SPINAL NERVES
DISORDERSOFTHE SPINE
Many disorders of the spine, despite
their different causes, result in just one
symptom:
b a c k p a in
.
Congenital disorders
Some children are born with a gap in
the vertebrae because part of one or
more vertebrae has failed to develop
completely. This leaves part of the spinal
cord exposed. The condition, known as
s p in a b ifid a
,
may cause paralysis of the
lower limbs and incontinence.
Infection
O steo m yelitis
(infection of bone and
bone marrow) may in rare cases affect
a vertebra, destroying both bone and
disc. The most common cause of
osteomyelitis is the spread of an
infection, such as
t u b e rc u lo s is
,
from
elsewhere in the body.
Inflammation
In
a n k ylo sin g s p o n d y litis
,
and in some
cases of
rh e u m a to id a rth ritis
,
the joints
in the spine become inflamed and
eventually fuse, causing permanent
stiffness.
O ste o ch o n d ritis ju v e n ilis
(inflammation of the growing area of
bone in children and adolescents) can
affect the vertebrae, when the disease
may cause deformity of the spine.
Injuries
Lifting heavy objects, twisting suddenly,
or adopting bad posture can cause any
of the following spinal injuries: sprained
ligament, torn muscle,
s p o n d y lo listh e sis
(dislocated vertebrae), dislocated facet
joint, or
d is c p ro la p se
(rupture of the
tough outer layer of the disc).
A direct blow, a fall from a height, or
sudden twisting can result in fracture
of one or more vertebrae.
Tumours
Tumours of the bones of the spine are
usually malignant; in most cases, they
have spread from cancer elsewhere in
the body (see
b o n e c a n c e r).
Degeneration
O steo a rth ritis
(degeneration of joint
cartilage due to wear and tear) affects
the spine joints of virtually everyone
over
6 0
, particularly people who do
heavy manual work or those whose
spines have already been affected by
disease or injury.
O ste o p o ro sis
(thinning and softening
of bone), which is most common in
postmenopausal women, can weaken
the vertebrae. Vertebrae may fracture and
collapse, under the weight of the trunk.
Other disorders
In some people, the spine is abnormally
curved. Excessive curvature may be
inwards in the lower back (see
lo rd o s is
),
outwards in the upper back (see
ky p h o sis
), or to one side (see
s c o lio s is
).
Causes include infection, osteoporosis,
and congenital and muscle disorders.
INVESTIGATION
Spinal disorders are investigated by
X - r a y s , C T s c a n n i n g ,
and
M R I.
Other bone
imaging techniques, such as
r a d i o n u c l i d e
s c a n n i n g ,
may also be performed.
STRUCTURE OF THE SPINE
The spine is made up of a column of
33 roughly cylindrical bones called
vertebrae. Running through the
centre of this bony structure is the
spinal cord.
C e r v ic a l s p i n e
S e v e n v e r t e b r a e ,
t h e t o p m o s t o f
w h ic h s u p p o r t s
t h e s k u ll.
w ife
-
T h o r a c i c s p i n e
T w e lv e v e r t e b r a e
t h a t r u n d o w n
t h e r e a r w a l l o f
L i
p
t h e c h e s t . A p a i r
*
o f r i b s i s a t t a c h e d
t o e a c h v e r t e b r a .
£
=
L u m b a r s p i n e
F iv e v e r t e b r a e .
T h is s e c t i o n is
i r 3 ^ ) v
j
t h e o n e u n d e r t h e
m o s t p r e s s u r e
d u r i n g liftin g .
k
Æ
k
=
\ P i
S a c r u m
F iv e f u s e d
fit
v e r t e b r a e .
C o c c y x
F o u r f u s e d
§ r
v e r t e b r a e .
a f f e c t m o v e m e n t a n d s e n s a t i o n b u t c a n
s o m e t i m e s b e r e l i e v e d b y s u r g e r y .
I n f e c t i o n s o f t h e s p i n a l c o r d a r e r a r e
b u t c a n c a u s e s e r i o u s d a m a g e . A n e x a m -
p l e o f s u c h a n i n f e c t i o n i s
p o lio m y e litis .
I n
m u lt ip le s c le r o s is ,
a d e g e n e r a t i v e d i s -
e a s e ,
t h e r e
i s
p a t c h y
l o s s
o f
t h e
i n s u l a t i n g s h e a t h s a r o u n d n e r v e f i b r e s .
s p in a l fu s io n
M
a j o r s u r g e r y i n w h i c h t w o
o r m o r e
a d j a c e n t
v e rte b ra e
a r e j o i n e d t o g e t h e r . I t
i s p e r f o r m e d i f t h e r e i s a b n o r m a l m o v e -
m e n t
b e t w e e n
a d j a c e n t v e r t e b r a e
t h a t
c a u s e s s e v e r e b a c k p a i n o r r i s k s d a m a g -
i n g t h e s p i n a l c o r d .
s p in a l in ju ry
D a m a g e t o t h e
s p in e
a n d s o m e t i m e s t o
t h e
s p in a l c o rd .
S p i n a l
i n j u r y
i s
m o s t
o f t e n t h e r e s u l t o f f a l l i n g f r o m a h e i g h t
o r o f a r o a d t r a f f i c a c c i d e n t .
D a m a g e t o t h e
v e rte b ra e
a n d t h e i r
lig a -
m e n ts
u s u a l l y
c a u s e s
s e v e r e
p a i n
a n d
s w e l l i n g o f t h e a f f e c t e d a r e a . D a m a g e t o
t h e s p i n a l c o r d r e s u l t s i n
p a ra ly s is
a n d / o r
l o s s o f s e n s a t i o n b e l o w t h e s i t e o f i n j u r y .
X -ra y s
a n d / o r
M R I
o r
C T s c a n n in g
o f t h e
s p i n e a r e c a r r i e d o u t t o d e t e r m i n e t h e
e x t e n t o f d a m a g e . I f t h e b o n e s a r e d i s l o -
c a t e d , s u r g e r y i s n e e d e d t o m a n i p u l a t e
t h e m b a c k i n t o p o s i t i o n . T r e a t m e n t w i t h
t h e
d r u g
m e t h y lp re d n is o lo n e
w i t h i n
a
f e w
h o u r s
o f a n
i n j u r y
a i d s
r e c o v e r y
f r o m s p i n a l - c o r d d a m a g e . S u r g e r y m a y
b e n e e d e d t o r e m o v e p r e s s u r e
o n t h e
c o r d , b u t d a m a g e d n e r v e t r a c t s c a n n o t
b e
r e p a i r e d .
P h y s io t h e ra p y
m a y
s t o p
j o i n t s l o c k i n g a n d m u s c l e s c o n t r a c t i n g
d u e t o p a r a l y s i s .
I f t h e r e
i s
n o
s p i n a l - c o r d
d a m a g e ,
r e c o v e r y i s u s u a l l y c o m p l e t e . I n c a s e s o f
s p i n a l - c o r d
d a m a g e ,
s o m e
i m p r o v e -
m
e n t m a y o c c u r f o r u p t o 1 2 m o n t h s .
s p in a l n e rv e s
A s e t o f 3 1
p a i r s o f
n e rv e s
t h a t c o n n e c t
t o t h e
s p in a l c o rd .
T h e n e r v e s e m e r g e i n
t w o r o w s f r o m e i t h e r s i d e o f t h e s p i n a l
c o r d a n d l e a v e t h e s p i n e t h r o u g h g a p s
b e t w e e n a d j a c e n t v e r t e b r a e . T h e y t h e n
b r a n c h
o u t t o s u p p l y
a l l p a r t s
o f t h e
t r u n k , a r m s , a n d l e g s w i t h s e n s o r y a n d
m
o t o r n e r v e f i b r e s .
S
707
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