Penyusun:

Oleh Dokter Muda Nurul Mahirah Binti Meor Halil

030.04.267

Fakultas Kedokteran Universitas Trisakti

Jakarta 2011

1. What is the main effect of descending motor systems on reflexes?

Answer : Motor cortex and descending motor pathways are generally involved in suppressing (inhibiting) reflexes.

2. What are the 7 Deep Tendon Reflex exams (DTRs)? What sensory/motor nerves are they testing?

Answer : Biceps - musculocutaneous nerve and mainly C6; Triceps - radial nerve and mainly C7; Brachioradialis (radial periosteal) - radial nerve and mainly C6; Finger flexor - musculocutaneous nerve and mainly C7-8; Patellar - femoral nerve and mainly L3-L4; Achilles' reflex (ankle jerk) - tibial nerve and mainly S1; Jaw jerk - trigeminal

3. What are the superficial reflexes?

Answer : Superficial reflexes include: abdominal, cremaster, plantar, anal wink.

4. What is the effect of damage to corticospinal fibers on myotatic (deep tendon) reflexes? What is the effect on superficial reflexes?

Answer : DTRs increase with damage to descending motor pathways; superficial reflexes decrease with damage to descending motor pathways.

5. What primitive reflexes emerge with diffuse bilateral hemispheric dysfunction?

Answer : Diffuse bilateral hemispheric dysfunction can dysinhibit grasp, glabellar, suck, rooting, oculocephalic and nuchocephalic reflexes. (refleks ini muncul kembali)

6. What happens to DTRs with lesions in the cerebellum & basal ganglia?

Answer : Usually no change, though may be sluggish with cerebellar damage.

7. How are DTRs graded?\

Answer : 0-4+. To grade a reflex as "0", you must try reinforcement. 4+ means there is sustained clonus. 1 is sluggish, 2 is "normal" and 3 is "brisk".

8. What is the most important consideration in testing reflexes?

Answer : Symmetry.

9. What reflex changes would occur in lesions of muscles?

Answer : No change unless end stage.

10. What reflex changes would occur in lesions of the neuromuscular junction?

Answer : Normal to decreased depending on severity of weakness.

11. What reflex changes would occur in lesions of the peripheral nerves?

Answer : Decreased in clinically affected areas.

12. What reflex changes would occur in lesions of the nerve root?

Answer : Decreased in clinically affected areas.

13. What reflex changes would occur in lesions of the spinal cord and brain stem?

Answer: Usually reflexes will be increased unless the gray matter (anterior horn cells, lower motor neurons) is damaged right at the reflex level. Acute spinal cord injury can result in spinal cord shock (flaccid, decreased reflex).

14. How can damage to sensory nerve fibers affect reflexes?

Answer : Damage to sensory nerve fibers may also decrease reflexes by damaging the afferent limb of the reflex arc.

15. What is the effect of neuropathy on muscle stretch reflexes?

Answer : Neuropathy often produces decreased reflexes out of proportion to weakness.

16. What are some visceral reflexes that can be tested?

Answer : Visceral reflexes include: pupillary light reflex, oculocardiac, carotid sinus, bulbocavernosus, rectal (internal sphincter) and orthostatic blood pressure regulation.