Nerve damage in the brain, also known as neurological damage, can result in a wide range of symptoms depending on the location and severity of the damage. Some common feelings and sensations caused by brain nerve damage include:
Numbness
One of the most common symptoms of nerve damage in the brain is numbness or a loss of sensation. This occurs when the nerves that carry sensations from the body to the brain become damaged. Numbness can affect the face, arms, legs, or other parts of the body depending on where the damaged nerves are located in the brain.
For example, damage to the trigeminal nerve can cause numbness or tingling in the face. Damage to the optic nerve can result in visual problems or blindness. Damage to the nerves in the spinal cord can cause numbness or loss of sensation in the arms, legs, chest, back, or abdomen.
The numbness may be mild or more severe depending on the extent of the nerve damage. Mild numbness may feel like pins and needles or a reduced ability to feel touch, pain, temperature, or vibration. More severe cases can result in a complete inability to feel anything in the affected area.
Burning or Painful Sensations
Nerve damage can also manifest as burning, stabbing, or shooting pains. This occurs because the damaged nerves misfire and send abnormal pain signals to the brain. The painful sensations may be constant or may come and go.
Common examples include trigeminal neuralgia, which causes facial pain, and neuropathy, which causes burning, tingling and pain often in the hands and feet. Migraine headaches are also thought to be related to problems with nerve cell signaling in the brain.
The pain from nerve damage can range from mild to excruciating depending on which nerves are affected and the extent of the damage. Sometimes the pain is described as a constant burning sensation. Other times it may come and go in sudden, severe bursts.
Muscle Weakness or Paralysis
Nerves control the contraction of muscles throughout the body. Damage to the nerves in the brain or spinal cord can result in loss of muscle movement, weakness, or paralysis. Examples include:
- A stroke can damage brain cells, resulting in weakness or paralysis on one side of the body.
- Amyotrophic lateral sclerosis (ALS) damages the nerve cells that control muscle movement, leading to paralysis.
- Multiple sclerosis damages the myelin sheath surrounding nerves, resulting in muscle weakness, numbness, and paralysis.
- Spinal cord injuries can damage the nerve fibers carrying signals to the muscles, causing paralysis below the level of injury.
In many cases, people experience limb weakness before paralysis sets in. The weakness may come and go at first. Over time, the muscles become weaker and cease functioning altogether without nerve signals telling them to move.
Loss of Coordination and Balance
Nerve damage in the cerebellum, the part of the brain responsible for coordination, can result in loss of coordination and balance. People may become clumsy and unsteady on their feet. They may have difficulty performing daily tasks like walking, buttoning clothing, or typing.
Cerebellar damage can be caused by stroke, tumor, injury, or diseases like multiple sclerosis. When the cerebellum cannot properly coordinate muscle movements, balance and coordination greatly suffer. People may stagger, sway, or have trouble moving their arms and legs in a controlled way.
Cognitive Changes
Since the brain controls thinking and reasoning, nerve damage can result in changes in cognition, behavior, learning, memory, and other mental faculties. Examples include:
- Memory loss
- Impaired reasoning
- Loss of language skills
- Difficulty concentrating
- Confusion
- Disorganized thinking
Damage to the brain’s frontal and temporal lobes tend to have the biggest effect on cognition and behavior. Strokes, traumatic brain injury, dementia, and other conditions can all damage the brain’s nerve connections involved in cognitive function.
Vision Problems
The optic nerve carries signals from the eye to the brain’s visual cortex where they are processed into vision. Damage to the optic nerve fibers can result in various vision deficits including:
- Blurry vision
- Double vision
- Altered color perception
- Loss of peripheral vision
- Blind spots
Glaucoma, tumors, stroke, and other conditions can damage the optic nerve and impair vision. Nerve damage can also occur in the nerves of the eye muscles, resulting in vision problems from an inability to move the eyes properly.
Dizziness
Nerve damage in the inner ear can lead to dizziness, vertigo, and problems with balance and equilibrium. The vestibular nerve sends balance signals from the inner ear to the brain. When it malfunctions, people can feel off-balance, dizzy, or like the room is spinning.
Vestibular neuritis, labyrinthitis, and Meniere’s disease are examples of conditions that inflame or damage the vestibular nerve. The affected person may have vertigo attacks that come on suddenly and be unable to maintain balance.
Sensory Disorders
Nerve damage can lead to problems in how sensations are perceived and processed in the brain. For example:
- Auditory processing disorder – Difficulty processing auditory information like distinguishing sounds or following conversations.
- Visual processing disorder – Inability to interpret visual information accurately.
- Sensory processing disorder – Hypersensitivity to sounds, touch, tastes, smells, or sights.
These sensory problems arise from faulty signaling between the sensory nerves and brain. People may misinterpret or be overwhelmed by normal sensory stimuli.
Seizures
Nerve damage in certain parts of the brain can cause seizures, which are sudden surges of electrical activity in the brain. Seizures cause involuntary muscle spasms, loss of consciousness, and other symptoms.
Common causes of nerve injury that leads to seizures include:
- Traumatic brain injuries
- Scarring on the brain after a head injury or stroke (post-traumatic epilepsy)
- Tumors pressing on nerve fibers
- Infections like encephalitis and meningitis
- Lack of oxygen to the brain during a stroke or heart attack
The type of seizure depends on where the damaged nerves are located in the brain. For example, temporal lobe seizures affect memory and emotions. Occipital lobe seizures cause visual hallucinations.
Changes in Sexual Function
Nerve signals control sexual arousal, pleasure, and functioning. Nerve damage affecting those pathways can result in problems like:
- Loss of libido
- Difficulty getting aroused
- Erectile dysfunction
- Inability to orgasm
- Pain during intercourse
Spinal cord injuries are a common cause of sexual dysfunction from nerve damage, but brain injuries, endocrine problems, and certain medications can also contribute.
Difficulty Swallowing
Swallowing requires coordination of several nerves that control the muscles in the mouth, throat, and esophagus. Damage to the cranial nerves impacting swallowing can make it difficult to chew food, move it through the mouth, and swallow it down the esophagus.
This is known as dysphagia. It causes problems like:
- Food getting stuck in the throat
- Choking or coughing when eating and drinking
- Drooling
- Unintentional biting of the cheeks or tongue
Stroke is a common cause of dysphagia when it impacts the cranial nerves. Neurodegenerative disorders like Parkinson’s disease can also progressively impair swallowing over time.
Speech and Communication Difficulties
Broca’s area and Wernicke’s area are parts of the brain involved in speech production and comprehension. Damage to the nerves in these areas makes communication difficult. Symptoms may include:
- Slurred speech
- Speaking very quickly or very slowly
- Problems pronouncing words
- Using nonsense words
- Difficulty understanding spoken or written language
These speech and communication disorders resulting from neurological damage are known as aphasias. They appear most often after strokes but also with brain tumors, head injuries, and other brain diseases.
Personality Changes
The frontal lobes control personality, behavior, judgement, emotions, and self-control. Damage to the nerves in this area of the brain can profoundly impact personality and interpersonal relationships.
For example, frontal lobe damage may cause:
- Lack of inhibitions
- Poor judgement
- Impulsiveness
- Social inappropriateness
- Inflexibility
- Apathy and lack of concern for others
- Lack of self-awareness
People with frontotemporal dementia often experience dramatic personality changes as the disease progressively damages areas of the frontal and temporal lobes.
Anosmia
Anosmia refers to loss of smell. It happens when there is damage to the olfactory nerve, which carries signals about odors from the nose to the brain. Causes include:
- Head injury
- Sinus infection
- Neurodegenerative diseases like Alzheimer’s and Parkinson’s
- Tumors pressing on the olfactory nerve
People with anosmia can’t detect smells and often have a reduced sense of taste as well. The loss of smell may be complete or partial depending on the extent of nerve damage.
Fatigue
Fatigue or lack of energy is commonly reported with neurological damage. Some possible reasons nerve damage leads to fatigue include:
- Sleep disturbances from pain, numbness, or other symptoms
- Depression resulting from the impacts of nerve damage
- Impaired nerve signaling reducing motivation and energy levels
- Medications aimed at nerve pain that have fatigue as a side effect
Fatigue can also arise indirectly from the impacts of nerve damage. For example, muscle weakness requires expending more energy for movement. Loss of mobility can result in physical deconditioning and increased fatigue. Managing other neurological symptoms can also be exhausting.
Emotional Changes
Nerve damage often has emotional consequences like:
- Depression
- Anxiety
- Irritability
- Mood swings
- Emotional lability (excessive emotional reactions)
These emotional issues may arise from changes in brain chemistry caused by the nerve damage. They can also develop in reaction to the impacts on quality of life, loss of abilities, pain, and other difficult symptoms associated with nerve injuries.
Sleep Disturbances
Many people with nerve damage experience sleep disturbances and disorders such as:
- Insomnia
- Excessive daytime sleepiness
- Frequent nighttime awakening
- Restless legs syndrome
- Sleep apnea
Pain from nerve damage can make it difficult to fall asleep and stay asleep. But nerve damage can also directly impair sleep by disrupting signals between the brain and body that regulate sleep-wake cycles.
Loss of Smell or Taste
The olfactory and gustatory nerves control the senses of smell and taste. Damage to either of these cranial nerves can result in loss of smell (anosmia), loss of taste (ageusia), or distortion of smell or taste.
This may occur after an upper respiratory infection, head injury, or in neurodegenerative disorders. Loss of smell and taste not only impact enjoyment of food but can also be dangerous if someone cannot detect spoiled food, leaking gas, smoke, or other hazards.
Conclusion
In summary, nerve damage in the brain can produce diverse symptoms depending on the nerves affected. Some of the most common feelings and impairments from neurological damage include numbness, weakness, pain, fatigue, sleep disturbances, sensory loss, vision problems, seizures, speech difficulties, loss of coordination, and changes in personality or emotions.
The effects of nerve damage range from mild to disabling depending on how many nerves are damaged and how severely they are injured. Prompt diagnosis and treatment of any underlying cause can help prevent permanent or progressive neurological damage.