In recent years, gadolinium-based contrast agents have been associated with different types of toxicity. In particular, nephrogenic systemic fibrosis, a progressive sclerotic-myxedematous systemic disease of unknown etiology, is related to gadolinium-based contrast agent administration in patients with kidney dysfunction. More recently, evidence of magnetic resonance signal intensity changes on pre-contrast T1-weighted images after multiple gadolinium-based contrast agent administrations resulted in the hypothesis of gadolinium brain accumulation in patients with normal renal function, subsequently confirmed in pathological samples. However, there is limited current data and further investigations are necessary before drawing definite conclusions on the clinical consequences of gadolinium-based contrast agent accumulation in human tissues and particularly in the brain. Gadolinium-based contrast agent-related toxicity appears connected to molecular stability, which varies together with the pharmacokinetic properties of the compound and depends on the individual characteristics of the subject. During a lifetime, the physiological changes occurring in the human body may influence its interaction with gadolinium-based contrast agents: the integrity and developmental stage of the organs has an effect on the dynamics of gadolinium-based contrast agent distribution and excretion, thus leading to different possible mechanisms of deposition and toxicity. Therefore, the aim of this work is to discuss the pharmacokinetics and pharmacodynamics of gadolinium-based contrast agents, with a special focus on the brain, and to explore potential predominant gadolinium-based contrast agent-related toxicity in two cornerstone periods of the human life cycle: fetal/neonatal and adulthood/aged.

Parry-Romberg syndrome (PRS) is a sporadic disease of unknown etiology with typical onset in childhood or in young adults. It is characterized by a slow and progressive atrophy affecting one side of the face, the skin, the subcutaneous tissue, the muscles, the cartilages, and the underlying bony structures. The neurological symptoms usually include focal epilepsy, migraine, and unilateral brain lesions on the same side as the atrophy. A common neuroimaging finding of the syndrome is white matter high signal intensity on brain magnetic resonance (MR) imaging. Rasmussen encephalitis (RE) is a rare and chronic inflammatory disease of the brain that begins in the first decade of life and more rarely in adolescents and adults. It usually involves one hemisphere with focal cortical inflammation. Neurologic symptoms are intractable seizures and progressive hemiplegia. Both PRS and RE are often associated with other inflammatory or autoimmune disorders and only 1 case of both syndromes has been reported in literature. We report the clinical and neuroradiological findings in a 6-year-old boy, presenting with focal hemifacial and arm motor seizures and progressive facial hemiatrophy. Serial MR imaging studies revealed progressive brain hemispheric signal alterations and atrophy. This would thus suggest acoexistence of PRS and RE.

BackgroundAcute cerebellitis (AC) is the most common neurological complication of varicella. Nevertheless, it has been scarcely studied. The objective of this study were to asses the occurrence of AC among children hospitalized for varicella and to analyze its specific clinical picture and outcome.MethodsWe retrospectively reviewed the medical records of children admitted to the hospital for varicella between 1st October 2003 and 1st June 2013 and we compared our results with literature. Children were all unvaccinated for varicella.ResultsIn our case series, AC was found out in 48 out of 457 patients (10.5%). The highest frequency of AC was observed in children from 1 to 5 years of age (60.9%). The most characteristic symptom of AC was a broad-based gait disturbance that progressed gradually over the course of a few days (95.8%). Other common symptoms included slurred speech (37.5%), vomiting (31.25%), headache (29.16%), dysmetry (25%) and tremor (22.91%). After a long hospitalization (median of 11 days), all but one children were dismissed without invalidating sequelae.ConclusionsData from this study may help to better address the problem of varicella cerebellar complications in hospitalized children and to monitor changes over time caused by an increase in vaccination coverage.

Our study shows severe heterogeneous brain MR abnormalities in cbl-C/D defect. We observed unusual basal ganglia lesions in 30 % of our cases and also found a high incidence of hydrocephalus and supratentorial white matter abnormalities.