The nervous system, a complex network controlling and coordinating all body activities, is composed of the brain, spinal cord, and peripheral nerves. Disorders affecting any part of this system can manifest in a wide variety of signs and symptoms, often impacting multiple bodily functions. Recognizing these general manifestations is crucial for identifying potential neurological issues.

These notes outline common signs and symptoms that may indicate an underlying nervous system disorder. It’s important to remember that these symptoms can also be caused by non-neurological conditions, and a thorough medical evaluation is necessary for accurate diagnosis.

Alterations in Consciousness and Mental Status

Changes in how a person is aware of themselves and their environment, as well as changes in cognitive function, are significant indicators of nervous system problems, particularly those affecting the brain.

• Changes in Level of Consciousness: This can range from mild confusion or lethargy to stupor or coma. It reflects impaired brain function, often due to injury, infection, metabolic disturbances, or structural lesions.

• Confusion and Disorientation: Difficulty thinking clearly, understanding their surroundings, or knowing their identity, time, or place.

• Memory Loss: Difficulty recalling recent or past events. This can be a symptom of various conditions, including dementia, head injury, or stroke.

• Difficulty with Concentration and Attention: Inability to focus or maintain attention on tasks.

• Changes in Behavior and Personality: Irritability, agitation, depression, anxiety, or inappropriate social behavior can be linked to neurological conditions affecting areas of the brain that control mood and behavior.

• Delirium: An acute state of confusion, often fluctuating, with reduced awareness of the environment. It can be caused by infections, metabolic imbalances, or medication side effects, sometimes related to underlying neurological vulnerability.

• Dementia: A progressive decline in cognitive function, including memory, thinking, and reasoning, severe enough to interfere with daily life.

Motor Symptoms

Disorders affecting the motor pathways in the brain, spinal cord, or peripheral nerves can lead to a variety of movement-related symptoms.

• Weakness (Paresis) or Paralysis (Plegia): Reduced strength or complete loss of muscle function in a part of the body. This can affect one side (hemiparesis/hemiplegia), both legs (paraparesis/paraplegia), or all four limbs (quadriparesis/quadriplegia).

• Tremors: Involuntary rhythmic shaking of a body part. Different types of tremors exist, associated with conditions like Parkinson’s disease or essential tremor.

• Ataxia: Lack of voluntary coordination of muscle movements, leading to difficulties with balance, gait, and fine motor skills. It often indicates problems with the cerebellum.

• Spasticity: Increased muscle tone, causing stiffness and resistance to movement. This is often seen after stroke or in conditions like multiple sclerosis.

• Rigidity: Stiffness and resistance to passive movement throughout the range of motion, characteristic of Parkinson’s disease.

• Dystonia: Involuntary muscle contractions that cause slow, repetitive movements or abnormal postures.

• Involuntary Movements: Other uncontrolled movements such as tics, chorea (jerky, irregular movements), or athetosis (slow, writhing movements).

• Gait Abnormalities: Changes in the way a person walks, such as shuffling, staggering, or difficulty initiating movement.

Sensory Symptoms

Damage to sensory pathways can result in altered sensations.

• Numbness or Tingling (Paresthesia): Abnormal sensations, often described as pins and needles.

• Loss of Sensation (Anesthesia): Inability to feel touch, pain, temperature, or vibration in a specific area.

• Pain: Neuropathic pain, caused by damage to nerves, can be burning, shooting, or sharp. Headaches are also a common neurological symptom, with various types and causes.

• Hypersensitivity (Hyperesthesia): Increased sensitivity to stimuli that are normally only mildly painful.

• Loss of Proprioception: Difficulty knowing the position of one’s body parts in space.

Cranial Nerve Dysfunction

The cranial nerves control various functions of the head and neck, including vision, hearing, taste, smell, facial movement, and swallowing. Dysfunction can lead to specific symptoms.

• Visual Disturbances: Blurred vision, double vision (diplopia), loss of peripheral vision, or complete vision loss.

• Hearing Loss or Tinnitus: Reduced ability to hear or ringing in the ears.

• Dizziness or Vertigo: Sensation of spinning or unsteadiness.

• Difficulty Swallowing (Dysphagia): Problems with the coordinated muscle movements required for swallowing.

• Facial Weakness or Drooping: Unilateral or bilateral weakness of facial muscles.

• Changes in Taste or Smell: Loss or alteration of these senses.

• Speech Difficulties (Dysarthria or Aphasia): Slurred speech (dysarthria) or difficulty with language comprehension or expression (aphasia).

Other General Symptoms

Several other symptoms can point towards a nervous system disorder.

• Headache: A very common symptom, but certain characteristics (sudden onset, severe intensity, associated neurological symptoms) can indicate a serious underlying issue.

• Seizures: Sudden, uncontrolled electrical disturbances in the brain that can cause changes in behavior, movements, feelings, or levels of consciousness.

• Fatigue: Persistent and overwhelming tiredness that is not relieved by rest.

• Sleep Disturbances: Insomnia, excessive sleepiness, or disrupted sleep patterns.

• Bowel and Bladder Dysfunction: Incontinence or difficulty controlling bowel and bladder function, often seen in spinal cord disorders or conditions affecting the nerves supplying these organs.

• Autonomic Dysfunction: Problems with the involuntary functions controlled by the autonomic nervous system, such as blood pressure regulation (orthostatic hypotension), heart rate, digestion, and sweating.