She discusses a problem but offers no solutions. That great stroke association president should be contacting all these researchers that never propose solutions to the problems they describe.
http://www.paneuropeannetworks.com/health/stroke-and-visual-disturbances/
Kristin Modalsli Sand is a member of the stroke research group at the
Center for Neurovascular Disease at Haukeland University Hospital in
Bergen, Norway, and project manager of the multicentre prospective study
NOR-OCCIP (Norwegian Occipital Ischemic Stroke Study), which focuses on
the management and outcome of visual field defects in occipital
cerebral infarction.
Speaking at the 3rd European Stroke Organisation Conference (ESOC)
2017, which Pan European Networks attended in Prague, Czech Republic, in
May, Sand took as her topic visual disturbances in ischaemic stroke
patients. Her presentation centred on three questions, namely ‘why
should we care about visual disturbances?’, ‘when should we suspect a
visual disturbance is actually an ischaemic lesion?’, and ‘should we
thrombolyse the patient?’
Why should we care about visual disturbances?
The first answer to this question, Sand explained, is simple: because
they happen frequently. Given the way that the brain is organised – the
eyes being at the very front, the occipital lobe being at the very
back, and the two of them very intricately communicating – “it’s not
difficult to understand that a lesion in … say, any part of the brain
could give some sort of problem with vision”.
This is also reflected in the literature, she continued, noting that
61% of the 1,200 patients included in a large study on VISTA (Virtual
International Stroke Trials Archive) had a vision problem and 50% a
visual field defect. “This is something that affects a lot of patients,
and we have to deal with it,” Sand said.
Poor functional patient outcomes are the second reason that we should
care about visual disturbances, she added, explaining that patients who
experience vision problems after a stroke have higher scores on the
National Institutes of Health Stroke Scale (NIHSS), higher modified
Rankin Scale scores, and lower Barthel Index scores compared to patients
who experience other problems or deficits after a stroke (and no vision
problems – something which has been confirmed by numerous studies).
Multiple pieces of evidence have also shown that patients who
experience vision problems after a stroke have a poor quality of life,
Sand added, pointing to one of her own studies as an example and
highlighting the “dose-response relationship” between increasing vision
problems and an increasingly poor quality of life.
“We were quite surprised when we did a study on mortality and visual
field defects, and we saw at first, in the acute phase with the severe
stroke patients, that there was a clear tendency for visual field defect
with hemianopia to have a higher mortality rate,” she continued.
“We then wanted to look at the mild strokes, asking: what about those
who have an NIHSS score of four or below and have a visual field
defect? We looked at them and in the acute phase we found what we
expected: there was not really any difference. Then we looked at the
long-term outcomes for these patients. Something happens after about
four years. Those who have a hemianopia after four years as their only
deficit after a small ischaemic stroke have higher mortality rates, and
this was also still significant after trending for confounding factors.
When you think about it, having a hemianopia, you’re prone to accidents.
When you cross the street, you might be hit by a car or you might fall,
so it’s not so difficult to imagine that this could actually be the
case.”
The third reason that we should care about visual disturbances is
because we can “fix” them, Sand said. Highly significant results from
VISTA show that patients who experience visual problems and are treated
with thrombolytic agents improve compared to patients who don’t receive
thrombolytic agents. This makes treatment “really important”.
Visual disturbances can also be fixed in the sense that patients can
receive training and visual rehabilitation. Sand explained: “We know
that when you have a motor problem in the tongue, or in the arm or the
leg, this can be trained. But somehow there’s a conception that a motor
problem in an eye muscle is not available for training, and this is a
really grave misconception.
“We have a short period of a ten-day programme to try to work with
[patients’] eye muscles and strengthen them, and they have a really
miraculous recovery, and we know that compensation techniques improve
reading speeds for patients, improve their search strategies, and
improve their activities in daily lifestyle function.”
She added that vision restitution therapy (VRT) is more
controversial, as some studies have demonstrated it has an effect (but
not necessarily as positive an effect as some had hoped), while others
have not. VRT is nonetheless important to consider, Sand said, because
“we know that VRT also improves reading speeds and significantly
improves the quality of life for the patient”.
When should we suspect that a visual disturbance is actually an ischaemic lesion?
Sand then turned her attention to how to tell whether a patient
presenting with an isolated vision problem is actually presenting with a
stroke.
“The hallmark of any acute stroke is the acute onset, but in vision
problems we have to be very critical … because the patient might just
present with nausea or a headache, and not really recognise at all that
they have a vision problem. So, you have to remember, in the acute
setting, to examine the visual field.”
Sand explained that most of the information designed to help people
recognise a stroke – for example FAST (Facial drooping, Arm weakness,
Speech difficulties and Time to call emergency services) – don’t say
anything about vision, so most people “don’t realise that an acute onset
of a vision problem is or could be a stroke”.
However, many of the symptoms which persist do provide an indication
of whether a stroke is more likely – for instance “if you have a
hemifield where [the patient] just can’t see as opposed to a hemifield
with flickering lights, which could of course also be a stroke”. Other
things to consider include whether the lesion is localisable and whether
you can you pinpoint a lesion from the patient’s symptoms. “Many times –
for example, with a migraine – the patient has more global symptoms,
and it’s more difficult to pinpoint the precise lesion,” Sand explained,
“so that’s important to consider.”
Of course, there are cases where you might not be able to tell if a
stroke has occurred, in which case you have to consider the patient’s
“comorbidity and risk factors for stroke” when deciding whether or not
to thrombolyse, and any of the numerous “differential diagnoses” which
might be more likely, among them migraine, epilepsy and other ocular
conditions.
Should we thrombolyse the patient?
Sand then returned to her final question: should we thrombolyse
patients with visual disturbances? Such patients often score zero or
else very low on the NIHSS, which might result in thrombolytic treatment
being withheld, but “of course we know better,” she said. “We know that
there’s actually increased mortality, poor post-stroke outcome, and
poor quality of life. So, no, it’s not too much to treat and we really
should do a lot of work to do better by these patients, because they
often don’t get the treatment that they deserve.”
Drawing her presentation to a close, Sand summed up her “take-home
message” to the ESOC audience: “When you have a visual disturbance in
the ER, you need to assess whether it’s an acute onset and be very
critical. Don’t forget to examine the patient when [they] present with
acute headache or acute vertigo or acute nausea … Where is the lesion?
Try to be critical. Can I explain all the patient’s symptoms with one
lesion?” she asked, urging her listeners to consider the whole picture –
that is, other risk factors for ischaemic stroke and whether a
differential diagnosis is more likely.
“Of course, my main message here today is that, no, visual disturbances are not too much to thrombolyse,” she concluded.
This article will appear in issue two of Pan European Networks: Health, which will be published at the end of August.
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