====== Temporal cortex ======

see also [[ventral temporal cortex]].

In neurosurgery there are several situations that require transgression of the [[temporal]] cortex. For example, a subset of patients with [[temporal lobe epilepsy]] require surgical [[resection]] (most typically, en-bloc [[anterior temporal lobectomy]]). This [[procedure]] is the [[gold standard]] to alleviate [[seizure]]s but is associated with chronic [[cognitive deficit]]s. In recent years there have been multiple attempts to find the optimum balance between minimising the size of resection in order to preserve [[cognitive function]], while still ensuring seizure freedom. Some attempts involve reducing the distance that the resection stretches back from the [[temporal pole]], whilst others try to preserve one or more of the temporal gyri. More recent advanced surgical techniques ([[selective amygdalohippocampectomy]]) try to remove the least amount of tissue by going under (sub-temporal), over (trans-Sylvian) or through the temporal lobe (middle-temporal), which have been related to better cognitive outcomes. Previous comparisons of these surgical techniques focus on comparing seizure freedom or behaviour post-surgery, however there have been no systematic studies showing the effect of surgery on white matter connectivity. The main aim of this study, therefore, was to perform systematic 'pseudo-neurosurgery' based on existing resection methods on healthy neuroimaging data and measuring the effect on long-range connectivity. We use anatomical connectivity maps (ACM) to determine long-range disconnection, which is complementary to existing measures of local integrity such as fractional anisotropy or mean diffusivity. ACMs were generated for each diffusion scan in order to compare whole-brain connectivity with an 'ideal resection', nine anterior temporal lobectomy and three selective approaches. For en-bloc resections, as distance from the temporal pole increased, reduction in connectivity was evident within the [[arcuate fasciculus]], [[inferior longitudinal fasciculus]], [[inferior frontooccipital fascicle]], and the [[uncinate fasciculus]]. Increasing the height of resections dorsally reduced connectivity within the uncinate fasciculus. Sub-temporal [[amygdalohippocampectomy]] resections were associated with connectivity patterns most similar to the 'ideal' baseline resection, compared to trans-Sylvian and middle-temporal approaches. In conclusion, we showed the utility of ACM in assessing long-range disconnections/disruptions during temporal lobe resections, where we identified the [[subtemporal]] resection as the least disruptive to long-range [[connectivity]] which may explain its better cognitive outcome. These results have a direct impact on understanding the amount and/or type of cognitive deficit post-surgery, which may not be obtainable using local measures of [[white matter]] integrity
((Busby N, Halai AD, Parker GJM, Coope DJ, Lambon Ralph MA. Mapping whole brain 
connectivity changes: The potential impact of different surgical resection
approaches for temporal lobe epilepsy. Cortex. 2018 Nov 17;113:1-14. doi:
10.1016/j.cortex.2018.11.003. [Epub ahead of print] PubMed PMID: 30557759.
)).