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Paraspinal muscles responses to tapping in healthy subjects: Preliminary observations
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FIO0 CUTANEOUSEFFECTS ON ANKLE EXTENSORAND FLEXOR MOTONEURONS
FUNASE K, KASAI T, MANABEM, SHIMIZU H*, TANAKA R.~ Department of Neurobiology, Tokyo Metropolitan I n s t i t u t e f o r Neurosciences; *Section of Anesthesiology, Tokyo Metropolitan Neurological Hospital, Fuchu, Tokyoj Japan Effects of the sural nerve stimulation on the soleus (Sol) and a n t e r i o r t i b i a l (TA) motoneurones were studied by the H-reflexes and e p i d u r a l l y recorded spinal root p o t e n t i a l s on 8 normal subjects. The sural nerve was stimulated at the level of the external malleolus through b i p o l a r surface electrodes ( r e c t angular pulses with I msec duration and i n t e n s i t y less than pain threshold). The e a r l i e s t effects were r e c i p r o c a l , f a c i l i t a t o r y on Sol and i n h i b i t o r y on TA, and the shortest interval f o r the effects was ca. 30 msec between condit i o n i n g and test stimulus. On the other hand, the e a r l i e s t effects of the medial plantar (mixed) nerve stimulation was inversely reciprocal and appeared at ca. 10 msec. Since the sural and medial plantar nerves have comparable conduction v e l o c i t y (Behse and Buchthal, 1971) and the a f f e r e n t volleys i n these nerves conduct the same distance to the lumbar segments, the difference of 20 msec may indicate the central latency difference of the cutaneous and muscular r e f l e x e f f e c t s . Epidural recording of the incoming volleys at the level of the Ist lumbar vertebra confirmed this estimation.
FI01 PARASPINALMUSCLES RESPONSESTO TAPPING IN HEALTHY SUBJECTS: PRELIMINARY OBSERVATIONS GABELLINI,A.S., MARTINELLI,P., GULLI,M.R., Neurological I n s t i t u t e of the University, Via U.Foscolo 7, Bologna, I t a l y L i t t l e a t t e n t i o n has been p~id to paraspinal muscles reflexes so f a r , and only recently D i m i t r i j e v i c (198o) made the f i r s t observations about them. In our study random taps were applied to paraspinal muscles at L5 vertebra level in lo healthy volunteers by an automatic r e f l e x hammer, and 16 responses from the homo-and c o n t r a l a t e r a l paraspinal muscles at L2 vertebra level were averaged f o r each test. Vibratory stimulations at loo Hz were also applied on the same muscles. The tests were performed both in standing and s i t t i n g position. The subjects wereasked f i r s t to relax and then to contract s l i g h t ly t h e i r paraspinal muscles; f l e x i o n and extension of the head and separate abduction of homo and c o n t r a l a t e r a l upper limb were also performed. Short latency (Rl) and longer latency (RII and R I l l ) r e f l e x responses were recorded in homo-and c o n t r a l a t e r a l paraspinal muscles. A tonic postural a c t i v i t y f a c i l i t a t e d these r e f l e x responses, even i f t h e i r appearance, p a r t i c u l a r l y concerning RI, remained inconstant. Vibration had a p o t e n t i a t i o n e f f e c t on longer latency responses and, inconstantly, a suppression e f f e c t on Rl. During postural changes of the head and upper limbs a f a c i l i t a t i o n of r e f l e x responses was also observed.
FIO0 CUTANEOUSEFFECTS ON ANKLE EXTENSORAND FLEXOR MOTONEURONS
FUNASE K, KASAI T, MANABEM, SHIMIZU H*, TANAKA R.~ Department of Neurobiology, Tokyo Metropolitan I n s t i t u t e f o r Neurosciences; *Section of Anesthesiology, Tokyo Metropolitan Neurological Hospital, Fuchu, Tokyoj Japan Effects of the sural nerve stimulation on the soleus (Sol) and a n t e r i o r t i b i a l (TA) motoneurones were studied by the H-reflexes and e p i d u r a l l y recorded spinal root p o t e n t i a l s on 8 normal subjects. The sural nerve was stimulated at the level of the external malleolus through b i p o l a r surface electrodes ( r e c t angular pulses with I msec duration and i n t e n s i t y less than pain threshold). The e a r l i e s t effects were r e c i p r o c a l , f a c i l i t a t o r y on Sol and i n h i b i t o r y on TA, and the shortest interval f o r the effects was ca. 30 msec between condit i o n i n g and test stimulus. On the other hand, the e a r l i e s t effects of the medial plantar (mixed) nerve stimulation was inversely reciprocal and appeared at ca. 10 msec. Since the sural and medial plantar nerves have comparable conduction v e l o c i t y (Behse and Buchthal, 1971) and the a f f e r e n t volleys i n these nerves conduct the same distance to the lumbar segments, the difference of 20 msec may indicate the central latency difference of the cutaneous and muscular r e f l e x e f f e c t s . Epidural recording of the incoming volleys at the level of the Ist lumbar vertebra confirmed this estimation.
FI01 PARASPINALMUSCLES RESPONSESTO TAPPING IN HEALTHY SUBJECTS: PRELIMINARY OBSERVATIONS GABELLINI,A.S., MARTINELLI,P., GULLI,M.R., Neurological I n s t i t u t e of the University, Via U.Foscolo 7, Bologna, I t a l y L i t t l e a t t e n t i o n has been p~id to paraspinal muscles reflexes so f a r , and only recently D i m i t r i j e v i c (198o) made the f i r s t observations about them. In our study random taps were applied to paraspinal muscles at L5 vertebra level in lo healthy volunteers by an automatic r e f l e x hammer, and 16 responses from the homo-and c o n t r a l a t e r a l paraspinal muscles at L2 vertebra level were averaged f o r each test. Vibratory stimulations at loo Hz were also applied on the same muscles. The tests were performed both in standing and s i t t i n g position. The subjects wereasked f i r s t to relax and then to contract s l i g h t ly t h e i r paraspinal muscles; f l e x i o n and extension of the head and separate abduction of homo and c o n t r a l a t e r a l upper limb were also performed. Short latency (Rl) and longer latency (RII and R I l l ) r e f l e x responses were recorded in homo-and c o n t r a l a t e r a l paraspinal muscles. A tonic postural a c t i v i t y f a c i l i t a t e d these r e f l e x responses, even i f t h e i r appearance, p a r t i c u l a r l y concerning RI, remained inconstant. Vibration had a p o t e n t i a t i o n e f f e c t on longer latency responses and, inconstantly, a suppression e f f e c t on Rl. During postural changes of the head and upper limbs a f a c i l i t a t i o n of r e f l e x responses was also observed.