Lecture6_NeuroMethods_Brain_injury_2025

Page 1: Introduction

• Title: Methods in Biopsychology & Brain Injury

• Course: PS11220

• Lecture: 6

• Instructor: Dr. Alexander Taylor

• Email: alt48@aber.ac.uk

• Location: Room 0.15, Penbryn 5

Page 2: Overview of Methods

Methods to Study the Living Human Brain:

• Structural/Static Imaging:

  • CT (Computed Tomography)

  • MRI (Magnetic Resonance Imaging)

  • DTI (Diffusion Tensor Imaging)

• Functional/Dynamic Imaging:

  • PET (Positron Emission Tomography)

  • fMRI (functional MRI)

  • EEG (Electroencephalogram)

• Stimulation Techniques:

  • TMS (Transcranial Magnetic Stimulation)

• Neuropsychology:

  • Lesion studies

Advantages & Disadvantages

• Each imaging and stimulation method varies in effectiveness, cost, and application.

Page 3: Resolutions in Imaging

Important Resolutions:

• Temporal Resolution: The ability to track changes over time (e.g., milliseconds for EEG).

• Spatial Resolution: The detail of images produced and size of areas examined (e.g., CT and MRI).

Example: ATHENS 2004 Olympic Games – Men's 100m Final

• Illustrated comparison of temporal and spatial resolution in a real-world scenario.

Page 4: Imaging Techniques and Resolutions

Techniques:

• MEG (Magnetoencephalography)

• EEG + ERP (Event-Related Potentials)

• fNIRS (Functional Near-Infrared Spectroscopy)

Injury and Lesion Types:

• Classification by severity: Mild, moderate, severe TBI (Traumatic Brain Injury).

Page 5: Historical Perspective

• Development and advancements in various imaging techniques began in the early 20th century.

Page 6: Historical Development of EEG

• 1929: Hans Berger introduced EEG through documented research on the brain's electrical activity.

Page 7: Event-Related Potentials (ERPs)

• Need for multiple trials to analyze ERP components like P100, N100, P200, etc.

Page 8: ERP Measurement

Averaging and Stimulus Categories:

• ERP correlates with attention and categorization in reaction to stimuli presented.

Page 9: ERPs and Cognition

Key Components:

• N400: Related to semantic processing.

• N170: Related to facial recognition.

Page 10: Application of EEG

• Low-cost EEG systems have been developed to assist locked-in patients communicate.

Page 11: CT Scanning Technology

• Prototype CT scanner created by Sir Godfrey Newbold Hounsfield.

Page 12: Computed Tomography (CT)

Process:

• Involves using X-ray source and detector for imaging.

• Allows for three-dimensional reconstruction of internal structures.

Page 13: CT Imaging Findings

• Highest regional cerebral blood flow (rCBF) observed at age 2 in grey matter.

Page 14: MRI Fundamentals

• Involves 3.0 Tesla scanner generating a magnetic field.

• Magnetic signals are crucial for aligning targeted atoms in biological tissue.

Page 15: MRI Imaging

Advantages:

• Notably safer as it has no radiation exposure and provides better spatial resolution compared to CT scans.

Page 16: DTI Imaging

Key Features:

• Quantifies the diffusivity of water molecules within axons to map white matter tracts.

Page 17: Comparisons of Imaging Techniques

MRI vs CT Advantages:

• MRI: No radiation, better resolution, clear distinction of brain tissues.

MRI vs CT Disadvantages:

• Generally more expensive and restrictive concerning metal in the setting.

Page 18: Challenges of MRI

• Rates and potential complications due to equipment limitations, including excessive costs.

Page 19: Functional Imaging Overview

• Structural Imaging: Analysis of anatomy.

• Functional Imaging: Studies biochemical functions and metabolic processes.

Page 20: Overview of PET Scanning

• PET is the first functional imaging method and relies on radioactive tracers to visualize brain activity.

Page 21: Growth of fMRI Research

• Rapid increase in the use of fMRI for studying brain connectivity since 1990.

Page 22: BOLD Response Analysis

Components of BOLD Response:

• Initial dip, overshoot, and post-stimulus undershoot measures to determine neuronal activity.

Page 23: fMRI Measurements

• Monitors BOLD signals in relation to stimulus presentations over time.

Page 24: Timing in fMRI Studies

Concepts:

• Involves region of interest (ROI) analysis and timing of fMRI signals to assess conditions efficiently.

Page 25: TMS Overview

Mechanism of Action:

• Uses pulsed magnetic fields to stimulate brain regions, altering neural activity patterns.

Page 26: Mechanisms of TMS

• Describes how rapidly changing magnetic fields induce electrical fields in the underlying cortex.

Page 27: Virtual Lesion Approach

• Explores the effect of brain stimulation to simulate lesions and assess cognitive functions.

Page 28: Media Reference

• Mention of relevance to BBC FOUR and neurology.

Page 29: Neuropsychology - Lesions

Brain Injury Causes:

• Stroke, hypoxia, tumors, degenerative disorders, and epilepsy are acknowledged causes of brain injury.

Page 30: Limitations of Lesion Studies

• Challenges include individuality and variability in brain mappings and the complexity of brain functions.

Page 31: Vulnerability of Brain Areas

• Certain areas of the brain are more susceptible to damage, necessitating careful study designs.

Page 32: Solutions to Misleading Lesion Overlays

• Implement subtraction methods to refine data analysis related to lesion comparisons.

Page 33: Summary of Imaging Techniques

• The trade-off between spatial and temporal resolution, costs, and other practical considerations in neuroimaging.

Page 34: Additional Materials for Part 1

• Recommended readings and video resources for an in-depth understanding of neuroimaging techniques.

Page 35: Introduction to Part 2

• Focuses on Brain Injury & Damage, outlining critical areas for study.

Page 36: Part 2 Overview

• Covers types of traumatic brain injury (TBI), treatment, and assessment mechanisms.

Page 37: Traumatic Brain Injury Information

TBI Facts:

• Significant health issue with 1.4 million yearly emergency department treatments in the US.

Page 38: Types of Head Injuries

• Distinction between Closed (blunt) and Open (penetrating) head injuries with examples.

Page 39: Focal Injury Characteristics

• Discusses mechanisms leading to neuronal damage and resultant axonal injury post-trauma.

Page 40: Primary vs Secondary Injury Mechanisms

• Exploring injury types and associated hypoxic conditions that complicate TBI.

Page 41: Intracranial Volume-Pressure Curve

• Illustrates progressive changes in intracranial pressure in varying pathological states.

Page 42: Glasgow Coma Scale (GCS)

• Tool for initial head injury assessment based on eye opening, verbal response, and motor skills.

Page 43: TBI Classification

• Classifies TBI severity levels based on GCS score ranges.

Page 44: Mild TBI Characteristics

Management Strategies:

• History taking, neurological exams, and imaging for decision-making.

Page 45: Mini Mental State Exam (MMSE)

Scoring and Implications:

• Cognitive assessments to evaluate degree of cognitive impairment and dementia risks.

Page 46: Moderate TBI Signs

• Identification includes confusion and altered consciousness; management includes CT scans and monitoring.

Page 47: Severe TBI Indicators

• Severe impairment of commands and prolonged unconsciousness requiring immediate assessment and intervention.

Page 48: TBI Treatment Approaches

• Strategies include managing intracranial pressure, ensuring blood flow, and long-term cognitive assessments.

Page 49: Cerebral Blood Flow Autoregulation

• Mechanism of cerebral blood vessels responding to maintain consistent blood flow under varying pressures.

Page 50: Cerebrovascular Incidents

Types:

• Hemorrhagic and ischemic strokes detailed with various causes and consequences.

Page 51: Terminology in Cerebrovascular Events

• Definitions of ischemia, thrombus, embolus, and their implications in brain injury.

Page 52: Stroke Mechanisms

Describes:

• Formation of thrombi and how emboli can lead to significant vascular blockages.

Page 53: Stroke Treatment Options

• Includes surgical interventions, anticoagulants, and rehabilitation as treatment pathways.

Page 54: Overview of Degenerative Disorders

• Presents various cognitive and motor disorders such as Alzheimer's and Parkinson's diseases and their implications.

Page 55: Alzheimer's Disease Mechanisms

• Involves amyloid plaques and neurofibrillary tangles contributing to cognitive decline.

Page 56: Brain Structure Changes in Alzheimer's Disease

• Comparison of brain imaging highlighting degeneration versus healthy brain structures.

Page 57: Tumor Characteristics

• Differentiation between benign and malignant brain tumors and basic treatment methods.

Page 58: Tumor Treatments

• Options available include radiation, chemotherapy, and surgical removal strategies.

Page 59: Tumor Compression Effects

• Illustrates the physical impacts of tumors on surrounding brain structures.

Page 60: Part 2 Summary

• Summarizes critical aspects of TBI, treatment strategies, and other brain-related incidents.

Page 61: Additional Materials for Part 2

• Suggested reading and video resources for further exploration of brain physiology and behavior.