Schievink, Wouter I.

Background A primary arteriopathy is often implicated in the etiology of spontaneous cervicocephalic arterial dissections, but its exact nature usually remains unknown. We describe the familial occurrence of spontaneous arterial dissections and congenitally bicuspid aortic valve (BAV) and propose a common developmental defect in these families. Summary of Report In the first family, a 63-year-old man suffered an extracranial internal carotid artery (ICA) dissection, and his 43-year-old cousin with BAV suffered an intracranial vertebral artery (VA) dissection. Two other family members had pathologically proven BAV. In the second family, a 31-year-old woman suffered bilateral extracranial ICA and VA dissections. Her father, at age 46, suffered an aortic dissection associated with cystic medial necrosis and BAV. Her paternal uncle died from an aortic dissection at age 59. In the third family, a 39-year-old woman suffered extracranial ICA and VA dissections, and her brother died at age 48 from an aortic dissection associated with a BAV. Conclusions The familial occurrence of spontaneous arterial dissections and BAV suggests a common developmental defect. The aortic valvular cusps and the arterial media of the aortic arch and its branches are derived from neural crest cells, suggesting that a neural crest defect may be the underlying abnormality in these families.

Nonaneurysmal perimesencephalic hemorrhage, a distinct form of subarachnoid hemorrhage, is a recently described variant of intracranial hemorrhage. We describe two patients who presented with unusual features of this type of subarachnoid hemorrhage and also two patients who had a perimesencephalic pattern of hemorrhage due to a ruptured posterior circulation aneurysm. The first patient, a 41-year-old woman with perimesencephalic hemorrhage, underwent an exploratory craniotomy because angiography had suggested an anomaly of the basilar tip. No source of hemorrhage could be identified at the time of surgery. The second patient was a 3-year-old boy who presented with opisthotonos and who was found to have a perimesencephalic hemorrhage. Angiography revealed no source for the hemorrhage. The third patient, a 54-year-old man, had a perimesencephalic pattern of subarachnoid hemorrhage from a vertebrobasilar junction aneurysm associated with a fenestration that was missed on the initial angiographic study. The fourth patient, a 43-year-old man, suffered a perimesencephalic pattern of subarachnoid hemorrhage from a small posterior cerebral artery aneurysm, which had not been recognized on two angiograms. These patients elaborate on the clinical spectrum of subarachnoid hemorrhage with a perimesencephalic pattern. First, a negative exploratory craniotomy suggests that the source of nonaneurysmal perimesencephalic hemorrhage may not be arterial. Second, nonaneurysmal perimesencephalic hemorrhage may also occur in children. Finally, the index of suspicion for a posterior circulation aneurysm should remain high in patients who present with a perimesencephalic pattern of subarachnoid hemorrhage, and these aneurysms may rise from unusual locations.

Heritable disorders of connective tissue are recognized in a small minority of patients with neurovascular diseases. In this report, we review the neurovascular manifestations of four heritable connective tissue disorders: Ehlers-Danlos syndrome, Marfan's syndrome, osteogenesis imperfecta, and pseudoxanthoma elasticum, as well as two other systemic disorders with potential vascular manifestations: neurofibromatosis and polycystic kidney disease. Typical neurovascular complications of Ehlers-Danlos syndrome are carotid-cavernous fistulae, intracranial aneurysms, and cervical artery dissections. Arterial dissections and intracranial aneurysms cause the majority of neurovascular symptoms in Marfan's syndrome. Neurovascular disease is uncommon in osteogenesis imperfecta, although carotid-cavernous fistulae and vertebral artery dissections have been reported. Neurovascular disease in pseudoxanthoma elasticum is characterized by intracranial aneurysms and cerebral ischemia caused by premature arterial occlusive disease. Intracranial occlusive arterial disease is the most common neurovascular manifestation of neurofibromatosis, followed by cervical arteriovenous fistulae and aneurysms and intracranial aneurysms. Intracranial aneurysms are the hallmark of polycystic kidney disease. Recognition of an underlying generalized connective tissue disorder may be of considerable importance, although marked phenotypic heterogeneity often complicates the diagnosis of these disorders. Conversely, the association of certain neurovascular anomalies with generalized connective tissue disorders and recognition of their basic molecular defect may offer clues to the etiology and pathogenesis of these neurovascular diseases in general.

A primary arteriopathy is suspected in most patients with spontaneous dissections of the carotid artery, although the nature of this arteriopathy usually remains elusive. Angiographic changes of fibromuscular dysplasia (FMD), however, are found in 10% to 20% of patients with carotid dissections. A 26-year-old woman with Marfan's syndrome presented with bilateral amaurosis fugax after surgical repair of an aortic dissection. Angiography revealed a dissection extending from the ascending aorta into the right internal carotid artery and, separate from the aortic dissection, a dissection of the left internal carotid artery. After surgery, microscopic examination of the right carotid artery revealed a medial dissection but no evidence of an underlying arteriopathy, while the left internal carotid artery displayed the typical features of FMD. Eighteen months later the patient died after resection of a large thoracoabdominal aortic dissecting aneurysm. Microscopic examination of the aorta revealed moderately extensive cystic medial necrosis. Carotid dissections associated with Marfan's syndrome may be the result of an extension of an aortic dissection or occur isolated from the aorta, even in the same patient. The occurrence of FMD in a patient with Marfan's syndrome in conjunction with previous reports of FMD in a variety of connective tissue disorders suggests that FMD, like cystic medial necrosis, may be a nonspecific disease entity.

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. 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. 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). 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.

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.

Abstract Neurofibromatosis is of particular interest to neurosurgeons because of the various central and peripheral nervous system tumors and, more rarely, cervicocerebral arterial lesions associated with the disease. In the present paper, we report two patients with neurofibromatosis Type 1 (von Recklinghausen's disease) who had anomalies of the extracranial vertebral arteries. A large extracranial vertebral artery' aneurysm was incidentally discovered in the first patient, a 43-year-old woman, after rupture of a subclavian artery aneurysm. The second patient, a 28-year-old woman, had an enlarging neck mass and was found to have an extensive extracranial vertebral artery arteriovenous fistula. The vascular lesions associated with neurofibromatosis Type 1 in general and those arising from the extracranial vertebral artery in particular are reviewed.

Recurrent dissections involving carotid, vertebral, or renal arteries have been described in patients with spontaneous cervical artery dissections, with a maximal interval between dissections of fourteen years. The authors describe 2 patients in whom aortic dissections developed twenty-five and forty years, respectively, following carotid artery dissections. These 2 patients constituted 8% of the total number of patients from Rochester, Minnesota, who were diagnosed with aortic dissection between 1987 and 1992. The first patient, a forty-five-year-old woman, presented in 1948 with right neck pain and headache, associated with several episodes of transient numbness of the right face and numbness and clumsiness of the left upper and lower extremities. Examination showed right miosis. Angiography showed a stenosis of the extracranial right internal carotid artery beginning several centimeters from the bifurcation. She died at age eighty- five from an aortic dissection. The second patient, a thirty-eight-year-old man, noted left orbital and frontotemporal headaches and drooping of the left eyelid in 1962. Examination showed left oculosympathetic palsy. Angiography showed stenosis and an aneurysm in the midportion of the extracranial left internal carotid artery. He died at age sixty-three from an aortic dissection. These cases suggest that following a carotid artery dissection the risk of a recurrent arterial dissection may remain elevated for a prolonged period of time and the recurrent dissection may involve the aorta.

AbstractOBJECTIVEAn 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.METHODSAmong 28 patients with spontaneous intracranial hypotension due to a documented spinal cerebrospinal fluid leak, four (14%) initially experienced an excruciating headaches of instantaneous onset.RESULTSThe 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.CONCLUSIONSpontaneous intracranial hypotension should be included in the differential diagnosis of thunderclap headache, even when meningismus is present.