SLEEP TERROR
a n d r e s u l t i n s n o r i n g . I f c o m p l e t e b l o c k -
a g e o c c u r s , b r e a t h i n g s t o p s . T h i s t r i g g e r s
t h e b r a i n t o r e s t a r t b r e a t h i n g ; t h e p e r s o n
m a y g a s p a n d w a k e b r i e f l y .
I n
c e n t r a l
s l e e p
a p n o e a ,
b r e a t h i n g
s t o p s
b e c a u s e
t h e
c h e s t
m u s c l e s
a n d
d ia p h ra g m m u s c le
t e m p o r a r i l y
c e a s e
t o
w o r k , p r o b a b l y d u e t o a d i s t u r b a n c e i n
t h e b r a i n ’s c o n t r o l o f b r e a t h i n g . C a u s e s
i n c l u d e p a r a l y s i s o f t h e d i a p h r a g m a n d
d i s o r d e r s o f t h e
b ra in s te m
( t h e p a r t o f
t h e b r a i n t h a t c o n t r o l s b r e a t h i n g ) . S n o r -
i n g i s n o t a m a i n f e a t u r e .
O v e r w e i g h t p e o p l e m a y f i n d t h a t l o s -
i n g w e i g h t h e l p s . ( I n c o n t r a s t , a l c o h o l a n d
s l e e p i n g d r u g s a g g r a v a t e s l e e p a p n o e a . )
I n o n e t r e a t m e n t , a i r f r o m a c o m p r e s s o r
i s
f o r c e d
i n t o
t h e
a i r w a y
v i a
a
m a s k
w o r n
o v e r
t h e
n o s e .
N i g h t - t i m
e
a r t i -
f i c i a l
v e n tila tio n
m a y b e n e e d e d .
T o n s ill-
e c to m y , a d e n o id e c to m y ,
o r s u r g e r y o n t h e
s o f t p a l a t e m a y b e p e r f o r m e d .
s le e p d e p riv a tio n
I n s u f f i c i e n t
s le e p .
I r r i t a b i l i t y a n d a s h o r t -
e n e d a t t e n t i o n s p a n m a y o c c u r a f t e r a
s h o r t n i g h t ’s s l e e p . L o n g e r s l e e p l e s s p e r -
i o d s l e a v e a p e r s o n l e s s a b l e t o c o n c e n -
t r a t e o r p e r f o r m n o r m a l t a s k s . T h r e e o r
m o r e s l e e p l e s s n i g h t s m a y l e a d t o
h a llu -
c in a tio n s
a n d , s o m e t i m e s , t o
p a r a n o ia
.
s le e p in g d ru g s
COMMON DRUGS
benzodiazepine drugs
•Flurazepam
• Loprazolam •Lormetazepam •Nitrazepam
•Temazepam
others
•Clomethiazole •Diphenhydramine
• Promethazine •Zolpidem •Zopiclone
A g r o u p o f d r u g s t h a t a r e u s e d f o r t h e
t r e a t m e n t
o f
in s o m n ia .
S l e e p i n g
d r u g s
i n c l u d e
b e n z o d ia z e p in e d r u g s
;
a n tih is t a -
m in e d ru g s ,
w h i c h
a r e
o f t e n
a v a i l a b l e
o v e r - t h e - c o u n t e r ;
a n t id e p re s s a n t d ru g s ;
a n d
c h l o r a l h y d r a t e . T h e s e
d r u g s p r o -
m o t e s l e e p b y r e d u c i n g t h e a c t i v i t y o f
n e r v e c e l l s i n t h e b r a i n .
S l e e p i n g
d r u g s
s h o u l d
a l w a y s
b e
t a k e n i n t h e s m a l l e s t e f f e c t i v e d o s e f o r
t h e s h o r t e s t p e r i o d o f t i m e . I n g e n e r a l ,
t h e y s h o u l d b e u s e d f o r n o m
o r e t h a n
t h r e e w e e k s ,
a n d p r e f e r a b l y
n o t e v e r y
n i g h t . S l e e p i n g d r u g s d o n o t t r e a t t h e
u n d e r l y i n g
c a u s e
o f i n s o m n i a ,
w h i c h
n e e d s t o b e i n v e s t i g a t e d .
ADVERSE EFFECTS
S l e e p i n g
d r u g s m a y c a u s e
d r o w s i n e s s ,
u n s t e a d i n e s s ,
a n d i m p a i r e d
c o n c e n t r a -
t i o n o n w a k i n g . T h e y c a n b e e s p e c i a l l y
h a z a r d o u s t o a n y o n e d r i v i n g o r
o p e r -
a t i n g
m a c h i n e r y
L o n g - t e r m
u s e
m a y
SLEEP PATTERNS
The brain does not rest when a person is sleeping, but there is some
reorganization of activity within it. EEGs (electroencephalograms) and other
recordings reveal cyclical patterns to this activity.
Awake
REM
Stage 1
Stage 2
Stage 3
Stage 4
Key
REM
sleep
NREM
sleep
1
Hours
1
2
3
4
5
6
7
Phases of sleep
There are two types of sleep, REM
(rapid eye movement) and NREM (nonrapid eye movement).
They can be distinguished by the presence of absence of REMs and by EEGs or other recordings.
The chart shows how a sleeper passes in cycles between the four stages of NREM
sleep during the
night, with bursts of REM
sleep.
Stage 1
v i A
REM sleep
REM sleep
The EEG (left) shows high-
frequency, low-voltage waves.
People awakened during REM
sleep often report dreams.
NREM sleep
This is sometimes called
orthodoxsleep; in adults it
makes up about 80 per cent
ofthe sleeping pattern. It has
four stages of progressively
greater “depth” of sleep,
characterized by EEG waves
(left) of increasingly larger
voltage (amplitude) and lower
frequency (number ofwaves
per second). People awakened
during NREM
sleep often
report they were “thinking”
about everyday matters but
rarely report dreams.
i n d u c e
t o le ra n c e
( n e e d i n g a h i g h e r d o s e
t o a c h i e v e t h e s a m e e f f e c t )
a n d
d e p e n -
d e n c e
( w i t h d r a w a l s y m p t o m s w h e n t h e
p e r s o n s t o p s t a k i n g t h e d r u g ) .
s le e p in g s ic k n e s s
A s e r i o u s i n f e c t i o u s d i s e a s e o f t r o p i c a l
A f r i c a c a u s e d b y t h e p r o t o z o a n p a r a s i t e
T r y p a n o s o m a b r u c e i , w h i c h i s t r a n s m i t t e d
t o h u m a n s b y t h e b i t e o f a t s e t s e f l y .
O n e
f o r m
o f
t h e
d i s e a s e ,
w h i c h
o c c u r s i n W e s t a n d C e n t r a l A f r i c a , t a k e s
a s l o w c o u r s e , w i t h b o u t s o f f e v e r a n d
l y m p h - n o d e e n l a r g e m e n t . A f t e r m o n t h s
o r
y e a r s ,
t h e
d i s e a s e
s p r e a d s
t o
t h e
b r a i n ,
c a u s i n g
h e a d a c h e s ,
c o n f u s i o n ,
a n d ,
e v e n t u a l l y
s e v e r e l a s s i t u d e . W
i t h -
o u t t r e a t m e n t ,
c o m a a n d d e a t h f o l l o w .
T h e
o t h e r ,
E a s t
A f r i c a n ,
f o r m
r u n s
a
f a s t e r c o u r s e . F e v e r d e v e l o p s a f t e r a f e w
w e e k s o f i n f e c t i o n , a n d t h e h e a r t m a y
s u f f e r f a t a l e f f e c t s b e f o r e t h e d i s e a s e h a s
r e a c h e d t h e b r a i n .
D r u g s
m a y
e f f e c t
a
c u r e ,
b u t
t h e r e
m a y
b e
r e s i d u a l
b r a i n
d a m a g e
i f t h e
i n f e c t i o n h a s a l r e a d y s p r e a d t o t h e b r a i n .
P e o p l e
i n
i n f e s t e d
a r e a s
s h o u l d
w e a r
l o n g c l o t h i n g f a s t e n e d a t t h e w r i s t s a n d
a n k l e s t o h e l p p r e v e n t t s e t s e f l y b i t e s .
s le e p p a ra ly s is
T h e s e n s a t i o n o f b e i n g u n a b l e t o m o v e
a t
t h e
m
o m
e n t
o f g o i n g
t o
s l e e p
o r
w a k i n g u p . I t u s u a l l y l a s t s o n l y a f e w
s e c o n d s , a n d m a y b e a c c o m p a n i e d b y
h a llu c in a t io n s .
S l e e p p a r a l y s i s m o s t o f t e n
o c c u r s i n p e o p l e w i t h
n a r c o le p s y
.
s le e p te rro r
S e e
n ig h t te rro r.
697
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