Thalamic Massa Intermedia in Children with and without Midline Brain Malformations

Abstract

BACKGROUND AND PURPOSE:The massa intermedia is a normal midline transventricular thalamic connection. Massa intermedia aberrations are common in schizophrenia, Chiari II malformation, X-linked hydrocephalus, Cornelia de Lange syndrome, and diencephalic-mesencephalic junction dysplasia, among others. We have noticed that massa intermedia abnormalities often accompany other midline malformations. The massa intermedia has never been formally evaluated in a group of exclusively pediatric patients, to our knowledge. We sought to compare and contrast the prevalence, size, and location of the massa intermedia in pediatric patients with and without congenital midline brain abnormalities.MATERIALS AND METHODS: Successive 3T brain MR imaging examinations from pediatric patients with and without midline malformations were procured from the imaging data base at a pediatric hospital. Massa intermedia presence, size, morphology, and position were determined using 3D-TIWI with 1-mm isotropic resolution. The brain commissures, septum pellucidum, hypothalamus, hippocampus, vermis, and brain stem were evaluated to determine whether alterations were related to or predictive of massa intermedia abnormalities. RESULTS:The massa intermedia was more frequently absent, dysmorphic, and/or displaced in patients with additional midline abnormalities than in those without. The massa intermedia was absent in 40% of patients with midline malformations versus 12% of patients with normal findings (P , .001). Massa intermedia absence, surface area, and morphology were predictable by various attributes and alterations of the commissures, hippocampus, hypothalamus, vermis, brain stem, and third ventricle. CONCLUSIONS:Most pediatric patients have a thalamic massa intermedia centered in the anterior/superior third ventricle. Massa intermedia abnormalities are commonly associated with other midline malformations. Normal-variant massa intermedia absence is a diagnosis of exclusion.

Agenesis of the Corpus Callosum with Facial Dysmorphism and Intellectual Disability in Sibs Associated with Compound Heterozygous KDM5B Variants

“…A brain MRI of the index case showed complete ACC with Probst bundles and hypoplastic anterior commissure suggesting a larger process of commissure development [ 12 ]. The absence of interthalamic adhesion is an aspecific finding, also found in the general population but overrepresented in midline malformations [ 13 , 14 ]. In our cases, it was more likely an incidental finding since it was not seen on the fetal MRI [ 14 ].…”

“…The absence of interthalamic adhesion is an aspecific finding, also found in the general population but overrepresented in midline malformations [ 13 , 14 ]. In our cases, it was more likely an incidental finding since it was not seen on the fetal MRI [ 14 ]. Neurohistopathological did not find any callosal structures, but Probst bundles, that are thick bundles of callosal axons that failed to cross the midline, were not identifiable.…”

Absence of the interthalamic adhesion (ITA) as a neuroanatomical association or risk factor for neuropsychiatric disorders: A systemic review and meta-analysis

“…Finally, 45 citations or studies were included in this meta-analysis [ Figure 1 ]. [ 5 , 9 , 10 , 12 , 13 , 14 , 16 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 , 47 , 48 , 49 , 50 , 51 , 52 , 53 , 54 ] These studies were classified according to study design. Among the 45, 25 were descriptive studies calculating the incidence of ITA, and the other 20 were comparative studies, either case–control or cohort, in which the OR of AITA was calculated.…”