Pediatric Use of Recombinant Human Nerve Growth Factor 20 μg/mL Eye Drops (Cenegermin) for Bilateral Neurotrophic Keratopathy in Congenital Corneal Anesthesia

PURPOSE

This study aimed to present the efficacy and safety of cenegermin eye drop (Oxervate; Dompè Farmaceutici, Milan, Italy) treatment in a pediatric patient affected by neurotrophic keratopathy (NK) with Goldenhar syndrome.

METHODS

This case reports an infant presenting ulceration and a small central opacity in the cornea of the right and left eyes, respectively. The NK bilaterally worsened despite the use of therapeutic contact lenses and temporary partial tarsorrhaphy. Magnetic resonance imaging showed absence and hypoplasia of the right and left trigeminal nerves, respectively. Cenegermin eye drops were administered 1 drop/each eye, 6 times daily for 8 weeks to promote corneal healing.

RESULTS

Complete healing was achieved in both eyes after treatment. During the 16-month follow-up period, no epithelial defect, recurrence, or complications were noticed, whereas corneal opacities progressively became clearer, although insignificant improvements in corneal sensitivity or in the reflex tearing were observed.

CONCLUSIONS

Cenegermin was effective in treating NK in an infant with Goldenhar syndrome.

Mandibular Myalgia and Miniscule Meckel's Caves

Trigeminal neuropathy manifests as episodic sharp, shooting pain in the maxillofacial region. Contributory etiologies are myriad, ranging from central pathology affecting its origin in the brainstem to peripheral processes affecting their distal-most insertion sites. We present a case of bilateral hypoplastic Meckel's caves in an adult patient leading to the clinical symptomology of trigeminal neuralgia. To the best of our knowledge, this is the only report of its kind highlighting this anatomic variant.

Neurotrophic keratopathy secondary to trigeminal nerve aplasia in patient with Goldenhar syndrome

CASE REPORT

A 4-year-old male diagnosed with Goldenhar syndrome, with an unremarkable ophthalmic history, develops a neurotrophic ulcer secondary to trigeminal nerve aplasia. It was treated with multilaminar amniotic membrane transplantation.

DISCUSSION

Trigeminal nerve aplasia is not usually reported in Goldenhar syndrome. Therefore, it seems necessary to perform routine eye examinations, from an early age, to prevent serious complications associated with corneal anaesthesia.

Bilateral Marcus Gunn jaw winking synkinesis with monocular elevation deficiency: a case report and literature review

Marcus Gunn jaw winking synkinesis (MGJWS) occurs due to an aberrant innervation of the levator palpebrae superioris muscle by a branch of the motor division of the trigeminal nerve that supplies the muscles of mastication. MGJWS is mostly unilateral occurring in isolation and is less frequently associated with ocular or systemic abnormalities. Although MGJWS is mostly unilateral, few bilateral cases have been reported. Here we describe a rare case of bilateral MGJWS in an 18 year-old male patient with asymmetric bilateral ptosis and monocular elevation deficiency in the right eye.

[Clinical characteristics of moderate and severe Marcus-Gunn jaw-winking synkinesis and its surgical treatment]

OBJECTIVE

To investigate the clinical characteristics of moderate and severe Marcus-Gunn jaw winking synkinesis and it surgical management.

METHODS

Thirty-three patients with Marcus-Gunn syndrome were enrolled from 1997 to 2003 in Zhongshan Ophthalmic Center. The clinical characteristics were analyzed based on the records. Unilateral levator excision and frontalis flap suspension were performed for the correction of ptosis and the results were analyzed.

RESULTS

The follow-up period varied from 1 to 6 years. Sixteen patients were male and 17 were female. The left eye was involved in 22 patients and the right eye in 11 patients. There was no family history. The amount of ptosis in each patient was more than 2 mm. At the end of observation, good results were achieved for ptosis correction in 26 (87%) of 30 patients, fair results in 3 (10%) patients.

CONCLUSIONS

The ptosis of patients with moderate and severe Marcus-Gunn syndrome needs to be treated surgically. Unilateral frontalis flap suspension combined levator excision can correct ptosis very well for patients with moderate and severe Marcus-Gunn syndrome.

[Locked-in syndrome due to bilateral cerebral peduncular infarctions with occlusion of persistent primitive trigeminal artery]

A 61-year-old woman with diabetes mellitus was admitted to our hospital with right hemiparesis and dysarthria. Brain MRI showed bilateral cerebral peduncular infarctions. Three days after admission, she was unable to generate any voluntary movements, except for those of the eye, suggesting locked-in syndrome (LIS). She could not speak, but showed good comprehension by blinking in response to verbal commands. Brain CT 5 days later revealed subarachnoid hemorrhage (SAH) around quadrigeminal and ambient cistern. Cerebral angiogram on the following day revealed no aneurysm, occlusion of right persistent primitive trigeminal artery (PPTA) and a little flow of the bilateral vertebral arteries. Eye movements were impossible in all directions on the 11th day and MRI showed new infarctions of the midbrain and the ventral portion of the pons. However, an EEG on the 20th day was almost normal. We speculated that low blood flow in the basilar artery from the PPTA caused bilateral cerebral peduncular infarctions, and that weakness of the PPTA caused SAH.

Congenital Corneal Anesthesia

Congenital corneal anesthesia is a rare clinical entity that poses a diagnostic dilemma, particularly in the pediatric age group. The sensory deficit may be confined to the cornea, or extend to other divisions of the trigeminal nerve. The sensory deficit may occur as an isolated abnormality, as part of a complex neurological syndrome, or it may occur in association with multiple somatic abnormalities and congenital insensitivity to pain. This condition usually presents between the ages of 8 to 12 months. Poor vision, photophobia, conjunctival injection, and corneal ulceration in the absence of pain and distress in a child should alert the clinician to the possibility of anesthetic cornea. In the early stages of presentation, punctuate keratopathy is the main feature, which may progress to non-healing persistent corneal epithelial defects. This stage may progress to acute corneal lysis and perforation. In most patients, conservative approaches such as copious lubrication, prevention of self-harm and cautious use of bandage contact lenses are effective in preventing progressive corneal damage. Tarsorrhapy is effective in promoting epithelial healing and permanent lateral tarsorraphy may prevent further development of epithelial defects. Amniotic membrane graft may be considered in order to improve epithelial healing. Corneal grafts carry a poor prognosis. Accurate initial diagnosis, evaluation, and proper management are paramount to prevent visual loss due to long-term complications of corneal anesthesia. This review of the literature outlines the problems and approaches in diagnosis, evaluation, and management of this rare condition.

GAP-43 heterozygous mice show delayed barrel patterning, differentiation of radial glia, and downregulation of GAP-43

GAP-43 heterozygous (HZ) mice exhibit abnormal thalamocortical pathfinding, fasciculation, and terminal arborization at postnatal day 7 (P7). Here we tested whether these defects are correlated with delayed development of HZ cortical patterns. We assessed the rate of barrel segregation and radial glia differentiation in wild-type (WT) and HZ cortices. Since GAP-43 is involved in some forms of neural plasticity, we also compared the duration of the critical period for lesion-induced plasticity in both genotypes. Cytochrome oxidase histochemistry revealed a delay of approximately 1 day in barrel pattern formation in GAP-43 HZ mice. GAP-43 WT barrels showed complete segregation between P2-P3, while HZ barrels did not reach the same level of segregation until P3-P4. We found a similar delay in the transformation of radial glia from monopolar to multipolar phenotypes, from P5 in WT to P7 in HZ cortex. Radial glial cells represent many of the neuronal progenitors in developing cortex and aid in cell migration. Thus, the delay in radial glial differentiation may contribute to the delay in HZ barrel segregation. Interestingly, we found no change in the extent of the critical period for HZ cortical responsiveness to early peripheral damage or in the time course of the cortical response. As expected, GAP-43 expression in HZ cortex is significantly reduced early in development. However, HZ GAP-43 expression remains at maximum levels after P9, when it is normally downregulated. As a result, HZ GAP-43 expression is near-normal by P26, by which time near-normal barrel dimensions have been restored. Our findings indicate that GAP-43 deficiency leads to early delays in barrel development and suggest that these failures are followed by homeostatic responses, including prolonged GAP-43 expression. These compensatory mechanisms may rescue normal cortical reorganization in neonates and near-normal barrel morphology and GAP-43 expression in adulthood.

Mash1 and Math3 are required for development of branchiomotor neurons and maintenance of neural progenitors

Basic helix-loop-helix (bHLH) transcription factors are known to play important roles in neuronal determination and differentiation. However, their exact roles in neural development still remain to be determined because of the functional redundancy. Here, we examined the roles of neural bHLH genes Mash1 and Math3 in the development of trigeminal and facial branchiomotor neurons, which derive from rhombomeres 2-4. In Math3-null mutant mice, facial branchiomotor neurons are misspecified, and both trigeminal and facial branchiomotor neurons adopt abnormal migratory pathways. In Mash1;Math3 double-mutant mice, trigeminal and facial branchiomotor neurons are severely reduced in number partly because of increased apoptosis. In addition, neurons with migratory defects are intermingled over the midline from either side of the neural tube. Furthermore, oligodendrocyte progenitors of rhombomere 4 are reduced in number. In the absence of Mash1 and Math3, expression of Notch signaling components is severely downregulated in rhombomere 4 and neural progenitors are not properly maintained, which may lead to intermingling of neurons and a decrease in oligodendrocyte progenitors. These results indicate that Mash1 and Math3 not only promote branchiomotor neuron development but also regulate the subsequent oligodendrocyte development and the cytoarchitecture by maintaining neural progenitors through Notch signaling.

Pure direct duplication (12)(q24.1 → q24.2) in a child with Marcus Gunn phenomenon and multiple congenital anomalies

Partial trisomy of the region 12q24.1-->q24.2 is rare and usually associated with other rearrangements. We report on the clinical and cytogenetic findings in a girl with a pure de novo direct duplication dup(12)(q24.1-->q24.2). She had developmental and growth retardation, facial dysmorphism with upslanting palpebral fissures, wide downturned mouth, short neck, and Marcus Gunn phenomenon. She also had single transverse creases, hypoplasia of the corpus callosum, and cardiac malformations consisting of a bicuspid aortic valve, multiple ventricular septal defects, and kinking of the aorta. The size of the duplication was characterized by molecular cytogenetics and comparative genomic hybridization (CGH) to be 11.5 Mb in size and extended from the BAC probe RP11-256L11 loci (108.2 Mb) +/- 1 Mb to the BAC probe RP11-665J20 loci (119.7 Mb) +/- 1 Mb. No such pure 12q24 duplication was detected out of the 23 patients reported in the literature with duplications in 12q region. Comparison with these reported 12q trisomies suggests the duplication dup(12)(q24.1-->q24.2) is associated with a recognizable phenotype consisting of characteristic facial dysmorphism, growth retardation, and cardiac malformation.

Early habituation of severe blepharoptosis in marcus gunn jaw-winking syndrome

A 23-day-old neonate had severe unilateral Marcus Gunn jaw-winking syndrome (MGJWS). By 2 1/2 months of age, she controlled the ptosis with jaw positioning. Habituation of the pterygoid-levator synkinesis has not been reported this early. Surgery can be delayed until a safer time in MGJWS with severe ptosis that lacks objective signs of amblyopia.

Management of Marcus Gunn jaw winking synkinesis

PURPOSE

To report the outcomes of a management protocol for Marcus Gunn jaw winking synkinesis.

METHODS

The records of 31 patients (16 female, 15 male) presenting to a tertiary referral center with Marcus Gunn jaw winking synkinesis between 1993 and 2003 were retrospectively analyzed. Generally, patients with mild wink and a small degree of ptosis underwent unilateral upper eyelid retractor surgery. Patients with a moderate or marked wink and ptosis underwent bilateral levator weakening procedures and brow suspension. Patients were assessed and treated for amblyopia and vertical strabismus before ptosis surgery.

RESULTS

Mean patient age was 11.23 years (median, 8 years; range, 10 weeks to 31 years). Ipsilateral hypotropia was noted in 8 patients (26%), with a median visual acuity in the ptotic eye of 20/30 (range, 20/20 to 20/40), compared with 20/20 in those without hypotropia. Patients who underwent unilateral surgery had good correction of ptosis, with equal palpebral apertures and symmetrical contour but had a detectable wink on formal testing. Patients who underwent bilateral surgery had equal palpebral apertures and symmetrical contour, with wink elimination. Mean follow-up was 31 months (all patients) and mean postoperative follow-up was 22 months.

CONCLUSIONS

Patients with Marcus Gunn jaw winking synkinesis can present at a wide age range. There may be an associated vertical muscle imbalance, which should be managed before ptosis surgery to avoid ptosis undercorrection and allow amblyopia management. Nearly all patients use the synkinesis to reduce the underlying true ptosis to a less noticeable "habitual" ptosis or to maintain binocularity. Surgical approach will differ, depending on whether the synkinesis, ptosis, or both are the main concern. Satisfactory results with a low complication rate can be achieved with the use of this management protocol.

Congenital unilateral adduction associated with jaw movement: a rare variant of trigemino-oculomotor synkinesis

A 21-year-old man had abnormal adducting movements of his left eye on mastication. This suggested an anomalous innervation of the medial rectus muscle from the motor branch of the trigeminal nerve that innervated the external pterygoid muscle.

Abnormal thalamocortical pathfinding and terminal arbors lead to enlarged barrels in neonatal GAP-43 heterozygous mice

GAP-43 has been implicated in axonal pathfinding and sprouting, synaptic plasticity, and neurotransmitter release. However, its effect on cortical development in vivo is poorly understood. We have previously shown that GAP-43 knockout (-/-) mice fail to develop whisker-related barrels or an ordered whisker map in the cortex. Here we used cytochrome oxidase (CO) histochemistry to demonstrate that GAP-43 heterozygous (+/-) mice develop larger than normal barrels at postnatal day 7 (P7), despite normal body and brain weight. Using serotonin transporter (5HT-T) histochemistry to label thalamocortical afferents (TCAs), we found no obvious abnormalities in other somatosensory areas or primary visual cortex of GAP-43 (+/-) mice. However, TCA projections to (+/-) primary auditory cortex were not as clearly defined. To clarify the mechanism underlying the large-barrel phenotype, we used lipophilic (DiI) axon labeling. We found evidence for multiple pathfinding abnormalities among GAP-43 (+/-) TCAs. These axons show increased fasciculation within the internal capsule, as well as abnormal turning and branching in the subcortical white matter. These pathfinding errors most likely reflect failures of signal recognition and/or transduction by ingrowing TCAs. In addition, many DiI-labeled (+/-) TCAs exhibit widespread, sparsely branched terminal arbors in layer IV, reflecting the large-barrel phenotype. They also resemble those found in rat barrel cortex deprived of whisker inputs from birth, suggesting a failure of activity-dependent synaptogenesis and/or synaptic stabilization in (+/-) cortex. Our findings suggest that reduced GAP-43 expression can alter the fine-tuning of a cortical map through a combination of pathfinding and synaptic plasticity mechanisms.

[Application of the insulating material teflon--pladgets (Genzyme-USA) during the microvascular decompression]

Various isolation materials have been used in the treatment of trigeminal neuralgia due to neuro-vascular conflict. Surgical treatment (MVD) currently utilizes for isolation soft teflon pladgets, which are, after appropriate preparation, placed in the form of wool between the conflicted structures. The materiał was used in 20 surgical procedures. The definite advantage of this materiał as compared to others is the possibility to position it correctly between the blood vessel and the nerve without additional fixation with e.g. a tissue adhesive. Observations indicate that this is the best isolation materiał of those used so far in MVD procedures.

Anatomical observations during microvascular decompression for idiopathic trigeminal neuralgia (with correlations between topography of pain and site of the neurovascular conflict). Prospective study in a series of 579 patients

BACKGROUND

The Micro-Vascular Decompression (MVD) procedure - developed for conservative treatment of idiopathic Trigeminal Neuralgia (TN) is based on the NeuroVascular Conflict (NVC) theory. Although MVD has become very popular over the last twenty years, its principles and value remain controversial. Detailed anatomical observations during posterior fossa exploration in patients with idiopathic TN may help to understand better the role of NVCs.

METHOD

In this article, the authors report the anatomical observations made under the operating microscope in a consecutive series of 579 patients suffering from idiopathic TN who were treated by MVD.

FINDINGS

In 19 cases (3.3%) no neuro-vascular conflict was found. In the remaining 560 (96.7%) one or several offending vessel(s) were identified. A superior cerebellar artery alone or in association with other "conflicting" vessel(s) was found in 88% of the patients, an anterior-inferior cerebellar artery (alone or in association) in 25.1%, a vein embedded in the nerve (alone or in association) in 27.6%, the basilar artery (alone or in association) in 3.5%. Of prime importance, several "conflicting" vessels were found in association in 37.8% of the patients. Location of the NVC was in the trigeminal root entry zone in 52.3% of the patients, in the midthird of the nerve in 54.3% and at the exit of the nerve from Meckel cave in 9.8%. The relation of the predominant conflict with the surface of the nerve was supero-medial in 53.9%, supero-lateral in 31.6% and inferior in 14.5%. The degree of severity of the main conflict was a simple contact with the nerve in 17.6%, a distorsion of the nerve in 49.2% and a marked indentation in 33.2%. Alteration of the whole trigeminal nerve was frequently observed. In 42% of patients, the nerve had a significant degree of global atrophy. In 18.2%, there was a local thickening of arachnoid membranes, adherent to the nerve. In 12.6%, the root had a marked angulation on crossing over the petrous ridge. Finally in 3.9%, the nerve was compressed between pons and petrous bone, due to the small size of the posterior fossa.

INTERPRETATION

It is concluded that NVC in this series played an important role as a causative factor of the neuralgia, as classical; but other - possibly responsible - anatomical factors were found, especially a global atrophy of the root, a focal arachnoid thickening, a ribbon-shaped and angulated root on crossing over the petrous ridge.

Temporomandibular region in the Franceschetti's Syndrome. Anatomical study

Franceschetti's syndrome is a rare, non-fatal, hereditary malformation, usually bilateral, which symmetrically affects orbits, mandible and ear. The authors propose an anatomical description of the temporomandibular region after the dissection of a newborn baby suffering from Franceschetti's Syndrome, dead soon after the birth. A discussion on the different etiopathogenical theories is made. The authors conclude that an alteration of the development of nerve trigeminal branches is the cause of the malformations.

Marcus Gunn jaw-winking phenomenon: a new supplemental test in the preoperative evaluation

PURPOSE

To introduce a new method for the evaluation of Marcus Gunn jaw-winking ptosis that more precisely defines the severity of blepharoptosis.

METHODS

A retrospective review of 16 consecutive patients with Marcus Gunn jaw-winking ptosis presenting to our institution between 1993 to 1999 was performed. The position of the affected eyelid was observed after applying a technique of jaw immobilization and disruption of fusion with temporary occlusion of the ipsilateral side.

RESULTS

In patients presenting with mild to moderate Marcus Gunn jaw-winking, the majority (62.5%) demonstrated a positive test, uncovering complete or near complete ptosis. Test results were partially positive in 3 patients (18.8%) with increased but not complete ptosis and negative in 3 patients (18.8%) with no change in eyelid position.

CONCLUSIONS

Blepharoptosis associated with Marcus Gunn jaw-winking phenomenon is often more severe than found by conventional clinical evaluation. This finding may explain the frequent undercorrection and unpredictable results following levator resection. In patients exhibiting a positive jaw-winking ptosis test, disappointing outcomes with levator resection may be avoided by instead proceeding with a frontalis suspension with levator disinsertion as recommended for ptosis with severe jaw winking.

A case of Marcus Gunn jaw winking and pseudo inferior oblique overaction

PURPOSE

To report the association of Marcus Gunn jaw-winking phenomenon and pseudo inferior oblique overaction.

METHODS

Case report.

RESULTS

A 21-year-old woman presented with right eyelid elevation on the chewing movement since infancy. Examination showed that both Marcus Gunn jaw-winking phenomenon and pseudo inferior oblique overaction coexist in this patient.

CONCLUSION

The association of Marcus Gunn jaw winking and pseudo inferior oblique overaction in one patient is reported. This coexistence in our case may provide some support to the existing concept that both phenomena are caused by an ocular aberrant innervation.

Marcus Gunn jaw winking with trigemino-abducens synkinesis

Congenital ocular aberrant innervation syndromes are a complex group of disorders involving abnormal miswiring of the extraocular muscles. This case report describes a child with both a right Marcus Gunn jaw winking phenomenon and a right trigemino-abducens synkinesis, which has not previously been reported in the literature. Clinically, this child presented with an intermittent elevation of the right eyelid and/or an intermittent right exotropia when opening her mouth while sucking or chewing. This case suggests the primary abnormality in this patient may be abnormal development of the trigeminal nerve resulting in the eyelid abnormalities and strabismus.

Congenital trigeminal anesthesia in two siblings and their long-term follow-up

PURPOSE

To alert ophthalmologists to congenital trigeminal anesthesia as a cause of corneal scarring and amblyopia and its effective treatment with tarsorrhaphies.

METHODS

Case reports. A 2-month-old infant presented with bilateral corneal erosions and complete corneal anesthesia. Her sister presented at age 3 years with a corneal ulcer and corneal hypoesthesia (sensation markedly decreased). The father and paternal grandmother of the siblings also had corneal hypoesthesia.

RESULTS

Further investigation of the infant revealed bilateral hearing loss, swallowing difficulties, and decreased sensation in the trigeminal nerve distribution. A diagnosis of congenital trigeminal anesthesia was made. The corneal erosions of the patient resolved with bilateral two-thirds width tarsorrhaphies. The girl continues to do well now at 10 years of age with ocular lubrication and superficial corneal scar removal. Her older sister initially required antibiotic ointment for her corneal ulcer but now requires only ocular lubrication for congenital trigeminal anesthesia.

CONCLUSION

This study describes the earliest reported use of tarsorrhaphies in an infant with congenital trigeminal anesthesia. The presence of this condition in her sister and relatives makes it one of the few reports of congenital trigeminal anesthesia in more than two generations. Early recognition of this condition is essential in the preservation of useful vision.

A clinical sign of the Marcus Gunn phenomenon. Case Report

We present a 33-year-old man with severe unilateral congenital blepharoptosis associated with the Marcus Gunn "jaw-winking" phenomenon. The most important factor in surgical treatment was elimination of the synkinetic reflex. We also thought that excision of as much of the levator muscle as possible was necessary. The result was both functionally and cosmetically satisfactory.

Management of moderate-to-severe Marcus-Gunn jaw-winking ptosis

OBJECTIVE

To report the results of levator excision and frontalis suspension for moderate-to-severe Marcus-Gunn jaw-winking ptosis.

DESIGN

A retrospective noncomparative case series.

PARTICIPANTS

Twenty-four patients with moderate-to-severe Marcus-Gunn jaw-winking ptosis (21 unilateral and 3 bilateral) were treated surgically between 1978 and 1997 by one surgeon.

INTERVENTION

Levator excision either in the involved eyelid or in both eyelids, followed by bilateral frontalis suspension, was performed.

MAIN OUTCOME MEASURES

Postoperative improvement of jaw-winking was determined. The surgical results of ptosis surgery were assessed as good, fair, or poor based on habitual upper eyelid heights and symmetry.

RESULTS

Postoperative follow-up periods ranged from 6 months to 153 months, with an average of 36.9 months. After levator excision in a total of 27 eyelids exhibiting jaw-winking, 10 eyelids (37.0%) showed complete resolution of jaw-winking, and 13 eyelids (48.2%) showed mild winking (1 mm or less) on the lateral jaw movement only (functionally and cosmetically not a problem). In four eyelids (14.8%), these results were not recorded. In the group of five patients undergoing bilateral frontalis suspension and levator excision only on the involved side, final results were good in two patients (40%) and poor in three (60%). Of the 19 patients who underwent bilateral levator excision, final results were good in 13 (68.4%) and fair in 6 (31.6%).

CONCLUSIONS

For moderate-to-severe jaw-winking ptosis, bilateral frontalis suspension after bilateral levator excision generally provided satisfactory correction of both jaw-winking and ptosis.

Defective whisker follicles and altered brainstem patterns in activin and follistatin knockout mice

Whisker pad innervation and whisker-specific pattern formation were examined in mice lacking the gene for activin betaA or for follistatin. Both strains of mice die within 24 h after birth. A normal array of whisker follicles is present in the snout of either phenotype. However, activin betaA-deficient mice lack whiskers, and in follistatin-deficient mice the whiskers are thin and curled. We examined the effects of aberrant, albeit innervated, follicles on the formation of whisker-specific patterns (barrelettes) in the trigeminal brainstem. Activin betaA knockout mice lack barrelettes, although the trigeminal afferent topography is not compromised. Physiological recordings suggest that trigeminal ganglion cells in these mice are less responsive to stimulation of whisker follicles. Barrelettes in follistatin-deficient mice are not as well developed as in controls, but can be discerned in some cases. These results are consistent with the notion that formation of barrelettes depends on neural activity initiated by the whiskers.

Disruption of semaphorin III/D gene causes severe abnormality in peripheral nerve projection

The molecules of the collapsin/semaphorin gene family have been thought to play an essential role in axon guidance during development. Semaphorin III/D is a member of this family, has been shown to repel dorsal root ganglion (DRG) axons in vitro, and has been implicated in the patterning of sensory afferents in the spinal cord. Although semaphorin III/D mRNA is expressed in a wide variety of neural and nonneural tissues in vivo, the role played by semaphorin III/D in regions other than the spinal cord is not known. Here, we show that mice homozygous for a targeted mutation in semaphorin III/D show severe abnormality in peripheral nerve projection. This abnormality is seen in the trigeminal, facial, vagus, accessory, and glossopharyngeal nerves but not in the oculomotor nerve. These results suggest that semaphorin III/D functions as a selective repellent in vivo.

[Unilateral trigeminal nerve hypoplasia]

BACKGROUND

Isolated unilateral corneal anaesthesia represents a very rare clinical entity. The underlying cause may be a hypoplasia of the trigeminal nerve.

HISTORY AND CLINICAL FINDINGS

A 7 year old otherwise healthy boy presented with mixed conjunctival injection of the left eye, fluorescein-positive punctuate epithelial keratopathy of the cornea and a central corneal ulcer OS. History revealed intermittent, painless redness of the left eye since the age of 4. Trigeminal defects caused by trauma or infection could be ruled out. Tyndall's phenomena was positive. There was no corneal sensitivity on the left side and facial sensitivity was reduced in all branches of the trigeminal nerve. All other ophthalmologic examination results were normal. Magnetic resonance tomography showed a hypoplastic left trigeminal nerve. Mesenchymal syndromes could be ruled out by neuropediatric examination.

THERAPY AND CLINICAL COURSE

Treatment with prednisolone and antibiotic ointment and eye patching were performed. The ulcer healed completely and artificial tear substitution was given for prophylaxis. Follow-up examinations after 4 and 6 years showed no signs of inflammation. Biomicroscopy showed only mild fluorescein-positive corneal epitheliopathy.

CONCLUSIONS

In cases with painless intermittent keratoconjunctivitis, sometimes associated with corneal ulceration, in early childhood, one should consider acquired or congenital trigeminal anaesthesia. This condition requires life-long corneal ulcer prophylaxis and regular ophthalmologic exams.

Congenital ocular aberrant innervation--new concepts

BACKGROUND

We have the impression that congenital aberrant innervations are more common than previously reported. Many varieties exist and typically involve the sixth nerve. The most common ocular miswirings are Duane's syndrome and Marcus Gunn jaw-winking ptosis. The second most common miswiring involves lateral rectus activation in upgaze causing a "Y" pattern exotropia (pseudo inferior oblique overaction). This commonly is confused with inferior oblique overaction but surgery on the obliques does not cure the condition. Lateral rectus recession and elevation are required.

METHODS

We selected demonstrative cases from our practices to illustrate a variety of congenital aberrant innervations. A literature search for previous reported cases of aberrant innervations was performed. This report is an eclectic collection of observations of individual selected cases.

RESULTS

We found aberrant innervations of unusual varieties. These miswirings involve simultaneous firing of the lateral rectus with other muscles, including: the ipsilateral superior rectus, causing "pseudo inferior oblique overaction"; the contralateral lateral rectus, causing synergistic divergence; the ipsilateral superior rectus, in upward saccades only; and the masticatory muscles, causing exotropia with sucking. The third nerve by itself rarely is involved in congenital miswirings, but commonly shows aberrant regeneration after traumatic injuries. We know of no cases of aberrant innervation involving the fourth nerve.

SUMMARY

We present cases describing these congenital aberrant innervations and discuss a unifying hypothesis as to their typical involvement of the sixth nerve.

Null mutation of Dlx-2 results in abnormal morphogenesis of proximal first and second branchial arch derivatives and abnormal differentiation in the forebrain

Genetic analysis of the development and evolution of the vertebrate head is at a primitive stage. Many homeo box genes, including the Distal-less family, are potential regulators of head development. To determine the function of Dlx-2, we generated a null mutation in mice using gene targeting. In homozygous mutants, differentiation within the forebrain is abnormal and the fate of a subset of cranial neural crest cells is respecified. The latter causes abnormal morphogenesis of the skeletal elements derived from the proximal parts of the first and second branchial arches. We hypothesize that the affected skull bones from the first arch have undergone a transformation into structures similar to those found in reptiles. These results show that Dlx-2 controls development of the branchial arches and the forebrain and suggests its role in craniofacial evolution.

Familial trigeminal anesthesia

Familial congenital trigeminal anesthesia as an isolated abnormality is an unusual disorder. To our knowledge, only one family has previously been reported. We report here a family with three affected members demonstrating facial anesthesia, bilateral corneal changes, and nasal septal damage secondary to self-traumatization. Magnetic resonance imaging demonstrated hypoplasia of gasserian ganglia and trigeminal nerves in the affected father of two affected sons. The pathogenesis of this disorder appears to be congenital hypoplasia of the trigeminal nerves and gasserian ganglia that is inherited in a dominant fashion.

Synergistic divergence and jaw-winking phenomenon

Synergistic divergence is a congenital syndrome of monocular adduction deficit, with simultaneous abduction of both eyes on attempted gaze into the field of action of the paretic medial rectus muscle. Based on electromyographic data, it has been speculated that it is a neural miswiring disorder related to Duane's retraction syndrome. The association between Duane's retraction syndrome and the Marcus Gunn jaw-winking phenomenon, another neural miswiring disorder, has been previously reported. The authors describe a patient with both bilateral synergistic divergence and Marcus Gunn jaw-winking phenomenon.

Dehiscence of the infraorbital nerve as a new cause of facial pain

Images

Congenital trigeminal anaesthesia. A review and classification

Forty-three patients with the syndrome of congenital trigeminal anaesthesia (CTA) have been reported to date. The cases have been divided into three groups based on the presence and nature of any associated clinical problems. Three additional cases are presented as characteristic of each of the groups. A different aetiology is proposed for each group. Group I consists of patients with CTA as an isolated finding. It is almost always bilateral, and typically involves the distribution of only the first division of the fifth nerve. There is no evidence of other neurological abnormalities or associated mesoectodermal congenital anomalies. The aetiology is suspected to be a primary neural hypoplasia. Patients with associated congenital mesenchymal anomalies were placed in the second group. CTA was often a minor part of another well defined, more extensive clinical syndrome, such as Möbius or oculoauriculovertebral dysplasia (OAVD). The sensory abnormality was either unilateral or bilateral. The skin of the face was almost always involved, as well as the cornea and conjunctiva. This may be a heterogenous group with multiple aetiologies having in common an injury early in embryogenesis. The third group is defined as patients with CTA without evidence of mesenchymal dysplasia. These cases differ from the first group primarily because of the presence of associated focal brainstem signs. The aetiology is thought to be due to focal neural dysgenesis secondary to a prenatal injury, possibly vascular in nature.

Marcus Gunn jaw winking and Duane's retraction syndrome

A three-month-old female presented with the unusual findings of Marcus Gunn Jaw Winking Phenomenon and Duane's Retraction Syndrome in the same eye. In considering suggested etiologies for these two disorders, a misdirection of peripheral innervation would account for both these entities co-existing. In reviewing the ophthalmic literature, the association of these disorders was first described around the turn of the century but much less in recent years.

Cerebellotrigeminal and focal dermal dysplasia: a newly recognized neurocutaneous syndrome

A female child with brachycephaly, hypertelorism, convergent strabismus, interstitial keratitis, analgesia on both sides of the face, absent corneal reflexes, and focal congenital alopecia of a zone of the occipital and posterior parietal scalp is presented. The patient also had generalized hypotonia in early life, and at age 4 years 9 months, she was found to be moderately mentally subnormal and to have severe cerebellar deficit consisting of gait and truncal ataxia. There was no clinical evidence of other cranial nerves being affected. It is postulated that the patient has a cerebellotrigeminal and focal dermal dysplasia due to a development arrest of the ectoderm, which gives rise to the alar plate of the rhombencephalon, the overlying epidermis, the motor nucleus of V, and the trigeminal placodes.

Neuroparalytic keratitis in Goldenhar-Gorlin syndrome

A 2-year-old boy had bilateral corneal ulceration with the Goldenhar-Gorlin syndrome. Initially, the patient received subconjunctival and topical antibiotics with minimal effect. With subsequent treatment of atropine, sterile ophthalmic petrolatum ointment, and humidification of the patient's crib, ulcers in both eyes healed in two weeks without further problems. He had a neuroparalytic keratitis with corneal anesthesia and decreased tear production bilaterally. Our evidence suggested that aplasia or hypoplasia of the trigeminal nuclei was the probable cause.

Congenital trigeminal neuropathy in oculoauriculovertebral dysplasia-hemifacial microsomia (Goldenhar-Gorlin syndrome)

A 2 1/2 year old child with clinical features of Goldenhar-Gorlin syndrome showed diminished pinprick sensation over the right half of the face. After surgery for the cleft lip, the child died. Neuropathological investigations showed agenesis of the right trigeminal nerve and hypoplasia of the right trigeminal brain-stem nuclei. Nosological aspects of the Goldenhar-Gorlin syndrome and previously reported cases of congenital trigeminal anaesthesia in this disorder are discussed. It is suggested that the hypoplasia of the trigeminal nerve is responsible for the diminished facial sensation seen in some patients with this craniofacial syndrome.

Unilateral lesion of the motor root of the trigeminal nerve

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