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Alterations of Neurologic Function

Alterations in Cognitive System and Cerebral Dynamics

  • Functional Adequacy: Involves cognitive, sensory, and motor neural systems. Alterations can lead to diseases affecting functional adequacy.

Cognitive Systems

  • Consciousness: Full awareness of self and environment includes arousal (state of being awake) and awareness (cognitive functions: memory, language, executive systems).
  • Cognitive Functions: Attentional, memory, and emotional systems; alterations can lead to dysfunctions like seizure disorders.

Arousal Alterations

  • Structural Causes:
    • Supratentorial: Above tentorium cerebelli (e.g., bleeding, tumors).
    • Infratentorial: Below tentorium; affects arousal (e.g., head injuries).
    • Subdural: Below dura mater; extracerebral pathologies affect arousal.
  • Metabolic Causes: Energy delivery issues, drugs/toxins affecting neurological functioning, leading to altered consciousness and responses.

Level of Consciousness Changes

  • Changes assessed via response patterns, indicating brain dysfunction (confusion to coma).
  • Breathing patterns relate to the consciousness level (e.g., hyperventilation apnea).

Neurological Responses

  • Pupillary Changes: Indicative of brainstem dysfunction; responses (dilated, fixed) signal hypoxia or drug effects.
  • Ocular Motor Responses: Tests for brainstem function (Doll's eyes reflex, ocular vestibular reflex).

Motor Responses and Brain Function

  • Responses can range from purposeful to non-existent, indicating brainstem integrity or damage.
  • Common pathological responses include vomiting and yawning associated with CNS injuries.

Brain Death vs. Cerebral Death

  • Brain Death: Irreversible cessation of brain function; no response or spontaneous breathing.
  • Cerebral Death: Loss of cerebral function; brainstem & autonomic functions may remain intact, allowing for basic metabolic functions.

Cognitive Function Alterations

  • Attention and Memory Issues: Deficits in selective attention, memory retention, and retrieval (retrograde & anterograde amnesia).
  • Aphasia: Disorders in language comprehension and production (Wernicke's, Broca's aphasia).

Delirium and Dementia

  • Delirium: Acute confusional state; causes include drug intoxication, infections.
  • Dementia: Progressive decline in cognitive function; various causes including genetics and vascular diseases (Alzheimer's as a common type).

Stroke Types and Consequences

  • Ischemic Stroke: Caused by thrombus or embolus; management via thrombolysis within a specific time window.
  • Hemorrhagic Stroke: Caused by bleeding; immediate control is critical to prevent further damage.

Neurological Tumors and Abnormalities

  • Primary vs. Secondary Tumors: Primary originate from neural tissues. Secondary (metastatic) spread from other body parts.
  • Common tumors: Gliomas, meningiomas, nerve sheath tumors (associated with specific symptoms).