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PubMed2006

Third, fourth, and sixth cranial nerve palsies following closed head injury.

BACKGROUND: The relationship between the circumstances and severity of closed head injury (CHI) and the clinical and imaging features of cranial nerve 3, 4, and 6 palsies has not been rigorously addressed in a large study. METHODS: Retrospective chart review of 210 consecutive patients with CHI examined at a single tertiary care center from 1987 to 2002. Patients were located by searching the ophthalmology inpatient consultation and neuro-ophthalmology outpatient databases and hospital emergency room billing codes for a diagnosis of traumatic 3, 4, or 6 cranial nerve palsy (Cranial Nerve Injury Group) and a diagnosis of CHI without traumatic 3, 4, or 6 nerve palsy (Control Group). The Cranial Nerve Injury Group was then subdivided into two groups: those with injuries to an individual cranial nerve and those with multiple (including bilateral) cranial nerve injuries. Comparisons between groups were based on age, gender, type of accident, Glasgow Coma Scale (GCS), documented loss of consciousness (LOC), type of ocular injury, presence of systemic injury, need for rehabilitation, physical therapy and cognitive scores, and imaging features. RESULTS: The Cranial Nerve Injury Group had a significantly higher severity of head injury, more CT abnormalities, and worse short-term neurologic outcomes as compared with the Control Group. These trends were also found when each cranial nerve injury subgroup was compared with the Control Group. Those with cranial nerve 3 palsy had the most severe head injury; those with cranial nerve 4 palsy had an intermediate level of head injury; and those with cranial nerve 6 palsy had the lowest level of head injury. There were no consistent associations between the location of the imaging abnormalities and which cranial nerve was damaged. CONCLUSIONS: CHI with palsy of an ocular motor nerve was more severe than CHI without ocular motor nerve palsy, as measured by the GCS, intracranial and skull imaging abnormalities, and a greater frequency of inpatient rehabilitation. Palsy of cranial nerve 3 was associated with relatively more severe CHI than was palsy of cranial nerves 4 or 6. The location of the imaging abnormalities did not correlate with a particular cranial nerve injury.

Abducens Nerve Diseases↗
PubMed1981

Paralysis of cranial nerves III, IV, and VI. Cause and prognosis in 1,000 cases.

An unselected series of 1,000 cases of paralysis of cranial nerves III, IV, and VI was retrospectively analyzed regarding ultimate recovery and final causal diagnosis. The frequency of involvement of the third, fourth, and sixth cranial nerves was relatively unchanged from earlier similar reports. The number of patients (263) whose cranial nerve paralysis was initially of undetermined cause was surprisingly high despite the availability of computerized tomographic scanning. Subsequently, the cause for the paralysis was diagnosed in only ten of the 127 patients who could be traced. About half (51%) of the patients with no known cause for paralysis underwent spontaneous remission. Forty-eight percent of all patients recovered. Cranial nerve impairment due to vascular disease (diabetes mellitus, atherosclerosis, or hypertension) was temporary in 71% of the patients, regardless of the cranial nerve affected. Patients with palsies caused by aneurysm, trauma, and neoplasm was predictably less likely to recover.

Abducens Nerve↗
PubMed2007

Forces necessary for the disruption of the cisternal segments of cranial nerves II through XII.

Manipulation of the cisternal segment of cranial nerves is often performed by the neurosurgeon. To date, attempts at quantifying the forces necessary to disrupt these nerves in situ, to our knowledge, has not been performed. The present study seeks to further elucidate the forces necessary to disrupt the cranial nerves while within the subarachnoid space. The cisternal segments of cranial nerves II through XII were exposed in six unfixed cadavers, all less than 6 hr postmortem. Forces to failure were then measured. Mean forces necessary to disrupt nerves for left sides in increasing order were found for cranial nerves IX, VII, IV, X, XII, III, VIII, XI, VI, V, and II, respectively. Mean forces for right-sided cranial nerves in increasing order were found for cranial nerves IX, VII, IV, X, XII, VIII, V, VI, XI, III, and II, respectively. Overall, cranial nerves requiring the least amount of force prior to failure included cranial nerves IV, VII, and IX. Those requiring the highest amount of force included cranial nerves II, V, VI, and XI. There was an approximately ten-fold difference between the least and greatest forces required to failure. Cranial nerve III was found to require significantly (P < 0.05) greater forces to failure for right versus left sides. To date, the neurosurgeon has had no experimentally derived data from humans for the in situ forces necessary to disrupt the cisternal segment of cranial nerves II through XII. We found that cranial nerve IX consistently took the least amount of force until its failure and cranial nerve II took the greatest. Other cranial nerves that took relatively small amount of force prior to failure included cranial nerves IV and VII. Although in vivo damage can occur prior to failure of a cranial nerve, our data may serve to provide a rough estimation for the maximal amount of tension that can be applied to a cranial nerve that is manipulated while within its cistern.

Aged↗
PubMed1981

[A case of hematoma localized to midbrain tegmentum following closed head injury (author's transl)].

UNLABELLED: CASEs of primary brain stem lesion following closed head injury, verified on CT scan, have been increasingly reported recently. However, most of them have supratentorial lesions in addition to brain stem, resulting in a poor outcome. In this paper, a case of localized brain stem hematoma following closed head injury, is reported based on CT findings. CASE: A 26-year-old man slipped down on his back and hit the right occipital area with following loss of consciousness for several minutes. Since then, he continued to have gait disturbance and visited our hospital on the next day. On admission, he presented truncal ataxia, left trochlear nerve palsy, right Horner's syndrome and left hemihypesthesia. CT scan revealed a small hematoma localized to the right midbrain tegmentum at the level of inferior colliculus, well correlating with his clinical presentation. He gradually improved on conservative treatment and returned to his former work one month after the accident. This case suggests that there may be cases of primary brain stem injury with no other intracranial lesion based on CT findings and with a good prognosis. Shear strain is said to be a probable mechanism for explaining brain stem injury, which is usually combined with other parenchymal lesions. In our case, however, more focal factor--nervous and/or vascular compression against the tentorial edge--is suspected for producing this localized midbrain lesion.

Adult↗
PubMed1983

Peripheral innervation of extraocular muscles.

In order to avoid injury to the nerves supplying the extraocular muscles during orbital surgery, I studied the anatomy of these nerves in five human orbits that had been serially sectioned. Each of the nerves, except for the trochlear, exists as bundles of fascicles rather than as a discrete trunk. I made two other observations of surgical importance. First, the nerve to the inferior oblique muscle may pass through the belly of the inferior rectus muscle and then course beneath it before it reaches its normal position. Second, a fibrous septum at the orbital apex separates the abducent nerve from the other motor nerves.

Abducens Nerve↗
PubMed1996

Meningiomas of the space of the cavernous sinus.

During the years 1985 to 1992, we encountered 59 patients with meningiomas involving the space of the cavernous sinus. In 29 of these patients, meningiomas were primarily located within the space of the cavernous sinus and were operated on without mortality and with low morbidity. A small subtemporal surgical approach was favored, which allowed initial tumor resection from the posterior aspect, where the Parkinson's triangle is wide, thus avoiding the additional morbidity of large-scale approaches. According to the relationships of the all-important cranial nerves passing within the lateral wall of the cavernous sinus, we divided the primary intracavernous meningiomas into four types, which reflected not only the preoperative cranial nerve deficit but also the feasibility of surgical resection. Cranial nerve function deteriorated after operations in 14% of oculomotor nerves, in one abducent nerve, in 58% of trochlear nerves, and in 21% of trigeminal nerves. We encountered improvement of function in 43% of oculomotor nerves, in 50% of abducent nerves, and in approximately 30% of the second and third but in only 7% of the first branches of trigeminal nerves. There was no improvement in trochlear nerve function. Improvement of oculomotor nerve function was observed only in moderately impaired nerves, which indicates that surgery should be undertaken early to preserve or improve oculomotor nerve function.

Cavernous Sinus↗
PubMed1994

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.

Abducens Nerve↗
PubMed2006

Custom-tailored transdural anterior transpetrosal approach to ventral pons and retroclival regions.

OBJECT: The extradural anterior petrosectomy approach to the pons and midbasilar artery (mid-BA) has the main disadvantage that the extent of resection of the petrous apex cannot be as minimal as desired given that the surgical target field is not visible during bone removal. Unnecessary or excessive drilling poses the risk of injury to the internal carotid artery, vestibulocochlear organ, and seventh and eighth cranial nerves. The use of a custom-tailored transdural anterior transpetrosal approach can potentially avoid these pitfalls. METHODS: A technique for a transdural anterior petrosectomy was developed in the operating theater and anatomy laboratory. Following a subtemporal craniotomy and basal opening of the dura mater, the vein of Labbé is first identified and protected. Cerebrospinal fluid ([CSF] 50-100 ml) is drained via a spinal catheter. The tent is incised behind the entrance of the trochlear nerve toward the superior petrosal sinus (SPS), which is coagulated and divided. The dura is stripped from the petrous pyramid. Drilling starts at the petrous ridge and proceeds laterally and ventrally. The trigeminal nerve is unroofed. The internal acoustic meatus is identified and drilling is continued laterally as needed. The bone of the Kawase triangle toward the clivus can be removed down to the inferior petrosal sinus if necessary. Anterior exposure can be extended to the carotid artery if required. It is only exceptionally necessary to follow the greater superior petrosal nerve toward the geniculate ganglion and to expose the length of the internal acoustic canal. The modified transdural anterior petrosectomy exposure has been used in nine patients-two with a mid-BA aneurysm, two with a dural arteriovenous fistula, one with a pontine glioma, three with a pontine cavernoma, and one with a pontine abscess. In one patient with a mid-BA aneurysm, subcutaneous CSF collection occurred during the postoperative period. No CSF fistula or approach-related cranial nerve deficit developed in any of these patients. There was no retraction injury or venous congestion of the temporal lobe nor any venous congestion due to the obliteration of the SPS or the petrosal vein. CONCLUSIONS: The custom-made transdural anterior petrosectomy appears to be a feasible alternative to the formal extradural approach.

Brain Stem Neoplasms↗
PubMed2000

[Clinical problems related to regeneration of cranial nerves supplying visual organ].

This review paper discusses problems related to regeneration of cranial nerves III-VII after their traumatic injuries. Details pertinent to the regeneration of particular nerves are reviewed. The problem of peripheral aberrant regeneration is more vastly discussed, as it is believed to underly certain clinical syndromes of oculomotor misdirection.

Abducens Nerve↗
PubMed2001

The lateral sellar nerve plexus and its connections in humans.

OBJECT: The aim of the present study was to elucidate the systematic topography of the lateral sellar (cavernous sinus [CS]) nerve plexus and its connections in humans. METHODS: Seven specimens of human CS and adjacent regions were dissected in steps and stained as whole-mount preparations by using a sensitive acetylcholinesterase method. Another specimen was frozen, cut on a frontal plane, and stained for acetylcholinesterase. The human CS contains an extensive nerve plexus with small ganglia. The plexus is composed of a main part, the lateral sellar plexus proper, which is located around the abducent nerve and medial to the ophthalmic nerve, and a lateral extension just underneath the outermost layer of the lateral CS wall, which is located lateral to the trochlear and ophthalmic nerves. The lateral sellar plexus is connected to the internal carotid nerve, the pterygopalatine ganglion, and the trigeminal ganglion. From the lateral sellar plexus, nerve branches run along the oculomotor, trochlear, ophthalmic, and abducent nerves into the orbit. In addition, the lateral sellar plexus has multiple connections with nerves located around the internal carotid artery. The presence of connections between the lateral sellar plexus and functionally defined neural structures suggests that the plexus receives sympathetic, parasympathetic, and sensory contributions. CONCLUSIONS: The plexus may distribute nerve subpopulations to several targets, including cerebral arteries and orbital structures. The presence of a mixed nerve plexus that projects to a variety of targets indicates that injury or disease in the CS may result in a variety of symptoms.

Aged↗
PubMed2004

Distribution of the galectin-1 mRNA in the rat nervous system: its transient upregulation in rat facial motor neurons after facial nerve axotomy.

Galectin-1 is a member of the animal lectin family that displays conserved consensus sequences and similar carbohydrate binding specificities. Recent analyses revealed that galectin-1 plays an important role in the process of nerve regeneration. We analyzed the topological expression of galectin-1 mRNA in adult rat nervous system. Galectin-1 mRNA was predominantly observed in the cell bodies of neurons such as oculomotor nucleus (III), trochlear nucleus (IV), trigeminal motor nucleus (V), abducens nucleus (VI), facial nucleus (VII), hypoglossal nucleus (XII), red nucleus, and locus ceruleus. Neurons in pineal gland and dorsal root ganglia expressed galectin-1 mRNA. We next tested whether the axotomy of facial nerve altered the expression of galectin-1 mRNA in motor neurons. In the adult rats, the axotomy of facial nerve induced transient upregulation of galectin-1 mRNA around 6 h after axotomy. These results indicate that galectin-1 may play roles in the early event of the nerve injury and regeneration through the transient change of its expression level.

Animals↗
PubMed2005

Intraorbital surgery for trigeminal neuralgia.

PURPOSE: First-division trigeminal neuralgia, or tic douloureux refractory to medications, presents problems to the surgeon because of the desirability of preserving corneal sensation. A new operation is described that may provide longer duration of pain relief than conventional supraorbital neurectomy, with preservation of the corneal reflex. METHODS: Four patients underwent resection of the supratrochlear and supraorbital nerves within the orbit accessed from an upper eyelid skin crease incision. RESULTS: Three patients with typical idiopathic trigeminal neuralgia involving branches of the frontal nerve are without pain 22 to 25 months after surgery. The final patient with atypical pain had no improvement after the procedure. Frontal nerve distribution anesthesia is present in all patients. Postoperative ptosis resolved in all patients within 4 months of surgery. CONCLUSIONS: This procedure should be added to the treatment options for patients with first-division trigeminal neuralgia. By avoiding injury to the trigeminal root and ganglion, this surgery carries no risk of facial motor dysfunction, dysthesia, and/or anesthesia in the other trigeminal branches including corneal anesthesia.

Blinking↗
PubMed2001

Palsies of the third, fourth, and sixth cranial nerves.

Diplopia is one of the most vexing problems to confront a physician. When diplopia is binocular, it commonly results from dysfunction of one or more of the ocular motor nerves. Ocular motor dysfunction may result from injury anywhere along the neuraxis, from the ocular motor nucleus to the myoneural junction. Identifying the location of the lesion is important for determining the etiology and prognosis of third-, fourth-, and sixth-nerve injuries. In this article, an anatomic approach is presented for the diagnosis and treatment of ocular motor nerve lesions. Emphasis is placed on the identification of associated neurologic and ophthalmologic findings that are critical for management of patients with acquired and congenital ocular motor palsies.

Abducens Nerve Diseases↗
PubMed1993

Calcitonin gene-related peptide increases following axotomy of trochlear motoneurons.

Neuropeptides have long been considered to act as neurotransmitters or neuromodulators, but they may also contribute to a variety of regulatory and trophic neuronal functions. In the present study, we determined the effects of axotomy on the levels of the neuropeptide calcitonin gene-related peptide (CGRP) in trochlear motoneurons (TMNs) of adult cats. The number of neurons with detectable CGRP immunoreactivity, and the intensity of their CGRP immunoreactivity, increased dramatically 1 week postaxotomy, gradually returned toward normal levels, but remained significantly higher than normal 12 weeks postaxotomy--a time when axonal regeneration and functional reinnervation of the superior oblique muscle should be complete. Our observation that CGRP levels in TMNs increase after axotomy suggests a role for this peptide in the response of motoneurons to injury and in regeneration. In addition, since many axotomized TMNs die, we suggest that the maintenance of high CGRP levels even after regeneration is complete may reflect an increased load on those TMNs that survive.

Animals↗
PubMed1999

Pathology of the peripheral nervous system.

In this review, the first four papers deal with an important chapter in peripheral nerve surgery: cranial nerve reconstruction after injury occurring during skull base surgery. The last paper discusses the problem of peripheral nerves affected by a ganglion cyst. Damage to a cranial nerve is no longer considered to be an absolutely irreparable event. The first two studies are related to facial nerve management during the surgical treatment of vestibular schwannomas. The most common mechanisms responsible for facial nerve injury during tumor removal and the technical means to avoid them are cited. The importance of intraoperative neurophysiologic monitoring to save the facial nerve is stressed. A comparison between microsurgery and radiosurgery results in the conclusion that for vestibular schwannomas, the first choice of treatment is microsurgery. These two large and exceptional series show that by using a refined technique it is possible to obtain both total tumor removal and preservation of the facial nerve in most of the vestibular schwannomas. In the minority of patients in whom the facial nerve is severed, there are several therapeutic options to re-establish facial nerve function. After facial nerve reconstruction, performed immediately during the same tumor operation, a satisfactory reinnervation was obtained in 74% of the cases. After facial nerve reanimation, using as donor nerve the hypoglossus and performed 1 week after the tumor operation, a satisfactory reinnervation was obtained in 96% of the cases. The other two papers deal with the intraoperative transection of the trochlear and abducens nerve during surgery for skull base tumors. These two cranial nerves, owing to their simply organized motor nerve system (they are purely motor nerves and supply one muscle each), show quite a good expectation of functional recovery. The behavior of ganglion cysts involving peripheral nerves is the topic of the last paper reviewed. These cysts are benign lesions that can cause permanent neurologic deficits of the involved nerve. The etiology, clinical presentation, surgical techniques, and recurrence rate are reported. In the present series, the outcomes after ganglion cyst excision are not as favorable as those reported in other series. Before surgery, patients must be informed about the possibility of residual motor deficits and recurrences.

Journal Article↗
PubMed1979

The superior oblique: a challenging extraocular muscle.

Isolated paralysis of one or both superior oblique muscles in a consecutive series of 43 patients was found to occur most often by indirect injury to the skull. The etiology in the group of spontaneous cases was mostly vascular. With rare exceptions the latter recovered spontaneously. Those with traumatic palsy may be due to "contrecoup" trauma at the decussation of the nerves or by decompensation of the cerebral fusional mechanism, with dissociation of the images of the two eyes and subsequent vertical deviation. The traumatic cases never recover spontaneously and recession or myectomy of the ipsilateral inferior oblique with or without recession of the contralateral inferior rectus is recommended but only in cases of more than 8 diopters squint, and in cases which do not adapt themselves by minor head-tilting.

Adult↗