Guide on the Basics of Increased Intracranial Pressure Pt 1

In this lecture, we are going to do a rundown on the following:

  1. Defining intracranial pressure
  2. Causes of increased ICP
  3. Coping mechanisms
  4. Signs and symptoms of increased ICP
  5. Neurological assessments

Defining Intracranial Pressure

Intracranial pressure (ICP) is the measurement of the brain tissue’s pressure with the cerebrospinal fluid surrounding and cushioning the spinal cord and the brain. How does pressure inside the brain increases?

The pressure inside the brain increases due to traumatic brain injury that can be from the following instances:

  • Blunt force to the head like being whacked with something hard like a baseball bat, or falling off a building head first
  • Car accidents
  • Stroke
  • Hemorrhage
  • An aneurysm

All these factors can cause increased pressure that can stress the brain. And it gets worse if, the cranium is still intact. We’ll explain further.

The Cerebrospinal Fluid

Right after the trauma, immediate changes happen inside the cranium.

Inside the skull, you have the dura mater, arachnoid mater, pia mater, and the subarachnoid mater. The subarachnoid mater, much like a moat between the brain and the skull crust, is the primary area where your cerebrospinal fluid rests.

The cerebrospinal fluid (CSF) is a colorless, transparent liquid surrounding and protecting your brain and spinal cord. Aside from helping the brain to float inside the skull, cushioning to prevent injury, the CSF is also responsible for bathing the spine and the brain with nutrients while eliminating waste products. If you are dehydrated, there will be decreased CSF making the brain to touch the sides of the skull which causes headaches.

So, what is the connection between CSF and closed head injuries to lead to increased intracranial pressure?

When the head experienced severe trauma, it instantly swells. If the trauma is a closed head injury, the increasing pressure has nowhere to go but down the brainstem which then causes herniation. If the brain stem herniates, the client’s respiratory rate and autonomic nervous system like your heart rate and blood pressure are severely compromised.

So, when the cranial content, brain tissues, blood, and cerebrospinal fluid are trapped inside the skull where there is little to no room for expansion, thus the increase of intracranial pressure.

Coping Mechanisms and Treatment

When there is increased intracranial pressure, immediate treatment is required. But before it worsens, the body initially compensates. Basically, there are two ways on how increased ICP is managed by the body:

  • Compensation by the body
  • Shunted from the cranial compartment

For a Contusion

On the onset of increased pressure inside the cranium, for example, you’ve been whacked by a bat, the body immediately compensates for the tragedy by shunting the cerebrospinal fluid into the subarachnoid space. The body is decreasing pressure from the affected area of the brain to be distributed to other areas so that the swelling can subside. This is how the body compensates for the contusion.

For a Brain Bleed

A bleeding brain creates extra fluid volume inside the brain, and the body will move this fluid into the subarachnoid area. If the moat cannot accommodate the increasing fluid, it will eventually travel down the brainstem and cause herniation which then affects the autonomic nervous system.

So, the body will be trying to continuously shunt the cranial fluid into the cranial compartments, or it will increase its rate of cerebrospinal fluid absorption. If both are unsuccessful, decreased cerebral perfusion will occur. No oxygen is going to go inside the brain which causes it to shut down eventually.

Signs and Symptoms of Increased ICP

If the increasing pressure is not treated immediately, the client will manifest the following signs and symptoms:

  • Head – headache, altered level of consciousness (ALOC), seizures
  • GI – nausea and projectile vomiting
  • Lethargy and weakness
  • Eyes – pinpoint pupils (early stage) then will progress to blown pupils (late stage)

If the brain has a bleed on just one side, the pupils will look off-set; meaning one of the pupils will be fully-dilated while the other one will be normal. Full-dilation of the pupils will indicate which part of the brain is bleeding.

For part 2 of our intracranial pressure lecture where we will further discuss neurological assessment and treatment options, visit simplenursing.com.

See you there!

Neurological Disorder Overview: Parkinson’s, MS, MG, & ALS

Here’s a quick rundown of the four primary neurological disorders mainly Parkinson’s disease (PD), multiple sclerosis (MS), myasthenia gravis (MG), and amyotrophic lateral sclerosis (ALS). We will be touching on the signs and symptoms, pathophysiology, and client goals. After which, we will go into specific details and dissect every disease.

Right now, we will be focusing on the basic overview of MS and Parkinson’s disease.

CNS and PNS

The nervous system is basically divided into two: the central nervous system (CNS) and the peripheral nervous system (PNS). The central nervous system consists of the brain and the spinal cord while the peripheral nervous system includes the ganglia and the nerves that are mainly outside the brain and spinal cord.

                        Nervous system = CNS and PNS

  • CNS = brain and spinal cord
  • PNS = ganglia and nerves (everything outside the brain and spinal cord)

It is essential to take note that multiple sclerosis and Parkinson’s disease primarily occurs in your central nervous system while myasthenia gravis and amyotrophic lateral sclerosis affect the peripheral nervous system. ALS is just a fancy word for Lou Gehrig’s disease.

  • CNS = MS and PD
  • PNS = MG and ALS

Pathophysiology of CNS Diseases

To easily remember your central nervous system diseases, think of C-M-P. CMP stands for CNS, MS, and PD.

  • C – CNS
  • M – MS
  • P – PD

Multiple Sclerosis

When you think of MS, automatically relate it to myelin sheath because there is myelin sheath degradation in multiple sclerosis.

            MS = myelin sheath = degradation

What are myelin sheaths and how important are they in your client’s CNS?

If you remember your nursing physiology pre-requisites, a particular topic specifically in the brain is knowing what a nerve cell is and identifying its parts. The axon, or what is also known as a nerve fiber, is responsible for conduction of motor impulses. On each neuron, are attached myelin sheaths that look like a small choo-choo train.

A neuron or nerve cell would look like a palm tree if you wanted something substantial to compare it to.

Aside from protecting the nerve fibers, the myelin sheaths are also responsible for electrical impulse conduction. Moving your fingers or twitching your hands happen due to normal myelin sheaths; this is referred to as an action potential.

In MS, the myelin sheaths have degraded causing problems in the transport of impulses. Some of the notable signs and symptoms are:

  • Numbness
  • Cramping
  • Muscle weakness

Parkinson’s Disease

In Parkinson’s disease, there is a significant decrease in the amount of dopamine in your brain. You can think of it this way: There is decreased dope in the park.

            PD = decreased dopamine

What is dopamine and what’s its importance to your CNS?

Again, in your pre-requisites, it was established that dopamine in your brain helps in regulating a few key aspects in your CNS and one of those things is your blood pressure. Which is why, every time a client codes or has a hypotensive episode, dopamine is given because it is a potent vasoconstrictor. Dopamine helps in increasing the amount of blood flow to the brain, into the heart, and dilating your kidneys. But one thing that you have to take note of regarding dopamine is that it helps with your CNS and a person’s ability to move.                                                             

What are the classic signs of clients with PD?

  • Shuffling gait – moving slowly while having a shuffling walk
  • Pill rolling – due to impaired dopamine levels the motor reflexes are affected
  • Tremors in your peripherals

Part two of our lecture we will be tackling about myasthenia gravis and amyotrophic lateral sclerosis or Lou Gehrig’s disease.

See you there!