p98 steroid therapy causes conduction slowing in human muscle fibers

1
Communications affich6es/Postem 71s P98 sTEROID THERAPY CAUSES CONDUCTION SLOWING IN HUMAN MUSCLE FIBERS W. Troni, R. Cavallo, L. Durelli and L. Bergamini, 1st Neurological Clinic, University of Turin, Turin (Italy) The possible deleterious side effects of high-do- sage steroid therapy (h.s.t.) on muscle are known since the early report by Cushing (1932). However, clinical and electrophysiological studies on this topic are few, in spite of the wide use of h.s.t. in clinical practice. In order to investigate the true incidence of muscle damage during steroid therapy, we determined the conduction velocity of the muscle fibers (m-CV) of the biceps, according to the method described by Troni et al. (1983),in 18 patients: they were 8 males and 10 females un- der h.s.t, for Myasthenia (6), Chronic Obstructive Pulmunary Disease (4), Multiple Sclerosis (4) and Endocranial Hypertension (4). In all of the pa- tients treated for more than 2-3 weeks, m-CV was significantly reduced as compared to that of con- trol subjects matched for sex and age. The degree of conduction slowing was grossly correlated to the duration of steroid therapy. The most usual finding was an increased dispersion of the laten- cies of single fiber action potentials due to the presence of a muscle fiber fraction with a very low conduction velocity. Although the meaning and the clinical correlation of this electrophysiolo- gical finding is unclear, some detrimental effect on muscle seems to be a constant feature of h.s,t, Serial determination of m-CV is a usuful tool to monitor patients under steroid therapy. Moreover, m-CV studies may be an interesting approach to evaluate the myopathio effects of different ste- roids as well as to define therapeutic schedules able to minimize this harmful side effect. PIO0 CENTRAL SOMATOSENSORY CONDUCTION IN DIABETES= C.Maeztu,F:Martinez-Campillo,J.A.Munoz,L-G--Sic! lia?A~Siaz-OrtuHo. Hoapital General.Murcia. SPAIN. We have studied the spinal and supraspinal con-- duction in a group of 20 diabetic patients,using an indirect method that include median and tibia nerve stimulation. We have found a slowing of the Ll-cortex,Li-C 7 - and C7-cortex conductions. No correlation was found with metabolic control, duration of the d~sease and peripheral nerve -- conduction.This study suggest that in addition - to impairment of peripheral nerve conduction, - patients with diabetes can have a defect in spi- nal and supraspinal afferent conduction. P99 USE OF SINGLE FIBRE EMG IN THE ASSESSMENT OF PATIENTS WITH CHRONIC FATIGUE SYNDROMES. S.Connolly, D.G.Smith, C.J.Fowler and D.Doyle. Department of Clinical Neurophysiology, Middlesex Hospital, London, Practice in Essex and Department of Neuropathology, Southern General Hospital, Glasgow. Single fibre (SF) EMG of extensor digitorum communis was performed on 26 patients who had presented with a syndrome of chronic fatigue, with or without myalgia. 22 patients had muscle biopsies. In 11 a positive diagnosis of acute onset post viral fatigue was made as there was a history of their illness being precipitated by a viral infection in an otherwise healthy individual, 8 patients had chronic fatigue with symptoms similar to those with post viral fatigue, but the onset of their symptoms had been insidious. The remaining 7 patients were clinically diagnosed as having primary muscle disease because their predominant symptom was of myalgia. In 17 patients, 9 with post viral fatigue, mean jitter was less than 37 usecs. In 6 patients increased fibre density was found and in 5 of these patients the muscle biopsy was reported as being abnormal. Whilst there remains a medical dichotomy as to whether chronic fatigue syndromes are physically or psychiatrically based, it is the responsibility of the neurophysiologist to detect eLectromyographic evidence of muscle disease. We h a v e found measurement of fibre density to be a sensitive means towards this aim. PIO1 NEUROTOXICITY OF HIGH -DOSE CARBOPLATIN CHEMQTHERAPY: A CLINICAL AND NEUROPHYSIOLOGICAL STUDY F. Rasi, F. Valzania, G. Rosti °, M, Marangolo ° Neurophysiol. Unit, Civil Hospital, Cesena (Italy) o Medical Oncology Unit, Civil Hospital, Ravenna (Italy) P.R. Ion 89110.1 Carboplatin (JM8) is a derivative compound of the second generation of platinum-containing drugs. It has been well established that JM8 has not renal toxicity and less neurotoxicity than cisplatin; the main dose-limiting side effect is myelosuppression. In consequence of this exclusive toxicity JM8 is a first choice drug for high dose chemotherapy, Peripheral neurotoxicity xas examined in 9 pts. suffering from germinal cell tumors before and one month after the treatment by a score drawn from a protocol including: Neurological Symptom and Disability Score, Sympathetic Skin Reflex, computerized Stabilography and EMG (MCV and F wave of peroneal n., SCV of sural n., SCV and MCV and F wave of median n.) According to the score, five degrees of peripheral nerve involvement were considered: Absent, Borderline, Mild, Moderate, Severe. Brain toxicity was examined by means of VEP and BAEP. Before treatment pts. showed a mean score of 4.87 and were classified as follows: I pt. Borderline, 6 Mild, 2 Moderate. One month after therapy the mean score was 6.37 and the classification was: 7 Mild, I Moderate, I Severe. EP study was normal but 2 pts. suffe- ring from brain metastasis. The surveillance of drug neurotoxicity showed a slight increase of the score without any significant shifting toward a more severe neurotoxicity. Even if limited, our data do not show significant neurotoxicity due to high-dose carboplatin chemotherapy.

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Communications affich6es/Postem 71s

P98

sTEROID THERAPY CAUSES CONDUCTION SLOWING IN HUMAN MUSCLE FIBERS

W. T r o n i , R. C a v a l l o , L. D u r e l l i and L. B e r g a m i n i , 1 s t N e u r o l o g i c a l C l i n i c , U n i v e r s i t y o f T u r i n ,

T u r i n ( I t a l y )

The p o s s i b l e d e l e t e r i o u s s i d e e f f e c t s o f h i g h - d o - sage s t e r o i d t h e r a p y ( h . s . t . ) on m u s c l e a r e known s i n c e t h e e a r l y r e p o r t by C u s h i n g ( 1 9 3 2 ) . H o w e v e r , c l i n i c a l and e l e c t r o p h y s i o l o g i c a l s t u d i e s on t h i s t o p i c a r e f e w , i n s p i t e o f t h e w i d e use o f h . s . t . i n c l i n i c a l p r a c t i c e . I n o r d e r t o i n v e s t i g a t e t h e t r u e i n c i d e n c e o f m u s c l e damage d u r i n g s t e r o i d t h e r a p y , we d e t e r m i n e d t h e c o n d u c t i o n v e l o c i t y o f t h e m u s c l e f i b e r s (m-CV) o f t h e b i c e p s , a c c o r d i n g t o t h e me thod d e s c r i b e d by T r o n i e t a l . ( 1 9 8 3 ) , i n 18 p a t i e n t s : t h e y w e r e 8 m a l e s and 10 f e m a l e s un - d e r h . s . t , f o r M y a s t h e n i a ( 6 ) , C h r o n i c O b s t r u c t i v e P u l m u n a r y D i s e a s e ( 4 ) , M u l t i p l e S c l e r o s i s (4 ) and E n d o c r a n i a l H y p e r t e n s i o n ( 4 ) . I n a l l o f t h e p a - t i e n t s t r e a t e d f o r more t h a n 2 - 3 w e e k s , m-CV was s i g n i f i c a n t l y r e d u c e d as c o m p a r e d t o t h a t o f c o n - t r o l s u b j e c t s matched f o r sex and age . The d e g r e e o f c o n d u c t i o n s l o w i n g was g r o s s l y c o r r e l a t e d t o t h e d u r a t i o n o f s t e r o i d t h e r a p y . The most u s u a l f i n d i n g was an i n c r e a s e d d i s p e r s i o n o f t h e l a t e n - c i e s o f s i n g l e f i b e r a c t i o n p o t e n t i a l s due t o t h e p r e s e n c e o f a m u s c l e f i b e r f r a c t i o n w i t h a v e r y low c o n d u c t i o n v e l o c i t y . A l t h o u g h t h e mean ing and t h e c l i n i c a l c o r r e l a t i o n o f t h i s e l e c t r o p h y s i o l o - g i c a l f i n d i n g i s u n c l e a r , some d e t r i m e n t a l effect on muscle seems to be a constant feature of h.s,t, Serial determination of m-CV is a usuful tool to monitor patients under steroid therapy. Moreover, m-CV studies may be an interesting approach to evaluate the myopathio effects of different ste- roids as well as to define therapeutic schedules able to minimize this harmful side effect.

PIO0

CENTRAL SOMATOSENSORY CONDUCTION IN DIABETES=

C.Maeztu,F:Martinez-Campillo,J.A.Munoz,L-G--Sic!

lia?A~Siaz-OrtuHo. Hoapital General.Murcia. SPAIN.

We have studied the spinal and supraspinal con-- duction in a group of 20 diabetic patients,using an indirect method that include median and tibia nerve stimulation. We have found a slowing of the Ll-cortex,Li-C 7 - and C7-cortex conductions. No correlation was found with metabolic control, duration of the d~sease and peripheral nerve -- conduction.This study suggest that in addition - to impairment of peripheral nerve conduction, - patients with diabetes can have a defect in spi- nal and supraspinal afferent conduction.

P99

USE OF SINGLE FIBRE EMG IN THE ASSESSMENT OF PATIENTS WITH

CHRONIC FATIGUE SYNDROMES.

S.Connolly, D.G.Smith, C.J.Fowler and D.Doyle.

Department of Clinical Neurophysiology, Middlesex Hospital,

London, Practice in Essex and Department of Neuropathology,

Southern General Hospital, Glasgow.

Single fibre (SF) EMG of extensor digitorum communis was

performed on 26 patients who had presented with a syndrome

of chronic fatigue, with or without myalgia. 22 patients had

m u s c l e b i o p s i e s . In 11 a p o s i t i v e d i a g n o s i s o f a c u t e o n s e t

p o s t v i r a l f a t i g u e was made as t h e r e was a h i s t o r y o f t h e i r

i l l n e s s b e i n g p r e c i p i t a t e d by a v i r a l i n f e c t i o n i n an

o t h e r w i s e h e a l t h y i n d i v i d u a l , 8 p a t i e n t s had c h r o n i c f a t i g u e

w i t h s y m p t o m s s i m i l a r t o t h o s e w i t h p o s t v i r a l f a t i g u e , b u t

t h e o n s e t o f t h e i r s y m p t o m s h a d b e e n i n s i d i o u s . T h e

remaining 7 patients w e r e clinically diagnosed as having

primary muscle disease because their predominant symptom was

of myalgia.

In 17 patients, 9 with post viral fatigue, mean jitter

was less than 37 usecs. In 6 patients increased fibre

d e n s i t y was f o u n d and i n 5 o f t h e s e p a t i e n t s t h e m u s c l e

b i o p s y was r e p o r t e d as b e i n g a b n o r m a l .

W h i l s t t h e r e r e m a i n s a m e d i c a l d i c h o t o m y as t o w h e t h e r

c h r o n i c f a t i g u e s y n d r o m e s a r e p h y s i c a l l y o r p s y c h i a t r i c a l l y

b a s e d , i t i s t h e r e s p o n s i b i l i t y o f t h e n e u r o p h y s i o l o g i s t t o

d e t e c t e L e c t r o m y o g r a p h i c e v i d e n c e o f m u s c l e d i s e a s e . We h a v e

f o u n d m e a s u r e m e n t o f f i b r e d e n s i t y t o be a s e n s i t i v e means

t o w a r d s t h i s a i m .

PIO1

NEUROTOXICITY OF HIGH -DOSE CARBOPLATIN CHEMQTHERAPY: A CLINICAL AND NEUROPHYSIOLOGICAL STUDY F. Rasi, F. Valzania, G. Rost i °, M, Marangolo ° Neurophys io l . Un i t , C i v i l Hosp i ta l , Cesena ( I t a l y ) o Medical Oncology Uni t , C i v i l Hosp i ta l , Ravenna ( I t a l y ) P.R. Ion 89110.1

Carbop la t in (JM8) is a d e r i v a t i v e compound of the second generat ion of p la t i num-con ta in ing drugs. I t has been wel l es tab l i shed t ha t JM8 has not renal t o x i c i t y and less n e u r o t o x i c i t y than c i s p l a t i n ; the main d o s e - l i m i t i n g side e f f e c t is myelosuppression. In consequence of t h i s exc lus i ve t o x i c i t y JM8 is a f i r s t choice drug fo r high dose chemotherapy, Per iphera l n e u r o t o x i c i t y xas examined in 9 p ts . s u f f e r i n g from germinal ce l l tumors before and one month a f t e r the t reatment by a score drawn from a p ro toco l i nc lud ing : Neuro log ica l Symptom and D i s a b i l i t y Score, Sympathetic Skin Ref lex , computerized Stab i lography and EMG (MCV and F wave o f peroneal n . , SCV of sura l n . , SCV and MCV and F wave of median n. ) According to the score, f i v e degrees o f per iphera l nerve involvement were considered: Absent, Border l ine , M i ld , Moderate, Severe. Brain t o x i c i t y was examined by means of VEP and BAEP. Before t reatment p ts . showed a mean score o f 4.87 and were c l a s s i f i e d as fo l l ows : I p t . Border l ine , 6 Mi ld , 2 Moderate. One month a f t e r therapy the mean score was 6.37 and the c l a s s i f i c a t i o n was: 7 Mi ld , I Moderate, I Severe. EP study was normal but 2 pts. s u f f e - r ing from bra in metastasis. The su rve i l l ance of drug n e u r o t o x i c i t y showed a s l i g h t increase o f the score w i thout any s i g n i f i c a n t s h i f t i n g toward a more severe n e u r o t o x i c i t y . Even i f l i m i t e d , our data do not show s i g n i f i c a n t n e u r o t o x i c i t y due to high-dose ca rbop la t i n chemotherapy.