Central Nervous System (CNS)
- Thalamus: Relay station. Sensory pathways form Synapses on way to cerebral cortex
- Hypothalamus: Control center. Vital function (HR, BP, T) control center, sleep center, ant. and post. Pituitary gland regulator, ANS coordinator, emotional status
- Cerebellum: Motor coordination of vol. movements, equilibrium, muscle tone
- Brainstem: Central core of brain
- Midbrain- Merges w/ thalamus and hypothalamus. Contains motor neurons and tracts, nuclei for CN III-IV; auditory & visual reflexes
- Pons- contains ascending and descending fiber tracts, nuclei for CN V-VII
- Medulla- Continuation of SC in brain. Contains all ascending & Descending fiber tracts connecting brain and SC. Vital autonomic centers (R, P, sneezing, coughing, vomiting), nuclei for CN VIII-XII, Pyramidal decussation occurs here.
- Spinal Cord: “highway” for descending and ascending fiber tracts connecting brain to spinal nerves; mediates reflexes
What is the spinothalamic tract responsible for in the CNS?
pain, temperature, light touch
What does the Corticospinal or Pyramidal Tract of the CNS mediate?
- skilled, discrete, purposeful movements.
- Impulses are directed from Upper motor neurons--->lower MN--->Perifery.
What is the Posterior Column responsible for in the CNS?
Postition, vibration, fine touch.
What are the extrapyramidal and cerebellar tracts of the CNS responsible for?
- Extrapyramidal: Maintain muscle tone and control body movements
- Cerebellar system: coordinates movement, maintains equillibrium and posture.
- Nerve- bundle of fibers outside CNS.
- Peripheral nerves- carry input to CNS via sensory afferent fibers & deliver output from CNS via motor efferent fibers.
- Reflex Arc: involuntary defense mechanism
- Deep Tendon Reflexes (DTRs)
- Pathologic (if early childhood reflexes return, thing pathology.)
Know the Cranial nerves and whether they are sensory (S), motor (M), or both (B).
- On = Olfactory- I. (S)
- Old = Optic- II. (S)
- Olympus =Oculomotor- III. (M)
- Towering = Trochlear- IV. (M)
- Tops = Trigeminal- V. (B)
- A = Abducens- VI. (M)
- Finn = Facial- VII. (B)
- And = Acoustic- VIII. (S)
- German = Glossopharyngeal- IX. (B)
- Viewed = Vagus- X (B)
- Some = Spinal Accessory- XI. (M)
- Hops = Hypoglossal- XII. (M)
Subjective Data CNS
- 1. Headache, ie "Is this the worst HA you've ever had?"
- 2. Head injury, if so, "Did you lose consciousness?"
- 3. Dizziness/Vertigo: Syncope. Caused by decreased blood supply to brain
- 4. Seizures
- 5. Tremors
- 6. Weakness
- 7. Uncoordinated (ataxic)
- 8. Numbness or tingling (paristhesia)
- 9. Difficulty swallowing (Dysphagia)
- 10. Difficulty speaking (Dysphasia)
- 11. Significant past history (espeically of seizures)
- 12. Environmental/
- occupational hazards
What is the clinical term for "stroke?"
Cerebral vascular accident (CVA)
What is the clinical term for "mini stroke?"
Transcient Ischemic Attack (TIA)
What does the Glasgow Coma Scale measure?
Best eye opening, motor response, and verbal response.
How do you assess for CN1 function?
- Assess nasal patency first: Hold nostril, sniff. Alternate.
- Use non-irritating smells: e.g. soap, coffee, vanilla
- Not typically tested
- Problems are usually due to nasal disease, smoking, cocaine.
How do you assess for CN2 functions?
- Examine the Optic Fundi
- Test Visual Acuity: Snellen chart
- Screen Visual Fields by Confrontation (Peripheral vision)
- Test Pupillary Reactions to Light
- Direct/Consensual Light Reflex
- Test Pupillary Reactions to Accommodation
How do you assess for CN3 function?
- Opens eye lids - Observe for Ptosis
- Check gaze in the six cardinal directions using a cross or "H" pattern
- Check slowly
- Check for nystagmus (ocular bounces at the extremes)
- Tests all eye movements except
- Lateral (CN6) and towards the nose (CN4)
- Test Pupillary Reactions to Light
How do you assess for CN5 function?
Test Temporal and Masseter Muscle Strength .Ask patient to both open their mouth and clench their teeth. Palpate as they do this.
- Test the Three Divisions for Pain Sensation
- Use a suitable sharp or dull object to test the forehead, cheeks, and jaw on both sides
- If you find an abnormality then:
- Test the three divisions for temperature sensation with a tuning fork heated or cooled by water
- Test the three divisions for sensation to light touch using a wisp of cotton
- Test the Corneal Reflex: Sensory response – blink bilaterally when an object is quickly moved in front of eye.
How do you assess for CN7 function?
- Moves facial muscles, closes eye lids - Observe for Any Facial Droop or Asymmetry
- Ask Patient to do the following, note any lag, weakness, or asymmetry:
- Raise eyebrows
- Close both eyes to resistance
- Show teeth
- Puff out cheeks
- Test the Corneal Reflex: motor
- Sensory: Taste on anterior 2/3 of tongue
How do you assess for CN9 function?
- Motor: Phonation, speech, swallow
- Listen to the patient's voice, is it hoarse or nasal?
- Ask Patient to Swallow
- Ask Patient to Say "Ahhh"
- Watch the movements of the soft palate, uvula, and pharynx
- Test Gag Reflex (Only on unconscious or uncooperative patient)
Sensory for CN IX-post tongue, for CNX-pharynx, larynx, and viscera. Can experience syncope and/or pain from internal distress.
How do you assess for CN11 function?
- From behind, look for atrophy or asymmetry of the trapezius muscles.
- Ask patient to shrug shoulders against resistance.
- Ask patient to turn their head against resistance. Watch and palpate the sternomastoid muscle on the opposite side.
How do you assess for CN12 function?
- Listen to the articulation of the patient's words, ie have them repeat, "Light. Tight. Dynamite."
- Observe the tongue as it lies in the mouth
- Ask patient to: Protrude tongue and move tongue from side to side.
What is the Romberg Test and what does it test for?
- Have pt stand feet together, arms down, eyes closed. Pt. must be able to stand without falling down for 30 seconds.
- Tests cerebellar function.
What is the tandem walking test?
Pt is able to walk in a straight line, heel of one foot to the toe of the other.
How do you assess for the Posterior Column Function?
- Vibration: Base of tuning fork to base of pt's great toe.
- Position (Kinesthesia): move pt's great toe up or down and have pt identify it's position.
- Tactile Discrimination:
- Two-point discrimination
- Point location
What is Stereognosis?
With eyes closed, pt identifies a familiar object placed in his hand.
What is Graphesthesea?
With eyes closed, pt identifies a number drawn on his palm.
What is two-point discrimination?
With eyes closed, pt identifies to asymetric points you are touching on his body.
What is Extinction?
With eyes closed, pt identifies which two symetrical points you are touching on his body bilaterally.
What is point location?
With eyes closed, pt identifies which single point you are touched on his body.
What is Reinforcement?
When you get a pt to relax via distraction in order to get a reliable reflex reaction.
- Depress tendon with thumb, strike own thumbnail with point of hammer
- Support arm so that pt is not using triceps. Strike with flat of hammer.
- Hold pt's thumb, strike with flat of hammer.
- Have pt scoot a little off bed so that back of knee is not resting against the bed. Strike with flat of hammer.
- Support foot with one hand, strike with flat of hammer with the other.
- Clonus: rapid twitching movement of foot with hammer strike. Indicates increased risk for seizure.
- Abdominal reflex: "Tickle" abd area near naval. Naval will twitch in that direction
- Cremasteric reflex: You know this one. Everyone knows this one.
- Plantar reflex: Uh....
- Babinski reflex: Stroke bottome of foot. Children<2, toes will flair. In adults, toes may curl. If toes flair in adults, it may be a sign of neurological damage.
Who is most at risk for peripheral neuropathy?
- May experience loss of sensation or tingling in extremeties.
- Can also be called peristhesia
Neurological considerations for Aging Adults
- ↓ neurons in brain and spinal cord
- ↓ muscle bulk, strength & tone
- Impaired coordination & agility
- Impaired reaction time and diminished sensations
- ↓ Cerebral blood flow→ dizziness, off-balance
- Senile tremors, dyskinesias
- Slower, more deliberate gait
- Loss of vibratory sense in ankle
- ↓ tactile sensation
- DTRs less brisk- gradual loss of typical reflex in distal areas