Merck Manual

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What Is a Neurologic Symptom?

What Is a Neurologic Symptom?

Neurologic symptoms—symptoms caused by a disorder that affects part or all of the nervous system—can vary greatly because the nervous system controls so many different body functions. Symptoms can include all forms of pain and can involve muscle function, sensation, the special senses (vision, taste, smell, and hearing), sleep, awareness (consciousness), and mental function (cognition).

The following are some relatively common neurologic symptoms:


Muscle malfunction

  • Tremor (rhythmic shaking of a body part)

  • Paralysis

  • Involuntary (unintended) movements (such as tics)

  • Abnormalities in walking

  • Clumsiness or poor coordination

  • Rigidity, stiffness, and spasticity (muscle spasms resulting from muscle stiffness)

  • Slowed movements

Changes in sensation

  • Numbness of the skin

  • Tingling or a pins-and-needles sensation

  • Increased sensitivity (hypersensitivity) to light touch

  • Loss of sensation for touch, cold, heat, or pain

  • Loss of position sense (knowing where parts of the body are in space)

Changes in the special senses

Other symptoms

Sleep problems

Changes in consciousness

Changes in cognition (mental ability)

  • Difficulty understanding language or using language to speak or write (aphasia)

  • Difficulty with common motor skills, such as striking a match or combing hair, despite normal strength (apraxia)

  • Inability to recognize familiar objects (agnosia) or familiar faces (prosopagnosia)

  • Inability to sustain concentration when doing a task

  • Inability to distinguish right from left

  • Inability to do simple arithmetic (acalculia)

  • Difficulty understanding spatial relationships (for example, being unable to draw a clock or becoming lost driving in a familiar neighborhood)

  • Dementia (dysfunction of several cognitive functions)

  • Neglect of one side of the body or denial that it exists (often due to a brain injury)