Progressive decrease in N-acetylaspartate/Creatine ratio in a teenager with type 1 diabetes and repeated episodes of ketoacidosis without clinically apparent cerebral edema: Evidence for permanent brain injury.

Recent data suggest that DKA may contribute to cognitive impairment in children with type 1 DM. We measured the NAA/Cr ratio in a teenager during and following 2 separate episodes of DKA without clinically apparent cerebral edema. The NAA/Cr ratio decreased during DKA and improved following recovery. However, the NAA/Cr value was lower after the second episode of DKA (1.76) than after the first (1.97). These findings provide support for the hypothesis that neuronal injury may result from DKA.

Cerebral proton magnetic resonance spectroscopy in children with diabetic ketoacidosis.

BACKGROUND AND PURPOSE: Subclinical cerebral edema occurs in many, if not most, children with diabetic ketoacidosis (DKA) and may be an indicator of subtle brain injury. Brain ratios of N-acetylaspartate (NAA) to creatine (Cr), measured by proton MR spectroscopy, decrease with neuronal injury or dysfunction. We hypothesized that brain NAA/Cr ratios may be decreased in children in DKA, indicating subtle neuronal injury. MATERIALS AND METHODS: Twenty-nine children with DKA underwent cerebral proton MR spectroscopy during DKA treatment (2-12 hours after initiating therapy) and after recovery from the episode (72 hours or more after the initiation of therapy). We measured peak heights of NAA, Cr, and choline (Cho) in 3 locations within the brain: the occipital gray matter, the basal ganglia, and periaqueductal gray matter. These regions were identified in previous studies as areas at greater risk for neurologic injury in DKA-related cerebral edema. We calculated the ratios of NAA/Cr and Cho/Cr and compared these ratios during the acute illness and recovery periods. RESULTS: In the basal ganglia, the ratio of NAA/Cr was significantly lower during DKA treatment compared with that after recovery (1.68 +/- 0.24 versus 1.86 +/- 0.28, P<.005). There was a trend toward lower NAA/Cr ratios during DKA treatment in the periaqueductal gray matter (1.66 +/- 0.38 versus 1.91 +/- 0.50, P=.06) and the occipital gray matter (1.97 +/- 0.28 versus 2.13 +/- 0.18, P=.08). In contrast, there were no significant changes in Cho/Cr ratios in any region. CONCLUSIONS: NAA/Cr ratios are decreased in children during DKA and improve after recovery. This finding suggests that during DKA neuronal function or viability or both are compromised and improve after treatment and recovery.

Delayed diffusion-weighted MR abnormality in a patient with an extensive acute cerebral hypoxic injury.

Diffusion-weighted (DW) MR imaging usually identifies acute cerebral infarction injury in symptomatic patients. We report a patient with severe hypoxic brain injury following suicide attempt by hanging, but with normal DW MR imaging 5-6 h after the event. Follow-up DW MR imaging 3 days after the event, and subsequent autopsy, revealed extensive cerebral anoxic injury.

Urinary effects of morphine in preterm infants.

AIM: To describe the association between morphine administration in preterm infants, hydronephrosis, and renal dysfunction. METHODS: The findings were based on serial ultrasound examinations and blood studies. RESULTS: Two preterm infants had bladder distension and hydronephrosis after they received intravenous morphine for analgesia. Morphine was used at a low dose. Each patient had a normal urine output and normal serum creatinine before the signs and symptoms of urinary retention were observed. Within 24 h of morphine administration, each infant concurrently developed oliguria and elevation of the serum creatinine. Cessation of morphine and urinary drainage resulted in rapid and complete resolution of the hydronephrosis and the elevated creatinine. CONCLUSION: Morphine, even at low dosages, can be associated with hydronephrosis in hospitalized preterm infants.

Chest radiography versus chest CT in the evaluation for pulmonary metastases in patients with Wilms' tumor: a retrospective review.

BACKGROUND: Determination of the presence of pulmonary metastases in children with Wilms' tumor is an important part of staging and treatment. We sought to compare the efficacy of chest radiography (CXR) and chest CT in the evaluation for pulmonary metastases in patients with Wilms' tumor. MATERIALS AND METHODS: This retrospective study included 83 children with Wilms' tumor diagnosed between 1980 and 1993. All patients with pulmonary nodules (n = 12) as well as 14 Wilms' tumor patients without pulmonary metastases (control group) had blinded review of the CXR and chest CTs by three pediatric radiologists. Presence, size, and certainty of metastatic diagnosis were recorded. Medical records were reviewed. The remaining 57 patients had review of their medical and imaging records to confirm the absence of pulmonary metastases. RESULTS: Ten of the 12 with pulmonary masses had imaging available for review. Eight had both positive CXR and chest CT examinations. Two patients had pulmonary nodules seen by CT only: one had a right cardiophrenic angle mass and died as a result of liver metastases. The other had a solitary nodule, which proved to be a plasma-cell granuloma. Overall, the CXR and chest CT data concur in 79/81 (98%). CONCLUSION: CXR alone appears adequate for the diagnosis or exclusion of pulmonary metastases in patients with Wilms' tumor.

Pattern of recurrence in children with midline posterior fossa malignant neoplasms.

BACKGROUND: Surveillance imaging of the brain and spinal neuraxis in patients with posterior fossa malignant tumors is commonly performed, with the assumption that early detection of tumor recurrence will improve outcome. However, the benefit of this imaging has not been proven. PURPOSE: To evaluate the usefulness of spinal surveillance imaging in children with nonmetastatic (at diagnosis, M0) posterior fossa ependymoma and medulloblastoma. MATERIALS AND METHODS: This retrospective study included 65 children (3 months to 16 years, mean 5.7 years) treated between 1985 and 1997 for ependymoma (22) and medulloblastoma (43). Medical records were reviewed for pathology and treatment data. Serial imaging of the head and spine was reviewed for evidence of tumor recurrence. RESULTS: Twenty-four patients (37 %) had tumor recurrence, including 13 with ependymoma and 11 with medulloblastoma. Of the 17/24 recurrent patients initially diagnosed as M0 (6 medulloblastoma and 11 ependymoma), 13 (76 %) had a cranial recurrence only, and 4 (24 %) presented with concomitant cranial and spinal recurrence. No M0 patient presented solely with spinal metastases at recurrence. CONCLUSION: This study suggests that spinal surveillance imaging in patients with posterior fossa ependymoma or medulloblastoma initially staged as M0 may not be useful, as these patients initially recur intracranially. Thus, until an intracranial recurrence is detected, these patients may be spared the time, expense and sedation risk necessary for spinal imaging.