Massa intermedia of the thalamus: an anatomical study using magnetic resonance imaging

Exploring the impact of the interthalamic adhesion on human cognition: insights from healthy subjects and thalamic stroke patients

The interthalamic adhesion (IA) is a structure that connects the median borders of both thalami. Its anatomical variants and functions remain poorly studied. The main objective of this study was to explore the role of the IA on cognition. 42 healthy subjects and 40 patients with chronic isolated thalamic strokes underwent a neuroimaging and a neuropsychological assessment. The presence, absence, or lesion of the IA and its anatomical variants were evaluated. 76% of participants had an IA, with a higher prevalence among women (92%) than men (61%). The presence or absence of an IA did not affect the neuropsychological performance of healthy subjects nor did the type of IA variant. Across all the tests and when compared to healthy subjects using a Bayesian rmANOVA, patients exhibiting more cognitive impairments were those without an IA (n = 10, BF10 = 10,648), while those with an IA were more preserved (n = 18, BF10 = 157). More specifically, patients without an IA performed more poorly in verbal memory or the Stroop task versus healthy subjects. This was not explained by age, laterality of the infarct, volume or localization of the lesion. Patients with a lesioned IA (n = 12) presented a similar trend to patients without an IA, which could however be explained by a greater volume of lesions. The IA does not appear to play a major role in cognition in healthy subjects, but could play a compensatory role in patients with thalamic lesions.

Massa intermedia in adults: incidence, dimension, location and clinical importance

PURPOSE

This retrospective magnetic resonance imaging investigation aimed to obtain information related to the anatomy of the massa intermedia (MI) in an adult population.

METHODS

The work conducted on MRI views of 1058 (539 males and 519 females) healthy adult samples aged with 48.93 ± 17.63 years. Initially, the presence or absence of MI was noted, and then if present, its numbers and location in the third ventricle were recorded. Its horizontal (HDMI) and vertical (VDMI) diameters were measured on MRI views, while the cross-sectional area (CSAMI) was calculated using its diameters.

RESULTS

MI was missing in 2.6% (27 cases) of 1058 adult samples. Six subjects (0.6%) had a double MI. HDMI, VDMI and CSAMI were measured as 4.83 ± 1.01 mm, 4.86 ± 0.98 mm, and 19.11 ± 7.23 mm2, respectively. MI size did not show a significant alteration from 19 up to 49 years, but then its size distinctly decreased between 50 and 60 years. After age 60, MI dimension did not display an important change. MI was settled in the antero-superior quadrant in 929 cases (90.63% of 1025 subjects), in the postero-superior quadrant in 22 cases (2.15%), in the antero-inferior quadrant in 32 cases (3.12%), in the postero-inferior quadrant in 8 cases (0.78%), and in the central part in 34 cases (3.32%).

CONCLUSIONS

The size, position and incidence of MI were not affected by sex, and its position and incidence were not affected by adult age periods. In adults, MI size demonstrated a significant decrease in the middle age.

Anatomic Features of the Interthalamic Adhesion in the Pediatric Population

OBJECTIVE

The main goal of this retrospective study was to examine the morphology of the interthalamic adhesion (ITA) in normal children aged between 1 and 18 years.

METHODS

The study universe consisted of magnetic resonance images of 180 healthy pediatric subjects (age, 9.50 ± 5.20 years, sex, 90 girls and 90 boys). The cross-sectional area (CSA), vertical diameter (VD), and horizontal diameter (HD) of the ITA were measured and in addition, its location was noted.

RESULTS

HD, VD, and CSA of the ITA were measured as 8.47 ± 1.64 mm, 7.59 ± 1.57 mm, and 52.06 ± 18.51 mm2, respectively. HD did not change from infancy until postpubescence, but then significantly decreased (P < 0.001). VD increased up to early childhood but then did not alter until the end of prepubescence. After that period, it decreased in postpubescence (P < 0.001). CSA tended to decrease in an irregular pattern according to pediatric age periods (P < 0.001). The ITA was located at the anterosuperior quadrant in 138 individuals (76.70%), at the anteroinferior quadrant in 7 individuals (3.90%), and the center of the lateral wall of the third ventricle in 35 individuals (19.40%). Linear functions were calculated as y = 9.490-0.107 × age (years) for HD, y = 8.453-0.091 × age (years) for VD, and y = 63.559-1.211 × age (years) for CSA.

CONCLUSIONS

ITA size irregularly decreases with advancing age from 1 to 18 years. Our calculated linear functions, showing the growth dynamics of the ITA by pediatric ages, may be helpful in estimating its dimension.

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

Background

This study aimed to provide an up-to-date account of the frequency of "the absence of interthalamic adhesion (AITA) as a risk factor or association" in healthy subjects and neuropsychiatric patients. Owing to the increased interest in the contribution of ITA to neurological function in previous literature, a meta-analysis of its frequency and sex dependency is required.

Aim

This study aimed to study whether the AITA is associated with neuropsychiatric disorders.

Settings and Design

This study is a meta-analysis and systemic review.

Methods and Material

Literature searches were conducted in PubMed, Web of Science, and Google Scholar using the keywords "interthalamic adhesion," "massa intermedia," "adhesio interthalamica," and "adhesion" along with the Boolean operators (OR, AND, and NOT). Three reviewers independently assessed the abstracts and full texts for validation based on the inclusion criteria. The meta-analysis was performed using Microsoft Excel 2019 for descriptive studies and RevMan 5.2 for comparative studies.

Results

The incidence of absent ITA was 15.3% in healthy subjects and 28.76% in neuropsychiatric subjects. The relative probability of AITA was 2.30 [95% confidence interval (CI), 1.96-2.70] in neuropsychiatric illness. Healthy men were 1.91 times more likely, and men with neuropsychiatric disorders were 1.82 times more likely to have absent ITA than women.

Conclusions and Relevance

In this study, a consistent association of AITA with psychiatric disorders was observed, rendering the condition to be treated as an associated risk factor affecting the function of the habenula nuclear complex via the stria medullaris thalami. A cohort or longitudinal study is needed to compare the incidence of psychiatric disorders in individuals with or without ITA and to calculate the attributed risk.

Angiographic classification of the inferior sagittal sinus based on the venous drainage patterns

PURPOSE

The inferior sagittal sinus (ISS) and its tributaries have received little attention because of its inconspicuous appearance, and its anatomical variations are also unknown. This study aimed to evaluate the morphological variations of the ISS.

MATERIALS AND METHODS

We retrospectively reviewed 518 patients in whom cerebral angiography was clinically indicated. The detailed angioarchitecture of the cerebral venous system, including the ISS and their tributaries, and the morphological variations of the ISS were evaluated. Abnormalities of the rostral third superior sagittal sinus (SSS) were also evaluated.

RESULTS

The ISS was visualized in 270 (52.1%) patients. We proposed an angiographic ISS classification according to the venous drainage patterns: Type 0, not visualized; Type 1, small ISS with faint tributaries; Type 2, moderate ISS with developed tributaries; and Type 3: large ISS with well-developed tributaries, which are responsible for the venous drainage of the anterior frontal lobe. The frequency of each ISS type was as follows: Type 0, 248 (47.9%); Type 1, 211 (40.7%); Type 2, 44 (8.5%); and Type 3, 15 (2.9%). The mean ISS size was significantly larger with an increase in the type of ISS (p < 0.0001). The rostral third SSS hypoplasia was observed in all cases of Type 3. The hypoplasia of the rostral third SSS and development of the ISS were strongly correlated and complementary to each other.

CONCLUSION

This study provided the angiographic ISS classification, and our proposed angiographic ISS classification could be helpful in better understanding of the ISS anatomy and its venous drainage pattern.