PubMed Health⌕ Search

Biomedical subjects

M C Brodsky

Publications and source records attributed to M C Brodsky.

At least 19 recordsLinked to original sources
PubMed2003

Retinal neovascular markers in retinopathy of prematurity: aetiological implications.

AIM: (1) To determine if expression of the blood-tissue barrier associated glucose transporter GLUT1 is preserved by the neovasculature of retinopathy of prematurity (ROP), in contrast with the reported loss of GLUT1 expression in preretinal vessels of proliferative diabetic retinopathy. (2) To compare the vascular immunophenotype of ROP to juvenile haemangioma, another perinatal neovascular disorder that has recently been shown to express placental type vascular antigens, including GLUT1 and Lewis Y antigen. METHODS: A retrospective case report was carried out. Immunoreactivities for GLUT1 and Lewis Y antigen were assessed in a human eye with stage 3 ROP and compared with those in a control (paediatric) eye. The presence or absence of endothelial GLUT1 and Lewis Y immunoreactivity was determined in preretinal and intraretinal vessels. RESULTS: Immunoreactivity was positive for GLUT1 and negative for Lewis Y in the intraretinal and preretinal neovasculature of the ROP affected eye and in the normal retinal vessels of the control eye. CONCLUSIONS: Retention of immunoreactivity for GLUT1 distinguishes ROP from proliferative diabetic retinopathy. Furthermore, absence of Lewis Y antigen co-expression distinguishes ROP from juvenile haemangioma, a perinatal form of GLUT1 positive neovascularisation that has recently been linked to placental vasculature.

Biomarkers↗
PubMed2001

Primary oblique muscle overaction: the brain throws a wild pitch.

BACKGROUND: Sensorimotor and orbital anatomical mechanisms have been invoked to explain primary oblique muscle overaction. METHODS: Review of primitive visuo-vestibular reflexes and neuroanatomical pathways corresponding to vestibulo-ocular reflexes, and correlation with known clinical abnormalities in patients with primary oblique muscle overaction. RESULTS: Bilateral superior oblique muscle overaction, which corresponds to a backward pitch in lateral-eyed animals, can occur when structural lesions involving the brainstem or cerebellum increase central otolithic input to the extraocular muscle subnuclei that modulate downward extraocular muscle tonus. Bilateral inferior oblique overaction, which corresponds to a forward pitch in lateral-eyed animals, may result from visual disinhibition of central vestibular pathways to the extraocular muscle subnuclei that modulate upward extraocular muscle tonus. CONCLUSIONS: Primary oblique muscle overaction recapitulates the torsional eye movements that occur in lateral-eyed animals during body movements or directional luminance shifts in the pitch plane. These primitive ocular motor reflexes become manifest in humans when early-onset strabismus or structural lesions within the posterior fossa alter central vestibular tone in the pitch plane.

Animals↗
PubMed2001

Accommodative esotropia: an unrecognized cause of hemifacial spasm in children.

Pediatric hemifacial spasm can be a sign of an intracranial tumor. We examined two females, ages 2 and 6 years, who presented with hemifacial spasm as an early sign of accommodative esotropia. Initial ophthalmologic examination disclosed high hyperopia without detectable esotropia. Both children developed an intermittent esotropia over the following month. In the first child, the hemifacial spasm resolved concurrent with the onset of amblyopia. In the second child, spectacle correction produced immediate cessation of the spasms. In both children, squinting to avoid diplopia produced an overflow facial movement that manifested as hemifacial spasm. Accommodative esotropia should be considered in the differential diagnosis of pediatric hemifacial spasm.

Amblyopia↗
PubMed2001

Magnetic resonance diagnosis of congenital hypopituitarism in children with optic nerve hypoplasia.

PURPOSE: To determine whether structural abnormalities of the neurohypophysis, as detected by magnetic resonance imaging (MRI), can be used to diagnose hypopituitarism in children with optic nerve hypoplasia. METHODS: Retrospective analysis of 67 children with optic nerve hypoplasia who had MRI and pediatric endocrinologic evaluation at Arkansas Children's Hospital from 1989 to 1999. RESULTS: A total of 26 children with optic nerve hypoplasia had pituitary hormone deficiency. MRI disclosed posterior pituitary ectopia in 16 of these cases, absence of the pituitary infundibulum and posterior pituitary bright spot in 7 of these cases, and a normal neurohypophysis in 3 of these cases. All 41 children with optic nerve hypoplasia and normal endocrinologic function had a normal neurohypophysis. CONCLUSION: MRI of the neurohypophysis can predict when congenital hypopituitarism will be associated with optic nerve hypoplasia.

Child, Preschool↗
PubMed2000

Congenital ocular motor apraxia with autosomal dominant inheritance.

PURPOSE: To document congenital ocular motor apraxia in five first-degree relatives. METHODS: Case series. Five family members with a history of horizontal head thrusting had neuro-ophthalmologic evaluation. Magnetic resonance imaging of the brain was obtained in the proband. RESULTS: Four siblings (one boy and three girls) had congenital ocular motor apraxia. The father had head thrusting as a child and displayed residual signs of the disorder. Magnetic resonance imaging disclosed no central nervous system abnormalities in the father. CONCLUSION: Congenital ocular motor apraxia can be inherited as an autosomal dominant trait.

Adult↗
PubMed2000

Ocular motor signs in an infant with carbohydrate-deficient glycoprotein syndrome type Ia.

PURPOSE: To document the evolution of ocular motor abnormalities in an infant with carbohydrate-deficient glycoprotein syndrome. METHODS: Case report. An infant with carbohydrate-deficient glycoprotein syndrome type 1a underwent magnetic resonance imaging and infrared eye movement recording. RESULTS: A 10-month-old male with carbohydrate-deficient glycoprotein syndrome type Ia had rapid horizontal oscillations of the eyes when startled or awakened from sleep. Clinical examination confirmed this finding and disclosed congenital ocular motor apraxia with a reduced vestibulo-ocular reflex. Infrared eye movement recording showed ocular flutter and square wave jerks superimposed on a horizontal pendular nystagmus. Magnetic resonance imaging showed diffuse cerebellar hypoplasia. CONCLUSION: Carbohydrate-deficient glycoprotein syndrome type Ia can be associated with multiple cerebellar eye signs including ocular flutter, square-wave jerks, and congenital ocular motor apraxia.

Apraxias↗
PubMed2000

The role of volitional effort in the Bielschowsky head tilt test: a clinical and oculographic assessment.

PURPOSE: To determine whether volitional effort on the part of the subject can influence the results of the Bielschowsky Head Tilt Test. PATIENTS AND METHODS: Bielschowsky Head Tilt testing was performed in five normal subjects. Vertical amplitudes were measured with prism alternate cover testing when the head tilt was voluntary (volitionally maintained in a tilted position by the subject), forced (restrained in the tilted position by the examiner while the patient actively resisted) and active (restrained in a tilted position by the examiner with the subject actively trying to increase the tilt). Three-dimensional scleral search coil recordings were performed in three additional normal subjects using the same paradigm to determine the effect of volition on the torsional positions of the eyes. RESULTS: No vertical deviation of the eyes was detectable with prism alternate cover testing in any position of tilt, regardless of whether the tilt was voluntary, forced, or active. Volitional attempts to tilt the head were preceded by a transient ipsiversive torsional movement of the measured eye, which was quickly followed by a normal ocular counterroll. Following completion of the counterroll, the position of the eyes was constant for any position of head tilt, regardless of whether the tilt was forced, active, or voluntary. CONCLUSION: Anticipatory torsional movements of the eyes are evoked by an attempted volitional head movement in the roll plane and its associated innervation to the cervical musculature. However, these volitional movements do not alter the final torsional position of the eyes, which is a function of the degree of head tilt and the normal ocular counterroll. These anticipatory torsional movements do not influence the results of the Bielschowsky Head Tilt Test clinically by prism alternate cover testing.

Adult↗
PubMed1999

Dissociated vertical divergence: a righting reflex gone wrong.

Dissociated vertical divergence (DVD) is an ocular motor disorder characterized by a slow, upward drift of 1 eye when the other eye is fixating a target. I propose that DVD is a dorsal light reflex in which asymmetrical visual input to the 2 eyes evokes a vertical divergence movement of the eyes. This primitive visuo-vestibular reflex functions as a righting response to restore vertical orientation in lower lateral-eyed animals by equalizing binocular visual input. The dorsal light reflex is suppressed in humans but can manifest as DVD when early-onset strabismus precludes normal binocular development.

Animals↗