Brain Anatomy and Traumatic Brain Injury: What Happens When Each Region of the Brain Is Damaged

When someone experiences a traumatic brain injury, the location of the damage determines the symptoms and guides the treatment plan. At our Kansas City clinic, we take a region-specific approach to post-concussion recovery—because healing the brain isn’t a one-size-fits-all process.

Whether your injury came from a car accident in Overland Park, a fall in Lee’s Summit, or a collision in North Kansas City, this guide breaks down the brain’s anatomy and what happens when different areas are affected.

🧠 The Cerebrum: Lobes of the Brain

The cerebrum makes up the largest portion of the brain and is divided into four lobes per hemisphere: frontal, parietal, temporal, and occipital. Each lobe processes different types of information and behaviors.

✅ Frontal Lobe

Location:

Front portion of the brain, behind the forehead; includes the prefrontal cortex, motor cortex, and Broca’s area (left side only).

Function:

• Executive function: planning, reasoning, judgment, decision-making

• Voluntary motor control (via the primary motor cortex)

• Speech production (Broca’s area, usually left hemisphere)

• Impulse control and social behavior

• Working memory and attention regulation

• Emotional expression and personality

What Happens When Injured:

• Impaired concentration and attention span

• Disinhibition, aggression, or apathy

• Poor planning or inability to multitask

• Word-finding difficulty (expressive aphasia)

• Motor weakness or paralysis on the opposite side of the body

• Flat affect or inappropriate social behavior

• Poor initiation and motivation (abulia)

Frontal lobe injuries are especially common in coup-contrecoup injuries, where the front of the brain hits the inside of the skull during rapid deceleration.

✅ Parietal Lobe

Location:

Upper middle section of the brain behind the frontal lobe; contains the primary somatosensory cortex.

Function:

• Sensory perception (touch, pain, pressure, temperature)

• Body awareness and proprioception

• Spatial orientation and navigation

• Integration of visual, auditory, and sensory input

• Right-left discrimination

• Hand-eye coordination

• Mathematical calculations and object manipulation

What Happens When Injured:

• Difficulty processing touch or body sensations

• Poor spatial awareness (bumping into objects)

• Hemispatial neglect (especially right parietal injury)

• Problems with dressing or using tools (apraxia)

• Dyscalculia (difficulty with numbers)

• Trouble with graphesthesia or stereognosis

• Inability to integrate visual and tactile input

Right parietal lobe damage often results in neglect of the left side of the body or space, a serious deficit in TBI patients.

✅ Temporal Lobe

Location:

Sides of the brain near the temples; includes the hippocampus, amygdala, and Wernicke’s area (left side only).

Function:

• Processing of auditory input and language comprehension

• Short- and long-term memory encoding (hippocampus)

• Emotional regulation (amygdala)

• Interpretation of music and tone

• Visual memory and recognition

• Receptive language (Wernicke’s area)

What Happens When Injured:

• Difficulty understanding spoken or written language (receptive aphasia)

• Memory deficits, especially short-term recall

• Emotional instability or fear-based reactions

• Auditory hallucinations or sound distortions

• Poor recognition of faces or voices

• Seizures originating in the temporal lobes (temporal lobe epilepsy)

Temporal lobe damage is a major contributor to post-TBI emotional and cognitive symptoms and is frequently involved in post-traumatic amnesia.

✅ Occipital Lobe

Location:

Back of the head, above the cerebellum

Function:

• Primary visual processing (light, shape, color, motion)

• Visual perception and depth recognition

• Interpretation of written words and images

What Happens When Injured:

• Partial or complete vision loss

• Visual field cuts (e.g., homonymous hemianopia)

• Visual hallucinations or distortions (palinopsia)

• Difficulty recognizing objects or faces (visual agnosia)

• Poor reading comprehension due to visual processing errors

Occipital injuries can occur even without direct impact if the brain rebounds into the rear of the skull during whiplash or falls.

🧠 Cerebellum: The Coordination Center

Location:

Underneath the occipital lobes, in the posterior cranial fossa

Function:

• Fine motor coordination

• Balance and postural control

• Motor timing and rhythm

• Eye movement coordination (especially smooth pursuit and VOR)

• Motor learning and procedural memory

What Happens When Injured:

• Ataxia (uncoordinated limb movement)

• Poor balance and difficulty standing or walking

• Dysmetria (overshooting or undershooting movements)

• Dysdiadochokinesia (inability to perform rapid alternating movements)

• Nystagmus (involuntary eye movements)

• Slurred, robotic speech (cerebellar dysarthria)

Cerebellar injuries are less common but very disruptive when present. Even mild dysfunction can impair balance and movement control long after the trauma.

🧠 Brainstem: Vital Life Functions

Divided into:

• Midbrain

• Pons

• Medulla oblongata

Function:

• Regulates breathing, heart rate, and blood pressure

• Coordinates arousal and consciousness (via the Reticular Activating System)

• Controls cranial nerve function (III through XII)

• Integrates vestibular input and eye movement

• Controls sleep-wake cycles and alertness

What Happens When Injured:

• Decreased consciousness or coma

• Dysphagia (difficulty swallowing)

• Impaired breathing or cardiovascular instability

• Cranial nerve palsies (facial weakness, hearing loss, vision changes)

• Dysautonomia (blood pressure, heart rate, and temperature dysregulation)

• Dizziness, vertigo, or persistent nausea

Brainstem injuries are life-threatening and may not always be visible on standard imaging. Even microtrauma can cause serious autonomic and cranial nerve symptoms.

Putting It All Together: Region-Specific TBI Recovery in Kansas City

At our Kansas City clinic, we go far beyond basic concussion care. We evaluate each patient’s symptoms in the context of functional neuroanatomy to determine:

• Which brain regions were affected

• How symptoms map to those regions

• What rehabilitation strategies will work best

From visual tracking therapy for occipital injuries to executive function retraining for frontal damage, our programs are built around how the brain actually works—not just symptom checklists.

Schedule Your Post-TBI Evaluation Today

If you've suffered a concussion or TBI and still struggle with focus, memory, speech, or balance, understanding which parts of your brain were affected is the first step to real recovery.

Call Dr. Lance Stevenson at 816-226-7476 to schedule a comprehensive neurological exam. We proudly serve Kansas City, Lee’s Summit, Overland Park, Shawnee, Liberty, Raytown, Blue Springs, and surrounding communities with advanced brain injury care.