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Biomedical subjects

J R Buncic

Publications and source records attributed to J R Buncic.

At least 19 recordsLinked to original sources
PubMed2000

The natural history and ophthalmic involvement in childhood myasthenia gravis at the hospital for sick children.

OBJECTIVE: To characterize signs, symptoms, and the natural history of myasthenic syndromes in pediatric patients. DESIGN: Retrospective noncomparative case series. PARTICIPANTS: Thirty-four patients with a diagnosis of myasthenia were identified from either the hospital's or treating physician's database. METHODS: Retrospective chart review, clinical examination, and telephone interview. MAIN OUTCOME MEASURES: Information pertaining to the ophthalmologic and neurologic examination, diagnostic interventions, and treatment was noted. Patients with active disease, attending during the study period, were examined at their outpatient visits. Those who no longer attended the hospital were contacted by means of a telephone interview to complete their follow-up. RESULTS: Thirty-four children were found to have myasthenia. Two had transient neonatal myasthenia, which resolved quickly. Seven (20.6%) patients had congenital myasthenic syndromes (CMS) and 25 (73.5%, 19 females) were affected with autoimmune myasthenia gravis (AMG). In those patients with severe CMS, three showed signs of generalized weakness, including failure to thrive, frequent apneas, and aspirations. In four patients with mild CMS, eye signs were relatively more prominent. In all patients with CMS, strabismus, ophthalmoplegia, and ptosis were the main ophthalmologic signs and remained relatively constant. Fourteen (56%) patients with AMG had ocular signs and symptoms, and five of them progressed to systemic involvement in 7.8 months on average (range, 1-23). The remaining nine patients with ocular AMG had either strabismus or ptosis and were treated with pyridostigmine (nine patients) and prednisone (two patients). Patients with ocular AMG were seen at 78 months on average, those with systemic AMG at 85.6 months. Systemic AMG was seen in 16 patients. No thymomas were found in 14 patients who underwent thymectomy. Of the 25 patients with AMG, 8 are still being treated, 8 are in remission for an average of 65.2 months and are asymptomatic, 4 patients are receiving long-term immunosuppressants (1 has likely sustained permanent damage to her extraocular muscles with complete ophthalmoplegia and ptosis), and 4 have been lost to follow-up. Finally, one patient died after aspiration because of bulbar weakness. CONCLUSIONS: Patients with CMS varied in the degree of severity. Apneic attacks, aspiration, and failure to thrive may obscure the diagnosis. Compared with AMG, their ophthalmologic signs and symptoms were usually permanent. Visual signs and symptoms were usually prominent in those patients with active AMG, but those in remission were asymptomatic. More than half of the patients with juvenile AMG had ocular symptoms. Generalization occurred in a minority in an average of 7.8 months. Patients entered remission after approximately 2 years of treatment and were visually asymptomatic. This study suggests that long-term permanent damage to the extraocular muscles as a result of juvenile AMG is rare. Myasthenia gravis is a life-threatening disease as evidenced by the death of one of our patients. Many of these patients are first seen by the ophthalmologist who can aid the diagnosis, screen for amblyopia, and monitor the patient's response to therapy.

Adolescent↗
PubMed2000

Which ocular and neurologic conditions cause disparate results in visual acuity scores recorded with visually evoked potential and teller acuity cards?

PURPOSE: We investigated whether disparity between visually evoked potential (VEP) acuity scores and Teller Acuity Card (TAC) scores varied according to presence of ocular or neurologic conditions. METHODS: Charts from 175 children (mean age, 34.8 months; range, 3 to 158 months) referred for visual acuity testing were examined. All children had been tested with pattern-alternation VEP and TAC and had undergone a complete eye examination. VEP and TAC acuity scores were relative to age-expected acuity scores for each acuity test. The absence and degree of macular abnormality, retinal abnormality, optic nerve hypoplasia, optic nerve atrophy, cortical visual impairment, developmental delay, cerebral palsy, seizures, and nystagmus were noted. Analysis of variance models were used to determine whether differences between VEP and TAC scores varied according to the presence of specific deficits. Logistic regression analysis determined whether degree of specific deficits was associated with a greater chance of inconsistency between VEP and TAC scores (>0.3 log unit difference). RESULTS: Inconsistent scores were found in 48% of children. Developmental delay was associated with relatively poorer TAC than VEP score, and the chance of inconsistency increased with severity of developmental delay. CONCLUSIONS: Diagnosis-dependent variability exists between TAC and VEP scores. Therefore knowledge of the clinical picture is necessary in interpretation of VEP and TAC scores. It is not clear which test is more useful when a disparity exists, either from this or previous studies. When visual acuity is assessed longitudinally in a given child, then consistency in method for acuity assessment is important.

Aging↗
PubMed1999

Pediatric tetracycline-induced pseudotumor cerbri.

BACKGROUND: Tetracyclines have long been recognized as a cause of pseudotumor cerebri in adults, but the role of tetracyclines in the pediatric age group has not been well characterized in the literature and there have been few reported cases. We present 6 cases to better delineate the problem, the patient profile, the response to treatment, and the sequelae. METHODS: We retrospectively analyzed the records of all patients admitted with a diagnosis of pseudotumor cerebri who had documented usage of a tetracycline-class drug immediately before presentation at the Hospital For Sick Children in Toronto, Canada, from January 1, 1986, to March 1, 1996. RESULTS: Six patients (5 female, 1 male) who met all inclusion and exclusion criteria were identified; their ages ranged from 12 to 17 years. All were being treated for acne vulgaris. Duration of use before diagnosis was as short as 2 weeks and as long as 10 months, with a mean of 4.4 months. Duration of symptoms ranged from 0.57 to 4 weeks. Symptoms included headache (6 of 6), nausea (5 of 6), and diplopia (4 of 6). All for whom height and weight data were known (5 of 6) were in the upper quartile for body mass index. Visual acuity was 6/6 in all but 1 eye of one patient (6/9) at diagnosis, and final visual acuity was 6/6 in all patients. All had normal color vision, where this was recorded (5 of 6). The only recorded field defect was enlargement of the blind spot (4 of 6). All patients responded to treatment, with loss of symptoms in 1 day to 4 weeks. CONCLUSIONS: Pseudotumor cerebri as a result of tetracycline-class drugs does occur in the pediatric population. With prompt and appropriate medical treatment, long-term sequelae can almost always be avoided. Physicians who treat patients with tetracyclines need to be aware of the potential complications in children.

Acetazolamide↗
PubMed1998

Pediatric Horner syndrome.

INTRODUCTION: The purpose of this study was to define the etiologies of Horner syndrome in the pediatric population. METHODS: A retrospective review was performed of the medical records of all pediatric Horner syndrome patients (< 18 years old) examined by the pediatric ophthalmology services at two large referral centers. RESULTS: Seventy-three pediatric Horner syndrome patients were identified. Of these, 31 (42%) were congenital, 11 (15%) were acquired without surgical intervention, and 31 (42%) were acquired after a surgical procedure of the thorax, neck, or central nervous system. Of the congenital Horner syndrome patients, a history of delivery with the use of forceps, vacuum extraction, shoulder dystocia, fetal rotation, or postterm delivery was elicited in 16 patients (53%). Concomitant brachial plexus injury was identified in only 3 patients. Two patients had congenital varicella syndrome and 1 patient was diagnosed with neuroblastoma. This patient had a palpable supraclavicular mass and stridor. Diagnosis of the patients with acquired Horner syndrome included neuroblastoma (2), trauma (1), rhabdomyosarcoma (1), brainstem vascular malformation (1), disseminated sclerosis (1), and not determined (5). CONCLUSION: In children with congenital Horner syndrome, a history of forceful manipulation of the infant during birth may reduce the need for extensive systemic evaluation. Without such history, a decision to proceed with further evaluation is made with consideration of the relative incidence of neuroblastoma by age and the physical findings. All acquired pediatric Horner syndrome patients without a known etiology require thorough evaluation because of the frequent association of serious underlying disease.

Birth Injuries↗
PubMed1997

Monozygotic twins discordant for Aicardi syndrome.

Aicardi syndrome is a developmental disorder characterised by agenesis of the corpus callosum, retinal lacunae, seizures, and developmental delay. It is believed to be X linked with lethality in males. We report a set of monozygotic female twins one of whom is healthy and intellectually normal while the other has the classical Aicardi phenotype with profound retardation. Family history is negative. Both had normal karyotypes. Monozygosity was established by blood grouping, chromosomal heteromorphisms, and DNA analysis using six hypervariable probes (five autosomal and one X linked) and three X linked RFLP probes. We tested the hypothesis that preferential inactivation of a different X chromosome had occurred in each girl. Methylation sensitive RFLP analysis of DNA from EBV transformed B lymphocytes and cultured skin fibroblasts using MspI/HpaII digestion and probing with M27 beta showed a very similar pattern of X inactivation in both twins with no evidence of preferential expression of one particular X chromosome. We conclude that the abnormalities in the affected twin are probably the consequence of a postzygotic mutation in early embryonic development.

Abnormalities, Multiple↗
PubMed1997

Keeping an eye on Crohn's disease: orbital myositis as the presenting symptom.

Episodic periorbital swelling due to presumed orbital inflammation and myositis caused intermittent apparent proptosis and was the presenting symptom of ileocecal Crohn's disease (CD) in a teenage female with a family history of autoimmune disorders and CD. Orbital myositis, a very rare extraintestinal manifestation of inflammatory bowel disease (IBD), likely represents a process of impaired immunoregulation related to the underlying intestinal inflammation. This rare manifestation of IBD simulates the more commonly encountered thyroid orbitopathy (ophthalmopathy), but IBD should be considered if all thyroid tests are negative. It is important to recognize that orbital myositis may be an extraintestinal manifestation of Crohn's disease so that the diagnosis can be made and appropriate therapy commenced.

Autoimmune Diseases↗
PubMed1996

Natural history of Alström syndrome in early childhood: onset with dilated cardiomyopathy.

Alström syndrome is an autosomal recessive disorder characterized by cone-rod dystrophy, obesity, hearing impairment, and diabetes caused by insulin resistance. By reviewing the charts of eight patients followed for periods of 2 to 22 years, we established the natural history of this syndrome during childhood. Five patients, in four families, were seen between the ages of 3 weeks and 4 months with a dilated cardiomyopathy, a previously unrecognized feature of the syndrome. Photophobia and nystagmus were first documented in the eight patients between the ages of 5 months and 15 months. In all patients, electroretinography initially showed a severe cone impairment with mild (2/8) or no (6/8) rod involvement. Electroretinograms, obtained again at ages 9 to 22 years for four patients, revealed extinguished rod-and-cone responses. Obesity developed during childhood in seven patients, in at least three of them before age 2 years. Hearing impairment (5/8) and diabetes/glucose intolerance (4/8) were diagnosed at the end of the first decade or during the second decade. This constellation of features should facilitate early diagnosis of the syndrome.

Adolescent↗
PubMed1996

Role of ocular involvement in the prediction of visual development and clinical prognosis in Aicardi syndrome.

AIMS/BACKGROUND: This study was undertaken to document visual function and acuity in patients with Aicardi syndrome, and to determine whether there is any relation between ocular features of the syndrome exhibited at birth and later visual function. METHODS: Fourteen patients with Aicardi syndrome, all examined and followed by the same ophthalmologist, were reviewed between 1975 and 1992 and their ocular characteristics and visual acuity described. It was hypothesised that larger lacunae may be associated with poorer clinical outcome and therefore the relation between these two variables was investigated. RESULTS: Visual acuity as documented by Snellen, Sheridan-Gardner, preferential looking, or pattern visual evoked potential tests was in the normal to low normal range in six eyes of four patients. Visual function correlated significantly with macular appearance. Good visual function was preserved if the fovea appeared normal on funduscopic examination and was uninvolved by lacunae. The size of the largest chorioretinal lacuna also correlated significantly with clinical outcome: patients with large lacunae were more likely to be immobile and to have no language skills. CONCLUSION: It was concluded that good visual function in patients with Aicardi syndrome may be anticipated if the fovea is normal. Although many patients have severe psychomotor retardation, the presence of predominantly small chorioretinal lacunae may indicate a better prognosis for mobility and language development.

Abnormalities, Multiple↗
PubMed1996

Abnormal ocular enhancement in Sturge-Weber syndrome: correlation of ocular MR and CT findings with clinical and intracranial imaging findings.

PURPOSE: To estimate the prevalence of abnormal ocular enhancement in children with Sturge-Weber syndrome as detected with MR imaging and CT and to correlate this with the clinical, fundoscopic, and intracranial imaging findings. METHODS: Fifteen children, 4 years old or younger, with Sturge-Weber syndrome were examined with enhanced CT and MR imaging. Eleven children had unilateral intracranial involvement and 4 had bilateral involvement, for a total of 19 abnormal hemispheres and related orbits. The presence of ocular enhancement was compared with the fundoscopic findings independently. Ocular enhancement was correlated with the extent of leptomeningeal disease, the severity of the cutaneous lesion, and the presence of glaucoma by the calculation of likelihood ratios and 95% confidence limits. RESULTS: Seven of the 15 patients had abnormal ocular enhancement, which was present in 10 (53%) of the eyes associated with the 19 abnormal hemispheres. MR imaging showed choroidal hemangioma in 7 of 8 patients in whom hemangiomas were shown at fundoscopy. The likelihood of ocular enhancement was increased with the presence of bilateral disease, extensive facial nevi, and glaucoma; there was no significant correlation with the extent of hemispheric involvement. CONCLUSION: Both enhanced MR imaging and CT can show diffuse choroidal hemangioma in patients with Sturge-Weber syndrome. However, MR imaging is more sensitive and is recommended to aid in the detection of abnormalities with preventable late complications.

Brain↗
PubMed1995

Eye problems in children with multiple sclerosis.

In a retrospective review, the eye symptoms of 17 children (mean age: 13 1/2 years) who had definite multiple sclerosis (Poser's criteria) and 15 who had probable multiple sclerosis over the last 18 years were evaluated. Follow-up varied from 3 weeks to 6 years. Of 94% of children (16 of 17) with ophthalmologic symptoms, 47% (8 of 17) presented with an initial disturbance of vision. Twelve children had optic neuritis, 1 progressive uveitis, and 4 brainstem symptoms (i.e., VIth nerve palsy, 1 1/2 syndrome, internuclear ophthalmoplegia). Four children had cerebellar signs (nystagmus, saccadic pursuit). In 4 children, clinical localization was less specific. Recovery was generally good in most of the children; cerebellar problems were most persistent. Multimodal potentials were more helpful for investigation of optic neuritis and cerebellar lesions than for brainstem lesions. In the cohort of probable multiple sclerosis of 15 children, 11 had eye symptoms (5 with neuromyelitis optica, 4 optic neuritis, 1 internuclear ophthalmoplegia, and 1 cerebellar symptoms). Ophthalmologic symptoms are slightly more frequent in children with multiple sclerosis than in adults and should be specifically investigated to establish the diagnosis.

Adolescent↗
PubMed1994

Joubert syndrome with congenital hepatic fibrosis: an entity in the spectrum of oculo-encephalo-hepato-renal disorders.

Joubert syndrome is an autosomal recessive inherited condition characterized by agenesis or hypoplasia of the cerebellar vermis, retinal dystrophy, chorioretinal colobomata, oculomotor abnormalities, episodic hyperpnea, ataxia, and mental retardation. Congenital hepatic fibrosis has not previously been described in Joubert syndrome. We report two unrelated children with Joubert syndrome and hepatosplenomegaly. On histopathological examination, both had congenital hepatic fibrosis. Both were also found to have congenital medullary cystic disease of the kidneys. Joubert syndrome appears to be one of a spectrum of congenital malformation syndromes involving the central nervous system, eye, liver and kidneys.

Abnormalities, Multiple↗
PubMed1994

Aicardi syndrome: natural history and possible predictors of severity.

Aicardi syndrome is defined by the clinical triad of infantile spasms, agenesis of the corpus callosum, and pathognomonic chorioretinal lacunae. Almost all patients are girls with severe cognitive and physical handicaps, and epilepsy. Fourteen patients with Aicardi syndrome, seen at The Hospital for Sick Children, Toronto, Ontario, Canada, between 1975 and 1992, were reviewed to document the natural history of the disease and obtain life-table estimates of survival. The relationship between 28 neurologic features present in infancy and clinical outcome, as measured by mobility and cognitive function also was examined. Life-table analysis indicated that the estimated survival rate was 76% at 6 years of age and 40% at 15 years of age. Three of the 14 girls (21%) could walk or crawl and 4 (29%) had some language ability. None of the 28 neurologic features was predictive of ultimate clinical outcome. This information should be discussed with parents of children with Aicardi syndrome.

Abnormalities, Multiple↗
PubMed1994

Ocular manifestations of frontonasal dysplasia.

The ophthalmologic findings associated with frontonasal dysplasia have not been defined previously in a large series of untreated children. We reviewed the ophthalmic manifestations of a series of patients with frontonasal dysplasia who were seen as part of their craniofacial evaluation. All had undergone a complete ophthalmologic examination before any manipulation of either the orbits or the soft tissues of the orbital contents. From 1986 to 1991, 23 patients with frontonasal dysplasia were seen; ophthalmologic abnormalities were found in 20 (87 percent). Abnormalities included significant refractive errors, strabismus, nystagmus, and eyelid ptosis. Three patients had amblyopia, a treatable cause of visual loss, from strabismus or anisometropia. Ten eyes in seven patients (30 percent) had severe structural anomalies, such as optic nerve hypoplasia, optic nerve colobomas, microphthalmia, cataract, corneal dermoid, or inflammatory retinopathy, that resulted in an acuity of 20/100 or worse. The high incidence of ocular abnormalities indicates that early assessment by an ophthalmologist should be part of the initial evaluation of patients with frontonasal dysplasia to detect treatable visual or ocular problems.

Abnormalities, Multiple↗
PubMed1993

Cervical spine subluxation associated with congenital muscular torticollis and craniofacial asymmetry.

The relationship between craniofacial asymmetry, congenital muscular torticollis, and cervical spine subluxation was examined in a study of 30 children who presented to our Craniofacial Program from 1987 through 1990. Twenty-six of the 30 patients had craniofacial asymmetry and muscular torticollis without true suture synostosis documented by head and neck CT scans. These 26 patients had positional skull molding with consistent flattening of the contralateral occipitoparietal region and the ipsilateral fronto-orbital region relative to the side of the torticollis. Thirteen of the 26 patients also were found to have a C1-C2 subluxation. C1 was rotated forward of C2 on the side contralateral to the muscular torticollis in 12 of 13 patients. None of the patients with subluxation had neurologic deficits or required spinal stabilization. Ophthalmologic evaluations demonstrated amblyopia (4 patients) and horizontal strabismus (1 patient), both thought to be coincidental, with no evidence of nystagmus in any case. Seven of the 26 patients required surgical therapy for their neck muscle tightness, while the remainder responded to physiotherapy. Only 2 of the 26 patients underwent cranio-orbital reshaping for correction of their upper face asymmetry. Recognition of cervical subluxation in patients with congenital muscular torticollis may help to explain residual head-neck posturing problems even after successful neck muscle therapy.

Birth Injuries↗
PubMed1993

Congenital aplasia of the iris sphincter and dilator muscles.

Congenital aplasia of the iris sphincter and dilator muscles is rare. We describe a 3-month-old boy with a patent ductus arteriosus who had this anomaly, with no other ocular or systemic abnormalities. The child, whom we followed for over 7 years, had reduced accommodative amplitudes. This anomaly, although it bears some similarity to Gillespie's syndrome, circumpupillary aplasia and aniridia, is an isolated, nonprogressive condition that general physicians need to differentiate from the neurologically dilated pupil so that misdirected, unnecessary investigations can be avoided.

Accommodation, Ocular↗