Nervous System Disorders

Consciousness

Consciousness

Awareness and responsiveness to the environment and oneself

Arousal

The state of being awake and alert, regulated by the reticular activating system

Awareness

Understanding and perception of one's surroundings and situation

Reticular Activating System

Neural network in the brainstem that regulates wakefulness and sleep-wake transitions

Brain Death

Complete and irreversible cessation of brain function, including the brainstem

Persistent Vegetative State

Wakeful unconsciousness; wakefulness without awareness

Minimally Conscious State

Condition of severely altered consciousness with minimal awareness and inconsistent but reproducible behavioral evidence of consciousness

Locked-In Syndrome

State of preserved awareness and cognition with complete paralysis of voluntary muscles except for eye movements and blinking

Doll’s Eye Response

Reflexive eye movement in response to head turning, indicating brainstem function

Seizure

Abnormal electrical activity in the brain resulting in sudden, involuntary changes in behavior, consciousness, movements, or sensations

Convulsion

Involuntary muscle contractions and relaxations (spasms), often associated with seizures

Agnosia

Inability to recognize or interpret sensory stimuli despite intact sensory pathways

Hemineglect

Inattention to or neglect of sensory input from one side of space, often due to brain injury

Dysphasia

Difficulty with language comprehension or expression

Aphasia

Loss of ability to understand or express speech due to brain damage

Wernicke’s Aphasia

Fluent aphasia with impaired comprehension and meaningless speech

Broca’s Aphasia

Non-fluent aphasia with difficulty in speech production and intact comprehension

Muscle Tone

Resting tension in muscles for posture and movement readiness

Hypotonia

Decreased muscle tone leading to floppy or limp muscles

Hypertonia

Increased muscle tone causing stiffness and resistance to stretching

Paresis

Weakness or partial paralysis of voluntary muscles

Paralysis

Complete loss of voluntary muscle function due to nerve damage

Hyperkinesia

Abnormally increased muscle movement causing involuntary movements

Hemi-

Refers to one side of the body

Para-

Refers to both lower limbs

Quadri-

Refers to all four limbs

Hypermimesis

Involuntary imitation of movements or gestures

Dyspraxia

Difficulty in planning and executing coordinated movements

Apraxia

Inability to perform purposeful movements despite intact motor function

Dysarthria

Difficulty in articulating speech due to muscle weakness or poor coordination

Agraphia

Loss of ability to write coherently due to brain injury

Primary Brain Trauma

Direct injury to the brain from a blow or impact

Secondary Brain Trauma

Indirect injury from processes initiated by primary trauma like swelling or bleeding

Focal Brain Injury

Damage to a specific area of brain due to trauma or disease.

Contusion

Bruising of brain tissue, often associated with focal brain injury.

Diffuse Brain Injury

Damage occurring over a more widespread area of the brain, often due to acceleration-deceleration forces.

Diffuse Axonal Injury

Widespread injury to axons in the brain, typically resulting from rotational forces.

Increased Intracranial Pressure

Elevated pressure within the skull, often due to swelling or bleeding.

Cerebral Perfusion Pressure

Pressure gradient that drives blood flow to the brain, calculated as the difference between mean arterial pressure and intracranial pressure.

Cerebral Edema

Swelling of brain tissue due to fluid accumulation.

Hydrocephalus

Excessive accumulation of cerebrospinal fluid within the brain's ventricles.

Cerebrovascular Disease

Conditions affecting blood vessels supplying the brain, leading to strokes or other vascular issues.

Ischemic Penumbra

Region of compromised but potentially salvageable brain tissue surrounding an ischemic core.

Cerebrovascular Accident (CVA)

Sudden onset of neurological deficits due to interruption of blood flow to the brain, either ischemic or hemorrhagic.

Stroke

Acute neurological deficit resulting from vascular injury to the brain, categorized as ischemic or hemorrhagic.

Ischemic Stroke

Stroke caused by occlusion of a blood vessel, leading to insufficient blood flow to brain tissue.

Hemorrhagic Stroke

Stroke caused by bleeding into brain tissue or surrounding spaces.

Thrombotic Stroke

Ischemic stroke caused by a blood clot in a cerebral artery.

Lacunar Stroke

Small, deep ischemic stroke affecting small penetrating arteries in the brain.

Transient Ischemic Attack (TIA)

Brief episode of neurological dysfunction caused by temporary focal ischemia without infarction.

Embolic Stroke

Ischemic stroke caused by a clot or debris from elsewhere in the body blocking a cerebral artery.

Contralateral Weakness

Weakness affecting the side of the body opposite to the brain lesion.

Flaccidity

Absence of muscle tone, leading to limp or floppy muscles.

Spasticity

Increased muscle tone causing stiffness, spasms, and difficulty with voluntary movement.

Monocular Blindness

Loss of vision in one eye due to damage to the optic nerve or retina.

Hemianopia

Visual loss affecting half of the visual field in both eyes.

Ataxia

Lack of voluntary coordination of muscle movements, affecting gait, balance, and speech.