Arteries of the thalamus in man. Choroidal arteries. I. Macroscopic study of individual variations. II. Systematization

One may describe 4 types of individual dispositions for the postero-median choroideal and thalamic system: Type A with a single artery of anterior origin, type P with two consecutive arteries (a mesencephalothalamic artery and a posteromedian artery of posterior origin), type D with two parallel arteries and type O. One may also describe 4 types of individual dispositions for the postero-lateral choroideal and thalamic system. Type C is constituted by a single postero-lateral chorideal artery giving off thalamic branches. Type D comprises two arteries, a postero-lateral choroideal and a postero-lateral thalamic artery. According to the relative importance of the two arteries one may describe subtypes Dc, De and Dt. Type T is constituted by a single postero-lateral thalamic artery giving off choroideal branches. In type H hippocampothalamic arteries intervene. We also studied the variations of the ending point of the anterior choiroideal artery.     

Non-bifurcating cervical carotid artery.

Three cases of an extremely rare anomaly of the carotid artery are described herein. In these patients, the common carotid arteries, without bifurcation in the cervical portion, supplied multiple arterial branches, which are more commonly branches of the external carotid artery. The non-bifurcating carotid artery continued into the cranium as a normal internal carotid artery. This anomaly can be attributed to a maldevelopment of the vascular network during embryogenesis.     

Long term survival after basilar artery occlusion. 4 cases

Four cases of basilar artery occlusion with a follow-up from 7 to 12 years are reported. The first patient, a 60 year old woman, had a proximal occlusion which was revealed by an acute brain stem ischemia. The second case was a 63 year old man with an aortic aneurysm who had a single episode of vertebro-basilar insufficiency. Cerebral angiography demonstrated a lower basilar artery occlusion. The third patient, a 60 year-old woman, had been operated from right carotid artery and left vertebral artery stenosis; 8 years later, without clinical manifestations, a left carotid artery stenosis and an occlusion of the lower part of the basilar artery were discovered. The evolution was eventless after a left carotid endarterectomy. The last case was a 60 year old man who had a lower basilar artery occlusion associated with a left internal carotid occlusion. There was a full recovery after a hemiplegic stroke. From our personal cases and the review of the literature, long term survival after basilar artery occlusion may occur in occlusions restricted to the lower or middle part of the basilar artery and with a good collateral supply from carotid and cerebellar arteries.     

Dysarthria during basilar artery balloon occlusion.

A 49-year-old woman presenting with recurrent, reversible brainstem symptoms and a distal basilar artery aneurysm underwent balloon test occlusion. Five minutes after balloon inflation she developed a reversible isolated dysarthria. Despite failing the test occlusion (and after an additional brainstem event), the patient underwent surgery with placement of a clip across the basilar artery. The operation was tolerated without complication. The authors conclude that 1) pure dysarthria may be a symptom of temporary basilar artery occlusion and 2) balloon testing may overestimate the risk of basilar artery clipping.     

Basilar artery dissection.

Dissection of the basilar artery caused sudden coma and death in a 40-year-old man. Atypical clinical features were explained at necropsy. A ventral dissection of the artery within its outer layers resulted in destruction of the pontine tegmentum with sparing of the basis pontis. An unsuspected defect in the internal elastic lamina in the left internal carotid artery was also found suggesting a more generalised disorder of arterial walls. Basilar artery dissection should be considered in the diagnosis of coma in young people.     

Deep perforators from the carotid system. Template of the vascular territories

Most reports on small infarcts in the territory of the deep perforators that arise from the internal carotid artery and its branches have focused on the anatomical structures. Recently, it has become possible to map the territories of the deep perforators from the carotid system, based on matching previous anatomical studies with recent data from computed tomographic and magnetic resonance imaging studies. The middle cerebral artery gives origin to two main groups of perforators: the medial and lateral lenticulostriate arteries. Rarely, the thalamotuberal artery may take origin from the middle cerebral artery but much more commonly it originates from the posterior communicating artery. The anterior cerebral artery gives origin to the anterior lenticulostriate arteries and the recurrent artery of Heubner. The anterior choroidal artery takes its origin from the internal carotid artery and exceptionally from the middle cerebral artery. In addition, a small group of perforators comes directly from the internal carotid artery. The anatomical structures supplied by these perforators are described, and a map of the territories is proposed.     

Computer-controlled acupuncture. Quantification and separation of specific effects.

The effects of acupuncture have been described and handed down empirically for centuries but there are few reports based on objective data. The aim of this study was to provide selective evidence of a specific effect of acupuncture on the brain and the eye using a Doppler ultrasound technique. A transcranial Doppler sonography arrangement was developed to monitor blood flow profiles in the supratrochlear and middle cerebral arteries simultaneously and continuously. Two acupuncture schemas were tested in a randomized cross-over study with 13 patients with ophthalmologic diseases. Applying acupuncture needles to special eye points increased the blood flow velocity in the supratrochlear artery significantly (p < 0.001) compared to the reference interval before acupuncture. In the middle cerebral artery only a minimal, non-significant increase in blood flow velocity was seen. In contrast, acupuncture of points that are held to increase cerebral blood flow velocity increased blood flow velocity in the middle cerebral artery significantly (p < 0.001) while leaving that in the supratrochlear artery unchanged. Specific acupuncture produce specific, reproducible quantifiable effects on blood flow velocity in arteries to the brain and eye.     

Bilateral spontaneous carotid artery dissection.

Bilateral internal carotid artery dissections have been reported, but spontaneous bilateral dissections are rare. Internal carotid artery dissection can present with a spectrum of symptoms ranging from headache to completed stroke. Two cases of spontaneous bilateral carotid artery dissection are presented, one with headache and minimal symptoms and the other with a stroke syndrome. No cause could be found in either case, making the dissections completely spontaneous. Bilateral internal carotid artery dissection (ICAD) should be considered in young patients with unexplained head and neck pain with or without focal neurological symptoms and signs. The increasing availability of imaging would sustain the higher index of suspicion.     

Inflammatory aneurysm due to neurocysticercosis.

A 69-year old man presented with a subarachnoid hemorrhage associated with a large intracerebral hematoma in the right temporal lobe. The oblique views of cranio-orbital computerized tomographic angiography (CTA) were suspicious for an aneurysm on a middle cerebral artery branch. At surgery, a cystic mass was found in the Sylvian fissure, associated with an aneurysm on a distal branch of the anterior temporal artery. The aneurysm was not situated at a bifurcation of the artery and was located beneath the cyst. It was secured by trapping. Pathological examination revealed that the cystic lesion was neurocysticercosis and that the aneurysm was inflammatory. We report a ruptured inflammatory aneurysm of a distal branch of the anterior temporal artery associated with neurocysticercosis, and present the histological findings. We believe this is the first report of such an inflammatory aneurysm with histological confirmation.     

Cervical root injury caused by vertebral artery dissection.

Vertebral artery dissection is a common cause of posterior circulation strokes in young and middle-aged adults. Peripheral motor deficits have been rarely described in association with vertebral artery dissection. Peripheral motor involvement may be due to compression of the spinal nerves by an enlarged vertebral artery. It may also result from ischaemia of the anterior horn or the spinal nerves by occlusion of a spinal radicular artery that originates from the vertebral artery. Magnetic resonance imaging (MRf) and magnetic resonance angiography (MRA) offer the possibility of easy, non-invasive diagnosis of a vertebral artery dissection. Acute treatment with anticoagulants is warranted to prevent the progression of neurologic deficits due to intraluminal thrombus or artery to artery emboli. This case report describes a patient in whom vertebral artery dissection was associated with an unusual presentation with a peripheral motor deficit in the upper limb and recurrent central ischaemic neurological events.     

New technique for vagal nerve stimulation.

INTRODUCTION: The vagus nerve travels in a neurovascular bundle with the carotid artery and internal jugular vein. The present study was designed to assess whether transvascular stimulation through the carotid artery of the dog can be used to directly stimulate the vagus nerve and increase parasympathetic tone. METHODS: In five anesthetized dogs, a steerable electrode catheter was positioned under fluoroscopic guidance in the right carotid artery in the mid neck via the femoral artery. Multipolar catheters were positioned transvenously through the femoral vein in the right atrium, across the tricuspid valve to record a His-bundle electrogram, and in the right ventricle. RESULTS: In all five animals, vagal nerve stimulation was successfully achieved with outputs ranging between 10 and 30 mA. Sinus cycle length increased from 473 +/- 113 ms at baseline to 894 +/- 315 ms (P < 0.025) during stimulation from the right carotid artery. There was an increase in the AH interval from 55 +/- 14 to 77 +/- 23 ms (P < 0.03), a shortening of the atrial effective refractory period from 136 +/- 8 to 126 +/- 6 ms (P < 0.01), and a fall in the systolic blood pressure from 135 +/- 20 to 117 +/- 20 mmHg (P < 0.005) with stimulation from the right carotid artery. A prolongation of the AV and VA block cycle lengths and the AV nodal effective refractory period was also noted with stimulation from the right carotid artery. Atrial fibrillation was not induced at baseline in any animal. During stimulation from the right carotid artery, atrial fibrillation was induced in three of five animals and persisted for the duration of stimulation from the right carotid artery. CONCLUSION: Cardiac parasympathetic stimulation can be achieved by positioning a catheter in the neurovascular bundle in the neck adjacent to the vagus nerve with resultant effects on cardiac electrophysiology.     

Critical carotid and vertebral arterial occlusive disease and cough syncope.

BACKGROUND AND PURPOSE: Cough syncope typically occurs in patients with known chronic lung disease. The mechanism usually involves a combination of decreased venous return, increased cerebrospinal fluid pressure, and secondary hypocapnia, all resulting in cerebral arterial vasoconstriction. Cough syncope has not in the past been associated with occlusive cerebrovascular disease. CASE DESCRIPTION: We describe a 50-year-old man with a 6-month history of episodes of loss of consciousness during paroxysms of coughing. Physical examination showed asymmetrical upper extremity blood pressures and carotid and subclavian artery bruits. Pulmonary function studies were normal. Ultrasound and angiography showed total occlusion of the left common carotid artery, right internal carotid artery, and right vertebral artery; tight stenosis of the right subclavian artery; and a hypoplastic left vertebral artery. The patient had a left subclavian-to-left common carotid artery bypass and has had no syncope since that time. CONCLUSIONS: To our knowledge, this is the first reported case of cough syncope and severe cerebrovascular disease in which surgery led to amelioration of symptoms. Cerebrovascular occlusive disease may contribute to cough syncope.     

Fusiform aneurysm of a persistent trigeminal artery.

OBJECTIVE: Fusiform aneurysms of the persistent trigeminal artery are rare and endovascular treatment of these aneurysms has not been attempted previously. We describe a case of persistent trigeminal artery with a fusiform aneurysm in its middle third, managed using Guglielmi detachable coils (GDC). CLINICAL PRESENTATION: A 50-year-old, diabetic and hypertensive patient presented with sudden onset headache and neck stiffness. On examination, she was conscious but disoriented, without cranial nerve or sensorimotor deficits. Four-vessel cerebral digital subtraction angiography revealed a fusiform aneurysm of the middle third of a persistent trigeminal artery on the left side with adult type posterior cerebral arteries. INTERVENTION: Guglielmi detachable coils were used for occlusion of the persistent trigeminal artery. RESULTS: The procedure was well tolerated but delayed ischemic neurological deficits developed due to vasospasm. CONCLUSIONS: (1) In spite of angiographically documented independence of the anterior and posterior cerebral circulation, occlusion of a persistent trigeminal artery using endovascular techniques may result in posterior circulation stroke due to a number of factors, including occlusion of brainstem perforators taking origin from the persistent trigeminal artery or vasospasm. (2) The timing for endovascular intervention following aneurysmal rupture remains poorly defined.     

The anterior cerebral artery. II. A computer model of its cortical branches estereotaxically obtained from anatomical specimens.

This article is a corrollary of a previously published anatomical study of the anterior cerebral artery. The authors propose a method to obtain a computer model of the anterior cerebral artery, based on a combined system of stereotaxic coordinates and a specially developed computer program. The graphic analysis, thus obtained, is projected on a model atlas brain and an ideal diagram of this anatomical structure is obtained. Forty anatomical specimens were used for this study.     

Traumatic middle cerebral artery occlusion from boxing.

A case of a traumatic middle cerebral artery occlusion resulting from a boxing injury is presented. A 22-year-old man, an amateur boxer, was admitted because of difficulty in speaking, that had appeared a day after a sparring fight. A computed tomographic scan showed low-density areas in the left globus pallidus and corona radiata. A carotid angiogram indicated complete occlusion of the left middle cerebral artery at its origin and an irregularity and narrowing of the left internal carotid artery in its supraclinoid portion. The patient was discharged 4 weeks after the admission with some persistent expressive dysphasia that diminished during the next month. The clinical features and mechanisms of the traumatic middle cerebral artery occlusion are discussed.     

Multifocal infarction of the basilar trunk region. Persistence of a trigeminal artery

A multifocal haemorrhagic infarction of the basilar artery territory, linked to the persistence of a trigeminal artery is reported. This was associated to hypoplasia of the basilar artery and of the posterior communicating arteries. The trigeminal artery supplied most of the distal part of the basilar territory. At post mortem there was no arterial occlusion and the infarction probably resulted from embolism from the heart or from the carotid artery.     

Carotid stenting and cerebral hyperperfusion syndrome.

We present a patient who became hemiparetic and drowsy 30 min after insertion of a carotid artery stent for severe (>80%) asymptomatic left common carotid artery stenosis. A carotid angiogram at this time showed widely patent vessels. Non-contrast head computed tomography showed a diffuse increase in signal intensity in the distribution of the left middle cerebral artery. Repeat computed tomography 8 days later showed no evidence of cerebral infarction or haemorrhage. The patient's arm remained weak for several months. A diagnosis of cerebral hyperperfusion syndrome was made. The features of this unusual cause of stroke are reviewed.     

Olfactory groove meningioma and multiple aneurysms. Case report.

We report a case of a patient with olfactory groove meningioma associated with multiple aneurysms. The association between intracranial aneurysms and meningiomas is infrequent and perhaps it is due to chance alone; many theories have been formulated to explain it. In the cases with both lesions, meningiomas are more frequently located at level of the convexity while aneurysms are more often located at level of the anterior cerebral-anterior communicating artery complex or at level of the middle cerebral artery.     

Inconspicuous visual field defect in anterior choroidal artery territory infarction.

We describe a patient with a right anterior choroidal artery territory infarction and an inconspicuous left visual defect. The anterior choroidal artery is a unique artery of the cerebral circulation. The occlusion of this artery can result in dysfunction of motor, sensory, and visual systems with only rare involvement of higher cortical function. Among symptoms reported, visual abnormalities are the most variable and the least common. However, the visual field abnormality may be overlooked and the incidence underestimated since some patients may not be aware of the problem until uncovered by formal visual field testing.     

Stent-graft placement in a traumatic internal carotid-internal jugular fistula and pseudoaneurysm.

Traumatic arteriovenous fistulas following carotid artery injuries are rare. Treatment of carotid artery-to-jugular vein fistula requires direct closure of the fistula or occlusion of the carotid artery above and below the level of the fistula, by a surgical or endovascular approach. A 32-year-old man presented with a right-sided pulsatile neck swelling 2 days following a stab wound. Neck computed tomography demonstrated a vascular mass protruding into the anterior neck. Digital subtraction arteriography demonstrated a bilobular large internal carotid artery pseudoaneurysm just distal to its bifurcation. There was simultaneous opacification of a dilated left internal jugular vein indicating a high-flow internal carotid-internal jugular fistula. A balloon-expandable stent-graft was delivered and successfully positioned across the fistula. The arteriovenous fistula and pseudoaneurysm completely disappeared and the right internal carotid artery was well preserved. The stent-graft is a promising technology to obliterate fistulae and preserve the parent artery with relative safety.