Lectorial Topic 5: Central Nervous System Cases

Questions and Answers

What causes the more severe paralysis in the upper limbs and face compared to the lower limbs during ischaemic stroke?

Greater blood supply to the lower limbs

Different regions of the brain controlling these areas (correct)

Length of nerve pathways for upper limbs

Differences in muscle strength between limbs

What part of the nervous system is likely affected when there is a loss of vision?

Occipital lobe (correct)

Cerebellum

Retina

Optic nerve

After David's brain trauma, which cognitive aspect is most likely impaired?

Memory retention

Problem-solving abilities (correct)

Visual processing

Language comprehension

In Jarrod's case of infection in the left foot and absence of pain, which part of the nervous system is likely damaged?

Peripheral nerves Signup and view all the answers

What behavior change in David indicates a likely area of damage in the brain?

Inappropriate social behavior Signup and view all the answers

The occlusion of which artery is most commonly associated with ischaemic strokes?

Middle cerebral artery Signup and view all the answers

When examining two patients with muscle paralysis in one leg, which condition could be ruled out if both demonstrate symmetry in reflex responses?

Spinal cord injury Signup and view all the answers

What could the absence of pain perception and yet the ability to move voluntarily indicate about the type of nervous system damage?

Sensory neuron damage Signup and view all the answers

What phenomenon likely caused the sudden onset weakness of the facial, arm, trunk, and leg muscles in the 80-year-old man?

A stroke in the right middle cerebral artery Signup and view all the answers

What is indicated by the man's inability to respond to pinpricks on the right side of his body?

Damage to the spinothalamic tract Signup and view all the answers

At which level of the spinal cord is it most likely that the stab wound affected the tracts described in Case 1?

Thoracic region Signup and view all the answers

If a thrombus from the common carotid artery travels to a cerebral artery, which artery is it most likely to occlude?

Middle cerebral artery Signup and view all the answers

What is the likely cause of the resistance to movement experienced when the nurse attempts to extend the man’s arm?

Spasticity following upper motor neuron damage Signup and view all the answers

What deficit is the man likely experiencing on the left side of his body due to the spinal injuries?

Loss of light touch and proprioception Signup and view all the answers

In which part of the nervous system would the injury likely need to occur to account for bilateral deficits resulting from a single lesion?

Brainstem Signup and view all the answers

When assessing the localization of the problem causing the man's symptoms, which area of the brain is most affected if the eyes deviate to the left?

Right frontal lobe Signup and view all the answers

What does the Wada test assess in an individual?

Dominant hemisphere for language Signup and view all the answers

If the left hemisphere is anaesthetised during the Wada test, how will the individual likely respond?

They will have no verbal response. Signup and view all the answers

Which area of the cerebral cortex processes visual information?

Visual association area Signup and view all the answers

What is the role of the association cortex?

To integrate and interpret information from multiple sources Signup and view all the answers

What do the lateralisation of function and the dominant hemisphere imply?

One hemisphere is typically dominant for specific cognitive functions. Signup and view all the answers

What type of sensory information does the spinothalamic tract primarily transmit?

Crude touch, pain, and temperature Signup and view all the answers

Which structure acts as a relay center for sensory and motor information in the brain?

Thalamus Signup and view all the answers

What is the primary function of the corticospinal tract?

Controlling voluntary movement Signup and view all the answers

In terms of structural organization, how is the spinal cord white matter arranged?

Based on sensory and motor functions Signup and view all the answers

What protective feature of the brain helps restrict harmful substances from entering neural tissue?

The blood-brain barrier Signup and view all the answers

What role does the gray matter in the spinal cord play during reflex actions?

Integrates sensory input and motor output Signup and view all the answers

Which region of the brain is primarily responsible for coordinating voluntary movements and balance?

Cerebellum Signup and view all the answers

What changes occur in the skull as the brain evolves over time?

There is a limit to the degree of size increase Signup and view all the answers

What role does the Circle of Willis serve in the human brain?

It connects the internal carotid arteries. Signup and view all the answers

Which layer of the meninges is closest to the surface of the brain?

Pia Mater Signup and view all the answers

What is one of the main purposes of the cerebrospinal fluid (CSF) in the brain?

To act as a cushion for the brain Signup and view all the answers

Which of the following accurately describes the protective functions of the brain's coverings?

The blood-brain barrier selectively permits substances to enter. Signup and view all the answers

Which structure is specifically responsible for maintaining arterial blood supply to the brain?

Circle of Willis and cerebral arteries Signup and view all the answers

What is a main issue related to the bony protection of the brain?

It does not allow for the expansion of the brain. Signup and view all the answers

Which component is NOT considered a part of the protective mechanisms for the brain?

Cranial nerves Signup and view all the answers

How does the blood-brain barrier primarily protect the brain?

By allowing only essential nutrients and molecules to enter Signup and view all the answers

What is the primary consequence of an increase in cranial volume?

Increase in intracranial pressure Signup and view all the answers

Which of the following represents a classic sign of raised intracranial pressure?

Deep, irregular respiration Signup and view all the answers

What effect does increased intracranial pressure have on blood flow to the brain?

Inhibits blood flow into the brain Signup and view all the answers

Which structure is directly involved in emotional learning and response to fear?

Amygdala Signup and view all the answers

What role does the hippocampus play in memory function?

Long-term memory conversion Signup and view all the answers

What happens during herniation of brain structures due to a space-occupying lesion?

Brain tissue may become compressed Signup and view all the answers

What is a function of the cerebellum?

Coordination of voluntary movements Signup and view all the answers

Which of the following is NOT a consequence of amygdala damage?

Enhanced ability to avoid risks Signup and view all the answers

Which part of the cerebral cortex is involved in the processing of auditory information?

Primary auditory cortex Signup and view all the answers

What is a major function of the cerebral cortex?

Reasoning and problem solving Signup and view all the answers

What does widening pulse pressure indicate in relation to intracranial pressure?

Compensatory response to raised intracranial pressure Signup and view all the answers

Which region of the brain is primarily involved in the integration of sensory information?

Cerebral cortex Signup and view all the answers

What is one effect of a significant increase in intracranial pressure?

Brain herniation Signup and view all the answers

What is the primary role of the pontine and medullary regions of the brainstem?

Regulation of vital functions Signup and view all the answers

Study Notes

Case 1 – The Mystery Injury

23-year-old male suffered a stab wound near the vertebral column on the left side.
Post-injury deficits:
- No response to pinpricks on the right side below the nipple.
- No response to light touch on the left side below the nipple.
- Lack of proprioception in the left leg.
- Inability to move the left leg against resistance.
Affected spinal tracts likely include the corticospinal tract (motor function) and dorsal columns (sensory function).
A single lesion could potentially account for all deficits if located at the appropriate level of the spinal cord.

Case 2 – The Travelling Thrombus

A thrombus from the common carotid artery can travel through the internal carotid artery.
Most likely end up in the middle cerebral artery due to its size and direct connection to the internal carotid.

Case 3 – Reading the Signs

80-year-old male exhibits sudden-onset weakness on the right side, especially facial and arm muscles, right-sided loss of sensation, and eye deviation to the left.
These symptoms likely caused by a stroke affecting the left hemisphere (right side weakness).
Location of the problem probably in the motor cortex controlling the face and arm.
Development of spasticity in the right arm and leg occurs due to upper motor neuron damage leading to increased muscle tone and resistance to movement.

Case 4 – Territories

Ischaemic strokes commonly occur from middle cerebral artery occlusion.
Muscle paralysis is more severe in the upper limbs and face because these areas have a greater representation in the motor cortex.

Case 5 – Visual Fields

Loss of vision can be traced to problems in the visual pathways.
Likely site of the issue in the occipital lobe or along the pathways connecting to visual processing areas.

Case 6 – Video Evidence

Videos will provide insights into brain damage and resulting deficits in patients.
Analysis of observed symptoms and behaviors can pinpoint damaged regions in the brain.

Case 7 – Socially Unacceptable

David experienced trauma resulting in behavioral changes: motivation loss, distraction, inability to problem-solve, and inappropriate behavior.
Likely damage to the frontal lobe affecting executive functions and social behavior.

Case 8 – Spinal Nerve, Root or Spinal Cord?

Jarrod's inability to feel pain in the left foot but maintaining voluntary movement suggests issues in the peripheral nervous system or spinal roots.
Poor withdrawal reflex indicates a problem with sensory pathways or spinal cord damage.

Case 9 – Whose Leg?

Two individuals exhibit muscle paralysis in one leg, necessitating a thorough neurological examination to determine underlying causes.

Integration in the CNS

Central Nervous System (CNS) integrates sensory information from both somatic and autonomic systems.
The CNS formulates and sends motor responses based on sensory input.
Spinal cord and brain both play vital roles in integration processes.

Spinal Cord and Reflexes

Integration occurs in the spinal cord's gray matter, influenced by brain input (both excitatory and inhibitory).
Sensory neurons enter via the dorsal root; motor neurons exit through the ventral root.
Spinal cord's white matter is segmented into tracts: ascending (sensory) and descending (motor).

Brain Overview

Composed of the brainstem, cerebellum, limbic system, and cerebral cortex.
Developmental changes result in brain curvature due to limited cranial expansion.

Blood Supply and Protection

The Circle of Willis supplies arterial blood; includes internal carotid and vertebral arteries.
Brain protection encompasses the cranium, meninges, cerebrospinal fluid (CSF), and the blood-brain barrier.
Intracranial pressure (ICP) increases if there's an addition to cranial volume (e.g., lesions).

Signs of Increased ICP

“Cushing’s triad” includes irregular respiration, widened pulse pressure, and bradycardia, indicating brain stress.

Brain Regions and Their Functions

Brainstem: Encompasses midbrain, pons, and medulla; essential for autonomic functions.
Cerebellum: Coordinates voluntary movements, postural adjustments, rapid movement planning, and movement learning.
Limbic System: Involved in emotional processing, survival motivation, learning, and memory, including structures like the cingulate cortex, hippocampus, and amygdala.

Amygdala and Emotional Responses

The amygdala is critical for emotional learning and fear recognition.
Damage to the amygdala affects fear responses and social interactions.

Hippocampus and Memory

Facilitates the conversion of short-term memory to long-term memory and spatial memory.

Cerebral Cortex Functions

Divided by cortical regions, responsible for sensory processing, voluntary movements, reasoning, language, and personality.
Each sensory and motor function is localized in distinct areas, with well-defined roles.

Sensory and Motor Processing Areas

Primary sensory areas include somatic, visual, gustatory, olfactory, and auditory cortices.
Motor areas consist of the primary somatic motor cortex, with areas organized topographically as homunculi.

Lateralization of Brain Function

Dominance in language and speech areas varies; identified via the Wada test, which assesses hemisphere function by temporarily anesthetizing one side.

Association Areas

Integrate and process information beyond primary areas, contributing to complex functions like reasoning and emotional regulation.
Include somatic sensory, visual, auditory, limbic, and prefrontal association areas.

Studying That Suits You

Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

Description

Explore 9 intriguing cases focused on the Central Nervous System, starting with a harrowing tale of a 23-year-old man who suffered a stab wound. This quiz will challenge your understanding of neurological responses and anatomical implications. Test your knowledge on case studies that reveal the complexities of human anatomy and injury recovery.