Drugs (Pregabalin) Modulates Hyperexcited Neurons

*Does not affect Ca++ influx in normal neurons

Woolf, 1994.

(4) Central Reorganization(Spinal Cord Injury)

Dorsal root ganglion

SuperficialSuperficial

DeepDeep

CC

AA

Sprouting of injury fiber alter the relationship and modified the pain between stimulant and response

After nerve injuryAfter nerve injury

(5) Loss of Inhibitory Control(Descending disinhibition)

NORMALNORMAL

INJUREDINJURED

Innocuous orInnocuous ornoxious stimulusnoxious stimulus

ExaggerateExaggeratepain responsepain response

To To brainbrain

CentralCentralDescendingDescendingLocalLocal

Dorsal horn neuronDorsal horn neuron

CentralCentralDescendingDescending

locallocal

To To brainbrain

Excitatory synapseExcitatory synapseInhibitory synapseInhibitory synapseMechanoreceptor

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

LOCATE LOOKNervous system

lesion / dysfunctionSensory abnormalities,

pattern recognition

Patient verbal descriptors,Q & A

神經評估Neurological Assessment

Holmes GM. Introduction to Clinical Neurology. Baltimore: Williams & Wilkins, 1952.

T10

T4

• History: onset, duration, character…

• Landmark of S level, distribution, location…

• Intensity, quality of pain

• Associated s/s, aggravated factors…

病史 : 問診還是最主要的

Complete information regarding pain

Use scales to aid in defining pain

McGill pain Questionnaire

Visual analog scale (VAS)

Activities of daily living scales (ADS)

Neuropathic pain scale (NPS)

• Quality

• Intensity

• Location

• pattern

也可利用疼痛問卷

Visual Analog Scales (VAS-疼痛評分 )

00 100100

NoNopainpain

ExcruciatingExcruciatingpainpain

00 100100

CompleteCompletepain reliefpain relief

NoNopain reliefpain relief

McQuay, 1998.

Note: Lines must be exactly 100 mm long

1. Tell us how intense your pain is.

The most intensepain sensation imaginable

2. Tell us how sharp your pain feels.

The most sharp

Not sharp sensation imaginable(“like a knife”)

3. Tell us how hot your pain feels.

The most hot

Not hot sensation imaginable

(“on fire”)

Neuropathic Pain Scale (NPS)

00 11 22 33 44 55 66 77 88 99 1010

Galer, 1997.

00 11 22 33 44 55 66 77 88 99 1010

00 11 22 33 44 55 66 77 88 99 1010

No painNo pain

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)

FullInterference

IntermediatePattern

Single UnitPattern

(肌電圖更難以判斷 =正常反應 ,不代表神經肌肉正常 )