1.1: Intracranial Regulation

What is intracranial regulation?

The mechanisms or conditions that impact intracranial processing and function

What is impaired intracranial regulation caused by?

• Alterations in perfusion

• Alterations in neurotransmission

• Pathology (tumors, infection/inflammation, degenerative disease)

What are neurotransmitters?

Endogenous chemicals that allow neurons to communicate with each other throughout the body

Adrenaline

“Fight or flight”

GABA

Calming

Noradrenaline

Concentration

Acetylcholine

Learning

Dopamine

Pleasure

Glutamate

Memory

What is the most common neurotransmitter?

Glutamate

Serotonin

Mood

Endorphins

Euphoria/well-being

What is a brain herniation?

Occurs when an elevated ICP in one brain compartment causes cerebral tissue to shift toward an area of lower ICP

What do traumatic brain injuries result from?

A severe jolt to the head or body

1. Falls (28%)

2. Motor vehicle accidents (20%)

3. Being struck by… (including sports) (19%)

What is a focal brain injury?

Localized damage to a specific area of the brain (e.g., contusion, laceration, hemorrhage)

What is a diffuse brain injury?

Widespread damage across large areas of the brain

What are the manifestations of a diffuse brain injury?

• Changes in LOC

• Changes in pupillary reflexes and eye movements

• Abnormal posturing

• Respiratory changes

What is decorticate posturing?

Abnormal flexion

What is decerbrate posturing?

Extension posturing

What is an epidural hemoatoma?

Usually caused by a head injury in which the skull is fractured, causing blood to collect between the skull and dura mater

What is a subdural hematoma?

Tearing of bridging veins, causing blood to collect between the dura and arachnoid mater

What is a traumatic intracerebral hematoma?

When blood collects within the brain tissue itself; can be single or multiple but usually happens in the frontal or temporal lobes

What is a concussion?

An immediate and transient loss of consciousness accompanied by a brief period of amnesia after a blow to the head

What is the recovery process like for a concussion?

Recovery happens in 24 hours, but symptoms can persist for months (headache, irritability, insomnia, poor concentration and memory)

What are the two origins of primary intracranial tumors?

• Within the brain tissue itself (arise from neurons or neuroglial cells - gliomas)

• Within the skull cavity, but not the brain tissue (meningiomas)

What is a metastatic tumor?

A tumor that originated outside of the brain and spreads to the CNS

What is a benign tumor?

A non-invading tumor with slow growth

What is a malignant tumor?

An invading tumor with rapid growth

What is meningitis?

Inflammation (usually from an infection) of the meninges that spreads rapidly and affects the pia mater, arachnoid, and CSF-filled subarachnoid space

What are the two types of meningitis?

• Acute purulent meningitis (bacterial)

• Acute lymphocytic meningitis (viral)

How is meningitis diagnosed?

With a lumbar puncture to examine CSF

What are the contents of CSF with acute purulent meningitis?

• Increased polymorphonuclear neutrophils

• Increased protein content

• Reduced sugar content

What are the contents of CSF with acute lymphocytic meningitis?

• Increased lymphocytes

• Moderately elevated protein content

• Normal sugar content

What are the manifestations of meningitis?

• Stiff neck

• Altered mental status

• Fever