White matter connections of the inferior parietal lobule: A study of surgical anatomy

Abstract

IntroductionInterest in the function of the inferior parietal lobule (IPL) has resulted in increased understanding of its involvement in visuospatial and cognitive functioning, and its role in semantic networks. A basic understanding of the nuanced white‐matter anatomy in this region may be useful in improving outcomes when operating in this region of the brain. We sought to derive the surgical relationship between the IPL and underlying major white‐matter bundles by characterizing macroscopic connectivity.MethodsData of 10 healthy adult controls from the Human Connectome Project were used for tractography analysis. All IPL connections were mapped in both hemispheres, and distances were recorded between cortical landmarks and major tracts. Ten postmortem dissections were then performed using a modified Klingler technique to serve as ground truth.ResultsWe identified three major types of connections of the IPL. (1) Short association fibers connect the supramarginal and angular gyri, and connect both of these gyri to the superior parietal lobule. (2) Fiber bundles from the IPL connect to the frontal lobe by joining the superior longitudinal fasciculus near the termination of the Sylvian fissure. (3) Fiber bundles from the IPL connect to the temporal lobe by joining the middle longitudinal fasciculus just inferior to the margin of the superior temporal sulcus.ConclusionsWe present a summary of the relevant anatomy of the IPL as part of a larger effort to understand the anatomic connections of related networks. This study highlights the principle white‐matter pathways and highlights key underlying connections.

Anatomy and white matter connections of the inferior frontal gyrus

“…To validate tractography results we sought to demonstrate the location of white matter tracts connecting to the IFG with gross anatomical dissections as ground truth (Catani et al ; Burks et al ; Burks et al ; Burks et al ). Postmortem dissections were performed using a modified Klingler technique (Koutsarnakis et al ).…”

The role of the arcuate and middle longitudinal fasciculi in speech perception in noise in adulthood

“…It was first discovered in the macaque monkey using autoradiographic techniques (Seltzer & Pandya, 1984), but several recent studies have confirmed its presence in the human brain (Burks et al, 2017;Maldonado et al, 2013). It was first discovered in the macaque monkey using autoradiographic techniques (Seltzer & Pandya, 1984), but several recent studies have confirmed its presence in the human brain (Burks et al, 2017;Maldonado et al, 2013).…”

“…Moreover, following resection of MdLF, no permanent language deficits were found(De Witt Hamer et al, 2010). Yet, given its connectivity, it is likely that MdLF has a role in cognition even if not as a principle pathway, as suggested by Burks et al(Burks et al, 2017). Because of its connectivity with the IPL, which is part of In a study from our group, we found that this modulation was age dependent(Bilodeau-Mercure et al, 2015), suggestive of a transformation in the role of DAN to the processing of speech in noise throughout adulthood, which could contribute to compensating for age-related decline occurring within the auditory and language networks.…”

“…Using direct electrical stimulation of left MdLF on eight awake patients, De Witt and colleagues were unable to interfere with a picture-naming task. Yet, given its connectivity, it is likely that MdLF has a role in cognition even if not as a principle pathway, as suggested byBurks et al (Burks et al, 2017). Yet, given its connectivity, it is likely that MdLF has a role in cognition even if not as a principle pathway, as suggested byBurks et al (Burks et al, 2017).…”

Neuroanatomical aspects of the temporo–parieto–occipital junction and new surgical strategy to preserve the associated tracts in junctional lesion surgery: fiber separation technique

“…Understanding the topographic locations and trajectories of the associated fibers with the TPOJ is essential for successful surgical access and planning a surgical strategy in patients with tumors and vascular lesions. Many research studies about the white matter of the brain have focused on microstructural niceties (6,23). Conversely, we emphasized the characteristic and nuances of medium and large fiber tracts of the TPOJ and surrounding fascicles as well as their functional and anatomical relationship to expose the surgical effects.…”