Chief complaint: “I can’t see”
History of Present Illness:
A 20 year old African
American female complains of an inability to see. Her symptoms started with the gradual onset
of headache around 4:00 am. At that time
vision was noted to be blurry, and this progressed to only being able to see
light/dark over the next 4 hours. She
presents to the ED 12 hours later because couldn’t find the phone and she had
to wait for someone to find her. At this
time she complains of severe bifrontal headache, worse than her typical
migraine. Nothing makes it better or
worse. She denies any other neurologic
signs or difficulty walking. Has had
some nausea. She denies any fever or
neck stiffness. She denies any other
weakness or numbness, or any problems speaking or swallowing. Otherwise her ROS
is negative.
Past Medical History:
She is 8 days postpartum
from a term vaginal delivery complicated by mild hypertension in the peripartum
period. Also has a history of migraines.
Meds: Motrin
Allergies: NKDA
Social: Lives at home with newborn and one other
child.
Family: No family history of
preeclampsia or clotting disorders.
· Vitals: BP 157/104
HR94 R18 T99.8
· Exam:
o Gen: Awake, alert but slow to answer questions.
o
HEENT: PERRL, EOMI.
No papilledema. Eyes seem normal. Eye grounds are normal (as far as you can
tell)
o
Pulm:
normal
o
CV:
normal
o
Abd: Soft, nontender, nondistended. No organomegaly.
o
Extr: Warm, well perfused. No edema is noted.
o
Neuro:
AAO x3. Only light perception both eyes,
no blinking on visual field confrontation.
Extra-ocular movement intact, pupils reactive to light. CN 3-12 normal. Strength, sensation normal. Cerebellar function normal as tested.
What is your differential diagnosis?
Differential Diagnosis of Neurologic
Symptoms in Pregnancy
· Eclampsia/Preeclampsia
·
Vascular
Vascular
o
Cerebral
Infarction
o
Intracranial
Hemorrhage
o
Hypertensive
Encephalopathy
o
Cerebral
Venous Thrombosis
·
Metabolic Encephalopathies
Metabolic Encephalopathies
o
Porphyria
o
Hepatic
Encephalopathy
o
Hyponatremia
·
Infective
Infective
o
Viral
Encephalitis
o
Cerebral
Malaria
o
Bacterial
Meningitis
·
Demyelinating
Demyelinating
o
Postinfective
Encephalomyelitis
o
Collagen
Vascular Disease (SLE)
·
Sheehan’s Syndrome
Sheehan’s Syndrome
·
Migraine Headache
Migraine Headache
Of these which are we really worried
about?
???????????????????????????????????????????
Work-up?
-Labs for pre-eclampsia are
sent (CBC, Basic 8, LFTs, uric acid, UA)
-CT vs. MRI?
A stat non-contrast CT brain
is obtained because it’s faster and more readily available
· CT shows low attenuation in
bilateral occipital lobes, an MRI is recommended.
An MRI is then performed:
TAKE A LOOK AT THOSE OCCIPITAL LOBES!!!!
Diagnosis:
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Posterior
Reversible Encephalopathy Syndrome (PRES)
(Secondary to eclampsia).
(Secondary to eclampsia).
WHAT???
Case Discusssion
Vascular Causes of Blindness:
Cortical Blindness in
Preeclampsia and Eclampsia
o
Vision
involvement in preeclampsia and eclampsia is common, affecting up to 50% of
patients.
o
Cortical
blindness is caused by lesions to bilateral occipital lobes and is
characterized by visual loss with normal pupillary responses and normal fundi.
o
Cortical
blindness occurs in 1-3% of women with severe preeclampsia or eclampsia.
o
The
Cortical blindness related to preeclampsia/eclampsia is due to Posterior Reversible Encephalopathy
Syndrome (PRES).
§ Also known as Posterior
Leukoencephalopathy Syndrome.
o
Characterized
by predominantly white matter edema affecting the occipital and posterior
parietal lobes of the brain
Posterior Reversible
Encephalopathy Syndrome (PRES)
·
Common
features include headache, altered mental status, seizures, vomiting, and
visual disturbances. Visual
problems may include hemianopia, visual neglect, or cortical blindness.
·
Some
patients with cortical blindness may deny any visual problems (known as Anton’s
syndrome). On
exam the patient may be confused, uncoordinated, and may have increased
reflexes. The
patient should have normal pupillary reflexes and normal fundi on exam.
·
There
are 2 main theories regarding cause:
·
1. May
result from a rapid rise in blood pressure that overcomes the brain’s ability
to autoregulate blood flow. This
is a form of hypertensive encephalopathy. Produces
dilation of endothelial tight junctions and leakage of plasma and red cells
into the extracellular space, producing edema. The
blood vessels in the posterior cerebral areas have less sympathetic adrenergic
innervation compared to other areas of the brain and may lead to less ability
to vasoconstrict.
·
2. The
other theory contends that the syndrome is caused by vasospasm secondary to
sudden and severe rises in blood pressure and ischemia of brain tissue. (This
theory is less likely because symptoms would be less reversible.)
Other causes of PRES
include:
· Common
o
Hypertensive
encephalopathy
o
Preeclampsia/Eclampsia
o
Immunosuppressive
agents and cytotoxic drugs
o
Renal
failure with hypertension
· Other reported causes
o
Collagen
vascular disorders
§ Lupus
§ Polyarteritis nodosa
§ Behcet’s syndrome
o
Thrombotic-thrombocytopenic
purpura
o
Acute
intermittent porphyria
o
Following
organ transplantation
PRES- Diagnosis
·
Patients
manifesting symptoms consistent with PRES require urgent MRI imaging.
o
CT
does not adequately differentiate between other potential causes on the
differential.
o
The
treatment for PRES is relatively contraindicated in other conditions so
differentiation should be made as soon as possible.
·
In
addition to the normal T1 and T2 weighted images the MRI study should include
diffusion weighted imaging.
o
This
technique can differentiate between cytotoxic edema due to ischemia from
vasogenic edema due to PRES several hours before conventional MRI techniques
can.
PRES- Treatment
o
In
the setting of preeclampsia or eclampsia, treatment should focus on aggressive
blood pressure management and treatment for eclampsia.
o
In
the setting of other conditions (i.e. immunosuppressive regimens) the treatment
should focus on treatment of the underlying cause and discontinuation of
potentially causative medications as well as aggressive blood pressure control
PRES- Prognosis
o
The
prognosis for PRES is usually good.
o
Most
cases of PRES due to eclampsia will completely resolve within 7-8 days with a
return of vision if treated in a timely manner.
o
Failure
to recognize and treat this disorder in a timely manner can lead to long term
neurologic consequences.
Some notes on post-partum
preeclampsia/eclampsia
o
Post-partum
preeclampsia and eclampsia has been documented out to 4 weeks post delivery
o
Up
to 69% of these patients have no signs of this condition prior to delivery
o
The
majority of cases occur within 10 days of delivery, with a mean around 5 days
post-partum.
o
We
in the emergency department need to have this under consideration for any
post-partum patient with hypertension, seizures, or acute vision
abnormalities.
Back to the case
o
The
patient is admitted to the neuro ICU.
Despite being started on magnesium and hydralazine, she became more
hypertensive and confused and had one generalized tonic-clinic seizure. She subsequently stabilized.
o
Vision
difficulties resolved over the next 3 days and the patient was discharged on
hospital day#4 with normal vision and no apparent lasting effects.
References
o
Chambers
K, Cain T. Postpartum Blindness: Two
Cases. Annals of Emergency Medicine 2004; 43(2):243-246.
o
Do
D, Rismondo V, et al. Reversible
Cortical Blindness in Preeclampsia.
American Journal of Opthalmology.
2002;134(6):916-918
o
Ebert
A, Hopp H, et al. Acute Onset of
Blindness During Labor: Report of a Case of Transient Cortical Blindness in
Association With HELLP Syndrome.
European Journal of Obstetrics and Gynecology and Reproductive Biology.
1999;84: 111-113.
o
Garg
R. Posterior Leukoencephalopathy
Syndrome. Postgrad Med J 2001;77:24-28.
o
Gregory
D, Pelac V, et al. Diffusion-Weighted
Magnetic Resonance Imaging and the Evaluation of Cortical Blindness in
Preeclampsia. Survey of Opthalmology
2003; 48(6):647-650.
o
Martin
J, Sidman R. Late Postpartum Eclampsia:
A Common Presentation of an Uncommon Diagnosis.
Journal of Emergency Medicine 2003;25(4):387-390.
o
Yancey
LM. Postpartum preeclampsia: emergency
department presentation and management.
J Emerg Med 2011;40(4):380-4.
Questions:
1) All of the following are common causes of posterior reversible encephalopathy syndrome (PRES) EXCEPT:
A) Chemotherapy
B) Severe hypertension
C) Preeclampsia
D) Status Epilepticus
2) A 2 week post-partum woman presents to the emergency department with peripheral edema, bilateral vision deficits, and confusion. Her blood pressure is 170/110. Acute management should include all of the Following EXCEPT:
A) Magnesium Sulfate 4g IV infusion
B) IV Heparin infusion
C) Aggressive treatment of hypertension
D) Urgent MRI to help acutely differentiate possible causes of her vision symptoms.
3) Which of the following causes of cortical blindness has increased frequency in peripartum women?
A) Top of the Basilar Syndrome/ Rostral Brainstem Infarction
B) Posterior Reversible Encephalopathy Syndrome (PRES)
C) Central Venous Thrombosis
D) B and C
E) All of the Above
4) Pre-eclampsia and Eclampsia has been documented as late as:
A) the immediate peripartum period
B) 1 week after delivery
C) 2 weeks after delivery
D) 4 weeks after delivery
5) Which of the following college football fan bases consist of backwards hillbillies who will ultimately live in awe of the University of Michigan football team once it rises to power asserts its destiny as the greatest team ever?
A) Louisiana State University
B) Any team from the state of Alabama
C) Ohio State
D) All of the above
Answers:
1) D
2) B
3) D
4) D
5) D!
Great case! Bowler for PRES-ident.
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