 87 patients with anterior circulation aneurysms, and 70% for the 30 patients with a presumed aneurysm (p < 0.0001). Rates for survival to 30 days were 11%, 57%, and 53%, respectively, in these three patient groups (p < 0.0001). Clinical grade on admission to the hospital, the main variable predictive of death within 48 hours, was significantly worse in patients with posterior circulation aneurysms than in others (p < 0.0001). The prognosis of ruptured posterior circulation aneurysms is poor. The high early mortality explains why posterior circulation aneurysms are uncommon in most clinical series of patients with subarachnoid hemorrhage. The management of incidentally discovered intact posterior circulation aneurysms may be influenced by these findings.

Some patients with aneurysmal subarachnoid hemorrhage (SAH) never reach the hospital alive ("sudden death") and, although their numbers are significant, they are not included in most studies of SAH. To clarify the clinical profile of sudden death from aneurysmal SAH, we reviewed the epidemiology and clinicopathologic features of patients with aneurysmal SAH who never reached medical attention. Using the medical record linkage system employed for epidemiologic studies for the population of Rochester, Minnesota, we identified all patients who were diagnosed with aneurysmal SAH between 1960 and 1989. There were 80 women and 33 men with a mean age of 55 years. Of these 113 patients, 13 (12%) died without reaching medical attention. The proportion of those with sudden death remained stable during the study period. In comparing patients with sudden death with those who reached medical attention, the only significant variable was the frequency of posterior circulation aneurysms that was found in 38%, compared with 14% in those who received medical attention (p = 0.042). At autopsy, intraventricular hemorrhage was present in 12 patients (92%) with sudden death, and intracerebral hemorrhage was present in two (15%). Twelve patients (92%) had acute pulmonary edema. In our community, the frequency of sudden death from aneurysmal SAH has not changed during the last three decades in spite of the advances in medical care. The typical clinical profile of sudden death in SAH includes intraventricular hemorrhage, pulmonary edema, and a ruptured posterior circulation aneurysm. Intracerebral hemorrhage is uncommonly associated with sudden death from aneurysmal SAH.

Aneurysms of the extracranial internal carotid artery (ICA) are uncommon. A significant proportion of such aneurysms are now recognized to be caused by arterial dissection. In some patients, surgical treatment may become necessary. The surgical treatment of 22 patients with spontaneous or traumatic dissecting aneurysms arising from the extracranial ICAs is reviewed. The mean age of the 7 women and 15 men was 39 years. The aneurysm arose from the proximal third of the extracranial ICA in 1 patient, from the middle third in 1 patient, and from the distal third in 20 patients. Five patients underwent cervical carotid ligation; in 13 patients, the aneurysms were resected, and the ICAs were reconstructed, and 4 patients underwent cervical-to-intracranial ICA bypasses. There were 2 postoperative strokes (9%). Facial and lower cranial nerve palsies were commonly seen after high cervical exposure, but these cranial nerve palsies were transient. There were no long-term neurological sequelae during a mean follow-up of 6.2 years. In our relatively limited experience, extracranial ICA dissecting aneurysms can be treated with acceptable morbidity using a variety of techniques. However, the indications for surgical intervention in these aneurysms remain limited.

Background and Purpose: The familial occurrence of intracranial aneurysms suggests the presence of a genetically determined underlying arteriopathy. The pattern of inheritance in these families usually is not known., Methods: A family with seven members with intracranial aneurysms is described and, from the literature before 1994, a total of 238 families with 560 affected members (56% female and 44% male) with intracranial aneurysms not associated with a known heritable disease are reviewed. A segregation analysis was performed on 73 of these families., Results: Two members were affected in the great majority of families (79%); five or more members were reported in only eight families (3%). The most common affected kinship was among siblings. Angiographic screening in 12 families detected an intracranial aneurysm in 29% of 51 asymptomatic relatives. Segregation analysis revealed several patterns of inheritance that were consistent with the compiled pedigrees, but no single mendelian model was the overall best fitting, suggesting that genetic heterogeneity may be important. Twenty-two percent of siblings of male probands had an intracranial aneurysm compared with 9% of siblings of female probands (P = .003)., Conclusions: Genetic heterogeneity may be important in the genetics of intracranial aneurysms. In families with intracranial aneurysms, siblings of an affected male proband may be at a higher risk of developing an aneurysm than siblings of an affected female proband. Screening for intracranial aneurysms in asymptomatic relatives should be considered in families with two or more affected members. In most families, the nature of the underlying arteriopathy remains obscure.

The pathogenesis of ruptured intracranial aneurysms and cervical artery dissections is poorly understood but may be similar in these two disorders. We report four patients with alpha 1-antitrypsin deficiency who developed a ruptured intracranial aneurysm or spontaneous dissection of the cervical internal carotid artery. Three patients were heterozygous for the deficient allele (PiMZ or PiGZ) and one was homozygous (PiZZ). A deficiency of alpha 1-antitrypsin or one of the other protease inhibitors could result in degradation of the arterial wall through an imbalance between proteolytic enzymes and their inhibitors, thereby predisposing the arterial wall to dissection or aneurysm formation.

The literature on the association of intracranial aneurysms in autosomal dominant polycystic kidney disease (ADPKD) consists mainly of case reports and small series of patients. To provide a more-detailed description of this association and its frequency, the records of all ADPKD patients with saccular intracranial aneurysms, all ADPKD autopsy cases including brain examination, and sex- and age-matched autopsy cases without ADPKD seen at the Mayo Clinic between 1950 and 1989 and of all Rochester residents with a diagnosis of subarachnoid hemorrhage or ADPKD between 1945 and 1984 were reviewed. The presentation of the 41 patients (22 men and 19 women; mean age, 46.4 yr) with this association was subarachnoid hemorrhage in 33, transient ischemic attacks in 2, incidental angiographic or autopsy finding in 5, and discovery during angiographic screening in 1. Thirty-one, seven, and three patients harbored one, two, and three aneurysms, respectively, arising from the middle cerebral artery (N = 23), anterior communicating artery (N = 16), internal carotid artery (N = 11), and vertebral or basilar artery (N = 4). A family history of intracranial aneurysm, subarachnoid hemorrhage, or intracranial hemorrhage at an early age was present in 22% of the patients. Small aneurysms (less than 5 mm) were less likely to have ruptured or caused symptoms (P less than 0.04). There was a trend for hypertension to be associated with the severity of the subarachnoid hemorrhage. Aneurysmal rupture occurred before age 50 in 64% of patients. Of the 89 ADPKD autopsy cases with brain examination, 22.5% had intracranial aneurysms.(ABSTRACT TRUNCATED AT 250 WORDS)

Background: A familial occurrence of intracranial aneurysms is defined by the presence of such aneurysms in two or more first to third-degree family members. Families with two affected members may represent accidental aggregation. Other families show a frequency compatible with an autosomal dominant mode of inheritance. A genetic basis is also suggested by the younger average age of familial cases with a ruptured intracranial aneurysm (42.3 years versus an age range of 50-54 years for nonfamilial cases), occurrence at the same site or a mirror site in sibling pairs, occurrence in identical twins, and the association of intracranial aneurysms with genetically transmitted disorders., Summary of Review: No reliable data are available about the occurrence of familial intracranial aneurysms among all patients with ruptured aneurysms; a frequency of 6.7% has been reported from a retrospective study, but a large part of the "familial" occurrence can be explained by fortuitous aggregation. The pathogenesis of familial intracranial aneurysms is not fully explained; a (partial) deficiency of type III collagen has been reported in sporadic, but not in familial, cases. Clinical decision analysis shows how the risk of harboring an intracranial aneurysm and the age of the patient are the main determinants for elective screening; lifetime risk of rupture (and therefore age) and surgical risks are the determinants for neurosurgical treatment., Conclusions: Surgical treatment is recommended for patients aged less than 70 years with a moderate or low surgical risk, and screening (preferably by intra-arterial digital subtraction angiography) is recommended only for relatives aged 35-65 years. Magnetic resonance angiography may develop into a useful alternative for screening, but the risks of diagnostic procedures play only a minor role in the decision analysis.

In a recent study from the Mayo Clinic on the natural history of intact saccular intracranial aneurysms, none of the aneurysms smaller than 10 mm in diameter ruptured. It was concluded that these aneurysms carry a negligible risk for future hemorrhage and that surgery for their repair could not be recommended. These findings and recommendations have been the subject of much controversy. The authors report three patients with previously documented asymptomatic intact saccular intracranial aneurysms smaller than 5 mm in diameter that subsequently ruptured. In Case 1, a 70-year-old man bled from a 4-mm middle cerebral artery aneurysm that had been discovered incidentally 2 1/2 years previously during evaluation of cerebral ischemic symptoms. A 10-mm internal carotid artery aneurysm and a contralateral 4-mm middle cerebral artery aneurysm had not ruptured. Case 2 was that of a 66-year-old woman who bled from a 4-mm pericallosal aneurysm that had been present 9 1/2 years previously when she suffered subarachnoid hemorrhage (SAH) from a 7 x 9-mm posterior inferior cerebellar artery aneurysm. Although the pericallosal aneurysm had not enlarged in the intervening years, a daughter aneurysm had developed. The third patient was a 45-year-old woman who bled from a 4- to 5-mm posterior inferior cerebellar artery aneurysm that had measured approximately 2 mm on an angiogram obtained 4 years previously; at that time she had suffered SAH due to rupture of a 5 x 12-mm posterior communicating artery aneurysm. These cases show that small asymptomatic intact saccular intracranial aneurysms are not innocuous and that careful consideration must be given to their surgical repair and long-term follow-up study.

The pathogenesis of intracranial aneurysms and spontaneous cervical artery dissection is incompletely understood but a primary arteriopathy, possibly similar in both disorders, may be of importance. To investigate the frequency of intracranial aneurysms in patients with spontaneous cervical artery dissection, the angiograms of 164 patients who were diagnosed at the Mayo Clinic as having spontaneous extracranial carotid or vertebral artery dissection were reviewed. Thirteen intracranial aneurysms were detected in nine (5.5%) of the 164 patients: eight (8.8%) of the 91 female patients and one (1.4%) of the 73 male patients. The frequency of intracranial aneurysms in these patients was significantly higher (p less than 0.01) than that observed in a recent angiographic study from the same institution, estimating the frequency of intracranial aneurysms in the general population (1.1%). The significance of these findings is discussed.

Background and Purpose: The familial occurrence of intracranial aneurysms and cervical artery dissections has been described in different families and supports the hypothesis that a primary arteriopathy may play a role in the pathogenesis of these disorders. Although the basis for this arteriopathy is generally not believed to be similar among cases of intracranial aneurysms and cervical artery dissections, several similarities exist in the epidemiology of these disorders and a common underlying arterial abnormality may be suspected., Summary of Reports: The medical records of all 175 patients with spontaneous dissections of the cervical arteries who were seen at the Mayo Clinic between 1970 and 1989 were reviewed to identify families in which intracranial aneurysms and cervical dissections coexisted. Three families were identified in which intracranial aneurysms and cervical artery dissections were observed among siblings. These families are described in detail., Conclusions: The familial occurrence of intracranial aneurysms and cervical artery dissections within the same families provides support to the importance of a common underlying arteriopathy in the pathogenesis of both these disorders. The underlying vascular defect may, at least in some cases, be inherited.

The screening of asymptomatic individuals in families with intracranial aneurysms has been advocated to detect unruptured aneurysms before a major hemorrhage occurs. We report a 39-year-old male member of a large Dutch family, with a documented history of intracranial aneurysms, who suffered a subarachnoid hemorrhage 2 years after cerebral digital subtraction angiography using intravenously administered contrast medium showed no abnormalities. Conventional arteriography demonstrated three intracranial aneurysms measuring 3 x 3 mm. Potential alternative screening procedures are discussed.

To determine the role of blood viscosity after surgical treatment of ruptured intracranial aneurysms, the relationship between blood viscosity and clinical condition was examined in 17 patients. A total of 213 blood samples were analyzed. An inverse correlation was found between blood viscosity and level of consciousness; in addition, blood viscosity was higher when focal neurologic deficit was observed. Hematocrit was similarly related to clinical condition, although the correlations observed were less strong. Postoperative plasma viscosity was higher in patients with focal neurologic deficit. Regular blood viscosity measurements are of value in patients at risk for developing cerebral ischemia.