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A delayed nonmatching-to-sample task with trial-unique stimuli (DNMS), similar to that used to test object recognition memory in primates, was adapted for use with rats. For each trial of the DNMS task, two stimuli were randomly selected from a pool of 250 small "junk" objects; one member of the pair was designated as the sample. On the first part of a trial, the rat traversed an elevated runway and displaced the sample for food reward. After a 10-s delay, the rat again traversed the runway to choose between the previously presented sample and the second member of the pair. Reward on the choice trial followed selection of the new object. Scores on the first day of DNMS were significantly above chance, and animals could consistently perform at approximately 75% accuracy. Extending the delay to 30 or 120 s lowered choice accuracy, but performance was still above chance. The DNMS taks for rats, unlike most other memory tests for rodents, does not require memory for spatial location. The similarity to tests used with primates should allow for more direct comparison of results of memory research across species.

BACKGROUND AND PURPOSE:Ischemic injury to the brain is a common complication of SCA. To better understand the neurologic impact of SCA, TBSS were applied to DTI data to investigate white matter injuries in pediatric patients with SCA.

A child with brainstem ganglioglioma underwent subtotal resection and focal radiation. Magnetic resonance imaging confirmed tumor progression 6 months later. Another partial resection revealed viable BRAF V600E-positive residual tumor. Vemurafenib (660 mg/m(2) /dose) was administered twice daily, resulting in >70% tumor reduction with sustained clinical improvement for 1 year. Vemurafenib was then terminated, but significant tumor progression occurred 3 months later. Vemurafenib was restarted, resulting in partial response. Toxicities included Grade I pruritus and Grade II rash. Vemurafenib was effectively crushed and administered in solution via nasogastric tube. We demonstrate benefit from restarting vemurafenib therapy.

Purpose Chemotherapy for relapsed medulloblastoma has been inadequate, and most patients succumb to disease. Methods We retrospectively reviewed nine cases of relapsed medulloblastoma treated with bevacizumab, irinotecan, ±temozolomide. Patients received one to three prior therapeutic regimens. Five patients received 10 mg/kg bevacizumab and 125–150 mg/m2 irinotecan IV every 2 weeks, with temozolomide, starting at a median dose of 150 mg/m2 orally for 5 days monthly. Two patients received bevacizumab and irinotecan, but not temozolomide, due to provider preference. Two of nine patients received 15 mg/kg bevacizumab IV, 90 mg/m2 irinotecan orally for five consecutive days, 100 mg/m2/day temozolomide IV for 5 days, and 1.5 mg/m2 vincristine IV, each administered every 21 days. Results Median time to progression was 11 months. Median overall survival was 13 months. Objective tumor response at 3 months was 67 %, including six patients with partial response (PR) and three patients with stable disease (SD). At 6 months, objective response was 55 %, with two patients with PR and three with complete response. Additionally, one patient had SD and three had PD. Two patients remain alive and progression free at 15 and 55 months; another is alive with disease at 20 months. Toxicities included two patients with grade III neutropenia, two with grade III thrombocytopenia, one with grade III elevation of liver function tests, and one patient with grade III diarrhea. Conclusions The combination of bevacizumab and irinotecan, with or without temozolomide, produces objective responses with minimal toxicity in children with recurrent medulloblastoma. Prospective clinical trials are needed to evaluate the efficacy of this strategy.

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In environments in which opioids are increasingly abused for recreation, children are becoming more at risk for both accidental and nonaccidental intoxication. In toxic doses, opioids can cause potentially lethal acute leukoencephalopathy, which has a predilection for the cerebellum in young children. The authors present the case of a 2-year-old girl who suffered an accidental opioid overdose, presenting with altered mental status requiring cardiorespiratory support. She required emergency posterior fossa decompression, partial cerebellectomy, and CSF drainage due to cerebellar edema compressing the fourth ventricle. To the authors’ knowledge, this is the first report of surgical decompression used to treat cerebellar edema associated with opioid overdose in a child.

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