Absence of the cavum septum pellucidum

multidisciplinary approach and diagnostic challenges in fetal medicine

Abstract

Introduction: The cavum septum pellucidum (CSP) is a cavity filled with cerebrospinal fluid, located between two thin sheets of the septum pellucidum. Its visualization is essential in the screening for anterior midline brain malformations, particularly due to its close relationship with the corpus callosum and the limbic system. The absence or alteration of the CSP is associated with various conditions, such as septo-optic dysplasia (SOD), agenesis of the corpus callosum, holoprosencephaly, and schizencephaly. Its persistence in adults, although often without implications, may be linked to neuropsychiatric disorders. Case Report: A 22-year-old nulligravida patient presented with absence of CSP visualization and mild ventriculomegaly detected on ultrasound at 23 weeks. Complementary examinations included neurosonography and fetal echocardiography, which revealed no other anomalies. At birth, the newborn showed normal conditions and appropriate development up to 10 months of age, with no signs of neurological impairment. Neurological follow-up and magnetic resonance imaging are still pending. Discussion: Although most cases of isolated CSP absence have a favorable outcome, it is important to consider that additional anomalies may be detected after birth, leading to unfavorable outcomes, such as alterations in neuropsychomotor development and hormonal deficiencies. Careful evaluation and postnatal follow-up are essential to identify potential complications and provide appropriate counseling to parents. Conclusion: The prenatal diagnosis of isolated absence of the septum pellucidum may have a more favorable prognosis compared to cases associated with other anomalies. However, postnatal follow-up is crucial, as there may be associations not detected during fetal life, such as septooptic dysplasia and other neurological deficiencies, which makes parental counseling a challenge.