Modified Raymond–Roy Classification

  • Class I: complete obliteration12.jpg
  • Class II: residual neck
  • Class IIIa: residual aneurysm with contrast within coil interstices
  • Class IIIb: residual aneurysm with contrast along aneurysm wall





<click here to access MS ppt file>




Hospital, Massachusetts. “Endovascular Procedures To Prevent Ruptured Brain Aneurysms”. Massachusetts General Hospital. N.p., 2016. Web. 11 Dec. 2016.

Mascitelli, Justin R et al. “An Update To The Raymond–Roy Occlusion Classification Of Intracranial Aneurysms Treated With Coil Embolization”. Journal of NeuroInterventional Surgery 7.7 (2014): 496-502.


Antiplatelets for Stent-Coil Techniques

  • ASA (325 mg daily) and clopidogrel (75 mg daily) x 5 days prior to procedure
  • platelet aggregometry 1–2 days before procedure
  • further loading of aspirin and/or clopidogrel PRN
  • unanticipated stenting
    • load with IV or IA abciximab intraprocedurally
    • then load and maintain on ASA and clopidogrel
  • systemic heparinization prior to guide catheter introduction, target activated clotting time 2–2.5 greater than baseline



Spiotta, Alejandro M et al. “Comparison Of Techniques For Stent Assisted Coil Embolization Of Aneurysms”. Journal of NeuroInterventional Surgery 4.5 (2011): 339-344.


Stent-Assisted Coiling Techniques

  1. ‘jailing’ of microcatheter
    • stent deployed after the aneurysm is catheterized but before coil deployment
    • microcatheter pinned between intima and stent, coils are kept within the aneurysm and outside of vessel lumen
    • A.jpg
  2. ‘coil through’
    • stent fully deployed across aneurysm neck
    • aneurysm catheterized through the tines of the stent
    • b
  3. ‘coil stent’
    • unassisted coil embolization to completion followed by stent deployment
    • capitalizes on biologic benefit of vascular remodeling or to constrain a prolapsed coil loop
    • C.jpg
  4. ‘balloon stent’
    • stent placement after completion of balloon assisted embolization
    • D.jpg
  5. other techniques
    • coiling with ‘Y stent’ configuration for basilar tip aneurysms
    • depositing single or multiple stents for flow diversion for blister dorsal carotid wall aneurysms







Spiotta, Alejandro M et al. “Comparison Of Techniques For Stent Assisted Coil Embolization Of Aneurysms”. Journal of NeuroInterventional Surgery 4.5 (2011): 339-344.



Treatment of Aneurysms

  • Clipping Most aneurysms
  • Coiling Most aneurysms
  • Flow diversion Large proximal ICA aneurysms, blister aneurysms
  • Flow diversion with adjunctive coiling Large and giant aneurysms with wide necks
  • Intrasaccular flow diversion Bifurcation aneurysms with neck ≥4 mm
  • Coiling with assistive stenting Wide-neck aneurysms and aneurysms with branch vessels near/incorporating aneurysm neck
  • Parent vessel sacrifice or branch vessel sacrifice with bypass Dissecting aneurysms, giant aneurysms with branch vessels incorporating aneurysm neck
  • Parent vessel sacrifice without bypass Distal PICA aneurysms, distal PCA aneurysms, distal mycotic aneurysms



Walcott, Brian P. et al. “Blood Flow Diversion As A Primary Treatment Method For Ruptured Brain Aneurysms—Concerns, Controversy, And Future Directions”. Neurocritical Care (2016): pp 1-9.

Tranexamic Acid in SAH


TXA Dose: tranexamic acid 1 g IV every 6 h not exceeding 48–72 h


Neither aminocaproic acid nor tranexamic acid is approved by the US Food and Drug Administration for prevention of aneurysm rebleeding.

AHA/ASA (2012)

For patients with an unavoidable delay in obliteration of aneurysm, a significant risk of rebleeding, and no compelling medical contraindications, shortterm (<72 hours) therapy with tranexamic acid or aminocaproic acid is reasonable to reduce the risk of early aneurysm rebleeding (Class IIa; Level of Evidence B). (Revised recommendation from previous guidelines)

NCS (2011)

An early, short course of antifibrinolytic therapy prior to early aneurysm repair (begun at diagnosis; continued up to the point at which the aneurysm is secured or at 72 h post-ictus, whichever is shorter) should be considered (Low Quality Evidence; Weak Recommendation). •

Delayed (>48 h after the ictus) or prolonged (>3 days) antifibrinolytic therapy exposes patients to side effects of therapy when the risk of rebleeding is sharply reduced and should be avoided (High Quality Evidence; Strong Recommendation). •

Antifibrinolytic therapy is relatively contraindicated in patients with risk factors for thromboembolic complications (Moderate Quality Evidence; Strong Recommendation). •

Patients treated with antifibrinolytic therapy should have close screening for deep venous thrombosis (Moderate Quality Evidence; Strong Recommendation). •

Antifibrinolytic therapy should be discontinued 2 h before planned endovascular ablation of an aneurysm (Very Low Quality Evidence; Weak Recommendation). •




Connolly, E. S. et al. “Guidelines For The Management Of Aneurysmal Subarachnoid Hemorrhage: A Guideline For Healthcare Professionals From The American Heart Association/American Stroke Association”. Stroke 43.6 (2012): 1711-1737.

Diringer, Michael N. et al. “Critical Care Management Of Patients Following Aneurysmal Subarachnoid Hemorrhage: Recommendations From The Neurocritical Care Society’S Multidisciplinary Consensus Conference”. Neurocritical Care 15.2 (2011): 211-240.

Sakusic, Amra and Alejandro A. Rabinstein. “Case Studies In Neurocritical Care”. Neurologic Clinics34.3 (2016): 683-697.



Collateral Circulation of the Brain

2 Sources of Collateral Circulation of the brain

  1. extracranial source
  2. intracranial route




  • a=facial a. with ophthalmic a.
  • b= maxillary a. with ophthalmic a.
  • c = middle meningeal a.with ophthalmic a.
  • d=  middle meningeal with dural artery
  • e= occipital with dural artery through mastoid foramen
  • f=occipital with dural artery through parietal foramen





  • a=pcomm a.
  • b=ACA and MCA (leptomeningeal anastomoses)
  • c=PCA and SCA (leptomeningeal anastomoses)
  • d=tectal plexus (PCA and SCA)
  • e=anastomoses of distal cerebellar arteries
  • f=acomm a.



  • a=pcomm a.
  • b=ACA and MCA (leptomeningeal anastomoses)
  • c=PCA and SCA (leptomeningeal anastomoses)
  • d=tectal plexus (PCA and SCA)
  • e=anastomoses of distal cerebellar arteries
  • f=acomm a.



*divided into primary or secondary collateral pathways


Primary collaterals = arterial segments of circle of Willis

  • Anterior COW
    • interhemispheric blood flow across Acomm
    • reversal of flow in proximal ACA
  • PComm supply either direction (ant / post)
  • Proximal PCA at posterior COW


Secondary collaterals = ophthalmic artery and leptomeningeal vessels

  • reversal of blood flow within ophthalmic artery
  • anastomoses between distal major cerebral arteries
    • between ACA and MCA
    • between MCA and PCA
    • between PCA and ACA
  • distal branches of cerebellar arteries (links vertebral and basilar segments)
  • leptomeningeal and dural arteriolar anastomoses with cortical vessels


Other collaterals less commonly encountered:

  • tectal plexus (supratentorial branches of PCA with infratent branches of SCA)
  • orbital plexus (ophthalmic artery with facial, middle meningeal, maxillary and ethmoidal arteries)
  • rete mirabile caroticum (ICA and ECA)




  • a=pterygoid plexus
  • b=deep middle cerebral vein
  • c=inferior petrosal sinus and basilar plexus
  • d=superior petrosal sinus
  • e=anastomotic vein of Trolard
  • f=anastomotic vein of Labbé
  • g=condyloid emissary vein
  • h=mastoid emissary vein
  • i=parietal emissary vein
  • j=occipital emissary vein




Liebeskind, D. S. “Collateral Circulation”. Stroke 34.9 (2003): 2279-2284. Web.

Classification of Hemorrhagic Transformation

Hemorrhagic infarction (HI) describes a heterogeneous hyperdensity in in an ischemic infarct zone.  Parenchymatous hematoma (PH) refers to a more homogenous, dense hematoma with mass effect.  Fiorelli, et al in 1999 refined these definitions to include two subtypes of HI and two subtypes of PH.

Definitions as per Fiorelli (1999):

  • HI is a petechial infarction without space-occupying effect.
  • PH is a hemorrhage (coagulum) with mass effect.
  • 2 subtypes of HI:
    • HI1 (small petechiae)
    • HI2 (more confluent petechiae)
  • 2 subtypes of PH:
    • PH1 (≤30% of the infarcted area with some mild space-occupying effect)
    • PH2 (>30% of the infarcted area with significant space-occupying effect, or clot remote from infarcted area)


Hemorrhages that occur within the first week after stroke were more likely to be PH2-type, whereas hemorrhages that occur later tend to be HI1, HI2 or PH1.  PH2-type was found to be a significant predictor of neurologic deterioration (OR32.3) and of 3 month mortality (OR 18.0) whereas HI1, HI2 and PH1 were not associated with either increased morbidity or mortality.



Subtypes of hemorrhagic transformation: HI1 (top left), HI2 (top right), PH1 (bottom left), and PH2 (bottom right).



Fiorelli, M. et al. “Hemorrhagic Transformation Within 36 Hours Of A Cerebral Infarct : Relationships With Early Clinical Deterioration And 3-Month Outcome In The European Cooperative Acute Stroke Study I (ECASS I) Cohort”. Stroke 30.11 (1999): 2280-2284.

Sussman, Eric S. and E. Sander Connolly. “Hemorrhagic Transformation: A Review Of The Rate Of Hemorrhage In The Major Clinical Trials Of Acute Ischemic Stroke”. Frontiers in Neurology 4 (2013): n. pag.

The Buffalo Score (AVM)

The Buffalo Score is a new grading system for the endovascular treatment of cerebral AVMs.  It is a 5-point system, and higher scores is associated with higher complication rates.  This new score was created because components of the Spetzler Martin Grading scale, while useful for determining suitability of surgical treatment of cerebral AVMs, may not be relevant in determining suitability for endovascular treatment.

For example, the diameter and number of arterial pedicles supplying the AVM nidus is an important factors to consider in endovascular intervention, since smaller vessels are more prone to injury with catheterization, and a greater number of arterial pedicles produces more risk with each embolization.  The actual size of the AVM nidus and venous drainage pattern is important when considering surgical resection, but is less important during endovascular embolization.

Points for Buffalo Score:

  • number of arterial pedicles
    • 1 point for 1–2 pedicles
    • 2 points for 3–4
    • 3 points greater than 5
  • arterial pedicle diameter
    • 1 point for less than 1 mm
    • 0 points for more than 1 mm
  • eloquence of the location
    • 1 point for eloquent location
    • 0 point for non-eloquent location




Buffalo System Vs. Spetzler Martin Grading System:


*arterial pedicles for Buffalo and draining veins for Spetzler Martin (black lines); nidus (black shading);  deep drainage (dashed lines)

  • Buffalo system = # arterial pedicles (N), diameter of pedicles (D), and eloquence (E)
  • Spetzler–Martin system = venous drainage (V), size (S), eloquence (E)



  1. Measurement of arterial pedicle diameter is made at a distal segment of the arterial pedicle, within 1 cm of the AVM nidus.
  2. Eloquent location is determined based on the nidus location and is defined according to the grading system of Spetzler-Martin.
  3. Any portion of AVM nidus located within motor or sensory cortex, language and vision, and deep eloquent areas (hypothalamus, thalamus, brainstem, cerebellar peduncles) is considered eloquent in location.
  4. This system has not been applied or validated yet.



Levy, EladI et al. “A Proposed Grading System For Endovascular Treatment Of Cerebral Arteriovenous Malformations: Buffalo Score”. Surgical Neurology International 6.1 (2015): 3.


Spinal Cord Injury SCI Scales


Asia impairment scale (modified from Frankel)

  • A=Complete. No sensory or motor function is preserved in the sacral segments S4-S5
  • B=Incomplete. Sensory but not motor function is preserved below the neurological level and includes the sacral segments S4-S5.
  • C=Incomplete. Motor function is preserved below the neurological level, and more than half of key muscles below the neurological level have a muscle grade less than 3.
  • D=Incomplete. Motor function is preserved below the neurological level, and at least half of key muscles below the neurological level have a muscle grade greater than or equal to 3.
  • E=Normal. Sensory and motor function is normal.





Key Sensory Points in SCI evaluation:

  • 0 = absent
  • 1 = impaired (partial or altered appreciation, including hyperaesthesia)
  • 2 = normal
  • NT = not testable

The testing for pin sensation is usually performed with a disposable safety pin; light touch is tested with cotton. In testing for pin appreciation, the inability to distinguish between dull and sharp sensation is graded as 0

  • C2=Occipital protuberance
  • C3=Supraclavicular fossa
  • C4=Top of the acromioclavicular joint
  • C5=Lateral side of the antecubital fossa
  • C6=Thumb
  • C7=Middle finger
  • C8=Little finger
  • T1=Medial (ulnar) side of the antecubital fossa
  • T2=Apex of the axilla
  • T3=Third intercostal space (IS)*
  • T4=Fourth IS (nipple line)*
  • T5=Fifth IS (midway between T4 and T6)*
  • T6=Sixth IS (level of xiphisternum)*
  • T7=Seventh IS (midway between T6 and T8)*
  • T8=Eighth IS (midway between T6 and T10)*
  • T9=Ninth IS (midway between T8 and T10)*
  • T10=Tenth IS (umbilicus)*
  • T11=Eleventh IS (Midway between T10 and T12)*
  • T12=Inguinal ligament at mid-point
  • L1=Half the distance between T12 and L2
  • L2=Mid-anterior thigh
  • L3=Medial femoral condyle
  • L4=Medial malleolus
  • L5=Dorsum of the foot at the third metatarsal phalangeal joint
  • S1=Lateral heel
  • S2=Popliteal fossa in the mid-line
  • S3=Ischial tuberosity
  • S4-5 = Perianal area (taken as one level)

*Asterisks indicate that the point is at the mid-clavicular line



Motor Points in SCI Evaluation:

  • C5 = Elbow flexors (biceps, brachialis)
  • C6 = Wrist extensors (extensor carpi radialis longus and brevis)
  • C7 = Elbow extensors (triceps)
  • C8 = Finger flexors (flexor digitorum profundus) to the middle finger
  • T1 = Small finger abductors (abductor digiti minimi)
  • L2 = Hip flexors (iliopsoas)
  • L3 = Knee extensors (quadriceps)
  • L4 = Ankle dorsiflexors (tibialis anterior)
  • L5 = Long toe extensors (extensor hallucis longus)
  • S1 = Ankle plantarflexors (gastrocnemius, soleus)



Jr, Frederick M Maynard et al. “International Standards For Neurological And Functional Classification Of Spinal Cord Injury”. Spinal Cord 35.5 (1997): 266-274. [pdf]

Epidural Blood Patch

Prior to Epidural Blood Patch:


  1. Encourage PO fluid intake.
  2. Supine position
  3. Oral analgesics (NSAIDS / opioids)


  1. Caffeine 500mg in 1L LR over 4 hours.
  2. Aminophylline 100 mg po BID.


  • consult anesthesiology or interventional radiology for possible epidural blood patch



Schematic section through the vertebral column, showing the cauda equina and its covering membranes with the dural leakage site before (A) and after (B) application of the epidural blood patch.


Post-blood patch orders:

  • supine x2 hours
  • no strenuous exercises x 3 weeks
  • Watch out for:
    • sciatica / immediate exacerbation of symptoms and radicular pain – PRN pain meds
    • bowel and bladder dysfunction
    • intracranial hypertension

If blood patch not an option:  oral or IV caffeine 300-500mg OD or BID (therapeutic doses have been associated with CNS toxicity and atrial fibrillation



“Brain Sag”. Peripheral Brain. N.p., 2016. Web. 24 June 2016.

R Oedit et al. Efficacy of the epidural blood patch for the treatment of post lumbar puncture headache BLOPP: A randomised, observer-blind, controlled clinical trial.  BMC Neurology 20055:12 DOI: 10.1186/1471-2377-5-12.

Click to access PDHD.pdf