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Biomedical subjects

A Q McCormick

Publications and source records attributed to A Q McCormick.

33 records · Page 2Linked to original sources

Clinical spectrum of congenital optic nerve hypoplasia: review of 51 patients.

Fifty-one patients with congenital optic nerve hypoplasia (CONH) were reviewed. It was found that the risk of having an affected child is higher in an adolescent mother, and that maternal alcohol or drug abuse may be important factors. Frequently the disorder is associated with other neuropsychiatric handicaps, and with neuro-endocrine abnormalities. The findings suggest that CONH probably is not a homogeneous group of disorders; some may be caused by primary failure of differentiation of the retinal ganglion cells, while others may be the product of an acquired transsynaptic degeneration of optic-nerve fibres.

Abnormalities, Multiple↗

Whiplash shaking syndrome: retinal hemorrhages and computerized axial tomography of the brain.

Three cases of whiplash shaking injury of infants are presented. All children presented with seizures and had minimal signs of external injury. Examination of the retina revealed extensive retinal hemorrhages. These were missed on initial examination and were only discovered after pupillary dilatation. The presence of these palecentered retinal hemorrhages suggested the diagnosis of child abuse and skeletal surveys and thorough social histories confirmed the diagnosis. Despite extensive retinal hemorrhages, computerized axial tomography (C.T.) scan showed minimal inter-hemispheric bleeding. In contrast to the "Battered Child Syndrome," all the findings in whiplash shaking syndrome of infants are subtle and demand an awareness, an index of suspicion and a thorough examination which may include extensive retinal examination following dilatation of the pupils. This latter examination is frequently not performed by family physicians and residents so that the syndrome may be missed. A fourth case is also discussed where shaking is admitted on initial presentation but said to be done for resuscitation. This poses an immense diagnostic dilemma to the pediatrician since in this case the child presented later with all the signs of physical abuse.

Brain↗

Eye-pressing by visually impaired children.

Many children with severely impaired sight exhibit stereotyped mannerisms. Visual self-stimulation, e.g. eye-pressing and light-gazing, normally is restricted to the visually impaired; prolonged eye-pressing is the most common. This behaviour depends on onset of visual impairment, age, degree and quality of residual light, type of ocular abnormality, the presence of additional handicaps, and the activities in which the child is involved. Children with bilateral optic-nerve defects never press their eyes; those with retinal disorders tend to press vigorously. A possible physiological explanation is that self-stimulation occurs when the demand of the brain for meaningful visual information is not adequately met.

Adolescent↗

Vestibular studies in Pelizaeus-Merzbacher disease.

Pelizaeus-Merzbacher disease is a rare sex-linked recessive neurological disorder. It presents with a slowly progressive neurological deterioration. It is liable to be misdiagnosed as cerebral palsy. A family history of similar disease is a clue to the diagnosis. A patient with this condition has been followed over many years. Nystagmus was noted to be present shortly after birth. Audiovestibular investigations were performed. All tests of peripheral hearing were normal. ABR indicated abnormal brainstem conduction. Several electronystagmographic abnormalities were present. These were of a central type. They included failure of fixation suppression, poor smooth pursuit, and impaired performance of optokinetic nystagmus at high stripe speeds. During caloric-induced nystagmus an excessively prolonged slow phase of nystagmus with wide eye excursions was seen. We have not seen this feature in any other diseases and we suggest it may be specific for this syndrome.

Adult↗

Aging of the optic nerve.

Histologic studies were carried out on 300 optic nerves covering ages from birth to 96 years. The optic nerve is small and nearly unmyelinated at birth. It rapidly grows and becomes medullated. With advancing years, the leptomeninges and fibrous septa become broader and occupy an increasingly larger proportion of the cross-sectional area of the nerve. The axons progressively diminish, and this probably reflects primarily a loss of ganglion cells and would contribute considerably to reduced visual acuity in the older population. Other age-associated degenerative changes are corpora amylacea and lipofuscin in astrocytic cytoplasm. In the older population, scars, swollen axons, and Schnabel's cavernous degeneration become common, indicating a high incidence of vascular impairment.

Adolescent↗

Neurological, psychological and educational sequelae of low birth weight.

In a prospective study of 501 infants of low birth weight (LBW) who mostly weighed 2,041 g (4 1/2 lb) or less, and of 203 control infants of full birth weight (FBW > 2,500 g), 335 LBW and 139 FBW children were followed beyond the age of 6 years and 6 months. The incidence of neurological defects was negatively correlated with birth weight, and the mean "global" IQ of different birth weight groups retained a direct relationship. While the relationship of birth weight to IQ gradually became less marked, the effect of social class was increasingly evident from the age of 2 years and 6 months. The preterm children whose birth weight was appropriate for gestational age (AGA) attained a slightly higher mean IQ and significantly better grade placement in the third school year than the children who were unduly light for their gestational age. Details of the neurological and ophthalmological defects are given, and the predictive significance of neonatal variables is analyzed.

Attention Deficit Disorder with Hyperactivity↗

The prophylactic treatment of retrolental fibroplasia.

10 premature infants with stage 3 retinopathy of prematurity have had photocoagulation and/or cryocoagulation therapy to one eye and have been followed for a period of 1-6 years. Although the long-term results of this therapy are not known, particularly in the prevention of retinal detachment, early observations suggest that treatment is neither harmful nor particularly beneficial. Macular dragging does not seem to be influenced by treatment. The refractive error, as one would expect, does not appear to be altered by this form of therapy. Marked amelioration of the vascular dilatation and tortuosity at the posterior pole is apparent shortly after treatment. It is stressed that this is a trial project and until more definite beneficial results are obtained, treatment of stage 3 retinopathy should be deferred. Retinal detachments (stage 4) may be quite amenable to a buckling procedure.

Child↗

Optic nerve hypoplasia with hypopituitarism. Septo-optic dysplasia with hypopituitarism.

Four children had optic nerve hypoplasia with hypopituitarism, and their clinical picture varied with age. The newborn had apnea, hypotonia, seizures, hyopglycemia, and prolong jaundice. The young infant had defective vision, behavioral delay, hypotonia, and seizures. Except for a mildly receding lower jaw and a high-arched palate, the appearance of the patients was not unusual. The fasting blood glucose level was mildly depressed. In two cases the liver was palpable and results of liver function tests were abnormal. The older child, who was blind and mentally retarded, had growth failure. The extent of the pituitary hormone deficiencies was variable, including diabetes insipidus. The septum pellucidum was not invariably absent. Clinical and pathological findings indicate that the brain lesion might be more diffuse than hitherto recognized. Early recognition of this syndrome and timely intervention might diminish serious sequels.

Abnormalities, Multiple↗