And then the last condition
that falls within this bucket
of trigeminal autonomic
cephalalgias is hemicrania continua.
This was previously
not considered a TAC,
but is now grouped with the TACs
and so we'll consider it in
that same group of conditions.
But it's different.
It has some key differences.
The duration of these headaches
is greater than 3 months.
It is continua,
continuous hemisided headache.
without side shift.
So with cluster, we said the the side of
head pain is locked during the cluster,
but can alternate between
the episodes of cluster
and here we see that
there is no side shift
with himecrania continua,
it's always on the same side
daily continuous head pain
without pain free periods.
And that's really one of
the prominent differences
between hemicrania continua
and all the other 3 TACs
is this lack of pain free periods in
between episodes of worsening head pain.
And the pain is typically moderate in
severity with exacerbations of severe pain.
But it's often not quite as bad as
the other TACs that we've discussed.
Patients will often describe and
have at least one autonomic finding,
nasal congestion/rhinorrhea, ptosis/miosis.
So it does fall in the category of
the TACs with autonomic features.
There is complete
response to indomethacin.
So similar to
we see that this is an
indomethacin responsive headache,
and it must not be attributed
to any other disorder.
So what does it look like?
How do patients describe and how do we
vizualise hemicrania continua in patients?
Well, compared to other TACs,
there's more prominent migrainous features
and less prominent cranial
And so that's different
than what we've discussed
paroxysmal hemicrania and SUNCT.
And this is what the
headache looks like.
So there's really an underlying headache
severity that is present at all times.
Patients never have a
headache free interval
where things go down to normal where
there's really not a severe headache.
And in between that there are
episodes of spiking headaches
that are much more severe,
again, followed by a
period of more chronic
and indolent headache that
is present at all times.
To differentiate hemicrania
continua from the other TACs,
we can consider a
number of features,
including the migrainous features and
the presence of autonomic features.
Headache attacks are short lasting with
something sooner lasting 10 minutes
and paroxysmal hemicrania
is around 30 minutes
and cluster is less
than 180 minutes
and we typically see headaches that
are longer with hemicrania continua.
The pain in hemicrania
continua is continuous.
That's why it's called
and that's critical in
making this diagnosis
and differentiating it
from the other TACs.
And the pain in hemicrania
continua usually not as severe
or excruciatingly severe as
that with the other TACs.
How do we treat
Well reported cases of indomethacin
failure have been described.
But this is really a
indomethacin responsive headache.
So we treat with indomethacin.
And it's likely that
those with prior failure,
it failed to get to an adequate
dose of this medication.
So this is really important
for these patients,
it can be one of the most
seeing the insets
may respond to topiramate
and occipital nerve blocks
can be attempted in some cases.
So, to end, we have a table
that describes each of the TACs.
Cluster, paroxysmal hemicrania,
SUNCT and hemicrania continua.
And this can be an important
reference as we look to differentiate
each of these prominent
autonomic episodic headaches,
both in their gender
predilection or sex predilection,
pain severity, attack
duration, which is key
that difference in attack duration is
key in differentiating these syndromes,
the attack frequency, triggers,
whether it's episodic or chronic.
The presence of migraine features which we
said is more common in hemicrania continua.
Whether there's a circadian
rhythm component to it,
sumatriptan or triptan response
and indomethacin responsiveness.
responsiveness is critical
for diagnosing paroxysmal
hemicrania and hemicrania continua.