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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6009_Библиотеки_им_академика_М_И_Перельмана.pdf
Remote Complications Overview
Terminology
Postoperative vision loss (POVL)
Ischemic optic neuropathy (ION)
General Medical Complications
Orthopedic surgery in total (including spine surgery) has a 15% incidence of cardiac death and nonfatal myocardial
infarction. Studies have shown a 3.4% incidence of cardiac
Remote Complications
complications in spine surgery with a mortality as high as 70%.
Highly functioning, cardiac asymptomatic patients who
tolerate 4 metabolic equivalents (METS) do not seem to
benefit from additional preoperative cardiac testing. For
reference, 4 METS is equivalent to daily activities, including
walking, eating, etc. Golf and climbing stairs requires more
than 4 METS. Most postoperative myocardial infarctions occur
in the first 48 hours after surgery. These are usually chest painfree events with tachycardia.
Pulmonary Complications
Pulmonary complications such as atelectasis, pneumonia,
respiratory failure, and bronchospasm are even more
common than cardiac complications. Patient risk factors for
pulmonary complications include COPD, stopping smoking < 8
weeks prior to surgery, continued smoking, surgery > 3 hours,
albumin < 3 g/dL, and BUN > 30 mg/dL. Patients with COPD
are 6x more likely to have complications. In 1 study of > 1,500
patients who underwent cervical corpectomy, pulmonary
complications were the most common type (8.5%). Eighteen
percent of patients in this study who underwent 3-level
corpectomy had reoperation.
Surgical Complexity
More complex surgeries, not surprisingly, have more
complications. One study of en bloc resections showed 34%
had complications with > 2% mortality. Increased risk of
complication in this group related to prior unsuccessful
treatment or open biopsy, which contaminated the epidural
space. Other factors that increased complication risk were
multisegmental resections and double combined approaches.
Devastating complications included 1 death due to vena cava
injury and 2 late deaths from aortic dissections. General
medical complications included myocardial infarction,
pulmonary embolus, and renal failure. Ten percent of patients
with a single posterior approach to tumor resection had a
complication, whereas 48% of double-approach en bloc
resections had a complication. Other risk factors include
increasing age, American Society of Anesthesiologists class,
history of disseminated cancer, and diabetes.
Remote Complication Categories
Remote complications can be viewed by the imager as either
intuitive or nonintuitive.
Intuitive Remote Complications
Intuitive complications can be logically deduced from the
nature of the surgery and the intraoperative adverse event.
These tend to be easier to recognize because they flow from
the procedure itself. For example, intracranial subdural
hematoma might not be an obvious complication from
physically remote spine surgery but not when placed into the
framework of an intraoperative unintended durotomy with
resultant CSF leak and intracranial hypotension. Cases of
remote cerebellar hemorrhage may occur after uneventful
spinal surgery when there is CSF loss. Again, intracranial
hypotension with brain sagging is considered a possible
mechanism for this complication. A distinct but seemingly
related complication after uneventful spine surgery is
described as pseudohypoxic brain swelling. This devastating
(and potentially fatal) complication can occur in spinal surgery
with minimal dural laceration and use of subfascial suction
drains. Even in the most experienced surgical hands,
unintended durotomy occurs at least in 1.6% of spine
surgeries. An additional example of an intuitive type of
complication is superior mesenteric artery (SMA) syndrome.
SMA syndrome is a known complication of spine osteotomy.
Although unusual, this makes sense given the marked change
in alignment of the spine that occurs when closing the
osteotomy with stretching of the ventral vessels.
Nonintuitive Remote Complications
Nonintuitive remote complications are ones that must be
individually defined because one cannot logically deduce that
they might occur. Examples of this type might be pancreatitis
related to spine surgery and POVL. Why pancreatitis? No one
really knows. Theories as to the cause of pancreatitis after
spine surgery (particularly scoliosis surgery in children and
adolescents) vary from nutritional status of the patient,
intraoperative positioning, hypotension, and drug effect to
derangement of the autonomic system affecting secretion of
the gland.
Postoperative Vision Loss
Vision loss after surgery is a unique complication associated
predominately with spine surgery. Factors affecting vision loss
related to ION include increased duration of surgery, large
degree of blood loss, and excessive use of replacement fluids.
Patient positioning (head below heart level) seems also to be
important. The incidence of POVL in all nonocular surgeries is
estimated to be 1 in 60,000. However, the incidence in spine
surgery is strikingly higher, on the order of 1 in 500. How can
the imager be of help? The differential of POVL is 4-fold:
External injuries such as corneal abrasion, central retinal artery
occlusion, cortical blindness, and ION. Ophthalmologic
examination allows the diagnosis of ION with classic fundal
changes. Imaging is important to exclude cortical blindness
with occipital infarction or more caudal causes of vessel injury
such as vertebral dissection from cervical screw malposition.
Selected References
1. Malham GM et al: Anterior lumbar interbody fusion using recombinant
human bone morphogenetic protein-2: a prospective study of
complications. J Neurosurg Spine. 21(6):851-60, 2014
2. Willson MC et al: Postoperative spine complications. Neuroimaging Clin N
Am. 24(2):305-26, 2014
3. Parpaley Y et al: Pseudohypoxic brain swelling (postoperative intracranial
hypotension-associated venous congestion) after spinal surgery: report of 2
cases. Neurosurgery. 68(1):E277-83, 2011
4. Williams BJ et al: Incidence of unintended durotomy in spine surgery based
on 108,478 cases. Neurosurgery. 68(1):117-23; discussion 123-4, 2011
5. Choi D et al: Outcome of 132 operations in 97 patients with chordomas of
the craniocervical junction and upper cervical spine. Neurosurgery. 66(1):5965; discussion 65, 2010
6. Dupanovic M et al: Management of the airway in multitrauma. Curr Opin
Anaesthesiol. 23(2):276-82, 2010
7. Goepfert CE et al: Ischemic optic neuropathy: are we any further? Curr Opin
Anaesthesiol. 23(5):582-7, 2010
8. Gonzalez-Garcia A et al: Ischemic optic neuropathy. Semin Ophthalmol.
25(4):130-5, 2010
9. He M et al: The use of diffusion MRI in ischemic optic neuropathy and optic
neuritis. Semin Ophthalmol. 25(5-6):225-32, 2010
10. Lee LA et al: Postoperative ischemic optic neuropathy. Spine (Phila Pa 1976).
35(9 Suppl):S105-16, 2010
11. Miglis MG et al: Intracranial venous thrombosis after placement of a lumbar
drain. Neurocrit Care. 12(1):83-7, 2010
370
Remote Complications Overview
12. Nasser R et al: Complications in spine surgery. J Neurosurg Spine. 13(2):14457, 2010
13. Onishi E et al: Cerebral infarction due to an embolism after cervical pedicle
screw fixation. Spine (Phila Pa 1976). 35(2):E63-6, 2010
14. Pierce V et al: Ischemic optic neuropathy after spine surgery. AANA J.
78(2):141-5, 2010
15. Radhakrishnan M et al: Perioperative stroke following anterior cervical
discectomy. Br J Neurosurg. 24(5):592-4, 2010
16. Eskander MS et al: Injury of an aberrant vertebral artery during a routine
corpectomy: a case report and literature review. Spinal Cord. 47(10):773-5,
2009
17. Kang BU et al: An analysis of general surgery-related complications in a series
of 412 minilaparotomic anterior lumbosacral procedures. J Neurosurg Spine.
10(1):60-5, 2009
18. Morofuji Y et al: Remote cerebellar hemorrhage following thoracic spinal
surgery. Neurol Med Chir (Tokyo). 49(3):117-9, 2009
19. Than KD et al: Postoperative management of incidental durotomy in
minimally invasive lumbar spinal surgery. Minim Invasive Neurosurg.
51(5):263-6, 2008
20. Baig MN et al: Vision loss after spine surgery: review of the literature and
recommendations. Neurosurg Focus. 23(5):E15, 2007
21. Cornips EM et al: Fatal cerebral and cerebellar hemorrhagic infarction after
thoracoscopic microdiscectomy. Case report. J Neurosurg Spine. 6(3):276-9,
2007
22. Smith-Hammond CA et al: Prospective analysis of incidence and risk factors
of dysphagia in spine surgery patients: comparison of anterior cervical,
posterior cervical, and lumbar procedures. Spine (Phila Pa 1976).
29(13):1441-6, 2004
Remote Complications
23. Ding R et al: Pneumonia in stroke patients: a retrospective study. Dysphagia.
15(2):51-7, 2000
24. Boriani S et al: Primary bone tumors of the spine. Terminology and surgical
staging. Spine (Phila Pa 1976). 22(9):1036-44, 1997
25. Tomita K et al: Total en bloc spondylectomy. A new surgical technique for
primary malignant vertebral tumors. Spine (Phila Pa 1976). 22(3):324-33,
1997
(Left) This patient had
resection of cervical
schwannoma with
preoperative left vertebral
occlusion and tumor
embolization. Postoperatively,
the patient developed
extensive pulmonary emboli
ſt, as can be seen on this axial
CECT. (Right) Postoperative
cerebellar hemorrhage is
shown on this axial
noncontrast CT study as linear
increased attenuation within
the left cerebellum following
spine surgery ſt. Remote
cerebellar hemorrhage may be
uni- or bilateral.
(Left) Sagittal T1WI MR shows
the typical appearance of
severe intracranial
hypotension and brain sag.
Note the descent and
distortion of the brainstem ſt,
flattening of the pons against
the clivus st, and low tonsils
. (Right) Coronal T1WI MR
following contrast shows the
typical diffuse dural
enhancement ſt of
intracranial hypotension.
371
Donor Site Complications
KEY FACTS
TERMINOLOGY
• Graft characteristics
○ Osteogenesis → create new bone
○ Osteoinduction → stimulate osteoblastic differentiation
of progenitor cells
○ Osteoconduction → scaffold for bone deposition
• Graft needs porosity to enhance bony ingrowth (cancellous-
Remote Complications
type bone)
○ Also needs load-bearing capacity (cortical-type bone)
• Autograft
○ Gold standard, 77% mean arthrodesis rate
○ Biocompatible
○ No disease transmission
○ Nonimmunogenic
• Graft morbidity
○ 20-30% suffer persistent graft site pain
○ 15% numbness
○ 12% impaired ambulation
(Left) Axial bone CT of an
unusual complication
following large iliac bone
graft harvest demonstrates
protrusion of the colon and
mesenteric fat through the
large right iliac wing bone
graft harvest site ſt. (Right)
Axial CT in the same patient
shows protrusion of the colon
through the large right iliac
wing bone graft harvest site
ſt.
• Other complications
○ Infection (7%)
○ Hematoma
○ Pelvic fracture
○ Peritoneal perforation
○ Gait disturbance
○ Ureteral injury
○ Hernia
• Allograft
○ Avoids donor site morbidity
○ Has risk of disease transmission
○ 74% rate of arthrodesis
• Synthetics
○ Multiple types
– Avoids donor site complications
– Biocompatible
– Limitless supply
372
(Left) Axial NECT shows the
typical appearance of an old
iliac crest donor site with
corticated margins ſt and a
small focus of heterotopic
bone formation st. (Right)
Axial NECT shows prior
anterior lumbar interbody
fusion with gas in the soft
tissue adjacent to the right
posterior iliac wing donor site,
reflecting soft tissue infection
ſt.
Deep Venous Thrombosis
KEY FACTS
Remote Complications
TERMINOLOGY
• Deep vein thrombosis: Condition where blood solidifies,
producing blood clot (thrombus) within deep venous
system, typically in lower limbs
• Can also be seen in upper limbs (especially related to
central venous catheters)
IMAGING
• Filling defect in deep veins or pulmonary arteries
○ CT, MR, or contrast venogram, pulmonary CTA
• Noncompressible vein with intraluminal echoes on
ultrasound examination
○ Duplex Doppler ultrasound 1st-line imaging tool; 90-
100% sensitivity and specificity for acute deep vein
thrombosis (DVT)
• CECT and CT/MR venography good noninvasive imaging
tools
○ Assessment of pelvic veins and inferior vena cava;
exclusion of pelvic and abdominal causes of DVT
• Conventional venography has 11% false-negative rate
○ Used in combination with catheter-directed or
mechanical thrombolysis
TOP DIFFERENTIAL DIAGNOSES
• Interpretation errors
• Technical errors
CLINICAL ISSUES
• Acute DVT: Swollen, tender lower limb (swelling extent
depends on DVT site), increased temperature
• Postthrombotic syndrome: Sequelae of DVT resulting from
chronic venous obstruction &/or acquired incompetence of
valves
○ Chronic leg swelling, ankle pigmentation, ulceration in
lower calf and ankle (gaiter zone)
• Anticoagulation therapy for above knee DVT and PE;
treatment for calf vein DVT controversial
• Heparin anticoagulation (unfractionated or low molecular
weight) initial treatment for acute DVT
(Left) Grayscale ultrasound of
the right upper thigh shows
extensive echogenic thrombus
ſt in the lumen of the deep
femoral vein st. This is a
typical case of deep venous
thrombosis. (Right) Color
Doppler ultrasound of the
right upper thigh shows
extensive echogenic thrombus
without flow ſt in the lumen
of the deep femoral vein,
which shows color blood flow
st. This is also a typical case
of deep venous thrombosis.
(Left) Axial T1WI MR at
admission shows acute venous
thrombosis with markedly
distended iliac veins ſt that
lack the usual flow void. Note
the normal arterial flow void
of iliac arteries . (Right) AP
venogram shows extensive
intraluminal filling defects ſt
in the superficial femoral vein
of the thigh. A small amount
of contrast outlines the
thrombus with a resultant
tram-track sign.
373
Pulmonary Embolism
KEY FACTS
TERMINOLOGY
• Pulmonary arterial blockage with resultant segmental
perfusion defect(s), most commonly caused by emboli
arising from pelvic or lower extremity deep vein thrombosis
IMAGING
• Central low-density filling defect within pulmonary arteries
Remote Complications
on CTA or angiography
• CTA examination of choice
• CXR poor sensitivity and specificity
• V/Q scan highly sensitive but nonspecific
TOP DIFFERENTIAL DIAGNOSES
• Tumor thrombus
• Primary pulmonary artery sarcoma
• Pulmonary vasculitis
• Laminar flow artifact
(Left) Ventilation study from a
V/Q scan with findings of
pulmonary embolism shows
normal ventilation. Multiple
segmental perfusion defects
were also present. (Right) V/Q
scan findings of pulmonary
embolism in the same patient
show high probability scan
multiple segmental perfusion
defects ſt and areas of
hyperperfusion .
CLINICAL ISSUES
• Thromboembolism prophylaxis
• Intermittent compression devices postoperatively
• Anticoagulation by either
○ Low-dose unfractionated heparin perioperatively
○ Low-molecular-weight heparin postoperatively
• Risk factors for spine surgery
○ Immobilization
○ Long operative times
○ Increased number of fused levels
○ Prone positioning with flexion of hips/knees
○ Spine distraction
○ Combined anterior/posterior surgery
• Anticoagulation is mainstay of treatment
○ Thrombolysis for severely symptomatic patients
○ Inferior vena cava filter if contraindications to drug
therapy
374
(Left) CECT reveals large lobar
artery thrombi and
enlargement of the main
pulmonary artery relative to
the ascending aorta st.
(Right) Axial CECT shows
marked increase in RV/LV
ratio and flattening of the
intraventricular septum .
The typical CT features of
right heart strain and
pulmonary arterial
hypertension from pulmonary
emboli are present.
Aspiration Pneumonia
KEY FACTS
Remote Complications
TERMINOLOGY
• Aspiration pneumonia: Pulmonary infection caused by
aspiration of colonized oropharyngeal secretions
• Aspiration pneumonitis: Acute lung injury caused by
aspiration of materials inherently toxic to lungs (gastric
acid, milk, mineral oil, and volatile hydrocarbons)
• Predisposing factors: Alcoholism, loss of consciousness,
structural abnormalities of pharynx and esophagus,
neuromuscular disorders, and deglutition abnormalities
IMAGING
• Gravity-dependent opacities
• Radiopaque material within airways (foreign body)
• Unilateral or bilateral airspace consolidation in dependent
distribution
• Diffuse perihilar consolidation
• Consolidation with cavitation
• Airspace consolidation, solitary or multiple; gravitational
distribution
• Atelectasis, segmental or lobar
TOP DIFFERENTIAL DIAGNOSES
• Diffuse bilateral opacities: Pulmonary edema, hemorrhage,
diffuse alveolar damage
• Multifocal (patchy) airspace opacities: Organizing
pneumonia, eosinophilic pneumonia, sarcoid, tuberculosis,
vasculitis
PATHOLOGY
• Pulmonary edema, hyaline membrane formation, and
alveolar hemorrhage (Mendelson syndrome)
○ Up to 50% death rate for patients who develop acute
respiratory distress syndrome from Mendelson
syndrome
CLINICAL ISSUES
• 300,000 to 600,000 cases per year in United States
• 5-15% of cases of community-acquired pneumonia
(Left) Anteroposterior
radiograph shows extensive
symmetrical bilateral
consolidation after massive
gastric aspiration. (Right) Axial
CECT in the same patient
shows left lower lobe
homogeneous consolidation
due to aspirated secretions
and atelectasis ſt. The air
bronchogram and opacified
vessels give a CT angiogram
sign.
(Left) Frontal radiograph
shows mediastinal widening
from achalasia and diffuse
central consolidation ſt from
massive aspiration. (Right)
Inflated tracheostomy
balloons do not necessarily
prevent aspiration. This AP
radiograph shows a
tracheostomy tube in the
normal position above the
carina with the balloon
inflated . Swallowed
barium passes the inflated
balloon into both lower lobes
ſt.
375
Acute Myocardial Infarction
KEY FACTS
TERMINOLOGY
• Atherosclerotic plaque rupture followed by thrombosis and
acute coronary occlusion leading to ischemic damage
○ Increased cardiac enzymes (troponin, CK, and CK-MB)
• Criteria for acute myocardial infarction
○ Detection of rise &/or fall of cardiac biomarker (cardiac
Remote Complications
troponin) with 1 value above 99th percentile limit with 1
of following (American Heart Association 3rd universal
definition)
– Symptoms of ischemia
– New ST-segment T wave changes or new left bundle
branch block
– Development of pathological Q waves on ECG
– Imaging evidence of new loss of viable myocardium or
new wall motion abnormality
– Intracoronary thrombus by angiography
IMAGING
• Coronary artery filling defect on coronary angiogram
(Left) Oblique coronary CT
angiogram shows occlusion of
the distal right coronary artery
st with calcified and
noncalcified plaque distal to
occlusion. (Right) Stress and
rest image of the left
ventricular myocardium using
Tc-99m tetrofosmin is shown.
The stress images (top row)
show perfusion defect located
at the distal inferior wall and
apex ſt that normalizes at
rest . This reversible
perfusion defect is consistent
with stress-induced ischemia in
this region.
• General findings
○ Diminished perfusion & function of affected area
○ Reduced regional contractility
○ Increased cell membrane permeability
○ Altered regional metabolism
TOP DIFFERENTIAL DIAGNOSES
• Old infarction
• Acute myocarditis
• Coronary vasospasm
• Unstable angina
CLINICAL ISSUES
• Chest pain: Substernal, pressing, occasionally radiating to
left arm
• Associated with dyspnea, nausea, palpitations, radiation to
jaw
• Spine surgery-related < 1%
376
(Left) Short-axis T2WI FS MR
shows an area of
hyperintensity in the anterior
and anterolateral walls st (8
to 1 o'clock) representing
myocardial edema in the
setting of anterior acute
myocardial infarction (AMI).
(Right) Short-axis MR cine in
systole shows area of
hypokinesis in the anterior and
anteroseptal walls associated
with increased myocardial
signal st (edema) indicating
AMI. Note the pericardial
effusion .
Cerebral Infarction
KEY FACTS
Remote Complications
TERMINOLOGY
• Hypotensive cerebral infarction (HCI)
○ Infarction resulting from insufficient cerebral blood flow
(CBF) to meet metabolic demands (low flow state)
○ Border zone or watershed infarction
IMAGING
• Best imaging tool
○ MR with DWI/ADC ± perfusion MR
• Cortical border zone (between major arterial territories)
○ Typically at gray-white matter junctions
○ Hypodensity between vascular territories
• White matter border zone (between perforating arteries)
○ Typically in deep white matter (centrum semiovale)
○ ≥ 3 lesions
○ Linear AP orientation → string of pearls appearance
○ If unilateral, look for stenosis of major vessel!
• Imaging recommendations
○ MR + GRE, DWI, MRA (both cervical, intracranial)
○ ± perfusion MR (may show ↓ CBF to affected areas)
○ NECT, perfusion CT, CTA if MR not available
○ CTA/DSA > MRA for determining total vs. near-occlusion
of internal carotid artery (ICA)
TOP DIFFERENTIAL DIAGNOSES
• Acute embolic cerebral infarction(s)
• Arteriosclerosis (small vessel disease)
• Posterior reversible encephalopathy (PRES)
• Vasculitis
• Pseudolaminar necrosis (other causes)
CLINICAL ISSUES
• Patient with high-grade ICA stenosis, transient hypotension
leading to acute cerebral infarction
• Resuscitated patient with profound asphyxia or prolonged
systemic hypotension
• Most common signs/symptoms
○ Altered mental status, coma
(Left) Axial FLAIR MR in a
patient with transient global
hypoperfusion secondary to a
hypotensive episode shows
multifocal hyperintensities
along the cortical watershed
zone ſt. Changes are most
severe at the confluence of
anterior cerebral artery,
posterior cerebral artery, &
middle cerebral artery cortical
vascular territories . (Right)
DWI shows corresponding
areas of restricted diffusion in
watershed zones bilaterally
ſt, most severe at trivascular
confluence . Diagnosis was
hypotensive watershed
cerebral infarctions.
(Left) Axial NECT scan
obtained a few hours after
circulatory arrest and
resuscitation shows diffuse
cerebral edema with almost
complete effacement of all
gray-white matter interfaces
in both the cortex and basal
ganglia. The ventricles appear
small and the sulci are
inapparent. (Right) Axial DWI
MR shows increased signal
intensity from infarcts
involving right thalamus ſt
and occipital lobe from basilar
embolus. Lesions such as this
should be excluded as a cause
of postoperative vision loss.
377
Cerebellar Hemorrhage
KEY FACTS
TERMINOLOGY
• Remote cerebellar hemorrhage (RCH)
○ Following supratentorial craniotomy
○ Less often after spinal surgery
○ Remote to primary surgical site
○ No underlying pathologic lesion
Remote Complications
IMAGING
• General features
○ Zebra sign (blood layered over cerebellar folia)
○ Location varies (in/over hemisphere, vermis)
○ Subarachnoid vs. superficial parenchymal bleed
○ Contralateral to side of surgery (29%)
○ Ipsilateral (22%)
○ Bilateral (33%)
○ Isolated vermian (9%)
• Imaging recommendations
○ NECT initial screen
(Left) Axial NECT in a patient
doing poorly immediately
after surgery to resect a
meningioma shows linear
hemorrhages (zebra sign)
bilaterally along the vermis
st. This is a common pattern
seen in remote cerebellar
hemorrhage. Cisternal
effacement is also present ſt.
(Right) Axial T2* GRE MR in
the same patient
demonstrates bilateral
blooming areas layering along
the vermis ſt and in the folia
of the superior cerebellar
hemispheres corresponding
to the hemorrhage seen on
prior CT.
○ MR ± contrast, MRA
○ Include T2* (GRE ± SWI)
TOP DIFFERENTIAL DIAGNOSES
• Hypertensive hemorrhage
• Coagulopathy-related spontaneous hemorrhage
PATHOLOGY
• CSF drainage → cerebellar "sagging" → vein stretching,
bleeding
• RCH usually seen in immediate postoperative period
• Most occur within hours to 1 day postoperatively
CLINICAL ISSUES
• True incidence unknown (estimated at 0.3-4% of
supratentorial craniotomies)
○ 0.08-0.29% after supratentorial craniotomy
• Occasionally asymptomatic, occult (not imaged)
• Death/disability in ~ 50% of cases
• Intervention for RCH rarely indicated
378
(Left) Axial NECT in a patient
with an uneventful left
temporal craniotomy st for
drainage of a left middle fossa
arachnoid cyst with subdural
hematoma shows a remote
right cerebellar hemorrhage
. (Right) Axial T2* GRE MR
shows hypointense signal in
the cerebellar hematoma ſt
in this patient following
frontal craniotomy. No other
abnormalities were identified.
Intracranial Hypotension
KEY FACTS
Remote Complications
TERMINOLOGY
• Headache caused by ↓ intracranial CSF pressure
IMAGING
• Classic imaging triad
○ Diffuse dural thickening/enhancement
○ Downward displacement of brain through incisura
("slumping" midbrain)
○ Subdural hygromas/hematomas
• Lack of 1 of 4 classic findings does not preclude diagnosis
• Dural enhancement is smooth, not nodular or "lumpybumpy"
• Veins, dural sinuses distended
TOP DIFFERENTIAL DIAGNOSES
• Meningitis
• Meningeal metastases
• Chronic subdural hematoma
• Dural sinus thrombosis
• Postsurgical dural thickening
• Idiopathic hypertrophic cranial pachymeningitis
CLINICAL ISSUES
• Severe headache (orthostatic, persistent, pulsatile, or even
associated with nuchal rigidity)
• Uncommon: CN palsy (e.g., abducens), visual disturbances
• Rare: Severe encephalopathy with disturbances of
consciousness
• Initial treatment: Lumbar or directed epidural blood patch
○ Spine surgery at leak site (imaging directed) if blood
patch fails or acute clinical deterioration
DIAGNOSTIC CHECKLIST
• Frequently misdiagnosed; imaging is key to diagnosis
• Only rarely are all classic findings of intracranial
hypotension present in same patient
• Look for enlarged spinal epidural venous plexi
(Left) Intracranial hypotension
(IH) with distended dural
sinuses , enlarged pituitary
, & herniated tonsils st is
shown. Central brain descent
causes midbrain "slumping,"
inferiorly displaced pons,
"closed" pons-midbrain angle
, & splenium depressing
Vein of Galen junction ſt.
(Right) Sagittal T1WI C+ FS
MR shows dura-arachnoid
venous engorgement ſt,
enlarged pituitary , &
suprasellar cistern st
effacement by inferior
hypothalamus displacement.
The angle between midbrain &
pons is decreased .
(Left) Sagittal T1WI C+ MR in a
patient with life-threatening
IH shows a "sagging" midbrain,
dural thickening/enhancement
, distended
torcular/superior
sagittal/straight/transverse
sinuses st, and downward
herniation of the splenium ſt
causing an acute angle
between ICV/V of G junction.
(Right) Coronal T1WI C+ MR in
same patient shows subdural
fluid , diffuse dural
thickening/enhancement, and
decreased angle between
lateral ventricle roofs due to
descent of central core brain
structures ſt.
379