Regional Differences in the Subacute Response of Rabbit Orbicularis Oculi to Bupivacaine-Induced Myotoxicity as Quantified With a Neural Cell Adhesion Molecule Immunohistochemical Marker

Purpose. This study examined the subacute myotoxic effects of injection of the local anesthetic bupivacaine on the orbicularis oculi muscle in the rabbit eyelid. In contrast to other muscles, the orbicularis oculi was resistant to injury by the usual anesthetic doses of bupivacaine when local infiltration is used. An attempt was made to assess the sensitivity of orbicularis oculi muscle to bupivacaine using a variety of increased bupivacaine concentrations and in combination with hyaluronidase. Methods. Bupivacaine was injected into rabbit lower eyelids at a variety of doses with and without the injection of hyaluronidase before bupivacaine treatment. Muscle injury was assessed immunohistochemically using an antibody to an isoform of neural cell adhesion molecule, anti-leu-19, a molecule shown to localize on the surface of regenerating muscle fibers. The number of neural cell adhesion molecule-positive muscle fibers was assessed 4 and 7 days after bupivacaine injection to determine the number of fibers that were injured. Results. When bupivacaine was injected into the lower eyelid at a dose of 1.5 mg, only 10% of the orbicularis oculi muscle was injured. The most effective injury involved either multiple injections of 3 mg bupivacaine or of hyaluronidase 20 minutes before the injection of 3 mg bupivacaine, resulting in injury of up to 58% of the muscle fibers. In all cases, the preseptal region of the orbicularis oculi showed a greater percentage of injury than the pretarsal portions of the muscle. Conclusions. Although multiple injections of bupivacaine and bupivacaine combined with hyaluronidase significantly increased the percentage of muscle cells injured, total destruction of the orbicularis oculi muscle was never seen. Neural cell adhesion molecule was a good marker for the quantification of the regenerating muscle fibers. It is proposed that the tight fasciculation of the orbicularis oculi muscle may play a role in preventing access of the local anesthetic to the individual muscle fibers. This demonstrates the relative clinical safety of local anesthetic injection into the eyelid. Invest Ophthalmol Vis Sci. 1993;34:3450-3458. skeletal muscle is susceptible to injury by a number of agents and methods that result in rapid degeneration of the muscle fibers. Some muscle toxic agents cause permanent muscle loss. These include x-ray irradiation 1 and doxorubicin. 2 " 4 Other agents cause muscle injury followed by regeneration. These include physi

Osteopetrosis - A Rare Disease: A New Treatment

Osteopetrosis describes a group of at least 8 inherited disorders of reduced osteoclast function that results in failure of bone resorption and a generalized increase in bone density. In some of these disorders there is an abnormality in bone marrow stem cells that affects osteoclasts and macrophages. Abnormalities of macrophages and neutophil activation partially explain the high susceptibility to infection. In other disorders abnormal osteoclast function may result from local environmental products that Influence cellular differentiation or regulation

Doxil Chemomyectomy: 2 Year Results of the Phase 1 Trial

To present the results two years after completion of treatment of the two patients who participated in the Phase I trial of DoxilTM Chemomyectomy for eyelid spasms

Issues in the Use of Botulinum Toxin Injections in the Early Management of Cranial Nerve Palsies, Particularly Abducens Palsy

It is recognized that botulinum toxin injections may be used to produce temporary paralysis of injected extraocular muscles and that this treatment may even have long term effects in patients with strabismus or long standing oculomotor palsies. There may be specific circumstances where medical considerations or patient preference favor BT injections over conventional surgical procedures. The specific issue to be discussed in this presentation is whether and/or when to introduce such injections within the first days to six months of the appearance of a presumed neurogenic paralysis of the extraocular muscles, particularly the lateral rectus. To answer these questions we need to consider the differential diagnosis and natural history of abducens palsy in patients who may be candidates for BT injections and the posssible risks and benefits from such intervention

An Improved Technique for the Prevention of Lower Eyelid Retractor Recession Accompanying Inferior Rectus Recession for Graves' Disease

Lower eyelid retraction is a common problem in Graves' ophthalmopathy. Common surgical approaches such as scleral spacer grafts, lysis of the lower eyelid retractors and advancement of the capsulopalpebral head yield unpredictable post-operative results

Chemomyectomy for Eyelid Spasms

To report our experience with doxorubicin chemomyectomy as an alternative to other treatments for hemifacial spasm (HFS) and in essential blepharospasm (BEB)

Treatment of Blepharospasm and Related Conditions

Blepharospasm Definition: Bilateral, simultaneous squeezing of the eyelids Complications include loss of vision when driving and deformities including brow ptosis, dermatochalasis, disinsertion of the elevator aponeurosis, and lateral central tendon laxity Most frequently occurs in older women Younger cases are more likely to be ""psychogenic"" Can be fibromyalgia of dystonia musculorum deformans or a finding in post-encephalitic Parkinsonism Absent during sleep.RStreatmento

Familial Hemifacial Spasm (HFS): An Autopsy

Twitching left eye progressing to involvement of the mouth and neck.An 83-year old female who at age 63 developed symptoms of left hemifacial spasm. Previous history significant for controlled diabetes, controlled hypertension, atherosclerotic heart disease and cervical cancer (Tx cobalt). Family history remarkable for daughter and niece who developed HFS.Spasms radiating upwards and laterally onto the left side of head.N/AEctopic excitation of facial nerve fibers; Vascular compressionBotulinum toxin1. Friedman A, Jamrozik Z, Bojakowski J: Familial hemifacial spasm. Mov Disord; 1989; (3): 213-8. 2. Baba T, Matsushima T, Fukui M, et al: Relationship between angiographical manifestations and operative findings in 100 cases of hemifacial spasm. No Shinkei Geka (NEUROLOGICAL SURGERY [TOKYO]); 1988; 16; 1355-62. 3. Carlos R, Fukui M, Hasuo K, et al: Radiological analysis of hemifacial spasm with special reference to angiographic manifestations. Neuroradiology; 1986; 28: 288-95. 4. Digre KB,Corbett JJ, Smoker WR, McKusker S: CT and hemifacial spasm. Neurology; 1988 ; 38: 1111-3. 5. Stopford JSB: The arteries of the pons and medulla oblongata. J Anat Physiol: 1915-1916:1, 131-164. 6. Jannetta PJ: Hemifacial spasm caused by a venule: case report. Neurosurgery; 1984 14: 89-92. 7. Moller AR: Hemifacial spasm: ephaptic transmission or hyperexcitability of the facial motor nucleus? Exp Neurol; 1987; 98: 110-9. 8. Moller AR, Jannetta PJ: Monitoring facial EMG responses during microvascular decompression operations for hemifacial spasm. J Neurosurg; 1987; 66: 681-5. 9. Horowitz SH: Hemifacial spasm and facial myokymia: electrophysio-logical findings. Muscle Nerve; 1987; 10: 422-7. 10. Nagahiro S; Matsukado Y; Wada S; et al: Blink reflexes in hemifacial spasm with special reference to the synkinetic responses. No To Shinkei; 1987: 39: 923-9. 11. Nielsen, V. K. Electrophysiology of the facial nerve in hemifacial spasm: ectopic/ephaptic excitation. Muscle Nerve; 1985;8: 545-55

Oculomotor Abnormalities in Albinism

Although there are anatomic abnormalities in the sensory system (foveal hypoplasia and misrouting of retinofugal projections, the abnormal ocular movements observed (spontaneous unidirectional and bidirectional jerk or pendular nystagmus and absent true horizontal OKN) are not simply explained (Table 1). Foveal hypoplasia leading to degraded sensorimotor feedback does not explain the vertical stability nor the presence of nystagmus at or soon after birth particularly since the anatomic development of the fovea is not normally completed until 4 months after birth. Moreover foveal hypoplasia is an obligate feature of albinism while nystagmus is not. The alternative hypothesis is that optic pathway abnormalities result in directional errors of senorimotor feedback. The problem with this explanation is the need to explain the other forms of congenital nystagmus not associated with abnormal retinal projections