Search results for " megalencephaly"
showing 3 items of 3 documents
A clinical review on megalencephaly: A large brain as a possible sign of cerebral impairment
2017
Megalencephaly and macrocephaly present with a head circumference measurement 2 standard deviations above the age-related mean. However, even if pathologic events resulting in both megalencephaly and macrocephaly may coexist, a distinction between these two entities is appropriate, as they represent clinical expression of different disorders with a different approach in clinical work-up, overall prognosis, and treatment. Megalencephaly defines an increased growth of cerebral structures related to dysfunctional anomalies during the various steps of brain development in the neuronal proliferation and/or migration phases or as a consequence of postnatal abnormal events. The disorders associate…
MACROCEPHALY FROM A NORMAL VARIANT TO A THREATENING CONDITION. A SINGLE CENTER RETROSPECTIVE STUDY ON 189 SUBJECTS
2020
Introduction: Macrocephaly, defined as a head circumference more than two standard deviations from the normal distribution, is among the most frequently requested neuropediatric consultations. Materials: we conducted a retrospective study on 189 subjects with macrocephaly, from birth to 18 years old, enrolled from October 2001 to December 2019, for diagnostic definition and/or neurodevelopmental assessment. Brain sonography has been performed in all infants and CT or MR in selected patients. Results: macrocephaly was prevalent in males (62.4%), a head circumference >3SD (8.5%) has been associated with a neurodevelopmental impairment. A genetic and/or concomitant malformation were present…
Sustained activation of mTOR pathway in embryonic neural stem cells leads to development of tuberous sclerosis complex-associated lesions
2011
SummaryTuberous Sclerosis Complex (TSC) is a multisystem genetic disorder characterized by hamartomatous neurological lesions that exhibit abnormal cell proliferation and differentiation. Hyperactivation of mTOR pathway by mutations in either the Tsc1 or Tsc2 gene underlies TSC pathogenesis, but involvement of specific neural cell populations in the formation of TSC-associated neurological lesions remains unclear. We deleted Tsc1 in Emx1-expressing embryonic telencephalic neural stem cells (NSCs) and found that mutant mice faithfully recapitulated TSC neuropathological lesions, such as cortical lamination defects and subependymal nodules (SENs). These alterations were caused by enhanced gen…