Browsing by Subject "Temporal lobe"

Now showing 1 - 5 of 5
  • Thumbnail Image
    Item
    External cortical landmarks and measurements for the temporal horn: Anatomic study with application to surgery of the temporal lobe
    (Wolters Kluwer, 2015-02-03) Tubbs, R. Shane; Sharma, Amit; Loukas, Marios; Cohen-Gadol, Aaron; Department of Neurological Surgery, IU School of Medicine
    BACKGROUND: The location of the temporal horn is important to neurosurgeons during procedures such as amygdalohippocampectomy and intraventricular electrode placement for temporal lobe seizure monitoring. However, sometimes the temporal horn is difficult to localize, especially without neuronavigation. The authors aimed to better localize this structure using superficial anatomic landmarks. METHODS: Twenty-two brain halves were dissected from the midline, and the fornix identified and followed toward the left and right temporal horns. Once the temporal horn was isolated from a mesial approach, 6-cm long needles were placed into its anterior and posterior walls of the temporal horn and passed laterally from the axial plane to the cortical surface. Pin exit sites were marked externally and measurements taken between the outer temporal lobe cortex and the underlying temporal horn. RESULTS: No statistical differences were noted between left and right sides. The temporal horn was generally directed anteroinferiorly and best marked externally by the inferior temporal sulcus. The mean length of the temporal horn was 4.4 cm. Mean distance from anterior temporal tip to anterior wall of the temporal horn was 3.3 cm. The mean distance from the anterior temporal tip to the posterior wall of the temporal horn was 7 cm. The anterior wall of the temporal horn was a mean of 3 mm superior to the inferior temporal sulcus. The posterior wall was a mean of 1.2 cm superior to the inferior temporal sulcus. CONCLUSIONS: These landmarks and measurements may help neurosurgeons better localize this part of the lateral ventricular system.
  • Thumbnail Image
    Item
    External cortical landmarks for localization of the hippocampus: Application for temporal lobectomy and amygdalohippocampectomy
    (Scientific Scholar, 2018-08-22) Tubbs, R. Shane; Loukas, Marios; Barbaro, Nicholas M.; Shah, Kushal J.; Cohen-Gadol, Aaron A.; Neurological Surgery, School of Medicine
    Background: Accessing the hippocampus for amygdalohippocampectomy and minimally invasive procedures, such as depth electrode placement, require an accurate knowledge regarding the location of the hippocampus. Methods: The authors removed 10 human cadaveric brains from the cranium and observed the relationships between the lateral temporal neocortex and the underlying hippocampus. They then measured the distance between the hippocampus and superficial landmarks. The authors also validated their study using magnetic resonance imaging (MRI) scans of 10 patients suffering from medial temporal lobe sclerosis where the distance from the hippocampal head to the anterior temporal tip was measured. Results: In general, the length of the hippocampus was along the inferior temporal sulcus and inferior aspect of the middle temporal gyrus. Although the hippocampus tended to be more superiorly located in female specimens and on the left side, this did not reach statistical significance. The length of the hippocampus tended to be shorter in females, but this too failed to reach statistical significance. The mean distance from the anterior temporal tip to the hippocampal head was identical in the cadavers and MRIs of patients with medial temporal lobe sclerosis. Conclusions: Additional landmarks for localizing the underlying hippocampus may be helpful in temporal lobe surgery. Based on this study, there are relatively constant anatomical landmarks between the hippocampus and overlying temporal cortex. Such landmarks may be used in localizing the hippocampus during amygdalohippocampectomy and depth electrode implantation in verifying the accuracy of image-guided methods and as adjuvant methodologies when these latter technologies are not used or are unavailable.
  • Thumbnail Image
    Item
    Frontotemporal Dementia and Parkinsonism Linked to Chromosome 17: A New Group of Tauopathies
    (Wiley, 1998-04) Spillantini, Maria Grazia; Bird, Thomas D.; Ghetti, Bernardino; Pathology and Laboratory Medicine, School of Medicine
    Frontotemporal dementia is a neurological disorder characterised by personality changes, deterioration of memory and executive functions as well as stereotypical behaviour. Sometimes a Parkinsonian syndrome is prominent. Several cases of frontotemporal dementia are hereditary and recently families have been identified where the disease is linked to chromosome 17q21-22. Although, there is clinical and neuropathological variability among and within families, they all consistently present a symptomathology that has led investigators to name the disease "Frontotemporal Dementia and Parkinsonism linked to chromosome 17." Neuropathologically, these patients present with atrophy of frontal and temporal cortex as well as of basal ganglia and substantia nigra. In the majority of cases these features are accompanied by neuronal loss, gliosis and microtubule-associated protein tau deposits which can be present in both neurones and glial cells. The distribution, structural and biochemical characteristics of the tau deposits differentiate them from those present in Alzheimer's disease, corticobasal degeneration, progressive supranuclear palsy and Pick's disease. No beta-amyloid deposits are present. The clinical and neuropathological features of the disease in these families suggest that Frontotemporal Dementia and Parkinsonism linked to chromosome 17 is a distinct disorder. The presence of abundant tau deposits in the majority of these families define this disorder as a new tauopathy.
  • Thumbnail Image
    Item
    Superficial cortical landmarks for localization of the hippocampus: Application for temporal lobectomy and amygdalohippocampectomy
    (Wolters Kluwer, 2015-02-03) Tubbs, R. Shane; Loukas, Marios; Barbaro, Nicholas M.; Cohen-Gadol, Aaron A.; Department of Neurological Surgery, IU School of Medicine
    BACKGROUND: Accessing the hippocampus for amygdalohippocampectomy and procedures such as depth electrode placement requires accurate knowledge regarding the location of the hippocampus. METHODS: The authors removed 10 human cadaveric brains (20 sides) from their crania, noted relationships between the lateral temporal neocortex and underlying hippocampus, and measured the distance between the hippocampus and superficial landmarks. RESULTS: Mean distances were as follows: 3.8 cm from the tip of the temporal lobe to the head of the hippocampus; 6.5 cm from the tip of the temporal lobe to the junction of the fornix and hippocampus; and 3.5 cm between the tail and head of the hippocampus. The head of the hippocampus ranged from 0 to 5 mm inferior to the inferior temporal sulcus. The tail of the hippocampus ranged from 2.2 to 7 mm superior to the inferior temporal sulcus. In two specimens, the tail was deep to the superior temporal sulcus. Generally the length of the hippocampus was along the inferior temporal sulcus and inferior aspect of the middle temporal gyrus. The hippocampus tended to be more superiorly located and shorter in females and left sides, but this was not statistically significant. CONCLUSIONS: Additional landmarks for localizing the underlying hippocampus may be helpful in temporal lobe surgery. Our study showed relatively constant anatomic landmarks between the hippocampus and overlying temporal cortex that may help localize the hippocampus during amygdalohippocampectomy and depth electrode implantation, verify the accuracy of image-guided methods, and used as adjuvant methodologies when these latter technologies are unavailable.
  • Thumbnail Image
    Item
    TAF15 amyloid filaments in frontotemporal lobar degeneration
    (Springer Nature, 2024) Tetter, Stephan; Arseni, Diana; Murzin, Alexey G.; Buhidma, Yazead; Peak-Chew, Sew Y.; Garringer, Holly J.; Newell, Kathy L.; Vidal, Ruben; Apostolova, Liana G.; Lashley, Tammaryn; Ghetti, Bernardino; Ryskeldi-Falcon, Benjamin; Pathology and Laboratory Medicine, School of Medicine
    Frontotemporal lobar degeneration (FTLD) causes frontotemporal dementia (FTD), the most common form of dementia after Alzheimer's disease, and is often also associated with motor disorders1. The pathological hallmarks of FTLD are neuronal inclusions of specific, abnormally assembled proteins2. In the majority of cases the inclusions contain amyloid filament assemblies of TAR DNA-binding protein 43 (TDP-43) or tau, with distinct filament structures characterizing different FTLD subtypes3,4. The presence of amyloid filaments and their identities and structures in the remaining approximately 10% of FTLD cases are unknown but are widely believed to be composed of the protein fused in sarcoma (FUS, also known as translocated in liposarcoma). As such, these cases are commonly referred to as FTLD-FUS. Here we used cryogenic electron microscopy (cryo-EM) to determine the structures of amyloid filaments extracted from the prefrontal and temporal cortices of four individuals with FTLD-FUS. Surprisingly, we found abundant amyloid filaments of the FUS homologue TATA-binding protein-associated factor 15 (TAF15, also known as TATA-binding protein-associated factor 2N) rather than of FUS itself. The filament fold is formed from residues 7-99 in the low-complexity domain (LCD) of TAF15 and was identical between individuals. Furthermore, we found TAF15 filaments with the same fold in the motor cortex and brainstem of two of the individuals, both showing upper and lower motor neuron pathology. The formation of TAF15 amyloid filaments with a characteristic fold in FTLD establishes TAF15 proteinopathy in neurodegenerative disease. The structure of TAF15 amyloid filaments provides a basis for the development of model systems of neurodegenerative disease, as well as for the design of diagnostic and therapeutic tools targeting TAF15 proteinopathy.