Anatomical map of the cranial vasculature and sensory ganglia.

There is growing evidence of a direct influence of vasculature on the development of neurons in the brain. The development of the cranial vasculature has been well described in zebrafish but its anatomical relationship with the adjacent developing sensory ganglia has not been addressed. Here, by 3D imaging of fluorescently labelled blood vessels and sensory ganglia, we describe for the first time the spatial organization of the cranial vasculature in relation to the cranial ganglia during zebrafish development. We show that from 24 h post-fertilization (hpf) onwards, the statoacoustic ganglion (SAG) develops in direct contact with two main blood vessels, the primordial hindbrain channel and the lateral dorsal aortae (LDA). At 48 hpf, the LDA is displaced medially, losing direct contact with the SAG. The relationship of the other cranial ganglia with the vasculature is evident for the medial lateral line ganglion and for the vagal ganglia that grow along the primary head sinus (PHS). We also observed that the innervation of the anterior macula runs over the PHS vessel. Our spatiotemporal anatomical map of the cranial ganglia and the head vasculature indicates physical interactions between both systems and suggests a possible functional interaction during development.

Arterial supply of the lower cranial nerves: a comprehensive review.

The lower cranial nerves receive their arterial supply from an intricate network of tributaries derived from the external carotid, internal carotid, and vertebrobasilar territories. A contemporary, comprehensive literature review of the vascular supply of the lower cranial nerves was performed. The vascular supply to the trigeminal, facial, vestibulocochlear, glossopharyngeal, vagus, spinal accessory, and hypoglossal nerves are illustrated with a special emphasis on clinical issues. Frequently the external carotid, internal carotid, and vertebrobasilar territories all contribute to the vascular supply of an individual cranial nerve along its course. Understanding of the vasculature of the lower cranial nerves is of great relevance for skull base surgery.

Multiple cranial neuropathy: Clinical findings in a case series of 142 patients.

INTRODUCTION: Multiple cranial neuropathies (MCN) is an entity frequently seen in clinical practice but there is a lack of studies published about this entity, with most of them based on case reports and small case series. OBJECTIVE: The aim of this study is to describe the clinical involvement of different cranial nerves, the location within the central or peripheral nervous system and the diagnosis in a group of patients with MCN managed in one hospital in Bogotá-Colombia. METHODOLOGY: A case series study was conducted using the electronic clinical records of a teaching hospital in Bogota-Colombia. Clinical data were collected from patients aged ≥18 with a clinical diagnosis of MCN between 2015 and July 2021. RESULTS: The cranial nerves most commonly affected were III and VII, with the most prevalent combinations being III-IV, III-VI, and V-VII. Among etiologies, the most frequently found were autoimmune, vascular and neoplastic and most common locations included peripheral nerves, neuromuscular junction, cavernous sinus and lateral medulla. CONCLUSIONS: The differential diagnosis of MCN is broad, but clinical clues may aid in identifying the underlying etiology. According to our results, MG was the most frequent etiology, so it should be considered in any patient with a clinical diagnosis of MCN associated with fatigability.

[Vascular compression syndromes of the cranial nerves]. / Az agyidegek vascularis kompressziós szindrómál.

The blood vessels which are running nearby the cranial nerves and the brainstem can be elongated; curves and loops of the vessels may develop mostly due to the degenerative alterations of ageing and these vessels can compress the surrounding neural elements. The authors report a review of vascular compression syndromes based on the literature and their own experience. The typical clinical symptoms of the syndromes subserving the proper diagnosis, the pathomechanism, the significance of imaging especially the magnetic resonance angiography, the experience with the surgical technique of microvascular decompression which is the only causal treatment of the syndromes are discussed. In cases of non-responsible medical treatment the microvascular decompression should be the eligible treatment in certain syndromes (trigeminal and glossopharyngeal neuralgia, hemifacial spasm) for it is a highly effective and low risk method.

The diagnostic dilemma of neuro-imaging in acute isolated sixth nerve palsy.

PURPOSE OF REVIEW: Microvascular ischemia is a frequent cause of acute isolated cranial nerve six (CN VI) palsy. Alternative etiologies of CN VI palsy with grave neurological implications often cannot be excluded without neuroimaging. However, the practice of obtaining neuro-imaging for every patient presenting with an acute, isolated CN VI palsy is a costly diagnostic paradigm. Recent studies have sought to delineate the risk factors for microvascular ischemic ocular motor cranial neuropathies and to investigate the utility of neuroimaging in the initial evaluation of such cases. The aim of this review is to provide an update on the issues and controversies of neuroimaging in the initial evaluation of an acute isolated CN VI palsy. RECENT FINDINGS: Diabetes mellitus, but not hypertension alone, is a risk factor for microvascular ischemic ocular motor cranial neuropathies. Small-scale prospective studies have suggested that immediate neuroimaging should be considered in the initial evaluation of all patients with CN VI palsy, regardless of the presence of microvascular ischemic risk factors. SUMMARY: There remains a lack of large-scale, prospective, age-specific studies to indicate the diagnostic yield of immediate neuroimaging in the setting of acute isolated CN VI palsy. An algorithm is offered for the evaluation of acute isolated CN VI palsy, which allows for initial expectant observation and re-consideration of obtaining neuroimaging upon follow-up if the ophthalmoplegia does not improve, progresses, or becomes nonisolated.

[Imaging anatomy of cranial nerves]. / Imagerie anatomique des nerfs crâniens.

Knowledge of the anatomy of the cranial nerves is mandatory for optimal radiological exploration and interpretation of the images in normal and pathological conditions. CT is the method of choice for the study of the skull base and its foramina. MRI explores the cranial nerves and their vascular relationships precisely. Because of their small size, it is essential to obtain images with high spatial resolution. The MRI sequences optimize contrast between nerves and surrounding structures (cerebrospinal fluid, fat, bone structures and vessels). This chapter discusses the radiological anatomy of the cranial nerves.

Implication of the inferolateral trunk of the cavernous internal CAROTID artery in cranial nerve blood supply: Anatomical study and review of the literature.

The inferolateral trunk (ILT) is one of the two more common branches of the cavernous internal carotid artery (ICA). Its knowledge is important for skull base surgery and endovascular interventional procedures. The ILT is described with superior, anterior and posterior branch, which is the complete form. These branches vascularize the oculomotor, trochlear, trigeminal and abducens nerves into the cavernous sinus and superior orbital fissure (SOF) courses, and through the foramens rotundum and ovale. We performed 21 injected embalmed cadaveric dissections combined with six specimen tomodensitometry. The ILT originates from the horizontal ICA segment and passes above the abducens nerve. Three branches arise from the ILT between the cavernous ICA and the ophthalmic and maxillary nerves initial courses. The main differences with the literature are the number of branches and their cranial nerves' blood supply. The more frequent ILT conformation is the incomplete form with anterior and posterior branch (13/21); the complete form is present in 5/13 sides (38%) and the ILT is in common with the meningohypophyseal trunk in 3/21 (14%) sides. The anterior branch always vascularizes the cranial nerves into the SOF course and most often the maxillary nerve through the foramen rotundum. The posterior branch always vascularizes the mandibular nerve through the foramen ovale course and sometimes the maxillary nerve. This study has demonstrated that there are anastomoses between these branches and arteries arising from the external carotid. This study explains why the sacrifice of a branch of the ILT does not implicate cranial nerve palsy.

The Rhomboid Lip: Anatomy, Pathology, and Clinical Consideration in Neurosurgery.

OBJECTIVE: To describe microsurgical anatomy of the rhomboid lip (RL) and to consider its role by presenting histology and clinical cases. METHODS: We examined 10 (20 sides) formalin-fixed adult human cadaveric heads injected with colored silicone. A total of 20 RLs were examined posteriorly. We examined the expansion of the RL in the cerebellopontine cistern. We assessed the relationship between the RL and choroid plexus and the RL and cranial nerve IX and classified the RL. We also observed these relationships in clinical cases during surgeries and examined histologic assessments of the RL. RESULTS: The RL was divided into 3 types, non-extension type, lateral extension type, and jugular foramen type, according to the relationship between the RL and choroid plexus. There were many variations of the extension of the RL. The jugular foramen type was rare. CONCLUSIONS: Histologically, the RL is the remnant of the fourth ventricle covered with ependymal cells. Knowledge of the detailed anatomy and proper dissection of the RL may help surgeons to obtain good visualization of structures around the foramen of Luschka.

The antero-medial triangle: the risk for cranial nerves ischemia at the cavernous sinus lateral wall. Anatomic cadaveric study.

OBJECTIVE: Vascular damage in the cavernous sinus can cause ischemic injury to the cranial nerves. An appropriate anatomical knowledge of the blood supply to the cranial nerves can help to reduce the morbidity associated with cavernous sinus surgery. MATERIAL AND METHODS: Three formalin-fixed and six adult cadaveric fresh heads, with common carotid arteries injected, were used for anatomical dissection in this study. A fronto-temporal craniotomy was performed and the cavernous sinus was explored according to the Dolenc technique. With microsurgical dissection and photographic documentation, we demonstrate the anatomy of the superior orbital fissure artery in the antero-medial triangle. RESULTS: The 12 explored cavernous sinuses demonstrated the presence of two principal branches directly from the intracavernous internal carotid artery that supply the cranial nerves: the infero-lateral trunk and the meningohypophyseal trunk. The artery of the Superior Orbital Fissure (SOF), originated more often from the infero-lateral trunk, and vascularized the III, IV, VI, and VI, and ophtalmic division of the trigeminal nerve (TGN VI) at their entry in the fissure. CONCLUSION: In this study we demonstrate that the superior orbital fissure artery is a branch from the infero-lateral trunk which runs immediately under the reticularis layer at the level of the anteromedial triangle in the lateral wall of the cavernous sinus. The blood supply to all cranial nerves in the SOF is at risk to injury when the lateral wall of the cavernous sinus is transgressed at the anteromedial triangle since the SOF-artery runs superficially at this level.

Arterial vascularization of the cranial nerves.

We discuss the arterial supply of the cranial nerves from their exit out of the brain stem to their exit from the skull base. Four distinct groups can be differentiated from an embryologic and phylogenetic standpoint. Understanding the arterial supply to the cranial nerves and the potential anastomoses is paramount in the endovascular treatment of dural AV shunts and highly vascularized tumors of the skull base to avoid neurologic deficits.

Macrovascular Decompression of the Brainstem and Cranial Nerves: Evolution of an Anteromedial Vertebrobasilar Artery Transposition Technique.

BACKGROUND: Tortuous and dolichoectatic vertebrobasilar arteries can impinge on the brainstem and cranial nerves to cause compression syndromes. Transposition techniques are often required to decompress the brainstem with dolichoectatic pathology. We describe our evolution of an anteromedial transposition technique and its efficacy in decompressing the brainstem and relieving symptoms. OBJECTIVE: To present the anteromedial vertebrobasilar artery transposition technique for macrovascular decompression of the brainstem and cranial nerves. METHODS: All patients who underwent vertebrobasilar artery transposition were identified from the prospectively maintained database of the Vascular Neurosurgery service, and their medical records were reviewed retrospectively. The extent of arterial displacement was measured pre- and postoperatively on imaging. RESULTS: Vertebrobasilar arterial transposition and macrovascular decompression was performed in 12 patients. Evolution in technique was characterized by gradual preference for the far-lateral approach, use of a sling technique with muslin wrap, and an anteromedial direction of pull on the vertebrobasilar artery with clip-assisted tethering to the clival dura. With this technique, mean lateral displacement decreased from 6.6 mm in the first half of the series to 3.8 mm in the last half of the series, and mean anterior displacement increased from 0.8 to 2.5 mm, with corresponding increases in satisfaction and relief of symptoms. CONCLUSION: Compressive dolichoectatic pathology directed laterally into cranial nerves and posteriorly into the brainstem can be corrected with anteromedial transposition towards the clivus. Our technique accomplishes this anteromedial transposition from an inferolateral surgical approach through the vagoaccessory triangle, with sling fixation to clival dura using aneurysm clips.

Ets-1 expression is associated with cranial neural crest migration and vasculogenesis in the chick embryo.

The transcription factor Ets-1 is expressed in many different migratory cell types, suggesting that it may play an important role in regulating motility. To determine whether its expression in the neural crest is consistent with such a function, we have performed a detailed analysis of its expression during early chick embryogenesis. Our results show that this transcription factor is up-regulated in the cranial neural folds and dorsal neural tube approximately 4-6 h prior to commencement of neural crest migration. c-Ets-1 continues to be expressed by migrating cranial neural crest cells and subsequently by some neural crest-derived tissues. In addition to neural crest, we find expression of c-Ets-1 in endothelial cells of blood vessels, in somitic and intermediate mesoderm, in limb buds and in the heart.

Neurons with access to the general circulation in the central nervous system of the rat: a retrograde tracing study with fluoro-gold.

Central nervous system neurons which have access to the general circulation were identified by injecting the retrograde tracer Fluoro-Gold peripherally. Fluoro-Gold does not penetrate the blood-brain barrier but is taken up by nerve terminals which project to areas supplied by fenestrated capillaries or to the periphery. Fluoro-Gold-accumulating neurons were present in the following regions or cell groups of the central nervous system: diagonal band of Broca; medial preoptic area; organum vasculosum of the lamina terminalis; subfornical organ; anterior periventricular area; paraventricular nucleus; arcuate nucleus; accessory magnocellular nuclei of the hypothalamus; motor neurons of cranial nerves III-VII, and IX-XII in the brainstem and spinal cord; autonomic ganglionic cells of cranial nerve III (Westphal-Edinger nucleus) in the mesencephalon and the intermediolateral column of the spinal cord; sensory ganglia of the cranial nerve V (mesencephalic trigeminal nucleus); and the C1-C2 and A2 adrenergic cell groups in the medulla. In addition, Fluoro-Gold-accumulating neurons were seen in the sensory ganglia of cranial and spinal nerves. Retrograde labeling with Fluoro-Gold can be combined with immunocytochemistry to identify the chemical messengers within Fluoro-Gold-labeled perikarya. Although a large number of neurons are labeled in the central nervous system with Fluoro-Gold when it is administered peripherally, this technique in combination with immunocytochemistry can be a powerful tool to identify selected neuronal systems in the central nervous system.

Aspirin use and the prevention of acute ischemic cranial nerve palsy.

PURPOSE: To assess the relationship of aspirin use and ischemic cranial nerve palsies among patients with diabetes mellitus and hypertension. METHODS: This retrospective case-control study involved 100 patients with ischemic cranial nerve palsies in association with diabetes, hypertension, or both (palsy cases) and 163 age-matched and sex-matched patients with diabetes, hypertension, or both but without ischemic cranial nerve palsies (nonpalsy control subjects). Comparisons were made with respect to duration of diabetes, dose and duration of aspirin use, dose and duration of tobacco use, and presence of cardiac or cerebrovascular disease. RESULTS: There were 20 oculomotor, 33 trochlear, 37 abducens, and 10 facial nerve palsy cases. The median duration of diabetes was 6 years for cases and 7 years for control subjects. There were 34 cases (34%) who had used aspirin for a mean duration of 5.5 years before the onset of the cranial nerve palsy and 49 control subjects (30.1%) who had used aspirin for a mean duration of 4.3 years. There were no significant differences between cases and control subjects for duration of diabetes (P =.94); aspirin use (P =.51), duration (P =.50), and dosage (P =.89); tobacco use (P =.73) and consumption (P =.45); and proportion of cardiac disease (P =.17). Cerebrovascular disease was significantly less common among palsy cases than nonpalsy control subjects (P<.001). There was no significant difference in the odds of a patient having cranial nerve palsy in the aspirin group compared with the nonaspirin group (odds ratio, 1.12; 95% confidence interval, 0.70-2.04). CONCLUSION: Aspirin use was not associated with a reduced rate of ischemic third, fourth, sixth, and seventh nerve palsies among patients with diabetes mellitus and hypertension. Aspirin appears to be ineffective in preventing ischemic third, fourth, sixth, and seventh cranial nerve palsies. Patients with ischemic cranial nerve palsy have a significantly lower rate of strokes and transient ischemic attacks than patients who have diabetes or hypertension but who do not have a history of cranial nerve palsy.

Transvenous embolization of a direct carotid cavernous fistula through the pterygoid plexus.

Closure of a direct carotid cavernous fistula with detachable coils by transpterygoid venous approach to the cavernous sinus is an alternative technique that may be applied in cases in which other techniques offer increased risk or in which other techniques have failed. In this case report, we present the details of the management of a direct carotid cavernous fistula by this method.

Lidocaine injection into external carotid branches: provocative test to preserve cranial nerve function in therapeutic embolization.

Endovascular obliteration of hypervascular lesions of the head and neck has become clinically accepted, but it may cause stroke and peripheral cranial nerve palsy. By using a flow-controlled technique to deliver the materials and by knowing the vascular anatomy of the cranial nerves, these problems are less likely to occur. Occasionally, though, vascular anatomy is distorted by the lesion or is anomalous in its distribution. A provocative test of lidocaine injected into the appropriate artery seems to offer a functional test of whether the capillary bed will tolerate small-particle or liquid plastic occlusion. Twenty-six patients had various branches of their external carotid arteries challenged with lidocaine. Three developed transient palsies, and their treatments were modified. None of the 26 patients developed a complication of embolization.

[Unilateral involvement of IX, X, Xi and XII in cervical zoster. Cranial nerve contribution to vascular pathology]. / Atteinte unilaterale des IX, X, XI et XII au cours d'un zona cervical. Contribution à la pathologie vasculaire des nerfs crâniens.

The authors report a case of a cervical zoster (C2 - C4) with unilateral involvement of the IXth, Xth, XIth and XIIth cranial nerves. Angiography failed to opacify the ascending pharyngeal artery on the same side, presumably because of a thrombosis secondary to the zoster infection. As the ascending pharyngeal artery is known to supply the last four cranial nerves, this study should be seen as a further example of the varied cranial nerve involvement which may arise on a vascular basis.

The blood supply of the intracavernous cranial nerves: an anatomic study.

Cranial nerve deficits are the most common complications of cavernous sinus surgery. Often the deficit occurs despite anatomic preservation of the nerve, and ischemic injury is thought to be the cause. A better understanding of the blood supply of these nerves may help to prevent such complications. The authors performed a cadaveric microsurgical study of the intracavernous cranial nerves and their blood supply in 20 cavernous sinuses. The oculomotor nerve received branches from the inferolateral trunk or its equivalent in all specimens (100%). The proximal trochlear nerve received branches from the inferolateral trunk in 80% of the specimens and from the tentorial artery of the meningohypophyseal trunk in 20%. The distal half was supplied by the branches from the inferolateral trunk only. In the region of Dorello's canal, the proximal third of the abducens nerve received branches from the dorsal clival artery of the meningohypophyseal trunk. The middle and distal thirds received branches from the inferolateral trunk. The ophthalmic and proximal maxillary segments of the trigeminal nerve received branches from the inferolateral trunk. The distal maxillary segment was supplied by the artery of the foramen rotundum. In the majority of cases, the medial third of the Gasserian ganglion received branches from both the inferolateral trunk and the tentorial artery. The middle third of the ganglion received branches from either the inferolateral trunk or the middle meningeal artery. Our findings indicate the important role the intracavernous branches of the internal carotid artery play in the blood supply of the intracavernous cranial nerves, and stress the need to preserve these branches to prevent or minimize postoperative deficits.

The clinical importance of the inferolateral trunk of the internal carotid artery.

The inferolateral trunk (ILT) of the internal carotid artery (ICA) is a branch that arises inferiorly from the C4 segment of the cavernous ICA. It provides blood supply to the 3rd, 4th, and 6th cranial nerves, as well as to the gasserian ganglion. The ILT anastomoses to branches of the internal maxillary artery, providing collateral circulation between the external carotid artery and the ICA systems. Retinal and cerebral emboli can arise from the external carotid artery system and travel via the ILT to the ICA. Cranial nerve palsies may result after occlusion of the ILT. We present the cases of four patients who had iatrogenic neurological dysfunction subsequent to intravascular procedures that involved the ILT. These cases provide further clinical confirmation of the importance of this blood vessel. A 5th case involving iatrogenic occlusion of the ILT and no neurological deficit is also presented, demonstrating that the ILT is not the sole blood supply of the cranial nerves in the cavernous sinus.