Magnetic resonance imaging in the evaluation of leukocoria

Leukocoria is an important clinical sign in ophthalmology. Conditions producing this white pupillary reflex must be differentiated from retinoblastoma to insure appropriate and timely treatment. Auxiliary diagnostic testing has been helpful in securing a clinical diagnosis. A new diagnostic modality, magnetic resonance imaging, provides similar morphologic information with the additional potential for biochemical characterization. A series consisting of 14 patients presenting with leukocoria as a result of retinoblastoma and simulating conditions was examined. The magnetic resonance imaging findings are discussed.     

Nonoperative management of benign postoperative biliary strictures

Selected benign biliary strictures can be treated safely and successfully by percutaneous balloon dilatation. Primary biliary strictures appear to be less responsive to balloon dilatation alone and require stenting with large catheters (16-20 F) for several months to permit scarring around the catheter. A long period of healing around such a large-bore stent is crucial to the success of such treatment. The most important physiologic indicators for successful dilatation are a long period of stricture challenge with a catheter placed proximal to the dilated segment to allow bile to drain internally across the previously strictured segment, and a near anatomic result as demonstrated by cholangiogram.     

Radiation therapy for retinoblastoma: comparison of results with lens-sparing versus lateral beam techniques

From 1979 through 1986, 170 children were seen at our institution diagnosed with retinoblastoma. Sixty-six of the children with involvement of 121 eyes, were referred for definitive external beam radiation to one or both eyes. During the study period, two distinct radiation techniques were used. From 1980 through mid-1984, a lens-sparing technique included an anterior electron beam with a contact lens mounted lead shield, combined with a lateral field, was used. Since mid-1984, a modified lateral beam technique has been used, mixing lateral electrons and superior and inferior lateral oblique split beam wedged photons. Doses prescribed were similar for both techniques, ranging from 3,850 to 5,000 cGy in 4 to 5 weeks. The lens-sparing and the modified lateral techniques are compared for local control. For eyes with Group I through III disease, the lens-sparing technique resulted in local control in 33% of the eyes treated, where the modified lateral technique controlled 83% of the eyes treated (p = .006). Mean time to relapse was identical in both groups, that is 24 and 26 months respectively. Most relapses were successfully treated with further local therapy, including laser or cryosurgery, or 60Co plaques. Five eyes required enucleation following initial treatment with the lens-sparing technique, but none thus far with the lateral beam technique. For eyes with Group IV and V disease, no significant differences were found between the two techniques in terms of local control or eventual need for enucleation. With a mean follow-up time of 33 months for the entire group, the 4-year survival is 93%. Two of the 4 deaths are due to second primary tumor, and all 4 have occurred in the lens-sparing group. Because follow-up time is more limited in the lateral beam group, this is not statistically significant and direct survival comparisons are premature.     

Reducing the cost of using contrast media: a look at discarded volumes

A study of the volume of radiopaque contrast media (ROM) discarded during angiographic procedures was conducted at one tertiary care teaching hospital to evaluate the potential cost savings from reducing that volume. Volumes of ROM used and discarded during 31 cerebral angiographic procedures and 16 percutaneous transluminal coronary angioplasties (PTCAs) were analyzed. An average of 98 mL of ROM was discarded during cerebral angiography and 175 mL during PTCA. When low-osmolality contrast media (LOM) were used, the cost of discarded ROM was 15.8% of the technical charge for cerebral angiography and 21.5% for PTCA. If LOM were used, a savings of $11,000 per year could be achieved if 80-mL, rather than 100-mL, bottles were used for cerebral angiography and $35,000 per year if a single 300-mL bottle with inverted-Y tubing were used, rather than two 200-mL bottles currently employed for PTCA. Substantial savings could be realized by modifying technical procedures and by increasing the range of bottle sizes in which ROM are marketed.     

Effect of age on the fulfilment of the IHS criteria for migraine in children at a headache clinic

In a headache clinic, 247 children suffering from severe recurrent headaches were studied in relation to the IHS criteria for migraine. Of the 247, 163 had migrainous headache, with 110 (67.5%) of these having migraine in accordance with the IHS criteria. The remaining 53 (32.5%) had headache attacks fulfilling all but one of the IHS criteria. Coverage of the IHS criteria for migraine was 93%. Symptoms of unilateral headache, aggravation by physical activity, and nausea showed the greatest differences in frequency between those with migraine and those with probable migraine. All children with aura fulfilled criteria for migraine. Children with migraine with aura (11.8, 95% CI: 11.0–12.6 years) were older than those without aura (10.1, 9.4–10.8 years; p = 0.001). Children with pulsating headache were slightly older than children without pulsating headache. No differences in age were detected for the other IHS criteria.     

Capillary hemangioma of the lids and orbit: an analysis of the clinical features and therapeutic results in 101 cases

The clinical records of 101 patients (biopsies done on 48) with capillary hemangiomas of the orbit, orbit and lids, and lids were analyzed. Lesions predominated in females and typically appeared at birth or within the first two months of life. The superior orbit and lids were definite sites of predilection. Telltale periocular cutaneous involvement occurred in one third of the cases. Pure proptosis caused by a deep orbital tumor without an anterior component was found in seven cases. Proptosis in general was mild, but in two cases was severe enough to cause corneal exposure. Findings suprortive of a diagnosis of an orbital or periorbital hemangioma include (1) change in tumor size on crying (46%); (2) a dark vascular coloration to the subcutaneous tissue (80%); and (3) the existence of nonperiocular strawberry marks (25). Diagnostic tests of most value were plain radiography, ultrasonography, computed axial tomography, and arteriography. The complication rate in the 50 patients followed up over five years was 80% (60% with amblyopia). Present treatment modalities do not appear to be achieving the desired goals of a good cosmetic and functional outcome. Radiotherapy and corticosteroids are both effective in individual cases, but many lesions are resistant to all forms of present treatment. Amblyopia therapy is difficult and often unsuccessful in these patients.     

March 2004: a 24-year-old woman with bifrontal headaches

A 24-year-old woman with bifrontal headaches was found to have a well-circumscribed lesion in the frontal lobe subcortical white matter. Microscopic examination showed clusters of small round cells separated by hypocellular neuropil-like areas, and a distinct border between tumor and surrounding white matter. Synaptophysin was diffusely positive in neuropil-like areas, and many tumor cells expressed NeuN. Based on these findings, a diagnosis of "extraventricular neurocytoma" was made. A double-label immunofluorescence stain was performed with NeuN and Ki-67 antibodies to determine if NeuN+ cells remained in the mitotic cycle. No colocalization of these markers was found, thus supporting the hypothesis that neuronal differentiation (as marked by NeuN expression) is incompatible with continued proliferation of tumor cells, as well as normal neurons.     

Acceleration of visually cued conditioned fear through the auditory pathway

Defensive responses elicited by sensory experiences are critical for survival. Mice acquire a conditioned fear response rapidly to an auditory cue but slowly to a visual cue, a difference in learned behavior that is likely to be mediated by direct projections to the lateral amygdala from the auditory thalamus but mainly indirect ones from the visual thalamus. Here, we show that acquisition of visually cued conditioned fear is accelerated in 'rewired' mice that have retinal projections routed to the auditory thalamus. Visual stimuli induce expression of the immediate early gene Fos (also known as c-fos) in the auditory thalamus and the lateral amygdala in rewired mice, similar to the way auditory stimuli do in control mice. Thus, the rewired auditory pathway conveys visual information and mediates rapid activity-dependent plasticity in central structures that influence learned behavior.