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Biomedical subjects

J D Wirtschafter

Publications and source records attributed to J D Wirtschafter.

At least 19 recordsLinked to original sources
PubMed1992

Severe but temporary injury to rabbit orbicularis oculi muscle using dihematoporphyrin ether and laser photochemomyectomy.

The use of local dihematoporphyrin ether (DHE) injections, followed by laser light activation, was investigated as a potential permanent myectomy treatment for muscle spasms, in particular blepharospasm and hemifacial spasm. DHE was injected into the eyelids of rabbits, followed by laser activation, as used in photochemotherapy. Four days after treatment, histological examination indicated that doses of greater than or equal to 0.5 mg of DHE and laser treatment with an energy density of at least 100 J/cm2 resulted in an almost total destruction of the orbicularis oculi muscle in the treated eyelid. The amount of muscle injury was dependent on both dose of DHE and energy density levels. Histologically, the tarsal glands and conjunctiva were damaged. Glandular tissue was markedly reduced, and the conjunctival epithelium showed hyperplasia and a loss of mucous cells. Six months after DHE and laser treatment, the majority of the muscle tissue had regenerated, although there was evidence of previous injury. While DHE injections combined with laser light activation were lethal to muscle at the site of treatment, this treatment was not permanent. The orbicularis oculi muscle retained its ability to regenerate. However, photochemomyectomy may be studied further as an adjuvant treatment to temporarily injure and debulk large muscles when botulinum toxin is contraindicated due to the large doses involved or as a permanent treatment when used together with an antimitotic agent such as doxorubicin.

Animals↗
PubMed1992

Papilledema and intraspinal lumbar paraganglioma.

Optic nervehead swelling is most frequently caused by ocular or intracranial lesions. The case presented here demonstrates that the spinal subarachnoid space must also be considered as a potential site for a lesion causing optic nervehead swelling. A 56-year-old man is presented with an intraspinal lumbar paraganglioma associated with increased cerebrospinal fluid protein, papilledema, transient obscurations of vision, and back pain. This may be the first reported case of a paraganglioma associated with optic nervehead swelling. Magnetic resonance imaging of the lumbosacral region revealed the lesion noninvasively. The papilledema, transient obscurations of vision, and back pain resolved after resection of the tumor. The mechanisms are not defined for optic nervehead swelling in association with spinal tumors in general and paraganglioma in particular. The measured abnormal elevation of cerebrospinal fluid protein may have resulted in increased intracranial pressure and papilledema.

Back Pain↗
PubMed1992

Esthesioneuroblastoma presenting as sudden unilateral blindness. Histopathologic confirmation of optic nerve demyelination.

We report here a case of esthesioneuroblastoma an 11-year-old girl presenting as acute loss of vision with minimal evidence of orbital, nasal, or paranasal sinus disease, a rare presenting symptom for this tumor. The initial diagnosis was postviral optic neuritis, a pattern of presentation not previously reported. When vision failed to improve, magnetic resonance imaging revealed a lesion in the posterior ethmoid and sphenoid sinuses. After a biopsy, the tumor was excised through the cranium and paranasal sinuses. A mass completely surrounding the optic nerve without invasion was found. Histochemical staining suggested demyelination secondary to compression, confirming the clinical impression of optic neuritis. Anti-Leu 7 monoclonal antibody is useful in characterizing of this tumor, since other immunochemical stains can be misleading. Radiation and chemotherapy were given after the tumor was removed. Two years later, the patient has had neither recurrence nor complications.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1991

Regional differences in the orbicularis oculi muscle: conservation between species.

The orbicularis oculi muscle is a complex facial muscle involved in eyelid closure. The central parts of pretarsal and preseptal regions of the palpebral part of the orbicularis oculi muscle in rabbit and cynomolgus monkey lower eyelids were examined histologically and were analyzed for muscle fiber number, muscle fiber cross-sectional area and fiber type composition. Distinct regional differences were seen in the muscle fiber composition in these two regions of the muscle. The pretarsal portion of the muscle, that closest to the eyelid margin, was quite homogeneous and almost completely composed of type 2 fibers. These fibers were the smallest in cross-sectional area. Type 2 fibers also predominated in the preseptal portion of the muscle, but this region contained between 10 and 20% type 1 fibers. They appeared to be a gradient in muscle fiber size, whereby the fiber size increased as a function of the distance from the eyelid margin. The same pattern of regional differences were found in both rabbit and monkey orbicularis oculi. Thus, there is a clear conservation of these regional differences in these two species. While the developmental significance is unknown, the identification of this pattern may facilitate the evaluation of chemomyectomy agents for treatment of eyelid spasms in humans and allow a more accurate analysis of biopsy material from this muscle.

Animals↗
PubMed1991

Clinical doxorubicin chemomyectomy. An experimental treatment for benign essential blepharospasm and hemifacial spasm.

Doxorubicin (DXR) was injected as a treatment for benign essential blepharospasm and hemifacial spasm. The other eyelids were treated concurrently with botulinum toxin (BT). No DXR-treated eyelid has maintained 0 strength (commonly achieved with BT). Two patients with benign essential blepharospasm and four patients with hemifacial spasm have achieved major improvement, sustained for more than 6 months. Eyelids have been swollen and inflamed for up to 3 months. No spontaneously irreversible complication has occurred. A single injection at the maximum safe dose (1 mg in the upper lid and 1.5 mg in the lower lid) has not proven sufficient to produce cure. Treatment of each lower eyelid of a muscular male with severe blepharospasm may require cumulative doses of up to 4.0 mg, delivered in three injection events separated by at least 2 months, with each injection no greater than 1.5 mg DXR per site. At the present time, there is no assurance that a permanent cure will result.

Aged↗
PubMed1991

Familial hemifacial spasm associated with arterial compression of the facial nerve. Case report.

This report of an 88-year-old woman with familial hemifacial spasm includes the first published postmortem description of hemifacial spasm with cross-compression of the seventh cranial nerve root exit zone by a redundant loop of the anterior inferior cerebellar artery and associated vascular plexus. Histological examination of the seventh and eighth cranial nerve complex suggested nerve degeneration because increased numbers of corpora amylacea were present just distal to the compression concavity. There was no evidence of demyelination or gliosis of the nerve. This case suggests that vascular compression of the nerve root exit zone is an important condition in the etiology of most of these cases. This is the third reported case of familial hemifacial spasm; to date, all such patients have had left facial involvement. The family pedigree in this case suggests a pattern of autosomal-dominant inheritance with partial penetrance. The genetic basis for familial hemifacial spasm may involve anatomical variants or anomalies of the posterior circulation, since both posterior inferior cerebellar arteries were congenitally absent in this case.

Aged↗
PubMed1988

Lateral orbitotomy without removal of the lateral orbital rim.

Lateral orbitotomy is used for the removal of orbital tumors and for orbital decompression. Most surgeons make saw cuts through the lateral orbital rim and remove and rewire the bone. This procedure is time-consuming and requires repair of the lateral canthal structures. We describe a technique using an air-driven "acorn-tipped" bur that removes the posterolateral lip of the frontal process of the zygomatic bone and effectively straightens the external surface of the lateral orbital wall. This permits removal of the bone without serious injury to the periorbita. The technique creates a trapezoidal orbitotomy measuring approximately 20 mm anteroposterior, 25 mm at the anterior vertical base, and 6 mm at the posterior base. The orbital soft tissues can thus be safely exposed without removal of the lateral rim. We operated on one patient with cavernous hemangioma (27 X 21 X 19 mm) and three patients with bilateral Graves' ophthalmopathy. We discuss anatomic considerations for the prevention of complications, including injury to the frontotemporal branches of the facial nerve, injury to the superior head of the lateral pterygoid muscle, and inadvertent penetration of the dura.

Dissection↗
PubMed1988

Optic nerve decompression for osteopetrosis in early childhood.

Visual failure in osteopetrosis may result from retinal degeneration or compression of the optic nerve in the narrowed optic canals. We report the evaluation and treatment of five children with osteopetrosis whose optic nerve dysfunction seems to have been related to the latter etiology. Evaluation of visual function was carried out by means of behavioral observation and flash visual evoked responses. Of six nerves evaluated both pre- and postoperatively, the visual evoked responses seemed to improve in four. Three nerves were serially evaluated without an operation, and one showed changes consistent with maturation. One nerve was evaluated with serial postoperative evoked potentials and showed no change. We conclude that surgical decompression of the optic nerve in patients with documented optic nerve dysfunction and osteopetrosis allows improvement in visual function and is, therefore, an important consideration in the evaluation and management of patients with this disease.

Age Factors↗
PubMed1986

Minimal pigment: a new type of oculocutaneous albinism.

Minimal pigment, a new type of oculocutaneous albinism (OCA), is described. At birth, affected individuals had no skin or eye pigment, and white hair and blue irides, but minimal amounts of pigment developed in the iris during the first decade of life. They had no measurable hairbulb tyrosinase activity. A characteristic and unusual pattern of parental activity was found in each of three families studied, with one parent having normal and the other parent having abnormally low tyrosinase activity. The melanocyte ultrastructure was normal and variations in premelanosomal pigmentation correlated with tyrosinase activity. This clinical and biochemical pattern has not been seen in any of the previously described types of OCA. The biochemical defect in minimal pigment OCA is unknown.

Albinism↗
PubMed1978

Transaqueous diffusion of acetylcholine to denervated iris sphincter muscle: a mechanism for the tonic pupil syndrome (Adie syndrome).

The accepted hypothesis for the pathophysiology of tonic pupil syndrome (Adie syndrome) was reexamined in light of recent developments concerning denervation supersensitivity of cholinergically innervated smooth muscle. Kinetic analysis suggests that enzymatic hydrolysis is unimportant relative to convective diffusion in the turnover of acetylcholine in the aqueous humor. We postulate that the greater response to near stimuli than to light stimuli and the delay in iris sphincter contraction and relaxation can be explained by release of acetylcholine from the neuromuscular junction of the ciliary muscle followed by transaqueous diffusion to receptor sites on denervated, supersensitive iris sphincter muscle.

Acetylcholine↗
PubMed1977

Intraocular axonal swelling produced by partial, immediately retrobulbar ligature of optic nerve.

This is the first report of an experimental intraorbital ligature producing papilledema characterized by axonal swelling and accumulation of mitochondria in the lamina retinalis of the optic disc of rhesus monkeys subjected to immediately retrobulbar ligature of a portion of the optic nerve. This is an improved technique for investigating the pathogenesis of papilledema and optic neuropathy.

Animals↗