neurological disorders Flashcards
Aphasia
- Definition: A language disorder caused by brain damage, affecting the ability to speak, understand, read, or write.
- Role in Assessment: Indicates potential damage to language centers in the brain, such as Broca’s (expressive aphasia) or Wernicke’s area (receptive aphasia). It helps identify the location and severity of a stroke, brain injury, or tumor.
Clonus
- Definition: A series of involuntary, rhythmic muscle contractions typically triggered by stretching a muscle.
- Role in Assessment: Suggests upper motor neuron lesions or neurological conditions like multiple sclerosis, spinal cord injuries, or strokes. It reflects hyperactive reflexes and is often seen in spastic paralysis.
Dysarthria
- Definition: Difficulty in articulating speech due to muscle weakness or coordination issues affecting speech production.
- Role in Assessment: Indicates damage to the motor pathways or cranial nerves controlling speech (e.g., cranial nerves IX, X, or XII) or conditions such as Parkinson’s disease or ALS.
Graphesthesia
- Definition: The ability to recognize a number or letter traced on the skin without visual input.
- Role in Assessment: Tests the sensory cortex and parietal lobe function. Deficits may indicate sensory cortical damage or parietal lobe dysfunction, often caused by strokes.
Extinction
- Definition: The inability to perceive simultaneous stimuli on both sides of the body, typically during bilateral testing.
- Role in Assessment: Indicates lesions in the contralateral sensory cortex, such as in strokes or tumors, affecting spatial attention.
Nystagmus
- Definition: Involuntary, rhythmic oscillation of the eyes, which can occur horizontally, vertically, or rotationally.
- Role in Assessment: Indicates dysfunction in the vestibular system, cerebellum, or brainstem, often seen in conditions like multiple sclerosis, inner ear disorders, or brainstem lesions.
Stereognosis
- Definition: The ability to recognize objects by touch without visual input.
- Role in Assessment: Tests higher sensory functions and integration in the parietal lobe. Impairments (astatognosis) suggest sensory cortical damage, as seen in strokes or brain injuries.
Two-point Discrimination
- Definition: The ability to differentiate two separate points touching the skin.
- Role in Assessment: Assesses the integrity of fine sensory pathways and cortical function. Impairments may suggest damage to the sensory cortex or peripheral neuropathy.
- Alzheimer’s Disease
o Cause: Amyloid plaques, neurofibrillary tangles.
o Symptoms: Memory loss, language issues, cortical atrophy.
- Parkinson’s Disease
o Cause: Dopamine depletion in substantia nigra.
o Symptoms: Tremor, rigidity, postural instability.
- Amyotrophic Lateral Sclerosis (ALS)
Symptoms: Weakness, muscle twitching, trouble speaking, swallowing, or breathing.
Cause: Mostly unknown; 5–10% genetic.
Progressive Muscle Weakness:
Affects muscles for movement, speech, swallowing, and breathing.
Motor Neuron Damage:
Upper and lower motor neurons degenerate, leading to muscle atrophy (wasting).
No Cure:
ALS is currently incurable, but treatments can help manage symptoms.
Huntington’s Disease
What: A genetic brain disorder causing progressive breakdown of nerve cells.
Symptoms: Uncontrolled movements, mood changes, memory loss, difficulty speaking/swallowing, dementia.
Cause: Genetic mutation; inherited from a parent (CAG repeats).
Multiple Sclerosis
What: A chronic disease where the immune system attacks the nervous system (brain and spinal cord).
Symptoms: Fatigue, vision problems, muscle weakness, numbness, coordination issues.
Cause: Unknown; likely immune-related with genetic and environmental factors.o Cause: Autoimmune destruction of myelin in CNS.
- Signs of Stroke or Increased Intracranial Pressure:
o Sudden headache, speech changes, or limb weakness.
o Visual disturbances or loss of consciousness.
- Seizure Red Flags:
o Sudden onset, motor activity, postictal confusion, triggers.