Hello and welcome to Healthcaremagic.com. This is going to be a rather long answer. Please bear with me as I talk through this. I will also quote a study on this disease process from a journal, Pediatrics. The article is entitled Acquired Microcephaly: Causes, Patterns, Motor and IQ Effects, and Associated Growth Changes. Acquired (also known as progressive) microcephaly is a condition in which a child s head circumference is within the normal range at birth and for an undefined period thereafter but then does not increase as fast as normal and, as a result, crosses percentiles to below the second percentile. In our experience, this is a relatively common form of microcephaly. Although there is extensive literature on microcephaly, there is little on this subtype. Recognized causes include acquired brain damage as well as Rett syndrome, Angelman syndrome, Down syndrome, and other rarer syndromes, but these account for a minority of cases. There are also differing head growth patterns for children with microcephaly, which have not been studied. As a result, there is no currently available information to give to most families whose children show acquired microcephaly. This is the first attempt to study acquired, or progressive, microcephaly systematically. Causes were divided initially into multiple subgroups, but a final review allowed these to be simplified into 5 groups, defined as follows: (1) idiopathic, that is, no cause could be recognized from the history, examination, or investigations, and there were no other abnormal findings; (2) familial, that is, a parent and/or sibling had a head circumference at or below the second percentile; (3) syndromic, that is, with associated anomalies; (4) symptomatic, that is, following a pathogenic event; or (5) mixed, that is, ≥2 of the aforementioned. My understanding of this disease process as it relates to your daughter is that she falls under the category of symptomatic. Following her cardiac event and the subsequent CPR, she developed a brain injury. This is evidenced by the MRI showing lesions in three lobes. The brain injury most likely resulted in the epileptic state. Her petite mal seizures are a result of the injury. Her acquired microcephaly is most likely also caused by the brain injury. The microcephaly your daughter has does not appear to be regressive in nature. There is a correlation between acquired microcephaly and a failure to thrive. The study shows there is a correlation between head circumference size and height and weight. Lower head circumferences generally lead to a lower height and weight. Her failure to thrive is the cause for the lack of appetite- not the microcephaly. There is little information on acquired microcephaly. I hope that I have answered your questions adequately. If you have additional questions or need clarification, please do not hesitate to contact me. Be well, Dr. Kimberly