Maps of the adult human hypothalamus

Abstract

The human hypothalamus is a small deeply located region placed at the crossroad of neurovegetative, neuroendocrine, limbic, and optic systems. Although deep brain stimulation techniques have proven that it could be feasible to modulate these systems, targeting the hypothalamus and in particular specific nuclei and white bundles, is still challenging. Our goal was to make a synthesis of relevant topographical data of the human hypothalamus, under the form of magnetic resonance imaging maps useful for mastering its elaborated structure as well as its neighborhood. As from 1.5 Tesla, Inversion-Recovery sequence allows locating the hypothalamus and most of its components. Spotting hypothalamic compartments is possible according to specific landmarks: the anterior commissure, the mammillary bodies, the preoptic recess, the infundibular recess, the crest between the preoptic and the infundibular recesses, the optical tract, the fornix, and the mammillo-thalamic bundle. The identification of hypothalamus and most of its components could be useful to allow the quantification of local pathological processes and to target specific circuitry to alleviate severe symptoms, using physical or biological agents.

Interhypothalamic Adhesion: A Series of 13 Cases

“…4 Various nuclei and white matter tracts are the foundation of this functionally diverse and critical organ. Although current imaging techniques are incapable of defining the precise boundaries of the hypothalamic zones and nuclei, Lemaire et al 3 have devised a scheme for segmentation based on universally visible anatomic landmarks.…”

“…IHA locations involved portions of the expected area of the dorsomedial (n ϭ 10), ventromedial (n ϭ 7), arcuate (n ϭ 6), paraventricular (n ϭ 5), and preoptic (n ϭ 3) nuclei; IHA locations were categorized on the basis of pre-existing literature. 3 In all cases, the IHA was isointense to gray matter on all sequences and connected the medial walls of the hypothalami horizontally. Additional brain abnormalities were detected in 12 of 13 patients; midline anomalies were present in 12 of 13 patients.…”

Asymptomatic Interhypothalamic Adhesions in Children

“…Other structural abnormalities were also recorded, including lack of midline cleavage, pituitary anomalies, and cortical malformations. The band of tissue was measured on MR imaging and, as performed in a previously published smaller case series, the possible nuclei involved in the hypothalamic connection were inferred from the segmentation scheme devised by Lemaire et al 10 on the basis of anatomic landmarks. 5 Hypothalamic dysfunction was surmised from history and clinical symptoms.…”

The hypothalamus at the crossroads of psychopathology and neurosurgery

“…18,19,50,97 Strategically placed at the crossroads of multiple functional systems, the hypothalamus is composed of a complex array of nuclei and thin fibers that run chiefly in the medial forebrain bundle, in the fornix, and in the ansa peduncularis. 39,50,51,69 In all vertebrate species, the hypothalamus is a paramedian division of the basal diencephalon that lies below the thalamus, where it makes up the floor and lateral walls of the third ventricle. 49 The complex anatomy of the hypothalamus is best represented by a combination of coronal, axial, and parasagittal sections alternatively stained for nerve fibers and cell bodies.…”

“…It contains several nuclei that sustain intricate connections with each other as well as with distant parts of the brain and the endocrine system through the hypophysis. 50,51 Creation of lesions and stimulation of discrete regions within the hypothalamus of experimental animals have proven their decisive contribution to the neural organization of fundamental approach (e.g., alimentary and sexual) and avoidance (e.g., fear) behaviors. 52,57,95,111,114 Targeting specific regions of the human hypothalamus has constituted a major technical challenge due to their location and myriad of passing fibers.…”