• Patient 1
29 year old woman,
without known risk factors.
She was in her 30th week of pregnancy,
transferred from surgery after an urgent cesarean for fetal distress,
probably in the context of eclampsia,
with arterial blood pressure levels of 145/96 and presenting with generalized seizures.
The first imaging test was a CT that showed a subcortical white matter hypodensity in the parasagital left parietal lobe with petechial hemorrhage within the lesion.
An MRI was perfomed one day later that showed vasogenic edema (hyperintensity on T2 and FLAIR with facilitated diffusion) except for a posterior region of restricted diffusion (low ADC values) that proved to be an infarct.
Notice the hemosiderin deposits on the T2* sequence due to the petechial hemorrhage (red arrow).
Fig 2: Follow-up MRI performed 2 months later shows gliosis and malacia as infarct sequelae (yellow arrow).
As atypical imaging findings in this case we have: ischemic infarction (restricted diffusion),
asymmetric almost unilateral distribution,
and petechial hemorrhage (Images 1,
2).
• Patient 2
54 year old woman,
smoker,
with medical history of chronic hypertension and a non-small cell lung carcinoma,
in her second cycle of chemotherapy,
including cisplatin. The patient consulted for acute visual impairment,
initially associated with headache and left homonymous hemianopia,
later accompanied by dizziness of sudden onset and progressive visual impairment that progressed to complete cortical blindness in a period of hours.
There were no other neurological,
motor,
sensory or language alterations.
CT images showed hypodense cortico-subcortical lesions in parasagital occipital regions and a similar lesion in superior right cerebellum,
suggesting ischemic lesions in the vertebrobasilar system.
CT angiography was completely normal.
MRI performed shortly after the CT scan,
shows bilateral occipital cortico-subcortical lesions that appear hyperintense on T2- weighted images and FLAIR,
hyperintense on diffusion and thin gyral enhancement on contrast- enhanced T1-weighted images.
A focal lesion of the same characteristics was seen in the right superior cerebellum.
These lesions were again highly suggestive of ischemic lesions in the vertebrobasilar system (Image 3).
MRI control was performed 9 months later ,
showing malacia and gliosis in parasagital occipital regions and focal malacia in right superior cerebellum,
that confirm the ischemic infarcts.
(Image 4).
Given that a thrombus was not found in vascular studies and that the patient was on cisplatin at the onset of symptoms,
cisplatin toxicity was assumed and the drug was removed.
This case illustrates a doubtful severe case of PRES with the atypical finding of extense infarction.
The real cause was never known.
• Patient 3
49 year old woman,
smoker,
with a history of hypertension and long-standing diabetes mellitus (DM).
Consults for a 72 hours clinical picture consisting of pulsatile headache,
phonophobia and photophobia,
starting after epidural catheter placement for anesthesia.
The patient underwent a lumbar puncture at the emergency department,
after which rapidly developed bilateral blindness.
CT perfomed at the emergency department showed bilateral parieto-occipital subcortical hypodensities,
highly suggestive of PRES.
MRI one day later a typical distribution of the lesions (holo-hemispheric pattern),
consisting in cortico-subcortical bilateral hyperintense lesions on long TR sequences,
suggestive of vasogenic edema,
predominantly in the posterior vascular territory (superior cerebellar hemispheres,
occipital and parietal lobes and right thalamus),
as well as in superficial water-shed territory (in the left temporal and bilateral frontal lobes) and deep water-shed territory.
Two of the lesions (left parieto-occipital and left occipital) show hyperintensity on diffusion weighted image (blue arrow), (Image 5).
The hypertension is corrected and the patient clinically improves,
being asymptomatic at discharge
Three weeks later.
Control MRI (Image 6),
radiological improvement with mild residual subcortical white matter vasogenic edema in occipital lobes.
Notice scarce focal lesions of gliosis in deep border territories,
and a small focus of peripheric malacia in the left occipital lobe,
suggesting sequelae of small infarctions (blue arrow).
• Patient 4
46 year- old woman,
heavy smoker,
hospitalized for 48 hours for of dyspnea of one month evolution a lymphoproliferative disorder,
The preset presents with cardio respiratory arrest following generalized seizures.
During admission presents new convulsive episodes,
dyplopia and low level of consciousness.
CT showed characteristic digitiform hypodensities of bilateral fronto-parietal subcortical white matter,
mainly on the left and mild cortical involvement without mass effect or enhancement after intravenous contrast administration.
MRI showed a typical pattern of symmetrical holohemispheric vasogenic edema.
Notice that right thalamus and left internal capsule are also involved.
(Image 7).
Final diagnosis was oat cell carcinoma with severe bone marrow infiltration.
Severe anemia and thrombopenia associated,
that precluded chemotherapy.
The patient presented multiorgan failure and died 16 days after admission.
The possible causes of PRES are a combination of leucoeritroblastic syndrome and severe thrombopenia,
with hypertension.
• Patient 5
51 year-old woman,
smoker,
who presents medical history of chronic hypertension and stage IV lung cancer diagnosed 1 month ago,
currently treated with the first cycle of cisplatin,
started 2 weeks ago.
Who attends to the emergency department with clinical symptoms that include left hemiparesis,
left central facial paresis and dysarthria.
MRI imaging shows an acute infarct in the right medial cerebral artery territory (MCA) (yellow arrow) and left hemispheric subcortical vasogenic edema in frontier territory of ACA-PCA/MCA (blue arrow) (Holohemispheric left asymmetric pattern).
This is an atypical case of left holohemispheric pattern of PRES with a right MCA ischemic infarct.
(Images 8 and 9).
The patient died 15 days after clinical manifestations onset.
• Patient 6
32 year-old woman,
24 weeks pregnancy.
Ex-smoker with a history of nephrotic syndrome,
renal function currently within normal limits.
Presents with severe headache and blurred vision ,
which evolves within hours to bilateral blindness.
Urgent cesarean is performed because of severe preeclampsia.
After treatment,
the patient shows complete recovery of vision,
although three medications were needed for arterial pressure control.
MRI shows bilateral symmetric holohemispheric pattern of vasogenic edema,
with scattered areas of facilitated diffusion.
Notice the involvement of other structures less frequently described in PRES,
such as splenium of corpus callosum,
basal ganglia and bilateral corona radiata (Image 10).
The patient shows complete recovery both clinically and on image studies after treatment,
(Image 11).
This case is typical both in clinical and imaging presentation and evolution.
Even in this case,
some atypical anatomical structures were involved along with the typical lesions.
• Patient 7
53-year-old woman,
smoker,
with long standing hypertension,
who presents at the emergency department with a hypertensive emergency with headache and seizures.
The MRI showed characteristic diffuse,
bilateral,
posterior lesions (primary parieto-occipital pattern) with bilateral deep water-shed zones and posterior limb of internal capsule involvement,
both after treatment,
the patient showed complete recovery of her clinical picture (Image 12).
• Patient 8
Pregnant 30 year-old woman with preclampsia,
who had undergone a cesary with epidural anesthesia 2 weeks before admission,
presents at the emergency department with orbital and hemicranial headache,
sensory and motor deficit with progressive impairment and tonic-clonic seizures.
CT showed bifrontal subarachnoid hemorrhage and left frontal hypodensity.
Heparin was started because of venous thrombosis suspicion.
The initial MRI showed supratentorially,
numerous cortico-subcortical bilateral vasogenic edema lesions in occipital,
parietal and frontal lobes.
Cerebellum was also involved (not shown).
In T1 and FLAIR small hyperintensities are observed in the left frontal convexity suggesting petechial bleeding or SAH (blue arrow).
T2* sequence showed hemosiderin subarachnoid deposits in the same localization.
The neurological signs and MR alterations quickly disappeared after anti-hypertensive treatment (3 weeks later).
DSA and venous MR angiography were normal, (Image 13).
No sequelae in imaging control two months later (Image14).
• Patient 9
51 year-old female smoker,
who presented a 5 day clinical picture of dizziness,
unsteadiness and asthenia associated with elevated blood pressure values (SBP 170 mmHg).
The patient consulted the emergency department for appearance of dysarthria and central facial paralysis.
Initial MR shows acute ischemic infarct in pons (blue arrow),
and bilateral occipital and posterior temporal subcortical vasogenic edema that reverses in follow-up imaging,
suggesting PRES.
Notice the focal hyperintensities in posterior periventricular white matter suggesting ischemic lesions from small vessel disease,
(Image 15).
Control MRI shows disappearance of the temporo-occipital lesions a chronic lacunar infarction in pons and periventricular white matter lesions of small vessel disease without change, (image 16).
• Patient 10
47 year- old woman,
with newly diagnosed hypertension,
who comes to the emergency room presenting a clinical picture of muscle and joint pain,
paresthesia and asthenia in all extremities with abnormal gait and increased support base.
Laboratory analysis performed at the emergency department shows important leukocytosis with eosinophilia,
hematuria and proteinuria.
In initial MRI shows cortico-subcortical,
bilateral occipital lesions,
bilateral internal watershed lesions and left cerebellar lesion,
all with restricted diffusion and patchy enhancement with intravenous contrast agent,
(Image 17) compatible with acute/subacute ischemic lesions in border territory,
predominantly in posterior territory.
MR angiography was also performed,
in which there were no pathological findings.
The patient was diagnosed of Churg-Strauss vasculitis.
She improved of her systemic clinical picture after steroid and anticoagulant therapy and was discharged without an imaging control.
This case represents either a case of atypical vasculitis (in border zones),
cardiac embolus or atypical PRES.
The confirmation was not possible.
• Patient 11
22 year- old male without known pathological antecedents,
who is brought to the emergency room for sudden loss of consciousness.
On arrival,
the patient presented with bilateral unresponsive miosis,
visual deviation to the left,
slight vertical nystagmus and unresponsive to painful stimuli.
Tracheal intubation was performed.
CT is performed as the initial image study showing no pathological findings (not shown).
Another CT scan is done 24 hours later (not shown),
that showed multiple patchy cortico-subcortical hypodensities predominantly in occipital,
parietal / temporal lobes and also in thalamus and cerebellar hemispheres.
No enhancement is seen after administration of CIV.
CT angiography shows no abnormalities.
MRI (image 18) shows multiple acute/early subacute ischemic lesions (restricted diffusion),
in occipital and temporal lobes,
superior cerebelar hemispheres and thalami (posterior circulation) Notice some milimetric lesions in basal ganglia
Control CT One week later (Image 18) shows hemorrhagic transformation of the infarcts localized in parietal and occipital lobes.
So we do not have control images control as the patient is transferred to another hospital.
The last news we have is that the patient clinically improved.
This atypical case couldn´t be confirmed.
Differential diagnosis was between top of basilar thrombosis (not evidenced on CT angiography 24 hours later to admission) or severe case of PRES.
RESULTS
-In our 11 cases,
10 were female patients with a mean age of 45 years.
-In 9 of the 11 cases,
the diagnosis of PRES was confirmed either with clinical evolution imaging controls.
-No clarification of the cause for the lesions seen in imaging studies was possible in the case of Churg-Strauss syndrome.
-Arterial hypertension was the prevalent risk factor in our series,
in accordance to the literature.-Other triggering factors were eclampsia,
cisplatin toxicity or renal failure,
(Table 2).
- We had infrequent risk factors like multiple organ failure and a rare cause (lumbar puncture).
- All 11 cases had initial neuroimaging studies,
with either MRI or computed tomography (CT) of the head.
-All patients showed parieto- occipital involvement on imaging studies,
in accordance to the literature,
(Table 3).
- Lesions were symmetric in half of the cases,
unilateral in 1 case and asymmetric en thee rest of the cases.
-All except one case had atypical imaging findings,
including basal ganglia or pons involvement,
or the presence of one or more severity signs such as enhancement after intravenous contrast administration,
diffusion restriction and hemorrhage,
(Table 4).
- Half of the patients had severe forms of the disease,
either because the presence of hemorrhage or sequelae,
(Table 4).
- The most common clinical presentation was headache,
visual disturbances and seizures,
(Table 2).