Safety and Diagnostic Efficacy of Gadobenate Dimeglumine in MRI of the Brain and Spine of Neonates and Infants.

BACKGROUND AND PURPOSE: Contrast-enhanced MR imaging provides essential information for pediatric imaging applications. We evaluated gadobenate dimeglumine for contrast-enhanced MR imaging of infants younger than 2 years of age. MATERIALS AND METHODS: Ninety children younger than 2 years of age (including 55 children younger than 1 year) who underwent enhanced MR imaging of the CNS with gadobenate dimeglumine at 0.1 mmol/kg body weight ± 25% by volume were retrospectively enrolled at 2 imaging centers. Safety data were assessed for adverse events and, when available, vital signs and electrocardiogram and clinical laboratory values obtained from 48 hours before until 48 hours after the MR imaging examination. The efficacy of gadobenate dimeglumine-enhanced MR imaging was evaluated prospectively by 3 blinded, unaffiliated readers in terms of the accuracy of combined pre- and postcontrast images relative to precontrast images alone for differentiation of tumor from non-neoplastic disease and the correct diagnosis of specific disease. Differences were tested using the McNemar test. A possible effect of dose on diagnostic accuracy was assessed using the Fisher exact test. RESULTS: Nine nonserious adverse events were reported for 8 (8.8%) patients. Five adverse events occurred in patients 12 months of age or older. All events occurred at least 24 hours after gadobenate dimeglumine administration, and in each case, the investigating radiologist considered that there was no reasonable possibility of a relationship to gadobenate dimeglumine. No clinically meaningful changes in vital signs, electrocardiogram results, or laboratory parameters were reported. Accurate differentiation of tumor from non-neoplastic disease and exact matching of each specific MR imaging-determined diagnosis with the on-site final diagnosis were achieved in significantly more patients by each reader following evaluation of combined pre- and postcontrast images relative to precontrast images alone (91.0%-94.4% versus 75.3%-87.6%, P < .04, and 66.3%-73.0% versus 52.8%-58.4%, P < .02, respectively). No significant differences (P > .133) in diagnostic accuracy were noted between patients receiving ≤0.08 mmol/kg of gadobenate dimeglumine and patients receiving >0.08 mmol/kg of gadobenate dimeglumine. CONCLUSIONS: Gadobenate dimeglumine is safe and effective for pediatric MR imaging.

High-resolution MRI evaluation of neonatal brachial plexus palsy: A promising alternative to traditional CT myelography.

BACKGROUND AND PURPOSE: Despite recent improvements in perinatal care, the incidence of neonatal brachial plexus palsy remains relatively common. CT myelography is currently considered to be the optimal imaging technique for evaluating nerve root integrity. Recent improvements in MR imaging techniques have made it an attractive alternative to evaluate nerve root avulsions (preganglionic injuries). We aim to demonstrate utility of MR imaging in the evaluation of normal and avulsed spinal nerve roots. MATERIALS AND METHODS: All study patients with clinically diagnosed neonatal brachial plexus palsy underwent MR imaging by use of a high-resolution, heavily T2-weighted (driven equilibrium) sequence. MR imaging findings were reviewed for presence of nerve root avulsion from C5-T1 and for presence of pseudomeningocele. The intraoperative findings were reviewed and compared with the preoperative MR imaging findings. RESULTS: Thirteen patients (9 male, 4 female) underwent MR imaging; 6 patients underwent nerve reconstruction surgery, during which a total of 19 nerve roots were evaluated. Eight avulsions were noted at surgery and in the remainder, the nerve injury was more distal (rupture/postganglionic injury). Six of the 8 nerve root avulsions identified at surgery were at C5-6 level, whereas 1 nerve root avulsion was identified at C7 and C8 levels, respectively. The overall sensitivity and specificity of MR imaging for nerve root avulsions was 75% and 82%, respectively. CONCLUSIONS: Our preliminary results demonstrate that high-resolution MR imaging offers an excellent alternative to CT myelography for the evaluation of neonatal brachial plexus palsy with similar sensitivity compared with CT myelography.

Gelastic syncope: an unusual condition.

Gelastic syncope or laughter-induced syncope is a rare disease often misdiagnosed as narcolepsy or cataplexy. We report a 54-year-old man with syncopal episodes. Each episode started after laughter, leading to light-headedness with blurring of vision and loss of consciousness for a few seconds. The episodes resolved spontaneously. The treatment of gelastic syncope is the same as that for neurally mediated syncope.