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Neuropathic Pain




V.V.AIexeyev.* A.V.Novikov,* N N.Yakhno,* Neurology Dept, Moscow Medical Academy, Moscow, 119021, Russia.

Aim of Study: To investigate the presence and extent of nerves injury in CRPS type I.

Methods: During 1993-1998 we observed 70 patients with CRPS (28 - type 1 and 42 - type II) according to International classification of chronic pain, ranging in age of 19-62 and duration of disease from 4 months to 2 years. Motor and sensory conduction velocities (CV) and somatosensory evoked potentials (SEP) were investigated

Results: There are no differences in clinical features between CRPS type I and type II. Analysis ofCV and early components of SEP in all cases detects the affection of peripheral fibers. The quality of pain, autonomic and trophic changes and movements disorder compared with extent of motor and sensory fibers affection

Conclusion: The base of differences between CRPS type I and type II is a nature of initiating event, which has no pathophysiological significance The base of clinical features in all cases of CRPS is affection of peripheral nervous fibers Thus the separation CRPS type I as a subtype of CRPS calls for discussion


Charles E Argoff. Grace Forde, Cohn Pain Management Center, Dcpt of Neurology, North Shore Uni\ Hospital, Manhasset, NY USA

Aim of Investigation: To investigate whether or not BOTOX ® injections into myofascial trigger points improv es the pain, other associated symptoms or function of patients with upper extremity CRPS Type1 (RSD).

Methods: Ten patients with upper extremity CRPS Type 1 and concurrent proximal ipsilateral mvofascial pain were treated in an open labeled manner with BOTOX ® injections into affected miofascial trigger points The diagnosis of CRPS Type 1 was made based upon currently accepted diagnostic criteria The most affected myofascial trigger points were identified by manual examination All patients had been previously treated with sympathetic nerve blocks without satisfactory responses Each patient underwent a single-blinded intravenous phcntolaminc infusion prior to treatment with BOTOX® Each patient was seen at two week intervals for 12 weeks and received physical therapy at least twice weekly during the study period

Results: All patients who participated in this initial study reported dramatic reduction not only in the ncuropathic pain, including the allodynia and hyperalgesia, in their affected limb, but also in the proximal ipsilateral myofascial pain which they had been experiencing before treatment Each patient also experienced obvious functional improvement as noted by their physical therapist Conclusions' Although all patients treated improved, it is not known based upon this study, what role, it any, the myofascial abnormalities commonly seen in patients with CRPS Type 1 play in perpetuating the autonomic abnormalities, the neuropathic pain or the dysfunctional state of the affected limb It is also not clear by what mechanism BOTOX ® injections helped. We have a begun a randomized, placebo controlled, double blinded study to further investigate the above findings


R. Baron". Y. Baron*2, 4, E. Disbrow*2, T.P L. Roberts*2, Depts of 'Neurology and radiology, Univ of California San Francisco, USA, Klinik fur Neurologie, Chnstian-Albrechts-Univ Kiel, Kiel, Germany, ''Radiologische Abteilung, Stadtisches Krankenhaus Kiel, Kiel, Germany

Aim of Investigation: To investigate, using functional magnetic resonance imaging (fMRl), the neural network that is activated by the pain component ofcapsaicm-induccd secondary mechanical hyperalgesia. Capsaicm-cvokcd hyperalgesia is a model for clinical neuropathic pain and central sensiti/ation

Methods: In nine healthy individuals the cerebral activation pattern resulting from cutaneous non-painful mechanical stimulation at the dominant forearm was imaged using fMRI Capsaicin was injected adjacent to the stimulation site to induce secondary mechanical hyperalgesia The identical mechanical stimulation was then perceived as painful without changing the stimulus intensity and location Both activation patterns were compared to isolate the specific pain-related component of mechanical hyperalgesia from the tactile component

Results: The pattern during non-painful mechanical stimulation included contralateral SI and bilateral SII activity. During hyperalgesia significantly higher activation was found in the contralateral prefrontal cortex, i e , the middle (Brodmann Area 6/8/9) and inferior frontal gyrus (BA 44/45) No change was present within SI, SII and the anterior cmgulate cortex

Conclusions: Prefrontal activation is interpreted as a consequence of attention, cognitive evaluation and planning of motor behavior in response to pain. The lack of activation of the anterior cingulate contrasts with physiological pain after C-nociceptor stimulation. It might indicate differences in the processing of hyperalgesia and C-nociccptor pain or might be due to habituation of affective sensations during hyperalgesia as compared with acute capsaicin pain. Acknowledgment- Supported by the Alexander von Humboldt-Foundation


Thomas K Baumann. Melissa Martcnson*, Dcpt of Neurological Surgery & Dept of Physiology and Pharmacology, Oregon Health Sciences Univ, Portland, OR 97201, LSA

Aim of Investigation: To determine if the cell bodies of human dorsal root ganglion (DRG) neurons from patients with neuropathic pain fire action potentials spontaneously Methods Human dorsal root ganglia were obtained from 20 patients treated surgically (by ganglionectomy) for chronic intractable pain I he ganglia were dissociated cn/ymatically and the cells placed in culture. Action potential discharge was recorded from individual neurons using the current-damp variant of the tight-seal, whole-cell (patch-clamp) method

Results: Most cultures (18 21) contained neurons which had spontaneous action potential discharge In the active cultures as many as 5 1 "u (median 19u) of the neurons had background discharge. Furthermore, 80" o of spontaneously active neurons responded when tested with capsaicin

Conclusions: Somata of DRG neurons fired action potentials in the absence of any intentional stimulus Since many of the spontaneously active neurons responded to capsaii-m, the results are compatible with the hypothesis that spontaneous activity emanating from the DRG is a likely source of pain in patients with neuro-pathic pain from nerve injury

Acknowledgments: Supported in pan by a grant from the American Cancer Society and a grant from the N1H (R01 NS37149) We would like to thank Dr K J. Burchiel for providing the human tissue


U. Baumgartner2, W Mageri, H C Hopf2, R -D Treede, Inst of Physiology and Pathophysiology and Neurological Clinic, Johannes-Gutenberg Univ, D-55099 Mainz, Germany

Aim of Investigation: The underlying mechanisms ofneuropathic pain vary across patients In this study, we tried to characterize different mechanisms of spontaneous pain by quantitative sensory testing

Methods: We investigated 30 consecutive neurological patients with dysaesthesia of various origins (peripheral, spinal or brain-stem lesions) Tactile thresholds were determined with calibrated von Prey hairs (0 1 1 mm, 0 5 - 4100 mN) Thresholds and stimulus-response functions for pricking pain were determined with a series of calibrated punctate mechanical stimulators (0 200 urn, 8 -512 mN), which activate A5-nociceptors Allodynia was tested by light stroking with a brush, Q-tip and cotton wisp Perceptual wind-up was tested by trains of punctate stimuli at 0 2 or 1 Hz

Results: A subgroup of patients (8/30) with minor sensory loss exhibited hyperalgesia All cases ofallodynia (4/30) fell into this group Another group of patients (10/30) was charactenzed by severe sensory loss With one exception, all patients suffering from spontaneous pain (12/30) were either members of the hyperalgesia (6/12) or deafferentation subgroup (5/10) independent of lesion site In both groups spontaneous pain was found significantly more often than in an intermediate group with moderate sensory loss (p <0 05, each) Perceptual windup did not correlate with hyperalgesia or ongoing pain

Conclusions: We conclude that neuropathic pain is based on two distinct mechanisms It can either be caused by central sensitization (secondary hyperalgesia, in patients with minor sensory loss) or by deafferentation (analgesia dolorosa, in patients with major sensory loss)


Mans Belfrage2. Karl-Frednk Sjolund, RolfKarlsten3, Marta Segerdahl, Staffan Amer, Torsten Gordh Jr3, AlfSollevi Karolinska Inst, Dept ofAnesthesiology and Intensive Care, Karolinska Hospital, St. Gorans Hospital, Uppsala Univ Hospital, Huddinge Hospital, Sweden.

Aim: To study the effects of systemic adenosme (ADO) infusion on spontaneous pain and sensory dysfunction in peripheral neuropathic pain

Methods: Twenty-six patients with long-lasting neuropathic pain following injury to a penpheral nerve and dynamic tactile allodynia were included ADO, 50ug/kg/mm and placebo were infused i v for 60 mm on different occasions (double-blind, crossover design) Spontaneous pain and sensory dysfunction were assessed before treatment and afrer 45 mm of infusion Wilcoxon's test for matched pairs was used for statistical analyses Results are given as median and quartiles.

Results: Spontaneous pain was before placebo 43 (30-56) and before ADO 38 (27-55) Spontaneous pain was reduced by ADO (p=0 006) but not significantly by placebo (p=0 102) The effect of ADO was not significant from placebo The area of tactile allodynia (range 15-780 cm2) was reduced following ADO 18 (0-67)% compared to the changes after placebo 0 (0-14)%, (p=0 048)Eleven patients reported a positive effect on their pain condition after ADO The duration was 10 h but in two cases the patients reported pain relief with a duration of more than 6 months Three patients reported transient improvement after placebo These overall positive subjective effects on the clinical condition after ADO were significant compared to placebo (p=0 028)

Conclusions: This study demonstrates reduction of the area of tactile allodynia and transient, or in a few cases long-lasting, pain relief following systemic ADO infusion in patients suffering of peripheral neuropathic pain The results suggest a therapeutic potential for ADO receptor stimulation in some neuropathic pain conditions


F Birklem. B Riedl*, B Neundorfer*, Neurologische Univer-sitatsklmik Eriangen, Schwabachanlage 6, D-91054 Eriangen, Germany

Aim of Investigation: CRPS occures after noxious events such as trauma, surgery, myocardial and brain mfarction Beside sympathetic vasomotor disturbances long standing pain and hyperalgesia are the most crippling symptoms The pathogenesis of the disorder is still unclear The aim of this study was to investigate the influence of low pH in the pathophysiology of pain in CRPS under the hypothesis that tissue acidosis due to vasomotor abnormalities is one important factor for pain in CRPS

Methods: We investigated 7 patients with CRPS at the upper extremity with a mean duration of the disease of 25 weeks (range 8-50 weeks) and 10 control subjects A motonzed syringe pump was used to infuse an acid buffer solution (pH 6,1) mtradermally on the back of hand and thereafter into the mterosseus I muscle on both sides A flow rate of 30 ml/h was chosen for mtradermal and 7,5 ml/h for intramuscular infusion over a penod of 10 minutes The magnitude of pain was rated on a visual analogue scale

Results: We found a significant hyperalgesia to protons on the affected side Low pH in the skin (affected 21 % VAS, unaffected 5 2% VAS, p<0,05) and in the muscle (affected 33 3% VAS, unaffected 19% VAS, p<0,05) resulted in significantly more pain on the affected side In controls there was no significant nght vs left difference The pain quality due to infusion into the muscle was described as being nearly the same "deep" pain present in CPRS

Conclusion: Our results suggest that pain and hyperalgesia due to tissue acidosis is an important factor in CRPS Whether this depends on a decreased buffer capacity in CRPS tissue or a sensitization ofnociceptors needs to be clarified Acknowledgement Supported by Deutsche Forschungsgemem-schaft SFB 353,C3


M E Isasi, M Acuna Mounn, E S Isasi, Centre de Terapia Gravi-tacional (CTG), Centro de Cardiologia del Hospital Maciel, Montevideo, Uruguay

We previously demonstrated that the endothehum is an important target for GS, and that GS constitutes a mechanical stimulus over the vessel wall that enhances PGI; and NO synthesis (Isasi & Isasi) Since the pathogenesis of pain in RSD involves "vascular diathesis", we have the idea to apply GS, to break the vicious pain cycle related with increased vasoconstnctor responses Fifty outpatients (31 F,t9 M, mean age 44 years) suffenng from RSD were studied RSD had been tnggered by trauma in 41 and by surgery in 9 cases The evolution time of RSD before GS was between If to 3 months (n=32), 3 to 6 m (n=l 1), 6 to 12m (n=5) and more than 12 months (n=2) After informed consent, all patients were exposed to GS (+GZ) The pts ran on a couch of a human centnfugation machine (Isasi's Model) and were exposed daily to accelerative and decelerative profiles (0-6 g), during 30 minutes and from 2 to 20 sessions. The diagnosis and evaluation was performed by the clinical evolution, digital photoplethysmographic (DPHG) response and delay static scintigraphic bone images (SBI) Prior and after GS vascular diathesis was put on evidence by DPHG at baseline or after cold test Clinical and DPHG improvement were observed in 46 patients (92%) Five patients had little or total analgesia once the first GS session was completed. SBI persisted positive in spite of clinical and DPHG improvements

Conclusion: Gravitational Stress demonstrated to be an effective treatment at early stages of reflex sympathetic dystrophy


Kountouris D* Center for Neurological Diagnosis, Michalako-poulou 45, 11528 Athens, Greece

Aim of Investigation: Trigeminal neuralgia (TN) is the most commonly described pain seen in MS patients The causes of both conditions are mutlifactonal with environmental and physiological influents The necessity of an appropriate and effective treatment is imperative since an inability in treatment could cause suicidal tendencies.

Method: In a period of three years 18 patients (8 male and 10 female) who suffered from MS were being observed They presented different intensity ofTN All these patients were administered car-bamazepme in the acute phase of TN 13 of those patient (10 female and 3 male) received mitoxantrone and IV1G for a penod of 3 years. All the results were recorded and studied before and after treatment

Results: After three years 8 patient who received mitoxantrone and IVIG released from pain without being given additional therapy Two others recovered fully continuing taking carbamazepine The remaining 3 patients as well as the other 5 the group who did not receive mitoxantrone and IVIG treatment kept suffering from periodic pain attacks

Conclusion: The suggested treatment with prolonged effectiveness in MS with TN seems to be the administration ofimmunosuppres-sive and immunomodulatory drugs. The sooner this treatment starts the more effective appear to be


P Bonara*, A Galli*,C Mocellm*, C Frugoni*. G De Benedittis (SPON: A. De Santis), 3rd Division of General Medicine, Laboratory of Flow Cytometry, IRCCS, Policlinico Hospital, Milan, "Pain Research & Treatment Unit, Inst ofNeurosurgery, Univ of Milan, Milan, Italy

Aim of Investigation: The efficacy of topical aspinn/diethyl ether (ADE) mixture in the treatment of acute neuralgia and postherpetic neuralgia had been recently established in open and double blind studies (De Benedittis et al. 1992; 1996) Moreover ADE significantly reduced the nsk of developing postherpetic neuralgia in treated patients and aspinn significantly inhibited the replication of VZV in vitro (Pnmache et al 1998). We therefore wished to study the effect of topical ADE and oral aspinn (OA) on lymphocyte subsets in order to assess a possible immunormodulation of the seventy of the herpes zoster infection.

Methods: The effect of topical ADE and OA (500mg) on lymphocyte subset was assessed in 10 patients with acute herpes zoster (HZ) and in 5 healthy controls (C), matched for age and sex The administration of the two routes (topical and oral) was randomized The evaluation was made after 1, 24, 48 hours and 7 days after drug administration. T-lymphocytes and their main subsets (helpers, cytotoxics, activated), B lymphocytes and Natural Killers (NK.) were studied by means ofmonoclonal antibodies against the followings CD: 3, 4+3+,8+3+,3+DR+,19, 19+5+, 56+16+3-, 57+8+Blood samples were labeled with specific antibodies, by using double fluorescence technique, and detected with flow cytometry technique

Results: Both topical ADE and OA induced an early, significant reduction of 57+8+ cells and total CD8 in HZ patients, furthermore, topical aspirin induced a significant reduction of CD56+16+3- cells On the other hand, controls showed a tendency toward a decrease of T-activated lymphocytes, following topical aspinn administration

Conclusions: We parsimoniously interpret these significant changes in cytotoxic cells observed in HZ patients as an immunomodulatory effect of the seventy of the herpetic infection induced by ASA, particularly topically administered


S H Butler. M Nyman*2and T Gordh2, Pain Center, Univ of Washington, Seattle, USA, Pain Center, Univ Hospital, Uppsala, Sweden

Aim of Investigation: The aim of the study was to verify that immobilization of healthy individuals was sufficient to induce signs and symptoms of CRPS(l) and a neglect-like state

Methods: After approval by the institutional ethics committee, 23 healthy volunteers had their non-dominant forearms placed in a standard scaphoid immobilizing cast After four weeks, the cast was removed, a 10 point examination for signs of CRPS(l) and neglect was performed They completed questionnaires on symptoms of CRPS(l) and neglect and then had Quantitative Sensory Testing including heat and cold thresholds and heat and cold pain thresholds done on the casted arm using the non-casted arm as the control Follow up on 16 subjects was done with the same measures after two weeks

Results: CRPS(l) exam scores - 2 9/10 +/- 0 82 (all had temperature variation between 0 4 and 2 6 C) CRPS(l) symptom scores -22/10 Neglect scores - 1 6/10 20/23 had increased sensitivity to cold pain on QST

Conclusions: QST testing showed changes compatible with neu-ropathy but the only consistent finding was the presence of cold pain in the majority not present on the contralateral signs All had temperature variation between the two hands and some other signs ofCRPS(l) with variable occurrence The signs and symptoms were almost resolved in those subjects followed for a further two weeks The neglect changes are included in a separate abstract commenting on PET results in a nine patient cohort


S H Butler. H Fischer*- M. Nyman*3 and T. Gordh3, Pain Center, Univ of Washington, PET Center, Academic Hospital, Uppsala, Sweden, Center, Academic Hospital, Uppsala, Sweden

Aim of Investigation: A neglect-like state has been identified in CRPS( 1) [ 1 ] It has been postulated that immobilization alone may provoke this PET scanning has been used to identify the changes of brain function associated with post-stroke states and is appropriate to identify central abnormalities produced by immobilization

Methods: After institutional approval, nine subjects were screened for the study. They then underwent four pet studies, two at rest, two performing a repetitive task with the non-dominant hand with H;0 5 as the tracer Immediately following this, casting of the non-dominant forearm was done and maintained for four weeks Immediately following cast removal, PET scanning was repeating as done pre-immobilization

Results: Statistical comparisons were made between the pre- and post-treatment state Eight of nine patients reported difficulty with the repetitive task during the second sequence This was specifically identified as a coordination process with tiredness or weak- ness secondary issue. Discoordination and lack of control increased during the repetitive task post-immobilization. Increased blood flow and pet scanning was seen in the accessary motor area of the contralateral cortex in a similar pattern to that seen in post-stroke patients during recovery.

Conclusions: Immobilization alone produced coordination problems during a repetitive motor task that were reflected by blood flow changes similar to those in post-stoke patients. [1] Galer, B. et. al: J. Pain and Symptom Manage 10(5):385-391, 1995.


J. Canals*. F. Capdevila*, A. Montero, M. Rovira*, E. Barallat*, Lamotrigine Study Group, Hospital Jaume d'Urgell, 25600 Balaguer, Spain

Aim of Investigation: To know if the new antiepileptic drug Lamotrigine has an analgesic effect on patients ofneuropathic pain.

Methods: We have given Lamotrigine to 30 patients complaining of different types ofneuropathic pain (related to cancer or not), starting at 25 mg daily and scalating doses according to the analgesic effect achieved (we have used a Visual Analogic Scale to measure it) on day 5, 10, 20, 30 and 40, up to 200 mg daily, in single doses. Analgesic effect has been finally evaluated according to the existence or not of the analgesic effect on the 40th day. After a 3-day time of previous analgesic wash-out, treatment was commenced. Minor analgesics were allowed for breakthrough pain.

Results: 23.7% of patients referred a complete analgesic effect dunng the treatment (VAS on the 40th day or earlier = 0). 35.2% of patients said that pain decreased > 70% in the VAS and 41.1% of patients improved pain > 50% in the VAS. No treatments were stopped because of side effects. 90% of patients (n=27) noticed an improvement in pan by the 5th day. No differences between male/ female patients were seen.

Conclusions: After having used Lamotrigine in 30 patients during 40 days each, we can conclude that: 1) according to our study, Lamotrigine seems to have an intrinsic analgesic effect when used in patients complaining ofneuropathic pain; 2) this analgesic effect has been seen by using Lamotrigine on a monotherapy regime; 3) after a close follow-up, no patients have complained of any kind of side effects that have made them withdraw the treatment; 4) the patients have noticed any analgesic effect by the 5th day of the treatment; 5) no interferences with other medical treatments (ace-nocumarol, dogoxine,. . .) have been seen during the trial; 6) the relationship cost - efficacy seems to be better by using the new antiepileptic drugs; 7) more trials are needed in order to find the correct place of Lamotrigine in the WHO analgesic scale.


Kristin Cecilie Carlsson* and Lene Cecilie Mathisen*, SPON: Hennk Hogstrem, The Pain Clinic, Aker hospital, Oslo, Norway

Aim of Investigation: Patients suffenng from neuropathic pain are difficult to treat with traditional analgesic substances. NMDA-receptor antagonists have been found to have effect on this particular type of pain. The only clinically available NMDA-recep-tor inhibitor so far is ketamine. However, adverse effects limit its use. Recently, the antitussive substance dextromethorphan has been found to have an antagonistic effect on the NMDA-receptor. This substance has less severe adverse effects than ketamine. It is therefore of interest to investigate the effect of dextromethorphan in neuropathic pain.

Methods: Fourteen patients with post-traumatic neuropathic pain participated in this double blind, randomised, cross-over study. On two different occasions, the participants received dextromethorphan 270mg or placebo. Pain intensity, adverse effects and serum concentrations were registered.

Results: Dextromethorphan caused statistically significant pain relief compared to placebo. The effect varied markedly among the patients. The patients reported dizziness as the most important adverse effect.

Conclusions: Dextromethorphan hydrobromide can be an alternative in some patients suffering from neuropathic pain. An increased dose may improve the analgesic effect.


Bibhukalyani Pas. S. Pahan & M. K. Bhattacharya, Niharika, 142 Ruby Park East, Calcutta, PIN-700 078, India

Aim of Investigation: Neuropathic pain is rather resistant to conventional analgesics and so difficult to treat. It may respond to anticonvulsants and tncyclic antidepressants which possess considerable side effects and are poorly tolerated by majority of patients. Aminoglycosides are powerful modulators of excitable tissues like nerves. Local Streptomycin injection was successfully tried by Sokolovic et al and Gallagher & Hamman in neuropathic pain. We have tried to evaluate Streptomycin in relieving neuropathic pain.

Methods: 200 patients suffering from neuropathic pain were included in this study. Streptomycin Sulphate Igm dissolved in 2ml of 0.25% Bupivacame injected close to the involved nerve, or infiltrated to target area. Six such injections were given at weekly intervals. Visual analogue scale was used to quantify pain relief. Minimum 3 years follow-up was done.

Results: After 6th injection - 62 out of 100 patients oftrigeminal neuralgia had complete pain relief for 3-18 months. 35 out of 50 post traumatic scar pain cases were painfree for 8-24 months. All 30 patients with Intercostal neuralgia had 80-90% relief and were supported by medications. 8 out of 20 amputation stump pain cases were painfree for 6-28 months. All patients had complete relief of dysaesthesia and allodynia. Side effects: 7 patients had local swelling and slight giddiness. None of the patients had oto or Nephro toxicity.

Conclusion: Use of injection Streptomycin with Bupivacaine for treatment of various neuropathic pain is promising and beneficial to patients in developing countries like India who cannot afford expensive modalities of treatment.


L. Gomez Femandez*. D. Calzada*, R. Monreal*.(SPON:L.Ochoa Zaidivar). Dept of Clinical Neurophysiology. CIREN. 25 th ave, 15805. Cubanacan, Playa. Havana 11300. Cuba

Aim of Investigation: To test the practical usefulness of electro-physiological examination for diagnosing tarsal tunnel syndrome (TTS) we study 7 patients with a possible diagnosis ofTTS.

Methods: Seven patients with a clinical diagnosis of TTS were evaluated by means of conventional nerve conduction studies (NCS) of motor and sensory fibers, and in 3 of those patients a new method consisting on segmental stimulation/recording method was carried out.

Results: Prolonged distal motor and sensory latencies in potentials from tibial nerve were found in 4 patients, with a classical clinical painful syndrome of the sole of the foot (57%). In 3 patients (43%), with normal (2) or with other affected nerves (1), conventional NCS did not let us to make the correct diagnosis. Segmental analysis of conduction velocity (CV) by sensory fibers was carried out. One patients suffered from diabetes mellitus and abnormalities consisting on decreased values of sensory CV in sural and median nerve were found too, diagnosis of TTS in the course of a peripheral diabetic polineuropathy was established according to results of segmental analysis ofCV of sensory action potentials. In the other two patients with normal conventional NCS, segmental recording of sensory action potentials demonstrated a selective decrement in conduction velocity in the segment including the tarsal tunnel.

Conclusions. The primary symptom ofTTS is pain in the sole of the foot, and electrophysiological studies are very helpful differentiating TTS from other causes of pain Segmental analysis ofCV could be useful for the diagnosis of TTS in approximately a 40% of patients


Makoto Fukusaki. Keiko Tsuji2, and k.oji Sumikawa2, Dept of Anesthesia, Nagasaki Rosai Hosp, Sasebo, Dept ofAnesthesiology, Nagasaki Univ School of Med Nagasaki, Japan

Aim of Investigation: The patients of multiple operated back (MOB) complain intractable pain This study was earned out to evaluate the sensory nerve function using current perception threshold (CPT) in MOB

Methods: The patients were divided into three groups for this study Group A (N=8,42-58yr) included cervical radiculopathy as acute pain, group B (N=6,33-59yr) included complex regional pain syndrome as neuropathic pain, and group C (N=6,42-65yr) included MOB MOB patients had undergone spinal surgery more than twice The CPT was measured at three levels of frequencies, i e , 2kHz, 250Hz, and 5Hz, both in affected and healthy hands or feet The affected versus healthy site ratio was measured for the CPT analysis Statistical significance (p<0 05) was determined using Kruskal-Wallis test

Results: The CPT ratios of group C were 1 1 0 3 at 2kHz, 1 00 3 at 250Hz and 1 80 4 at 5Hz Although groups A and B tended to have lower and higher ratios, respectively, compared to group C, there were no significant differences among the groups

Conclusions: The results suggest that C-fibres are damaged in the patients of MOB, and the damage might be similar to those in cervical radiculopathy and complex regional pain syndrome References 1 ChadoHN Pain Digest 1995,5 127


Mary E. Greipp*. Audrey F Thomas, Rutgers The State Univ of New Jersey-CCAS, Camden, NJ 08102, USA

Aim of Investigation: To evaluate the present symptom experiences and functional statuses of 27 young adults with reflex sympathetic dystrophy syndrome (RSDS) Subjects were originally diagnosed with RSDS and studied over ten years ago to identify causes, and similarities in the sample and effects of various treatment modalities

Methods: IRB approval was granted by the Univ. A descnptive exploratory research design was utilized An interview survey tool was designed to gather data about daily living variables, psychoso-cial variables and symptom vanables While many questions required the use ofLikert scales, there were some open ended questions to capture the qualitative descriptions of the subjects' symptom experiences Basic descnptive statistics have been used to analyze the data

Results: Only 17 of the onginal 27 study subjects could be located Data from this follow-up study reveal subjects who have moved on with their lives overcoming mild and severe disabilities to do so While most are able to perform activities of daily living, many do so with difficulty The most significant and persistent complaint remains their pain Most of these 17 subjects have to rely on some form of medication including morphine pumps and dorsal column stimulators. Most scored themselves very positively on psychoso-cial vanables.

Conclusions: Diminished functional status and continued pain over twelve years is evident in the majonty of this study sample


Aki Hietahanu. Richard Croft*2, Rezaul Alam*2, Maija Haanpaa, Dept of Neurology, Tampere Univ Hospital, Tampere, Finland, Danish Bangladesh Leprosy Mission, Nilphaman 5300, Bangladesh

Aim of Investigation: To show that patients with treated multi-bacillary (MB) type leprosy may suffer from chronic neuropathic pain

Methods: Patients with treated MB leprosy complaining of neuropathic pain for more than 6months were included in the study The patients were collected by leprosy workers from four outpatient clinics in Nilphaman Distnct of Bangladesh Leprosy control in this district, which is highly endemic for leprosy, is earned out by Danish Bangladesh Leprosy Mission (DBLM), a large nongovernment organisation Assessment of the patients included clinical neurological examination and quantitative sensory testing (QST) Pinprick sensory thresholds were determined by using a weighted needle apparatus, and tactile sensation thresholds by using Semmes-Wemstem graded monofilaments Neuroanatomic distribution of the pain was assessed by using pain drawings

Results: Altogether 16 out of 29 patients fulfilled the inclusion cntena Continuous burning, tingling, pnckmg, cutting or biting pain was complained by 7 patients In 9 patients, pain was intermittent, it followed a diumal pattern in 3, and a periodic course in 6 patients Nine patients had a symmetrical sensory loss with a "glove and stocking" distribution, corresponding with the areas charted in the individual pain drawings In all of them the QST assessments indicated total sensory loss

Conclusions: Contrary to the common belief that leprosy is not associated with neuropathic pain, our results indicate that there may be a number of leprosy patients suffering from chronic pain of neurogenic origin The ongoing WHO leprosy eradication campaign and the emerging "care after cure" programmes prompt further epidemiological studies to corroborate our findings

Acknowledgments: The authors thank the medical, field and nursing staff of DBLM for their help in this study


David D. Hood. James C Eisenach, Gina Curry,* Dept ofAnesthe-siology. Wake Forest Univ School of Medicine, Winston-Salem, NC, USA 27157-1009

Aim of Investigation: To estimate the relative potency ofclonidme by epidural and mtrathecal routes in the treatment ofcapsaicin-mduced hyperalgesia and allodynia as a model of centra] hypersen-sitivity and of noxious heat as a model of acute pain

Methods: Twenty-four healthy volunteers were randomized to receive either mtrathecal clonidme (75, 150, or 300 ng) or epidural clonidine (150, 300, or 600 ^ig) Volunteers rated pain from a Peltier-controlled thermode at a lumbar, thoracic, and cervical dermatomal site before and after drug administration In addition, they rated pain from mtradermal capsaicm injections at a lumbar dermatome before and 60-mm after clonidine injection and indicated the areas of hyperalgesia and allodynia to mechanical stimuli

Results: Clonidme's effect differed with route of administration and modality of sensory testing. For acute thermal pain, mtrathecal clonidine produced a dose-dependent analgesia with a lumbar > thoracic > cervical gradient, whereas only one dose of epidural clonidine reduced thermal pain and this was at the thoracic testing site In contrast, the potency of epidural and mtrathecal clonidine to reduce capsaicm-mduced allodynia was similar, and for hyperalgesia, mtrathecal clonidine was only slightly more potent than epidural clonidine

Conclusions: These data support clinical studies from noncom-parative tnals and suggest there is a > 6 fold potency ratio ofm-trathecal epidural administration of clonidine for acute pain, but a < 2 fold potency ratio for these routes for mechanical hypersensi-tivity

Acknowledgments: Supported in part by NIH grants GM48085 and M01 RR07122 and a grant from Roxane Laboratories, Inc; Dr. Eisenach is a consultant for Roxane.


Renko Hosoda. Akiko Yamashita*, Tomomasa Kimura, Yasuhiro Shimada*, Ryogo Nakamura*. Dept ofAnesth and Orthoped. Nagoya Univ School ofMed, Nagoya 466-4560, JAPAN

Aim of Investigation: To investigate the clinical characteris- tics of aim neuropathic pain patients and to reexamine new CRPS definition, retrospective analysis of 100 patients and follow-up survey were performed.

Methods: One hundred patients formerly enrolled as RSD (46) or Causalgia (54) by criteria ofLankford or Gibbons were studied during 20 years. They were re-classified by new CRPS definition. Clinical characteristics (cause, affected region, sign, symptom), therapy and follow-up questionnaire were analyzed.

Results: 54/54 were grouped into Type-11, 39/46 were Type-1 and the remaining 7/46 were unclassified because of lack of noxious event. In 54 cases with Type-11, injured nerves were median in 32 (45.7%), radial in 27 (38.6%) and ulnar in 11 (15.7%). 47/54 (92.6%) manifested dysesthesia, hyperalgesia and, 30 (55.6%) had burning pain. 46 (85.2%) were underwent total 129 times of surgery. Follow-up survey showed that 71.4% still complained of intolerable pain. In 26 (64.1%) cases with Type-1, bone fracture triggered. Main symptoms were contracture (94.9%), spontaneous pain (87.2%) and swelling (87.2%). In 5/39 cases, pain was not main symptoms. The follow-up survey showed that 10 patients answered that pain was improved or disappeared. Seven unclassified cases were all non traumatic dystrophy. Their clinical features were the same as those of Type-1.

Conclusion: In the present study, new CRPS definition was suitably corresponded to Type-11. However the cases with RSD who were not associated with noxious event were excluded from Type-1, In addition, patients who did not complain or disappeared spontaneous pain were not correctly grouped into Type-1, Therefore we prefer to sub-classify Type-1 in new CRPS definition.


Yoshiki Imamura, Masatsugu Iwamoto*. Eiji Sakamoto*, Shunji Shiiba*, Hiroshi Kawahara, and Osamu Nakanishi, Dept ofAnes-thesiology, Kyushu Dental College, Kitakyushu, Japan

Aim of Investigation: Sometimes patients complain of some kinds of abnormal sensation after dental treatment, and in some cases, pain and dysesthesia persist for a long time. These neurological complications are due to nerve and tissue injury during the procedure. We discussed if we can predict them from their initial self-reported symptoms.

Methods: 60 patients who visited the orofacial pain and neurofunc-tion clinic in the Kyushu Dental College Hospital with a complaint of abnormal sensation after dental treatment or orofacial surgery enrolled in this study. 40 patients visited us within one month after injury (fresh cases) and 20 visited over one month later (advanced cases). Self-reported symptoms were categorized in combinations of spontaneous pain, hypoesthesia, hyperalgesia, allodynia and dysesthesia. Self-reported symptoms were assessed again twelve months later and prognosis of prolonged abnormal sensation was discussed.

Results: Twenty-two patients showed complete sensory recovery and the other thirty-eight patients complained of abnormal sensation even after twelve months from their first visit. Thirty-two of thirty-eight patients with sequellae complained of dysesthesia. Those who completely recovered had likely visited us earlier than those showed sequellae. In fresh cases, those who had nothing but hypoesthesia in the affected region showed a good result in treatment.

Conclusions: We can roughly predict prolonged abnormal sensation from initially self-reported symptoms in fresh cases. Patients with hypoesthesia but no other symptoms tend to recover satisfactorily. Prognosis of abnormal sensation in advanced cases and patients with dysesthesia, allodynia and hyperalgesia need further investigation.


Jayalakshmi TS. Dureja GP, Bhalla AP* Pain Clinic Dept ofAn-aesthesiology and Intensive care All India Inst of Medical Sciences, New Delhi - 29. India

Aim of Investigation: To Investigate the efficiency ofmultimodal-ity regime without surgical approach in the management ofGN.

Methods: 18 consecutive patients ofGN ofunilatral side studied for one year. Two combinations of treatment modalities were used. Group A received carbamazepine (100-300 mg), amitryptilline (10-25 mg), local injection of 0.25% 2 ml bupivacaine extra orally along with TENS therapy (10 Sittings). Group B received the same as A except the local anaesthetic injection which was given intra oral route and acupuncture therapy instead of TENS. They were reviewed every 4 weeks and if required the same regime repeated. Both groups recieved oral drugs for one year. Results: Out of 18 patients group A had three males and six females and group B two males and seven females. Age varied from 22-40 years except one who was 50 years. None had any associated medica problems. Ten had pain in and around the ear, 12 in the tonsillar area and throat, 4 in the pharynx and 3 in the root oftoun-gue. 1 had cancer tongue who had radiotherapy; except this patient all were in good health. None had any history ofsyncopial attack. The relief of symptoms were equally good in both groups.

Conclusion: GN poses significant problem for the pain therapist and it is quite distressing to the patients too. Non surgical modalities were better then one drug regime. Extra oral injection was safer and accepted by the patients than intra oral route. Multimo-dality regime avoids high dosage of drugs and surgical interventions.


Ellen Jorum. Per-Kristian Opstad2 *, Alfred Arvesen3 *, The dept. of Neurology, The National Hospital, The Norwegian Defence Research Establishment2 and The dept. of Surgery, Baerum Hospital3, Norway.

Aim of Investigation: to study the function of thick and thin nerve fibers in a total of 26 soldiers and officers who suffered from cold-injuries during a 5-day boat ride in open boats along the Norwegian coast January 1998

Methods: The investigation found place in March and April 1998. The function of thick myelinated nerve fibers was studied by neu-rography of nerves in upper and lower-extremity while the function of the thin A-5 and C-fibers was measured by Somedics Ther-motest. Clinical examinations were also peformed. Neurography-and thermotest values were compared to a healthy control group (n=20) from The Norwegian War Academy.

Results: 4 subjects complained of numbness in the feet and 15 subjects reported painful sensations in hands and/or feet upon exposure to cold. A total of 14 subjects had reduced nerve conduction velocities. For the group as a total we found significant reductions in the motor amplitudes of the median and ulnar nerves and significant reductions in peroneal motor amplitude and distal delay, tibial nerve motor amplitude and conduction velocities in tibia] and sural nerves compared to the control group.We found significant reductions in cold and heat-detection thresholds in the feet (p< 0.05 and p < 0.01) as well as a significant decrease in cold pain threshold (pain at a higher temperature) in the feet (p < 0.01) compared to the control group.

Conclusions: The material is unique for further studies of cold allodynia which is frequently seen in neuropathic pain conditions and where the mechanisms are unknown.


Hae Ja Kim. Mi Jung Ahn, Won Hyung Lee, Dept ofAnesthesiology, Chungnam National Univ, Taejeon, Korea

Aim of Investigation: We evaluated the analgesic effects of 32 patients with neuropathic pain syndroms due to spinal stenosis, spinal compression fracture and hemiated nucleus pulposus which had poor pain control with conventional medical therapy enrolled.

Method: First, they had received 0.5 mg of morphine and 10 mg of ketamine which was added to 10ml of saline into epidural space. After then, they had been administered small dose of morphine (1-2 mg) and ketamine (lOmg) with low dose of local anesthetics through an epidural catheter continuously. And we had given them single bolus injections of ketamine (10 mg) with saline (10 ml) once a day when it was needed. Visual Analog Scale (VAS) 0-10 was used for clinical pain measurement after infusion were observed in patients and the side effects were recorded. Result: The average duration of the therapy was 17 days (range 8-21 days) except 4 patients who had operations scheduled. We could get the result of excellent pain relief (VAS 0-2) from 26 patients. We could only discover the dizziness in 40% due to administration with single epidural injection.

Conclusion: It is possible to provide adequate analgesia with small doses of epidural opioid and ketamine which was added to low dose of local anesthetics in patients of neuropathic pain who fail to adequate relief with conventional treatment.

9th WORLD CONGRESS ON PAIN, 1999, Vienna, Austria, p.50 - 56


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