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Convergence of afferents from superior sagittal sinus and tooth pulp on cells in the upper cervical spinal cord or in the thalamus of the cat
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CONVERGENCE OF AFFERENTS FROM SUPERIOR SAGITTAL SINUS AND TOOTH PULP ON CELLS IN THE UPPER CERVICAL SPINAL CORD OR IN THE THALAMUS OF THE CAT. Olausson B., Angus-Leppan H.‘, Boers P.’ and Lambert GA.* Department of Neurology, The Prince Henry Hospital, Sydney, Australia
Poster 43 GREY Mon-Tues Exhibit
Hall
Abs
86
No
:n Cells ._ sinus_ (SSS) . . .stimulatioh . . . have.. .previously bee _-_ excited . by superior._ sagittal (DLA)in the upper cervical spmal cord and m the thalamx medial ventropostenor (VPM) nucleus in cats. Cells excited by electrical tooth pulp (TP) stimulation have also been described in the thalamus in the shell region of the basal ventromedial nucleus (VMB). The present study was undertaken to investigate convergence of TP and SSS afferents on cells in the DLA and in the thalamus in cats. METHODS: Glass insulated tungsten electrodes were used to record extracelluar cell activity in the DLA and ‘in the thalamus. Electrical stimulation was applied to SSS and to canine teeth. Cooling of one canine was used as a natural stimulus. Cells excited by either SSS or TP stimulation were also investigated with respect to their cutaneous receptive fields. RESULTS: In the DLA 11 cells was found with SSS and TP convergence out of 21 investigated. The mean onset latency was 25.5 ms and 9.8 rns following electrical TP and SSS stimulation respectively. Following TP stimulation a lower firing probability was observed, compared to SSS stimulation. The investigated cells in the DLA usually had cutaneous receptive fields in the ipsilateral fore paw or face. In 4 of these cells action potentials with short and stable latency could be evoked by electrical stimulation in the medial VPM. In the thalamus 35 cells out of 93 investigated, were excited by electrical stimulation in TP and SSS stimulation. Cells with TP and SSS convergence were located in the medial VPM in the lateral border of VMB. Their mean onset latencies were 24.9 ms and 16.7 ms following electrical TP and SSS stimulation respectively. Thirteen of the cells with TP and SSS convergence was excited by cooling of the tooth and 21 were excited by nociceptive stimulation of the skin in the contralateral side of the face, out of these 21 cells 8 were also excited by non noxious fascial stimulation. CONCLUSION: The results of this investigation indicate that the DLA is an important relay in mediating afferent information from SSS. A part of the TP afferents may also relay via the DLA. A substantial convergence of SSS and TP afferents was also shown in the medial VPM. This convergence in the spinal cord and in the thalamus have implications for craniovascular and tooth related pain phenomena such as cluster headache.
AIM . .OF INVESTIGATION: . . _ _
described in the dorsolateralarea
DRUG INDUCED HEADACHE PATIENTS: LOCUS OF CONTROL, PAIN VARIABLES AND THE EFFECT OF WITHDRAWAL P.Nllaes, E.Wlchmann. H.U.Gerbershagen DRK-Schmerzzentrum, D-6600 Main& West Germany
~ Exhibit
Hall
Abs
87
No
/ Aim of Invest&&@& Chronic headache is often related to the use or abuse of drugs initially taken against headache. Our intention was to study pain impact, activities and locus of control in a clinical population with drug induced headache (DIM, Due to the effect of withdrawal we expected difference6 between DIH population and an other sample of headache patients in the reduction of headache during treatment. ðods: A standardized interview was used for the classification of 127 consecutive patients in a drug induced headache (DIH) group. Criteria were: Use of drugs against headache, more than 20 days with headache per month, headache lasting more then 10 hours a day. A German version of the WHYMPI, a questionnaire to a66888 locus of control (KKG) and pain variables (VAS) were used. A headache diary with four dally measures 10-g) was given to a sample of 71 inpatients during the first two weeks of treatment. JZesults: The whole population showed remarkably low scores for internal locus of control and elevated scores for chance. as compared to normal$ve da& Both scores proved unrelated to time since onset of headache. In the sample of 127 headache patients. 64 fulfilied the criteria for DIH. No differences were found between groups in time since onset of pain while differences on internal locus of control, life control and aspects of activity (WIiYMPI) followed the expected directions. The subgroup with 71 inpatients (3f DIH) showed highly significant differences in pain intensity during the first week. In the second week the differences in average pain intensity had disappeared. Due to initial differences between groups a negative relation was observed between degree of improvement and the score for life control while positive relations exist with pain intensity, ptinishing reaction and external locus of control (P). Concl&&B& The data reveal a clear relation of drug intake to pain variables. Complete withdrawal alone proved to effectively reduce pain in DIH-patients. The data suggest that locus of control dimensions are related to the development of severe intensity DIH.
/ ;
CONVERGENCE OF AFFERENTS FROM SUPERIOR SAGITTAL SINUS AND TOOTH PULP ON CELLS IN THE UPPER CERVICAL SPINAL CORD OR IN THE THALAMUS OF THE CAT. Olausson B., Angus-Leppan H.‘, Boers P.’ and Lambert GA.* Department of Neurology, The Prince Henry Hospital, Sydney, Australia
Poster 43 GREY Mon-Tues Exhibit
Hall
Abs
86
No
:n Cells ._ sinus_ (SSS) . . .stimulatioh . . . have.. .previously bee _-_ excited . by superior._ sagittal (DLA)in the upper cervical spmal cord and m the thalamx medial ventropostenor (VPM) nucleus in cats. Cells excited by electrical tooth pulp (TP) stimulation have also been described in the thalamus in the shell region of the basal ventromedial nucleus (VMB). The present study was undertaken to investigate convergence of TP and SSS afferents on cells in the DLA and in the thalamus in cats. METHODS: Glass insulated tungsten electrodes were used to record extracelluar cell activity in the DLA and ‘in the thalamus. Electrical stimulation was applied to SSS and to canine teeth. Cooling of one canine was used as a natural stimulus. Cells excited by either SSS or TP stimulation were also investigated with respect to their cutaneous receptive fields. RESULTS: In the DLA 11 cells was found with SSS and TP convergence out of 21 investigated. The mean onset latency was 25.5 ms and 9.8 rns following electrical TP and SSS stimulation respectively. Following TP stimulation a lower firing probability was observed, compared to SSS stimulation. The investigated cells in the DLA usually had cutaneous receptive fields in the ipsilateral fore paw or face. In 4 of these cells action potentials with short and stable latency could be evoked by electrical stimulation in the medial VPM. In the thalamus 35 cells out of 93 investigated, were excited by electrical stimulation in TP and SSS stimulation. Cells with TP and SSS convergence were located in the medial VPM in the lateral border of VMB. Their mean onset latencies were 24.9 ms and 16.7 ms following electrical TP and SSS stimulation respectively. Thirteen of the cells with TP and SSS convergence was excited by cooling of the tooth and 21 were excited by nociceptive stimulation of the skin in the contralateral side of the face, out of these 21 cells 8 were also excited by non noxious fascial stimulation. CONCLUSION: The results of this investigation indicate that the DLA is an important relay in mediating afferent information from SSS. A part of the TP afferents may also relay via the DLA. A substantial convergence of SSS and TP afferents was also shown in the medial VPM. This convergence in the spinal cord and in the thalamus have implications for craniovascular and tooth related pain phenomena such as cluster headache.
AIM . .OF INVESTIGATION: . . _ _
described in the dorsolateralarea
DRUG INDUCED HEADACHE PATIENTS: LOCUS OF CONTROL, PAIN VARIABLES AND THE EFFECT OF WITHDRAWAL P.Nllaes, E.Wlchmann. H.U.Gerbershagen DRK-Schmerzzentrum, D-6600 Main& West Germany
~ Exhibit
Hall
Abs
87
No
/ Aim of Invest&&@& Chronic headache is often related to the use or abuse of drugs initially taken against headache. Our intention was to study pain impact, activities and locus of control in a clinical population with drug induced headache (DIM, Due to the effect of withdrawal we expected difference6 between DIH population and an other sample of headache patients in the reduction of headache during treatment. ðods: A standardized interview was used for the classification of 127 consecutive patients in a drug induced headache (DIH) group. Criteria were: Use of drugs against headache, more than 20 days with headache per month, headache lasting more then 10 hours a day. A German version of the WHYMPI, a questionnaire to a66888 locus of control (KKG) and pain variables (VAS) were used. A headache diary with four dally measures 10-g) was given to a sample of 71 inpatients during the first two weeks of treatment. JZesults: The whole population showed remarkably low scores for internal locus of control and elevated scores for chance. as compared to normal$ve da& Both scores proved unrelated to time since onset of headache. In the sample of 127 headache patients. 64 fulfilied the criteria for DIH. No differences were found between groups in time since onset of pain while differences on internal locus of control, life control and aspects of activity (WIiYMPI) followed the expected directions. The subgroup with 71 inpatients (3f DIH) showed highly significant differences in pain intensity during the first week. In the second week the differences in average pain intensity had disappeared. Due to initial differences between groups a negative relation was observed between degree of improvement and the score for life control while positive relations exist with pain intensity, ptinishing reaction and external locus of control (P). Concl&&B& The data reveal a clear relation of drug intake to pain variables. Complete withdrawal alone proved to effectively reduce pain in DIH-patients. The data suggest that locus of control dimensions are related to the development of severe intensity DIH.
/ ;