Drugs (Pregabalin) Modulates Hyperexcited Neurons
*Does not affect Ca++ influx in normal neurons
(4) Central Reorganization
(Spinal Cord Injury)
Ab
Dorsal root ganglion
Superficial
C
Deep
After nerve injury
 Sprouting of injury fiber alter the relationship and
modified the pain between stimulant and response
Woolf, 1994.
(5) Loss of Inhibitory Control
(Descending disinhibition)
Central
Descending
local
To
brain
NORMAL
Dorsal horn neuron
Local
Central
Descending
To
brain
INJURED
Innocuous or
noxious stimulus
Exaggerate
pain response
Excitatory synapse
Inhibitory synapse
Mechanoreceptor
Woolf, 1999.
Brain-Gate Theory
(閘門理論)
• Melzack and Wall (1965)
• Melzack-wall-Casey (1982)--- modified theory:
cognitive control+ descending brain-stem control
block NE and
serotonin reuptake
臨床診斷
(3L)
LISTEN
Patient verbal descriptors,
Q&A
LOCATE
LOOK
Nervous system
lesion / dysfunction
Sensory abnormalities,
pattern recognition
神經評估
Neurological Assessment
T4
• History: onset, duration,
character…
T10
• Landmark of S level,
distribution, location…
• Intensity, quality of pain
• Associated s/s,
aggravated factors…
Holmes GM. Introduction to Clinical Neurology. Baltimore: Williams & Wilkins, 1952.
病史: 問診還是最主要的
Complete information
regarding pain
Use scales to aid
in defining pain
• Quality
McGill pain Questionnaire
• Intensity
Visual analog scale (VAS)
• Location
Activities of daily living
scales (ADS)
• pattern
Neuropathic pain scale (NPS)
也可利用疼痛問卷
Visual Analog Scales (VAS-疼痛評分)
No
pain
Excruciating
pain
0
100
Complete
pain relief
No
pain relief
0
100
Note: Lines must be exactly 100 mm long
McQuay, 1998.
Neuropathic Pain Scale (NPS)
1.
Tell us how intense your pain is.
No pain 0 1 2 3 4 5 6 7 8 9 10
2.
Tell us how sharp your pain feels.
The most sharp
sensation imaginable
(“like a knife”)
Not sharp
3.
The most intense
pain sensation imaginable
0 1 2 3 4 5 6 7 8 9 10
Tell us how hot your pain feels.
The most hot
sensation imaginable
(“on fire”)
Not hot
0 1 2 3 4 5 6 7 8 9 10
Galer, 1997.
Dull, cold,
sensitive, itchy
臉部表情評分表
NCV(神經傳導)
脕隧道症候群(Carpal tunnel syndrome)
However, small fiber disease can not be detectable
(亦即神經傳導正常,不代表神經沒有病變)
EMG(肌電圖)
(neurogenic or myogenic)
Full
Interference
Intermediate
Pattern
Single Unit
Pattern
(肌電圖更難以判斷=正常反應,不代表神經肌肉正常)