Afferents of cranial sensory ganglia pathfind to their target independent of the site of entry into the hindbrain

In vertebrates, sensory neurons interconnect a variety of peripheral tissues and central targets, conveying sensory information from different types of sensory receptors to appropriate second-order neurons in the central nervous system (CNS). To explore the possibility that the different rhombomere environments where sensory neurons enter into the hindbrain affect the pathfinding capability of growth cones, we studied the development of the VIIIth ganglion afferent both in vivo and in vitro. We focused on the vestibular nerve because it is the only cranial nerve projecting to the cerebellum, allowing for ready identification from its pattern of projection. Embryonic rat brain was cut along the dorsal midline and, with the VIIIth and Vth ganglia still attached, flat mounted and visualized with antibodies specific for sensory ganglia. Axons reached the cerebellar primordium at embryonic day (E) 13, then splayed out towards the edges of the rhombic lip of rostral hindbrain. In vitro, the VIIIth ganglion showed development similar to that in vivo and innervated the cerebellum, an appropriate target, indicating that mechanisms for axon guidance and target recognition are preserved in vitro. When the VIIIth ganglion was transplanted to the position of the Vth ganglion, axons from the transplanted ganglion entered the cerebellar primordium with a trajectory characteristic of the VIIIth nerve. These results indicate that the central projection pattern of the VIIIth nerve is not affected by the environment of nerve entry into the brainstem, suggesting that axons of sensory cranial ganglion intrinsically possess the capacity to find their target correctly.     

Paralysis of the 3d cranial nerves in diabetes and common oculomotor vascularization]

The purpose of this paper is to present explanations for various patterns of IIIrd cranial nerve involvement in diabetes mellitsus, based on its vascularisation. Three clinical cases of diabetes with numerous attacks of IIIrd nerve paralysis are reported. The following patterns were observed: (1) isolated; (2) associated with Vth nerve involvement and; (3) associated with invovlement of the Vth, IVth, VIth, and occasionally IInd and VIIth nerves. An anatomical study of IIIrd nerve vascularisation demonstrates three territories which could correspond to the 3 patterns of clinical expression. The arterial branches to the IIIrd nerve give off no collaterals in the posterior region of the circle of Willis. In the supra-cavernous region, vascularisation of the IIIrd nerve may be associated with that of the IVth. Eventually, vascularisation of the IIIrd nerve in the intracavernous region is associated with that of the Vth, IVth, VIth, and occasionally IInd and VIIth cranial nerves. Thus, a painless paralysis of the IIIrd nerve (isolated or associated only with an involvement of the IVth) would predictably be related to a vascular disturbance limited to the first or second portion of this nerve, whereas a painful paralysis of the IIIrd nerve, without or with associated involvement of other cranial nerves, would relate to a vascular distrubance in the intra-cavernous region. The anatomo-clinical relationships that have been presented: (1) support the vascular basis of IIIrd nerve paralysis in diabetes; (2) explain the various clinical patterns of IIIrd nerve involvement in that disorder and; (3) act as a model which can be applied to the study of ischemic pathology in other cranial nerves and other etiologies.     

Localization of immunoreactive thyrotropin releasing hormone in the lower brainstem of the rat

The distribution of thyrotropin releasing hormone (TRH) in individual nuclei of the rat brainstem was examined by radioimmunoassay. TRH was detectable in 36 of 40 brainstem nuclei investigated and the localization of TRH in the brainstem was unlike other known brainstem neuropeptides. By far the highest concentration of TRH in the brainstem (1.2 ng/mg protein) is present in the nucleus of the solitary tract. The concentration of TRH was relatively high in the motor nuclei of the IIIrd, Vth, VIIth, Xth and XIIth cranial nerves, and less high in the area postrema, nucleus gracilis, locus coeruleus, lateral reticular nucleus (A1-catecholamine cell group), dorsal raphe and central gray matter. Cerebellum and pontine nuclei contained very low levels (<0.03ng/mg protein) of TRH.     

Regional distribution of substance P-like immunoreactivity in the lower brainstem of the rat

A radioimmunoassay was used to quantify substance P-like immunoreactivity in the lower brainstem of the rat. The peptide was detectable in all brainstem nuclei investigated. A very high concentration was found in the substantia nigra, and high concentrations in the interpeduncular nucleus and central gray matter. Levels in the pons, the parabrachial nuclei; in the medulla, the nucleus tractus spinalis of the Vth nerve and the nucleus of the solitary tract were higher than the brain average.     

MuSC, a novel member of the immunoglobulin superfamily, is expressed in neurons of a subset of cranial sensory ganglia in the mouse embryo

In contrast to the spinal sensory ganglia which reiterate a basic organizational and functional unit, each cranial ganglion mediates a distinct sensory modality and exhibits a characteristic pattern of peripheral and central neuronal connectivity. Molecules responsible for establishment and maintenance of the cranial ganglion-specific networks are not known. Our hamster monoclonal antibody 802C11 strongly stained neurons and their processes of the VIIIth cranial ganglion (hearing and equilibrium), but not of the Vth cranial (somatosensory) or spinal ganglia in the mouse embryo. The cellular staining pattern of positive neurons suggested that the antigen was associated with the cell membrane, and biochemical analyses of the antigen from adult mouse brain showed the antigen to be a glycosylated intrinsic membrane protein of ≈100 kDa. The antigen was purified, and based on the partial amino acid sequences, its entire cDNA was cloned. A bacterially expressed polypeptide encoded by the cDNA was recognized by the antibody. The deduced amino acid sequence revealed that the antigen belongs to the immunoglobulin superfamily with a significant homology (73.5% identity) to chicken SC1 protein. Chicken SC1 has been shown to be a cell–cell adhesion molecule in vitro with a proposed role in neurite extension of spinal motor neurons. These results suggest that our murine SC1-related protein (MuSC) is involved in the pathfinding and/or fasciculation of specific cranial sensory nerve fibres.     

Trigeminal afferent fibers in the trunk of the oculomotor nerve of lambs.

In lambs, chronic section of the oculomotor nerve at the base of the skull just proximally to the cavernous sinus induced degeneration of some fibers in the central stump, although the peripheral stump contained some normal fibers. On the other hand, chronic section of the ophthalmic branch just distally to the semilunar ganglion was followed by degeneration of a certain number of medium and large caliber fibers in the ipsilateral oculomotor nerve. The presence of trigeminal afferent fibers in the trunk of an oculomotor nerve is supported by electrophysiologic experiments. Single-shock electrical stimulation of the frontal and nasociliary nerves and of the conjunctiva of the superior and inferior eyelids elicited short-latency evoked potentials, not only in the semilunar ganglion but also in the ipsilateral oculomotor nerve at the base of the skull. Such responses did not appear in those animals in which the ipsilateral ophthalmic and maxillary branches of the trigeminal nerve had been chronically cut. Thus, we can affirm that afferent trigeminal impulses enter the brain stem also through the third nerve. The perikarya of such a pathway are localized in the semilunar ganglion; the peripheral processes attain the conjunctiva of the superior and inferior eyelids through the ophthalmic and maxillary branches, and the central processes enter the oculomotor nerve by anastomoses between IIIrd and Vth cranial nerves after a short passage in the two trigeminal branches. The trigeminal nature of these fibers is also shown by the fact that electrical stimulation of the central stump of the IIIrd nerve can influence the dorsal neck muscles in the same way as other trigeminal afferents.     

The numb chin in breast cancer

Numbness of the chin, an uncommon neurological symptom, was observed in 15 patients with cancer. Thirteen had breast cancer. This symptom usually heralded progressive involvement of the cranial nerves or cerebrum and denoted a poor prognosis in patients with a short `tumourfree interval'. The pathogenesis is commonly related to dural involvement of the Vth cranial nerve at the base of the brain, although metastasis to the mandible might sometimes be implicated. The reason for the peculiar predilection for the mandibular branch of the trigeminal nerve to be affected by breast cancer is not known.     

In vitro culture observations on neurinoma induced experimentally in the rat by ethylnitrosourea

Summary Five neurinomas of the Vth cranial nerve, produced experimentally in rats by ethylnitrosourea, were cultivatedin vitro: they show a great resemblance with the human neurinomas. It must be emphasized that the resemblance is evident also in cultures of tumours which are characterized histologically by poor differentiation and by high invasiveness.The morphological and histochemical characteristics are described. In one case a mixed cell population developed in the same culture, with a neurinomatous and an oligodendroglial features. This finding is discussed in relation to tumour differentiation, regression and association with oligodendrogliomas. Particular attention is paid to the possibility of Gitterzellen transformation on the grounds of their morphological and histochemical behaviour.The research was partially supported by the Italian National Council for Research (CNR), Rome.     

Benign triton tumor of the trigeminal nerve

Benign triton tumor (neuromuscular hamartoma) is a rare tumor of the peripheral nerves, comprising mature neural and striated muscle elements. We report the third case, according to the literature, of a benign triton tumor affecting the Vth cranial nerve in a 4-year-old male child. The tumor was seen to involve the mandibular division of the trigeminal nerve in the infratemporal fossa and extend intracranially by eroding the base of middle cranial fossa. The mass was totally excised. In the tumor, bundles of axons intermingling with fascicles of relatively mature skeletal muscle were found. This type of hamartomatous lesions of neuroectodermal-mesenchymal origin could have arisen as the result of incorporation of mesenchymal tissue into nerve sheaths during embryogenesis or aberrant differentiation of neuroectodermal component into mesenchymal elements. Received: 2 February 1998     

Cylindroma of the base of the skull with longstanding neurological disturbances. Anatomo-clinical correlation

The authors present the clinico-pathological correlation in a women who developed at the age of 43 years progressive pain in the left hemiface with motor and sensitive disorders of the left trigeminal nerve. Progressive involvement of the left IIIrd, IVth and Vth cranial nerves appeared with persistence of intractable facial pain which was not responsive to treatment by Tegretol, nor by thermocoagulation of the left Gasserian ganglion. Partial resection of a tumor was performed. The biopsy revealed its cylindromatous nature. The patient died after eight years of evolution. Autopsy confirmed an extensive tumoral invasion of the left temporal bone with invasion of the dura, the left cavernous sinus, and tumoral infiltration of the IIIrd, IVth, Vth and VIIIth cranial nerves on the left side. Metastases of the cylindromatous epithelioma were found in the liver and adrenals. The precise origin of the tumor could not be ascertained.     

Cranial nerve palsies accompanying pituitary tumour

We reviewed 12 patients with pituitary tumour and cranial nerve palsy to analyse the clinical characteristics, the radiographic appearances, and the outcome after surgery. All patients had pathologically nonfunctioning macroadenomas with evidence of apoplexy. The third cranial nerve was the most frequently affected, followed by the sixth and fourth cranial nerves. Third cranial nerve palsy manifested as a symptom sequence comprising mydriasis, followed by limitation of gaze and ptosis. These symptoms recovered in reverse order of development. The time taken for recovery of cranial nerve palsy after surgery was significantly correlated with the length of time between the onset of symptoms and surgery. Pituitary apoplexy appears to be the primary cause of cranial nerve palsy with pituitary tumour. Early surgical intervention is most likely to bring about rapid recovery from cranial nerve dysfunction.     

Malignant non-Hodgkin lymphoma presenting with Garcin's syndrome

INTRODUCTION: R Garcin described progressive unilateral cranial nerve palsy in 1926. Garcin syndrome is characterized by progressive involvement of the cranial nerves culminating in total unilateral paralysis of all cranial nerves. Carcinoma of the skull base or ENT regions is the most common etiology. CASE REPORT: A 74-year-old man developed signs involving the left Vth (V2 and V3) cranial nerve then the VIth, VIIth and VIIIth cranial nerves and finally the IXth and Xth. MRI showed involvement of these cranial nerves with gadolinium uptake and involvement of the pons at the terminal phase. Careful ENT explorations failed to reveal a cause. The lymphocyte count was elevated in the cerebrospinal fluid. The patient died one year after diagnosis and the general autopsy was normal. The neuropathological studies led to the post-mortem diagnosis of type B non-Hodgkin lymphoma. CONCLUSION: In patients with Garcin syndrome, lymphoma is a possible diagnosis when carcinoma of the ENT regions or of the skull bases are not present.     

Surgical treatment of jugular foramen schwannomas

ObjectiveWe present our experience with surgery of jugular foramen schwannomas with special consideration of clinical presentation, surgical technique, complications, and outcomes.MethodsThis retrospective study includes ten patients with jugular foramen schwannomas treated by the senior author between January 2007 and December 2012. Three patients had undergone partial tumour resection elsewhere. The initial symptom for which they sought medical help was hearing loss, dysphagia, hoarseness, and shoulder weakness. Preoperative glossopharyngeal and vagal nerve deficits were the most common signs. In our series, tumour extension was classified according to Kaye-Pellet grading system. In two cases the tumours were classified into type A and 8 patients presented with type D tumours. A retromastoid suboccipital craniotomy was performed for type A tumours and modifications of cranio-cervical approach were suitable for type D.ResultsNo death occurred in this series. Four patients deteriorated after surgery: in two patients preoperative cranial nerve deficits deteriorated after surgery while new cranial nerve palsy occurred in 2 other patients. In four patients, the cranial nerve dysfunction had improved at the last follow-up examination. In all other patients, the cranial nerve dysfunction remained the same. One patient experienced tumour recurrence over a follow-up period of 40 months. This patient underwent a successful second surgery without further evidence of tumour growth.ConclusionsJugular foramen schwannomas can be radically managed with the use of skull base surgery techniques. However, the surgical treatment of jugular foramen schwannomas carries a significant risk of the lower CN deficits.     

Painful ophthalmoplegia: the Tolosa-Hunt syndrome.

Painful ophthalmoplegia is characterized by unilateral involvement of the IIIrd, IVth and VIth cranial nerves, as well as supra- and retro-orbital pain, i.e. participation of the Vth cranial nerve. The pain is relieved within 48-72 h with steroid therapy. The paresis of the eye muscles in various combinations usually subsides gradually from within a few weeks to several months. The etiology is unknown. The few pathological examinations reported in the literature showed an unspecific inflammatory granulation tissue around the intracavernous portion of the carotid artery and on the dura mater in the vicinity of the cavernous sinus. Carotid arteriography may show stationary waves of this artery and narrowing of its intracavernous portion. With orbital phlebography the occlusion of the supraorbital vein and obstruction of the cavernous sinus are sometimes demonstrable. The syndrome is well defined and its etiology still unknown.     

Blink reflex measurement of effects of trichloroethylene exposure on the trigeminal nerve.

Trichloroethylene (TCE) exposure is known to have specific toxic effects on cranial nerves, the trigeminal nerve (V) in particular. The electrophysiological measurement of the blink reflex (BR) can quantify latency changes in the Vth and VIIth cranial nerve reflex arc. Prior study looked at the blink reflex measurement in a community group exposed to TCE in their drinking water. This study evaluated the use of the electrophysiologic blink reflex as an indicator of neurotoxic effects of TCE in occupationally exposed workers. The BR was tested in individual cases with documented histories of exposure to known chemical neurotoxins including TCE (n = 18). When compared with the nonexposed laboratory control values (n = 30), the subjects with a significant history of TCE exposure demonstrated the most prolonged latencies (greater than or equal to 3.0 SD above the nonexposed group mean) in the R1 component of the blink reflex measurement. The electrophysiological study of the blink reflex has application in assessing TCE exposure and in documenting the neurotoxic effects of that exposure on trigeminal nerve functions in humans.     

MRI findings of optic pathway involvement in Miller Fisher syndrome in 3 pediatric patients and a review of the literature

Background: Miller Fisher syndrome (MFS) is a rare demyelinating condition which may have involvement of cranial nerves. There are a few case reports of optic pathway involvement in children. We describe 3 patients with optic pathway enhancement in pediatric patients with MFS. Case series: We retrospectively reviewed brain imaging findings in 17 pediatric patients with of Guillain–Barré syndrome (GBS) meeting Brighton criteria who had brain MRIs performed during their acute illness. Cranial nerve enhancement was seen in 6/17 patients and optic nerve/chiasm enhancement was seen in 3 patients. Conclusion: Cranial nerve enhancement and optic pathway in particular, can be seen in patients with MFS. Imaging findings do not always correlate with clinical manifestations of cranial nerve involvement.     

Morphological evidence for a direct projection of trigeminal nerve fibers to the primary gustatory center in the sea catfishPlotosus anguillaris

The central projections of the ramus mandibularis were examined in the Japanese sea catfish, Plotosus anguillaris by using the technique of transganglionic tracing with horseradish peroxidase (HRP). This ramus receives fibers from both the trigeminal and facial nerves and supplies primarily the two mandibular barbels. Two pathways for a direct trigeminal projection to the facial lobe (FL) were found: one from the main descending root of the Vth nerve (MRDV) to the medial portion of the FL, approximately midway between the rostro-caudal axis of the FL and a second, from deep RDV to the intermediate nucleus (NIF), beneath the medial lobule of the FL. The facial fibers project exclusively onto the medial portion of the FL and the NIF. The results show that fibers of these two cranial sensory nerves supplying the mandibular barbels converge centrally on the medial portion of the FL, indicating that the FL of the Japanese sea catfish is a highly differentiated center for both gustation and somatosensation.     

Application of 2D1H NMR spectroscopy to the study of the brain,spinal cord,and sciatic nerve

Homonuclear¹H 2D NMR spectroscopy (COSY experiments at 400 and 600 MHz) were used to study the rat brain in vivo and the rabbit spinal cord and sciatic nerve in vitro. The following metabolites were identified: lactate, alanine, threonine, GABA, glutamine/glutamate,N-acetyl aspartate, aspartate, taurine, inositol derivatives, choline derivatives, and glucose. The sciatic nerve spectra showed characteristic COSY graphs of saturated and unsaturated fatty acids, and linoleic and linolenic type structures were identified.     

Medial sphenoid ridge meningiomas: early and long-term results of surgical removal using the fronto-temporo-orbito-zygomatic approach

Background and purposeThe fronto-temporo-orbito-zygomatic approach (FTOZA) is an alternative to the pterional approach in surgical resection of meningiomas of the medial part of the lesser wing of the sphenoid bone. The purpose of this study is to present our results of treatment of these meningiomas using the FTOZA.Material and methodsThirty patients (19 women, 11 men) with a central skull base tumour were included in the study. The neurological status of the patients was assessed before and after surgery as well as at the conclusion of treatment. The approximate volume of the operated tumour, its relation to large blood vessels, cranial nerves and brainstem, as well as consistency and vascularisation were assessed.ResultsThe symptom duration ranged from 1 to 36 months (median: 6 months). Impaired visual acuity was the predominant symptom in 27.5% of patients. Less frequent symptoms included paresis/paralysis of the third cranial nerve, headache, psychoorganic syndrome and epilepsy. Approximate volume of the tumours ranged from 5 to 212 mL (median: 63 mL). Total or subtotal resection was achieved in 77% of patients. The postoperative performance status improved in 16.5%, did not change in 52.8% and deteriorated in 26.4% of patients. One (3.3%) patient died after the surgery.ConclusionsThe FTOZA is a useful technique for removal of tumours expanding superiorly to the middle cranial fossa base without significant compression of the brain. Ability to remove tumours through the described approach decreases as the degree of infiltration of the clivus increases.     

Surgical treatment of jugular foramen meningiomas

ObjectWe present our experience with surgery of jugular foramen meningiomas with special consideration of clinical presentation, surgical technique, complications, and outcomes.MethodsThis retrospective study includes three patients with jugular foramen meningiomas treated by the senior author between January 2005 and December 2010. The initial symptom for which they sought medical help was decreased hearing. In all of the patients there had been no other neurological symptoms before surgery. The transcondylar approach with sigmoid sinus ligation at jugular bulb was suitable in each case.ResultsNo death occurred in this series. All of the patients deteriorated after surgery mainly due to the new lower cranial nerves palsy occurred. The lower cranial nerve dysfunction had improved considerably at the last follow-up examination but no patient fully recovered. Two of three patients with preoperatively impaired yet functional hearing deteriorated after surgery with no subsequent cranial nerve VIII function improvement. In one case postoperative stereotactic radiosurgery was performed due to non-radical tumour resection (Simpson Grade IV) and tumour remnant proved stable in the 4-year follow-up. None of the patients have shown signs of tumour recurrence in the mean follow-up period of 56 months.ConclusionsJugular foramen meningiomas represent one of the rarest subgroups of meningiomas and their surgical treatment is associated with significant risk of permanent cranial nerve deficits.