STUDY - Technical - New Dacian's Medicine
Deep
tendon reflexes, abnormal (Classical / Allopathic
Medicine)
A hyperactive deep
tendon reflex (DTR) is an abnormally brisk muscle contraction
that occurs in response to a sudden stretch induced by sharply
tapping the muscle's tendon of insertion. This elicited sign
may be graded as brisk or pathologically hyperactive.
Hyperactive DTRs are commonly accompanied by clonus.
The corticospinal
tract and other descending tracts govern the reflex arc - the
relay cycle that produces a reflex response. A corticospinal
lesion above the level of the reflex arc being tested may
result in hyperactive DTRs. Abnormal neuromuscular
transmission at the end of the reflex arc may also cause
hyperactive DTRs. For example, a deficiency of calcium or
magnesium may cause hyperactive DTRs because these
electrolytes regulate neuromuscular excitability.
Although
hyperactive DTRs commonly accompany other neurologic findings,
they may be of specific diagnostic value. For example, they're
an early, cardinal sign of hypocalcemia.
A hypoactive DTR
is an abnormally diminished muscle contraction that occurs in
response to a sudden stretch induced by sharply tapping the
muscle's tendon of insertion. It may be graded as minimal (+)
or absent (0). Symmetrically reduced (+) reflexes may be
normal.
Hypoactive DTRs
may result from damage to the reflex arc involving the
specific muscle, the peripheral nerve, the nerve roots, or the
spinal cord at that level. Hypoactive DTRs are an important
sign of many disorders, especially when they appear with other
neurologic signs and symptoms.
Documenting deep
tendon reflexes
Record the patient's deep tendon reflex scores by drawing a stick figure and entering the grades on this scale at the proper location. The figure shown here indicates hypoactive deep tendon reflexes in the legs; other reflexes are normal.
Key
0 absent
+ hypoactive (diminished)
++ normal
+++ brisk (increased)
++++ hyperactive (clonus may be present)
HISTORY:
Ask the patient about spinal cord injury or other trauma and about prolonged exposure to cold, wind, or water.
If the patient is female, ask her if she's pregnant.
Ask the patient about the onset and progression of associated signs and symptoms.
Ask the patient about paresthesia, vomiting, and altered bladder habits.
Record the patient's deep tendon reflex scores by drawing a stick figure and entering the grades on this scale at the proper location. The figure shown here indicates hypoactive deep tendon reflexes in the legs; other reflexes are normal.
Key
0 absent
+ hypoactive (diminished)
++ normal
+++ brisk (increased)
++++ hyperactive (clonus may be present)
HISTORY:
Ask the patient about spinal cord injury or other trauma and about prolonged exposure to cold, wind, or water.
If the patient is female, ask her if she's pregnant.
Ask the patient about the onset and progression of associated signs and symptoms.
Ask the patient about paresthesia, vomiting, and altered bladder habits.
PHYSICAL
ASSESSMENT:
Take the patient's vital signs, and perform a neurologic examination.
Evaluate the level of consciousness, and test motor and sensory function in the limbs. (See Documenting deep tendon reflexes.)
Check for ataxia or tremors and for speech and vision deficits.
Test for Chvostek's and Trousseau's signs and for carpopedal spasm.
Take the patient's vital signs, and perform a neurologic examination.
Evaluate the level of consciousness, and test motor and sensory function in the limbs. (See Documenting deep tendon reflexes.)
Check for ataxia or tremors and for speech and vision deficits.
Test for Chvostek's and Trousseau's signs and for carpopedal spasm.
SPECIAL
CONSIDERATIONS:
Administer muscle relaxants and sedatives to relieve severe muscle contractions. Provide a quiet, calm atmosphere to decrease neuromuscular excitability.
Administer muscle relaxants and sedatives to relieve severe muscle contractions. Provide a quiet, calm atmosphere to decrease neuromuscular excitability.
PEDIATRIC
POINTERS:
Hyperreflexia may be a normal sign in neonates. After age 6, reflex responses are similar to those of adults.
When testing DTRs in infants and small children, use distraction techniques to promote reliable results; assess motor function by watching the infant or child at play.
Cerebral palsy commonly causes hyperactive DTRs in children.
Reye's syndrome causes generalized hyperactive DTRs in stage II; however, in stage V, DTRs are absent.
Adult causes of hyperactive DTRs may also appear in children.
Hypoactive DTRs commonly occur in those with muscular dystrophy, Friedreich's ataxia, syringomyelia, and spinal cord injury. They also accompany progressive muscular atrophy, which affects preschoolers and adolescents.
Hyperreflexia may be a normal sign in neonates. After age 6, reflex responses are similar to those of adults.
When testing DTRs in infants and small children, use distraction techniques to promote reliable results; assess motor function by watching the infant or child at play.
Cerebral palsy commonly causes hyperactive DTRs in children.
Reye's syndrome causes generalized hyperactive DTRs in stage II; however, in stage V, DTRs are absent.
Adult causes of hyperactive DTRs may also appear in children.
Hypoactive DTRs commonly occur in those with muscular dystrophy, Friedreich's ataxia, syringomyelia, and spinal cord injury. They also accompany progressive muscular atrophy, which affects preschoolers and adolescents.
PATIENT
COUNSELING:
Provide emotional support to the patient and family. Teach them how to perform range-of-motion exercises to help the patient preserve muscle integrity.
Provide emotional support to the patient and family. Teach them how to perform range-of-motion exercises to help the patient preserve muscle integrity.
Bibliography:
1. Rapid Assessment, A
Flowchart Guide to Evaluating Signs & Symptoms, Lippincott
Williams & Wilkins, 2004.
2. Professional Guide to
Signs and symptoms, Edition V, Lippincott
Williams & Wilkins, 2007.
3. Guide to common
symptoms, Edition V, McGraw - Hill, 2002.
Dorin,
Merticaru (2010)