Leo Hochhauser

Postnatal dexamethasone therapy and cerebral tissue volumes in extremely low birth weight infants.

OBJECTIVE. Our goal was to relate postnatal dexamethasone therapy in extremely low birth weight infants (birth weight of ≤1000 g) to their total and regional brain volumes, as measured by volumetric MRI performed at term-equivalent age. METHODS. Among 53 extremely low birth weight infants discharged between June 1 and December 31, 2003, 41 had high-quality MRI studies; 30 of those infants had not received postnatal steroid treatment and 11 had received dexamethasone, all after postnatal age of 28 days, for a mean duration of 6.8 days and a mean cumulative dose of 2.8 mg/kg. Anatomic brain MRI scans obtained at 39.5 weeks (mean) postmenstrual age were segmented by using semiautomated and manual, pretested, scoring algorithms to generate three-dimensional cerebral component volumes. Volumes were adjusted according to postmenstrual age at MRI. RESULTS. After controlling for postmenstrual age at MRI, we observed a 10.2% smaller total cerebral tissue volume in the dexamethasone-treated group, compared with the untreated group. Cortical tissue volume was 8.7% smaller in the treated infants, compared with untreated infants. Regional volume analysis revealed a 20.6% smaller cerebellum and a 19.9% reduction in subcortical gray matter in the dexamethasone-treated infants, compared with untreated infants. In a series of regression analyses, the reductions in total cerebral tissue, subcortical gray matter, and cerebellar volumes associated with dexamethasone administration remained significant after controlling not only for postmenstrual age but also for bronchopulmonary dysplasia and birth weight. CONCLUSIONS. We identified smaller total and regional cerebral tissue volumes in extremely low birth weight infants treated with relatively conservative regimens of dexamethasone. These volume deficits may be the structural antecedents of neuromotor and cognitive abnormalities reported after postnatal dexamethasone treatment.

Pituitary gland. Variable signal intensities on MRI. A pictorial essay.

The anterior pituitary gland may exhibit high signal on T1-weighted (T1w) images and/or low signal on T2-weighted (T2w) images in several normal and pathological states. High T1w signal may be seen in normal fetuses, neonates, and in pregnant and postpartum women. It may also occur in Rathkes cleft cyst, craniopharyngioma, subacute hemorrhage, manganese deposition, melanoma, dermoid, and lipoma. Low T2w signal may be seen in hemorrhage, calcification, cystic lesion, hemochromatosis, melanoma, and vascular lesions. These are described and illustrated.

Automatically Quantified Diffuse Excessive High Signal Intensity on MRI Predicts Cognitive Development in Preterm Infants

BACKGROUND Cognitive and language impairments constitute the majority of disabilities observed in preterm infants. It remains unclear if diffuse excessive high signal intensity on magnetic resonance imaging at term represents delayed white matter maturation or pathology. METHODS We hypothesized that diffusion tensor imaging-based objectively quantified diffuse excessive high signal intensity measures at term will be strong predictors of cognitive and language development at 2 years in a cohort of 41 extremely low birth weight (≤1000 g) infants. Using an automated probabilistic atlas, mean diffusivity maps were used to objectively segment and quantify diffuse excessive high signal intensity volume and mean, axial, and radial diffusivity measures. Standardized neurodevelopment was assessed at 2 years of age using the Bayley Scales of Infant Development, third edition. RESULTS Thirty-six of the 41 infants (88%) had complete developmental data at follow-up. Objectively quantified diffuse excessive high signal intensity volume correlated significantly with cognitive and language scores at 2 years (P < 0.001 for both). The sum values of the three diffusivity measures in detected diffuse excessive high signal intensity regions also correlated significantly with the Bayley scores (r(2) 34.7%; P < 0.001 for each). Infants in the highest quartile for diffuse excessive high signal intensity volumes had scores between 19 and 24 points lower than infants in the lowest quartile (P < 0.01). When diagnosed subjectively by neuroradiologists however, Bayley scores were not significantly lower in infants with extensive diffuse excessive high signal intensity. CONCLUSIONS These findings lend further evidence that diffuse excessive high signal intensity is pathologic and that objectively quantified diffusion-based diffuse excessive high signal intensity volume at term is associated with cognitive and language impairments. Our approach could be used for risk stratification and early intervention for such high-risk extremely preterm infants.

Primary thalamic and caudate hemorrhage in term neonates presenting with seizures.

Two previously well term neonates who presented with seizures are described: one with thalamic hemorrhage and the other with thalamic and caudate hemorrhage. These 2 patients were the only neonates found with thalamic hemorrhage in a review of 54 term infants with intracranial hemorrhage at The Hospital for Sick Children over a 10 year period (1976-1986). Partial seizures occurred at 5 and 7 days after birth and were easily controlled. Prognosis was generally good in these 2 patients, as well as in 4 previously reported patients.

Computed tomographic diagnosis of pulmonary sequestration

Two cases of pulmonary sequestration demonstrated by CT scans of the chest are described. In one, CT demonstrated the anomalous artery. This finding may obviate the need for angiography when surgery is not contemplated.

MR of post traumatic spinal cord lesions Unexpected improvement of hemorrhagic lesions

Fifteen patients who sustained spinal cord trauma were evaluated by MR within 72 hours of injury. Nine patients had hemorrhagic and six had nonhemorrhagic traumatic spinal cord lesions. Three patients with hemorrhagic and all six patients with nonhemorrhagic lesions showed some degree of neurological improvement on follow-up examinations. In two of the three patients with hemorrhagic lesions who improved, the hemorrhage was extensive. This supports the observation that hemorrhagic lesions are not always associated with a poor clinical outcome.

Radionuclide tagged blood cell patch to monitor spine coverage for spontaneous diffuse CSF leaks

We present a 14-year-old female patient with a 2 yr history of positional headache secondary to spontaneous diffuse cerebrospinal fluid (CSF) leaks. We treated the leak with an epidural blood patch which was radioactively labeled by a well- established nuclear medicine technique. Because spontaneous CSF leaks were frequently multifocal or diffuse throughout the spine, the extent of coverage or distribution of an epidural patch was generally determined by best estimate. Traditional radiographic contrast media mixed with the blood cellshad been used to monitor the patch coverage and it is questionable whether the contrast can be representative of the cell distribution. We applied a nuclear medicine technique to label the autologous red blood cells to monitor the range of spinal cord coverage of each epidural patch. After two visible epidural patches covered both the lumbar and thoracic spine, computed tomography myelogram demonstrated significantly decreased leakage when compared to the pre-patch images. However, the patients symptoms remained essentially unchanged in the long term, which is consistent with refractory spontaneous CSF leaks. We believe that this sophisticated nuclear medicine blood labeling technique is a simple and accurate way to monitor the true cell coverage of the spine and the pattern of distribution.

Prolapse of an ectopic ureterocele into both urethra and ipsilateral orthotopic ureter

Ectopic ureteroceles frequently prolapse into the urethra. Inversion of ureteroceles into their own ureters has also been described. This patient showed a ureterocele which not only prolapsed into the urethra but also into the ipsilateral orthotopic ureter. We have not seen nor found a description of prolapse of a ureterocele into the ipsilateral orthotopic ureter.