<s>
Hypsarrhythmia	B-Algorithm
is	O
very	O
chaotic	O
and	O
disorganized	O
brain	O
electrical	O
activity	O
with	O
no	O
recognizable	O
pattern	O
,	O
whereas	O
a	O
normal	O
brain	O
electrical	O
activity	O
shows	O
clear	O
separation	O
between	O
each	O
signal	O
and	O
visible	O
pattern	O
.	O
</s>
<s>
It	O
is	O
an	O
abnormal	O
interictal	O
pattern	O
,	O
consisting	O
of	O
high	O
amplitude	O
and	O
irregular	O
waves	O
and	O
spikes	O
in	O
a	O
background	O
of	O
chaotic	O
and	O
disorganized	O
activity	O
seen	O
on	O
electroencephalogram	B-Application
(	O
EEG	B-Application
)	O
,	O
and	O
frequently	O
encountered	O
in	O
infants	O
diagnosed	O
with	O
infantile	O
spasms	O
,	O
although	O
it	O
can	O
be	O
found	O
in	O
other	O
conditions	O
such	O
as	O
tuberous	O
sclerosis	O
.	O
</s>
<s>
Gibbs	O
and	O
Gibbs	O
described	O
hypsarrhythmia	B-Algorithm
(	O
originally	O
spelled	O
with	O
one	O
'	O
r	O
 '	O
)	O
in	O
1952	O
as	O
"	O
random	O
...	O
high	O
voltage	O
waves	O
and	O
spikes	O
.	O
</s>
<s>
In	O
most	O
cases	O
of	O
infantile	O
spasms	O
,	O
hypsarrhythmia	B-Algorithm
either	O
disappears	O
or	O
improves	O
during	O
a	O
cluster	O
of	O
spasms	O
and/or	O
REM	O
sleep	O
.	O
</s>
<s>
Hypsarrhythmia	B-Algorithm
rarely	O
persists	O
beyond	O
the	O
age	O
of	O
24	O
months	O
.	O
</s>
<s>
Through	O
the	O
use	O
of	O
video	O
EEG	B-Application
and	O
continuous	O
monitoring	O
,	O
five	O
variants	O
of	O
the	O
"	O
classical	O
"	O
hypsarrhythmic	O
pattern	O
have	O
been	O
identified	O
:	O
</s>
<s>
Hypsarrhythmia	B-Algorithm
with	O
increased	O
interhemispheric	O
synchronization	O
.	O
</s>
<s>
Asymmetric	O
hypsarrhythmia	B-Algorithm
.	O
</s>
<s>
Hypsarrhythmia	B-Algorithm
with	O
a	O
consistent	O
focus	O
of	O
abnormal	O
discharge	O
.	O
</s>
<s>
Hypsarrhythmia	B-Algorithm
with	O
episodes	O
of	O
voltage	O
attenuation	O
.	O
</s>
<s>
Hypsarrhythmia	B-Algorithm
with	O
little	O
spike	O
or	O
sharp	O
activity	O
.	O
</s>
<s>
The	O
"	O
H	O
"	O
in	O
PEHO	O
syndrome	O
stands	O
for	O
hypsarrhythmia	B-Algorithm
.	O
</s>
<s>
Together	O
with	O
developmental	O
regression	O
and	O
infantile	O
spasms	O
,	O
hypsarrhythmia	B-Algorithm
is	O
one	O
of	O
the	O
diagnostic	O
criteria	O
for	O
West	O
syndrome	O
.	O
</s>
