QUANTITATIVE THERMAL AND VIBRATORY THRESHOLD MEASUREMENTS IN HEALTHY PERSONS. J.F. Frederiksenl , J. Brennuml and T.S. Jensen2, Depts. of Neurology, 1Gentofte Hospital and 2Rigshospitalet, Univ. of Copenhagen, Copenhagen, Denmark

Aim of investigation: In neurological diseases, changes in thermal sensibility is often seen together with disturbances in other sensory modalities, as for example vibration sense. This study determined warm (WPT) and cold (CPT) perception thresholds, vibratory perception (VPT) and disappearance (VDT) thresholds in both hands and in both feet. In addition, we investigated the interrelation between these thresholds.

Methods: Thirtysix healthy persons aged lo-70 years participated in the stum female and six male in each interval from 10-29, 30-49 and SO-70 years. To judge intraindividual variation and reproducibility, all measure- ments were done twice in the same day and once within 2 months. One of the investigators did all thermal, another all vibratory threshold measurements. WPT and CPT were measured with Thermotest (Somedic A/B) which is based on a Peltier principle. VPT and VDT were measured with both Biothesiometer (Ohio) and Vibrameter type III (Somedic A/B; the application pressure was 500 g.

Results: WPT were fourfold higher in the feet (3.5'C) than in the hands (0.8oC), CPT only being increased twofold (1.2'C versus 0.6OC). No sex and age differences were observed. The feet-hand ratio of VPT and VDT were 4 (Vibrameter) and 2 (Biothesiometer). Both the mean and the range of VPT and VDT measurements tended to increase with age, particularly after the age of 50 years. This trend was most pronounced in feet. Men showed clearly higher values of VPT and VDT than women in hands, but not in feet; the greatest sex difference being observed with Vibrameter.

Conclusion: Establishment of quantitative measures of cutaneous sensation and relationship between various modalities (in individual persons) is important in order to evaluate sensory disorders in disease.

A CLINICA\ INVESTIGAT{ON OF CENTRAL POS;-STROKE PAIN. G. Leijon , J. Eoivie and I. Johansson , Department of

Neurology1 and Radiology2, University Hospital, Linkoping, Sweden.

Aim of investigation: In textbooks central pain (CP) following cerebro- vascular lesions (CVL) has almost invariably been classified as thalamic pain. It is known, however, that such pain can be caused by nonthalamic brain lesions as well. The present study intends to find out if all patients (pts) with CP caused by stroke have thalamic lesions, if their pain differ according to the location of the CVL and which neurological symptoms and signs they have in addition to pain.

Patients and Methods: 20 men and 7 women were extensively investigated. Results from neurological examination, CT scanning and characterization of the pain will be reported. Care was taken to differentiate nociceptive, peripheral neurogenic and psychogenic pain from CP.

Results: 3 pts had haemstomas, 22 infarctions (11 supra-, 8 infra- and 3 supra- or infratentorial), 2 had unidentified CVL. The CT scans showed no signs of thalamic involvement in 67% of the pts. The onset of pain ranged from O-24 months. The characteristics of the pain did not differ between pts with brain stem, thalamic and extrathalamic supratentorial lesions. It was usually described as burning, aching, pricking or lacerating and was aggravated in all by either touch, warmth, cold or joint movements. All pts had abnormalities in cutaneous sensibility, including hypaesthesia, dys- aesthesia and overreactions. 3 pts had severe, 10 slight and 14 no paresis. Otherwise the pts had a wide range of neurological symptoms.

Conclusion: The results indicate that extrathalamic CVL can also give rise to CP similar to the thalamic pain syndrome. Besides the pain abnormal cutaneous sensibility was the only symptom common to all pts. We propose that this CP is called central post-stroke pain.