Basic Neurology
The Central Nervous System (CNS) is composed of the brain and the spinal cord. Seizures come from the brain.
Brain Anatomy
The brain has two main hemispheres: the left and right hemispheres.
Each hemisphere is divided into 4 parts, or lobes:
- Frontal Lobe (front)
- Temporal Lobe (sides)
- Parietal Lobe (top of brain)
- Occipital Lobe (back of brain)
Another part at the bottom of the hemispheres is called the cerebellum.
The bottom of brain that connects to the spinal cord is called the brain stem.
What Do Parts of the Brain Do?
The four lobes each have unique important functions:
- Frontal: thought, judgment, personality, memory (short-term), concentration, speech, and movement.
- Temporal: language, learning, and long-term memory.
- Parietal: sensory input and processing information.
- Occipital: vision and object recognition.
The cerebellum is responsible for controlling balance, coordination, and movement.
The brain stem is important for eye movements, breathing, blood pressure control, and movement. It connects all the information from the cerebral hemispheres to the spinal cord.
Dominant/Non-Dominant Brain Lobes
Anatomically, the brain has two different sides, the right and the left.
Functionally, the brain has a “dominant” side where language function mainly resides. The non-dominant side is still important and is used for visual memory and visual perception.
Right brain dominance means that your language is mostly on the right side and left brain dominance means that the language is mostly on the left.
The majority of people who are right-handed will be left brain-dominant (70-95%). However, even if you are left-handed, about 70% of you will still have left brain dominance.
Memory Centers
- Memory centers are located in the temporal lobes, and the good news is that we have two. We need both of these to make new memories. Sometimes, when seizures come from one temporal lobe, memory can be severely impacted.
Brain Control is Criss-Crossed
- The right side of the brain controls motor function on the left side of the body and vice versa. Similarly, sensation in the left side of the body is monitored by the right side of the brain. The left occipital lobe computes vision from the right visual field in both eyes.
A Closer Look at the Brain
Neurons are the brain cells that connect different parts of the brain. They carry and send messages to and from the brain and spinal cord to the muscles and skin. They make us move, think, see, hear and feel.
Neurons are made of different parts:
- Dendrites- takes electrical signals (information) to the cell body.
- Cell body- contains nucleus, which contains genetic information.
- Axons- takes electrical signals (information) away from the cell body.
- Myelin- a fatty layer surrounding the axon to make messages travel faster.
Connecting the Brain with Anatomy
Neurons send electrical signals creating messages to different parts of the brain.
Sometimes, these neurons can be damaged by strokes, trauma, infection, and tumors/cancer. Patients can also be born with abnormal neurons and brain malformations.
When these neurons misfire, they can cause a seizure.