It is a pictorial review or MRI and/or CT features of toxic and metabolic acute encephalopathies in newborns, children and adults with regards to the causative agent.

Metabolic variations and various toxins can adversely affect central nervous system (CNS). Blood brain-barrier protects of reversible or irreversible lesions but sometimes, it can to lead to an encephalopathy. Clinical symptoms often are nonspecific with a neurological deficit and patients can be refereed for a stroke mimic. Medical history is very important to find the causative agent; however imaging, primarily MRI and CT in some cases, has an important role to guide the diagnosis and treatment. Morphologic sequences such as T1, T2, FLAIR are helpful...

1. Neonatal Exogenous toxic exposure during pregnancy leads to various deleterious effects on the fetal development (not developed here). Neurotoxicity in neonates is mostly due to endogenous causes. Neonatal encephalopathy can be caused by numerous causes such as hypoxia-ischemia, stroke, infection or severe trauma among others. Hypoglycemia is the most common metabolic disorder to affect the newborn. In severe hypoglycemia (PGL ≤ 25 mg/dL), MRI shows diffuse cortical and subcortical white matter (WM) damage, the parietal and occipital lobes being primarily and most severely affected....

Neuroimaging of toxicity is difficult because clinical symptoms and imaging findings are nonspecific. MRI is the most sensitive diagnostic tool to evaluate lesions, orient the treatment and manage disease progression. MR diffusion, perfusion and spectroscopy allow characterizing and understanding biochemical and spectral changes. These abnormalities may be reversible if early treated that underlying the importance for the radiologist to recognize such specific pattern and to guide the clinician.

[1]C. C. Quattrocchi, D. Longo, L. N. Delfino, Y. Errante, C. Aiello, G. Fariello, and B. Bernardi, “MR differential diagnosis of acute deep grey matter pathology in paediatric patients,” Pediatr. Radiol., vol. 43, no. 6, pp. 743–761, Jun. 2013. [2]M. Bekiesinska-Figatowska, H. Mierzewska, and E. Jurkiewicz, “Basal ganglia lesions in children and adults.,” Eur. J. Radiol., vol. 82, no. 5, pp. 837–49, May 2013. [3]A. Poretti, S. I. Blaser, M. H. Lequin, A. Fatemi, A. Meoded, F. J. Northington, E. Boltshauser, and T. A. G....