Cavum Septum Pellucidum Research Articles

Exploring the septum pellucidum: Short review of anatomical insights and the clinical impact of septum pellucidum and cavum septi pellucidi

BackgroundThe septum pellucidum (SP) is a thin, triangular, and delicate structure in the brain. It consists of two layers of white and gray matter and topographically is located between the lateral ventricles. The SP is part of the limbic system, which involves emotions, behavior, and memory. AimThis concise review provides an overview of the anatomy, development, and clinical significance of the SP, with a specific focus on cavum septi pellucidi (CSP). It also discusses its implications for brain function and its potential link to neurological disorders. ConclusionsAs an essential structure within the limbic system, the SP and its associated variations, like CSP, offer valuable insights into brain development and function, particularly concerning emotions, memory, and psychiatric disorders. Understanding the role of the septum pellucidum and its developmental anomalies may shed light on various neuropsychiatric conditions and help guide future research and clinical practices.

Cavum Septum Pellucidum in Former American Football Players: Findings From the DIAGNOSE CTE Research Project.

Exposure to repetitive head impacts (RHI) is linked to the development of chronic traumatic encephalopathy (CTE), which can only be diagnosed at post-mortem. The presence of a cavum septum pellucidum (CSP) is a common finding in post-mortem studies of confirmed CTE and in neuroimaging studies of individuals exposed to RHI. This study examines CSP in living former American football players, investigating its association with RHI exposure, traumatic encephalopathy syndrome (TES) diagnosis, and provisional levels of certainty for CTE pathology. Data from the DIAGNOSE CTE Research Project were used to compare the presence and ratio of CSP in former American football players (n = 175), consisting of former college (n = 58) and former professional players (n = 117), and asymptomatic unexposed controls without RHI exposure (n = 55). We further evaluated potential associations between CSP measures and cumulative head impact index (CHII) measures (frequency, linear acceleration, and rotational force), a TES diagnosis (yes/no), and a provisional level of certainty for CTE pathology (suggestive, possible, and probable). Former American football players exhibited a higher CSP presence and ratio than unexposed asymptomatic controls. Among player subgroups, professional players showed a greater CSP ratio than former college players and unexposed asymptomatic controls. Among all football players, CHII rotational forces correlated with an increased CSP ratio. No significant associations were found between CSP measures and diagnosis of TES or provisional levels of certainty for CTE pathology. This study confirms previous findings, highlighting a greater prevalence of CSP and a greater CSP ratio in former American football players compared with unexposed asymptomatic controls. In addition, former professional players showed a greater CSP ratio than college players. Moreover, the relationship between estimates of CHII rotational forces and CSP measures suggests that cumulative frequency and strength of rotational forces experienced in football are associated with CSP. However, CSP does not directly correlate with TES diagnosis or provisional levels of certainty for CTE, indicating that it may be a consequence of RHI associated with rotational forces. Further research, especially longitudinal studies, is needed for confirmation and to explore changes over time.

Can cavum septum pellucidum width and length measurements also be reliable indicators of corpus callosum measurements in normal fetuses?

Can cavum septum pellucidum width and length measurements also be reliable indicators of corpus callosum measurements in normal fetuses?

Evaluation and Significance of Nonvisualization of the Cavum Septum Pellucidum on Prenatal Ultrasonography

ABSTRACT Importance The identification of the cavum septum pellucidum (CSP) is an integral part of the routine second trimester fetal anatomy scan. The absence or nonvisualization of the CSP has significant clinical implications and requires further evaluation and counseling for the pregnant patient. Objective The aim of this review is to review the importance of accurate sonographic identification of the CSP and the underlying pathologies that can be associated with nonvisualization of this structure. Evidence Acquisition A literature review was performed with PubMed using key words including CSP, fetal anatomy ultrasound, and fetal anomalies. Results The absence of the CSP is associated with several central nervous system pathologies, all with a wide range of phenotypic outcomes, ranging from normal to very severe or lethal. Relevance Most obstetrician-gynecologists will have a patient in whom a CSP is not identified on fetal ultrasound. Thus, it is imperative to have a general understanding of this relatively common entity. Target Audience Obstetricians and gynecologists, family physicians Learning Objectives After completing this activity, the learner will be able to describe the CSP, the importance of accurate identification on ultrasonography, and the pitfalls to avoid/be aware of; explain the additional workup required in the setting of absent CSP including utility of antenatal ultrasound, fetal magnetic resonance imaging, and genetic counseling; and discuss the various pathologies that have an association with the absence of the CSP and patient counseling regarding the absence of the CSP.

Evaluation and Significance of Nonvisualization of the Cavum Septum Pellucidum on Prenatal Ultrasonography.

The identification of the cavum septum pellucidum (CSP) is an integral part of the routine second trimester fetal anatomy scan. The absence or nonvisualization of the CSP has significant clinical implications and requires further evaluation and counseling for the pregnant patient. The aim of this review is to review the importance of accurate sonographic identification of the CSP and the underlying pathologies that can be associated with nonvisualization of this structure. A literature review was performed with PubMed using key words including CSP, fetal anatomy ultrasound, and fetal anomalies. The absence of the CSP is associated with several central nervous system pathologies, all with a wide range of phenotypic outcomes, ranging from normal to very severe or lethal. Most obstetrician-gynecologists will have a patient in whom a CSP is not identified on fetal ultrasound. Thus, it is imperative to have a general understanding of this relatively common entity.

A rare case of ethmoidal encephalocele with corpus callosal dysgenesis

A 6 mm defect is seen over anterior aspect of face in between both orbits with a 2.6 x 2.5 cm sized cystic collection herniating through the defect possibly arising from ethmoid s/o Ethmoidal encephalocele. CSP (Cavum Septum Pellucidum) is not well visualised with bilateral parallel orientation of lateral ventricles.

Neonatal cerebral ultrasound: anatomical variants and age-related diseases.

Cerebral ultrasound is a non-invasive imaging technique widely used for the assessment of brain anatomy and diseases in neonates and infants. Indeed, it allows a precise characterization of common variants such as cavum septum pellucidum or diseases like intraventricular hemorrhage. The aim of this pictorial review is to provide a comprehensive overview of the main ultrasound features of the most common cerebral anatomical variants and disorders detectable by cerebral ultrasound using an age-related approach which could support non-subspecialized radiologists.

Solid pilocytic astrocytoma in cavum septum pellucidum: a description of two cases and an analysis of misdiagnosis

Solid pilocytic astrocytoma in cavum septum pellucidum: a description of two cases and an analysis of misdiagnosis

Revisiting the Implications of a Wide or Narrow Fetal Cavum Septi Pellucidi.

To investigate short-term neonatal developmental outcomes in fetuses with an isolated wide or narrow cavum septi pellucidi (CSP) using new reference ranges. A cross-sectional study on fetuses at 16 + 0 to 36 + 6 weeks of gestation between December 2020 and January 2022. CSP width reference ranges were constructed from low-risk pregnancies. Wide and narrow CSPs were defined as measurements above the 95th percentile and below the 5th percentile, respectively. For the primary outcome fetuses with normal neurosonograms were included. Neonatal developmental outcomes were assessed using the Survey of Well-being of Young Children (SWYC). A total of 352 fetuses were included in this study, of whom 138 were healthy and had uncomplicated neonatal outcomes. These fetuses constituted the control group and were used to construct the CSP width reference ranges. Of 185 fetuses in the neurosonography group, 9.7% had wide and 7.6% had narrow CSPs, of whom 33.3% and 22.2%, respectively, scored below the SWYC threshold for expected developmental milestones, a rate similar to that reported in the general population. The presence of a prenatally isolated wide or narrow CSP does not appear to increase the risk of neonatal neurodevelopmental delay.

Arachnoid cyst in the pediatric patient: What the radiologist needs to know.

Arachnoid cysts are the most common incidentally discovered intracranial lesions on imaging and the most common cystic intracranial lesions. They may be developmental or secondary. A relative lack of recent literature and any comprehensive radiological review on arachnoid cysts has led to a general lack of awareness among radiologists of symptomatic or complicated arachnoid cysts. This is particularly concerning in pediatric patients. While arachnoid cysts are asymptomatic in most cases, they can cause clinical symptoms in a minority of cases, especially when they occur in unusual sites. These include intraventricular locations where they may cause hydrocephalus, the basal cisterns where they may compress cranial nerves, the cerebellopontine angle where they have to be differentiated from a number of cystic lesions, the cavum septum pellucidum or cavum velum interpositum, the choroid fissure where they can entrap the temporal horn and compress the hippocampus, the posterior fossa where they need to be differentiated from other posterior fossa cystic lesions, and within the spinal canal where there is a concern for cord or nerve root compression. Larger cysts are more prone to complications such as mass effect, hemorrhage, and rupture. Hemorrhage and rupture often present with acute symptoms. Ruptured cysts lose their characteristic imaging appearance and can mimic several ominous pathologies. It therefore becomes vital to accurately diagnose these cases as complications of pre-existing arachnoid cysts for appropriate management. A detailed review of all diagnostic imaging aspects of arachnoid cysts will help fill in the existing information void on this important entity.

AN UNCOMMON PRESENTATION OF SEPTUM PELLUCIDUM ANATOMICAL VARIATIONS: A CASE REPORT OF GENERALIZED TONIC-CLONIC SEIZURE IN A HEALTHY ADULT

ABSTRACT:
 Introduction: The septum pellucidum (SP) is a thin, transparent, dual-membrane structure located between the lateral ventricles of the brain. Incidentally identified through imaging modalities, this variation, while rare, may manifest with symptoms such as neuropsychiatric disorders, headache, dizziness, seizures, nausea, and vomiting. In this report, we present the case of a healthy middle-aged man with CV and CSP, who sought medical attention in the emergency department (ED) due to a generalized tonic-clonic seizure (GTCS).
 Case Report: A 40-year-old male without any known medical history presented to our emergency department with a GTCS. Considering this as the first seizure, blood and imaging tests were conducted, all of which showed no abnormalities. Non-contrast computed tomography revealed sequel cystic encephalomalacic areas in the left occipital and right frontal cerebral hemispheres, consistent with a parapharyngeal epidermoid cyst, and the presence of cavum septum pellucidum et vergae. Emergency consultation from the neurological clinic was sought, and an electroencephalogram showed no seizure activity. He was subsequently discharged with a recommendation for follow-up at the neurology outpatient clinic.
 Conclusion: This case prompts critical considerations in the emergency medicine realm regarding the potential relationship between anatomical variations in the septum pellucidum and emergent seizure activity.
 Keywords: Septum pellucidum, seizure, cavum vargae, emergency

Enlarged cavum septum pellucidum and small thymus as markers for 22q11.2 deletion syndrome.

Enlarged cavum septum pellucidum (CSP) and hypoplastic thymus are proposed extra-cardiac fetal markers for 22q11.2 deletion syndrome. We sought to determine if they were part of the fetal phenotype of our cohort of fetuses with 22q11.2 deletion syndrome. Case-control study of fetuses evaluated from 2016 to 2022. The study group included fetuses with laboratory confirmation of 22q11.2 deletion syndrome. The control group included pregnancies with conotruncal cardiac anomalies with normal microarray as well as structurally normal fetuses with normal microarray. The CSP and thymus were routinely measured during anatomical ultrasound in all patients at their initial visit at 27.1±4.7weeks. The CSP and thymus measurements were classified as abnormal if they were >95% or <5% for gestational age, respectively. The groups were compared using analysis of variance or Kruskal-Wallis for continuous variables and Fisher's exact test for categorical variables. Logistic regression was performed, and a Receiver Operating Characteristic (ROC) curve was constructed. We identified 47 fetuses with 22q11.2 deletion syndrome and compared them to 47 fetuses with conotruncal anomalies and normal microarray and 47 structurally normal fetuses with normal microarray. 51% (24/47) of fetuses with 22q11.2 deletion syndrome had an enlarged CSP compared to 6% (3/47) of fetuses with a conotruncal anomaly and normal microarray and none of the structurally normal fetuses (p<0.001). Of the fetuses with 22q11.2 deletion syndrome, 83% (39/47) had a hypoplastic or absent thymus compared to 9% (4/47) of the fetuses with a conotruncal anomaly and normal microarray and none of the structurally normal fetuses (p<0.001). 87% (41/47) of the fetuses with 22q11.2 deletion syndrome had conotruncal cardiac anomalies. Logistic regression revealed that both enlarged CSP and hypoplastic/absent thymus were associated with 22q11.2 deletion syndrome. The area under the ROC curve for the two markers was 0.94. An enlarged CSP and hypoplastic/absent thymus appear to be part of the fetal phenotype of 22q11.2 deletion syndrome. These markers are associated with conotruncal anomalies in the setting of 22q11.2 deletion syndrome but not in normal controls or fetuses with conotruncal defects and normal microarrays.

2028 Incidence of cavum septum pellucidum on CT brain in patients referred from memory clinic, an observational pilot study

Abstract Background Septum pellucidum is a double-membrane separating the frontal horns of the lateral ventricles of the brain. [1] Cavum septum pellucidum (CSP) refers to a potential space between these membranes. CSP is associated with some psychiatric disorders. [2] Radiological CSP has been evaluated as a possible in-vivo biomarker for chronic traumatic encephalopathy (CTE), a neurodegenerative condition affecting, particularly, retired athletes who experienced repetitive, low impact head trauma. [3] Method Our study evaluated the incidence of radiological CSP among a cohort undergoing investigation for cognitive impairment in memory clinic. A list of patient Community Health Index (CHI) numbers corresponding to patients referred to CT brain from a community memory clinic in North West Glasgow between October 2019 and March 2020 was generated. Approval for use of imaging for research purposes was granted by local imaging department. Images were viewed by first author following a session from second author on basic relevant anatomy. Positive cases were defined as those with a visible CSP. Results There were twenty-eight (n=28) cases in total. CSP was observed in one (n=1) case. Radiological CSP has been suggested as a potential biomarker for CTE. While this study does not involve review of the clinical or personal history of the subjects, it does include a cohort with clinically-relevant symptoms. We included CT only, while current evidence makes observations on MRI [3]. Locally CT is more available and the initial assessment of such patients uses CT in the first instance. Conclusion Further evidence is required to establish CSP as a reliable in vivo biomarker of CTE. [1] Das et al, in StatPearls [Internet], 2022 [2] Wang et al, J Neuropsychiatry Clin Neurosci. 2020; 32(2):175-184 [3] Alosco et al Neurotherapeutics. 2021; 18(2):772-791

Perforation of cavum septi pellucidi in open spina bifida and need for hydrocephalus treatment by 1 year of age.

In-utero repair of an open neural tube defect (ONTD) reduces the risk of developing severe hydrocephalus postnatally. Perforation of the cavum septi pellucidi (CSP) may reflect increased intraventricular pressure in the fetal brain. We sought to evaluate the association of perforated CSP visualized on fetal imaging before and/or after in-utero ONTD repair with the eventual need for hydrocephalus treatment by 1 year of age. This was a retrospective cohort study of consecutive patients who underwent laparotomy-assisted fetoscopic ONTD repair between 2014 and 2021 at a single center. Eligibility criteria for surgery were based on those of the Management of Myelomeningocele Study (MOMS), although a maternal prepregnancy body mass index of up to 40 kg/m2 was allowed. Fetal brain imaging was performed with ultrasound and magnetic resonance imaging (MRI) at referral and 6 weeks postoperatively. Stored ultrasound and MRI scans were reviewed retrospectively to assess CSP integrity. Medical records were reviewed to determine whether hydrocephalus treatment was needed within 1 year of age. Parametric and non-parametric tests were used as appropriate to compare outcomes between cases with perforated CSP and those with intact CSP as determined on ultrasound at referral. Logistic regression analysis was performed to assess the predictive performance of various imaging markers for the need for hydrocephalus treatment. A total of 110 patients were included. Perforated CSP was identified in 20.6% and 22.6% of cases on preoperative ultrasound and MRI, respectively, and in 26.6% and 24.2% on postoperative ultrasound and MRI, respectively. Ventricular size increased between referral and after surgery (median, 11.00 (range, 5.89-21.45) mm vs 16.00 (range, 7.00-43.5) mm; P < 0.01), as did the proportion of cases with severe ventriculomegaly (ventricular width ≥ 15 mm) (12.7% vs 57.8%; P < 0.01). Complete CSP evaluation was achieved on preoperative ultrasound in 107 cases, of which 22 had a perforated CSP and 85 had an intact CSP. The perforated-CSP group presented with larger ventricles (mean, 14.32 ± 3.45 mm vs 10.37 ± 2.37 mm; P < 0.01) and a higher rate of severe ventriculomegaly (40.9% vs 5.9%; P < 0.01) compared to those with an intact CSP. The same trends were observed at 6 weeks postoperatively for mean ventricular size (median, 21.0 (range, 13.0-43.5) mm vs 14.3 (range,7.0-29.0) mm; P < 0.01) and severe ventriculomegaly (95.0% vs 46.8%; P < 0.01). Cases with a perforated CSP at referral had a lower rate of hindbrain herniation (HBH) reversal postoperatively (65.0% vs 88.6%; P = 0.01) and were more likely to require treatment for hydrocephalus (89.5% vs 22.7%; P < 0.01). The strongest predictor of the need for hydrocephalus treatment within 1 year of age was lack of HBH reversal on MRI (odds ratio (OR), 36.20 (95% CI, 5.96-219.12); P < 0.01) followed by perforated CSP on ultrasound at referral (OR, 23.40 (95% CI, 5.42-100.98); P < 0.01) and by perforated CSP at 6-week postoperative ultrasound (OR, 19.48 (95% CI, 5.68-66.68); P < 0.01). The detection of a perforated CSP in fetuses with ONTD can reliably identify those cases at highest risk for needing hydrocephalus treatment by 1 year of age. Evaluation of this brain structure can improve counseling of families considering fetal surgery for ONTD, in order to set appropriate expectations about postnatal outcome. © 2023 International Society of Ultrasound in Obstetrics and Gynecology.

We are Reporting an Infant with Genito Patellar Syndrome and KAT6B Gene Mutation Presenting with Facial Dysmorphism, Bilateral Genu Recurvatum, Hip Dislocations, Absence of Cavum Septum Pellucidum, Anal Abnormality and Hydronephrosis

A preterm female infant was admitted to neonatal intensive care unit with respiratory distress, facial dysmorphism, bilateral genu recurvatum, hip dislocations, absence of cavum septum pellucidum, anal abnormality, and hydronephrosis. Exome study confirmed the diagnosis of Genito patellar syndrome.

A genetic variant in the MAST1 gene is associated with mega-corpus-callosum syndrome with hypoplastic cerebellar vermis, in a fetus.

Mega-corpus-callosum syndrome with cerebellar hypoplasia and cortical malformations is a rare neurological disorder that is associated with typical clinical and imaging features. The syndrome is caused by pathogenic variants in the MAST1 gene, which encodes a microtubule-associated protein that is predominantly expressed in postmitotic neurons in the developing nervous system. Fetal DNA from umbilical cord blood samples and genomic DNA from peripheral blood lymphocytes were subjected to whole-exome sequencing. The potential causative variants were verified by Sanger sequencing. A 26-year-old primigravid woman was referred to our prenatal center at 25 weeks of gestation due to abnormal ultrasound findings in the brain of the fetus. The brain abnormalities included wide cavum septum pellucidum, shallow and incomplete bilateral lateral fissure cistern, bilateral dilated lateral ventricles, hyperplastic corpus callosum, lissencephaly, and cortical dysplasia. No obvious abnormalities were observed in the brainstem or cerebellum hemispheres, but the cerebellum vermis was small. Whole-exome sequencing identified a de novo, heterozygous missense variant, c.695T>C(p.Leu232Pro), in the MAST1 gene and a genetic diagnosis of mega-corpus-callosum syndrome was considered. This study is the first prenatal case of MAST1-related disorder reported in the Chinese population and has expanded the mutation spectrum of the MAST1 gene.

Clinical phenotype and genetic characteristics of SZT2 related diseases: A case report and literature review

PurposeSeizure threshold 2 protein homolog gene (SZT2, MIM: 615463) related diseases are extremely rare autosomal recessive disorders with a wide spectrum of clinical phenotypes ranging from mild intellectual impairment to severe developmental epileptic encephalopathy (DEE). Most SZT2 related diseases are accompanied by craniofacial malformation and corpus callosum malformation. This study attempts to analyze and summarize the clinical phenotype and genetic characteristics of SZT2 related diseases, providing a basis for early diagnosis, treatment, and prognosis. MethodWe analyzed the clinical characteristics of a Chinese child with pathogenic variants of SZT2. We also performed whole-exome sequencing (WES) on the patient. In addition, we conducted a literature review of previously reported patients with pathogenic mutations in the SZT2 gene. ResultThe proband was a boy aged 1 year and 9 months with severe global developmental delay, transient drug-controlled focal epilepsy, cluster epilepsy, autism spectrum disorder, craniofacial deformity, hypotonia, focal EEG discharge, corpus callosum malformation, and persistent cavum septum pellucidum. WES revealed that the patient carried the SZT2 gene c.7584dupA and c.6302A>C complex heterozygous variants; the former being Likely Pathogenic (LP) and the latter Uncertain Significance (VUS) according to ACMG classification guidelines. According to our literature review, 43 cases of SZT2 related diseases have been reported so far; these include 15 cases with homozygous variations and 28 cases with complex heterozygous variations. A total of 57 types of variation were found, including 47 genetic variants, 2 de novo variants, and 8 unknown genetic modes. In addition, 2 high-frequency variants were found (c.5949_5951delTGT and c.6553C>T). The main clinical manifestations of the 40 patients were global developmental delay (GDD) of varying degrees (38/40, 95.00%), seizures (36/40, 90.00%), cranial deformity (27/40, 67.50%), facial deformity (22/40, 55.00%), hypotonia (22/40, 55.00%), abnormal interseizure EEG discharge (26/40, 65.00%), slow background activity (20/40, 50.00%), corpus callosum deformity (18/40, 45.00%). There was also one case of sudden unexpected death in epilepsy (SUDEP) and 3 cases of death from infection. In addition, three fetuses with the same variant had hydrocephalus and encephalocele. ConclusionThe compound heterozygous mutation of c.7584dupA and c.6302A>C in the SZT2 gene is the genetic etiology of this patient, expanding the mutation spectrum of SZT2 related diseases. Early genetic testing is the best choice for clear diagnosis, treatment, and prognosis.

A Case Report of a Complex Constitutional Karyotype Resulting in Three Derivative Chromosomes Characterized by Chromosomal Analysis, Florescent in situ Hybridization (FISH), and Chromosome Microarray

Abstract Introduction/Objective Structurally complex karyotypes are rarely identified in the postnatal constitutional setting. Abnormalities involving multiple chromosomes are likely to have a deleterious effect or be incompatible with life. Herein, we describe a case of a structurally complex karyotype in a newborn male. Methods/Case Report A newborn male presented at birth with microcephaly, severe ventriculomegaly, cerebellar hypoplasia and absent cavum septum pellucidum. Seizures, optic nerve dysplasia, and feeding difficulties were later noted. Microarray testing revealed eight small deletions of unclear significance on chromosome 7, with three located on the p arm and five clustered on the q arm. The deletions were gene poor, and none contained known haploinsufficient genes. Based on this finding a structural abnormality involving chromosome 7 was suspected. Karyotype revealed a structurally abnormal chromosome 7 and a complex rearrangement between chromosomes 11 and 18. Chromosome paint and metaphase FISH studies were performed to further characterize the abnormalities. Based on results from these cytogenetic tests, the observed abnormalities were characterized as an insertion on chromosome 7, and a translocation between chromosome 11 and 18 with an inversion on the derivative 18 [46,XY,ins(7)(p21q22q11.2),der(11)t(11;18)(q14.2;p11.2),der(18)(11qter→11q21::18q11.2→18p11.2::11q14.2→11q21:: 18q11.2→18qter)]. Rapid whole genome sequencing was done at an outside institution which was negative. Results (if a Case Study enter NA) NA Conclusion The exact cause of this individual’s phenotypic findings is unknown. Although the genomic imbalance detected by CMA is small, the complex structural abnormalities likely contribute to the clinical findings. Further supporting a deleterious effect of the karyotype findings is the negative whole genome sequencing results in this individual. Some apparently balance rearrangements have been shown to disrupt genes or important regulator elements. It is possible that a gene was disrupted at the breakpoint of one or more of the detected abnormalities or the rearrangement resulted in abnormal gene regulation. Additional submicroscopic abnormalities may also be present that were not detectable by the methodologies used.

Anomalies of the Corpus Callosum in Prenatal Ultrasound: A Narrative Review for Diagnosis and Further Counseling.

The corpus callosum is the major interhemispheric tract that plays an important role in neurological function. Understanding the etiology and embryology development helps the ultrasound diagnosis for disorders of the corpus callosum and further counseling. The nonvisualization of cavum septum pellucidum or dysmorphic cavum septum pellucidum in axial view are indirect signs for beginners to diagnose complete agenesis of corpus callosum (cACC) and partial agenesis of the corpus callosum (pACC). Further coronal view, sagittal view, and fetal magnetic resonance imaging are also important for evaluation. Genetic testing plays an essential tool in anomalies of corpus callosum by revealing the underlying genetic pathophysiology, such as chromosomal anomalies and numerous monogenetic disorders in 30%-45% of ACC. Diagnosis and prediction of prognosis for hypoplasia or hyperplasia of the corpus callosum are more difficult compared to cACC and pACC because of the limited reports in the literature. However, the complex types often had poorer prognostic outcomes compared to the isolated types. Hence, it is important to evaluate and follow fetal conditions thoroughly to rule out intracranial or extracranial anomalies in other systems.

57 Traumatic Brain Injury and Concussion in Patients with Frontotemporal Dementia Spectrum Diagnoses

Objective:Traumatic brain injury (TBI) and concussion are associated with increased dementia risk. Accurate TBI/concussion exposure estimates are relatively unknown for less common neurodegenerative conditions like frontotemporal dementia (FTD). We evaluated lifetime TBI and concussion frequency in patients diagnosed with a range of FTD spectrum conditions and related prior head trauma to cavum septum pellucidum (CSP) characteristics observable on MRI.Participants and Methods:We administered the Ohio State University TBI Identification and Boston University Head Impact Exposure Assessment to 108 patients (age 69.5 ± 8.0, 35% female, 93% white or unknown race) diagnosed at the UCSF Memory and Aging Center with one of the following FTD or related conditions: behavioral variant frontotemporal dementia (N=39), semantic variant primary progressive aphasia (N=16), nonfluent variant PPA (N=23), corticobasal syndrome (N=14), or progressive supranuclear palsy (N=16). Data were also obtained from 217 controls (“HC”; age 76.8 ± 8.0, 53% female, 91% white or unknown race). CSP characteristics were defined based on width or “grade” (0-1 vs. 2+) and length of anterior-posterior separation (millimeters). We first describe frequency of any and multiple (2+) prior TBI based on different but commonly used definitions: TBI with loss of consciousness (LOC), TBI with LOC or posttraumatic amnesia (LOC/PTA), TBI with LOC/PTA or other symptoms like dizziness, nausea, “seeing stars,” etc. (“concussion”). TBI/concussion frequency was then compared between FTD and HC using chi-square. Associations between TBI/concussion and CSP characteristics were analyzed with chi-square (CSP grade) and Mann-Whitney U tests (CSP length). We explored sex differences due to typically higher rates of TBI among males.Results:History of any TBI with LOC (FTD=20.0%, HC=19.2%), TBI with LOC/PTA (FTD:32.2%, HC=31.5%), and concussion (FTD: 50.0%, HC=44.3%) was common but not different between study groups (p’s&gt;.4). In both FTD and HC, prior TBI/concussion was nominally more frequent in males but not significantly greater than females. Frequency of repeat TBI/concussion (2+) also did not differ significantly between FTD and HC (repeat TBI with LOC: 6.7% vs. 3.3%, TBI with LOC/PTA: 12.2% vs. 10.3%, concussion: 30.2% vs. 28.7%; p’s&gt;.2). Prior TBI/concussion was not significantly related to CSP grade or length in the total sample or within the FTD or HC groups.Conclusions:TBI/concussion rates depend heavily on the symptom definition used for classifying prior injury. Lifetime symptomatic TBI/concussion is common but has an unclear impact on risk for FTD-related diagnoses. Larger samples are needed to appropriately evaluate sex differences, to evaluate whether TBI/concussion rates differ between specific FTD phenotypes, and to understand the rates and effects of more extensive repetitive head trauma (symptomatic and asymptomatic) in patients with FTD.