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cervical artery dissection: quick review

23 May

CAROTID (AND VERTEBRAL) DISSECTIONS: QUICK HITS


first consult call to Neurologists (less commonly Vascular Surgeons)


–Vascular imaging is a must, but CTA is more sensitive than MRA.  


–To catch on MRI, specific sequences are required so check with your Neurologist/Radiologist to figure out which.  


Dissections that extend intracranially have a high incidence of forming SAH, especially when heparin is started, thus making heparin have higher mortality than anti-platelet drugs.  


Extracranial dissections are usually treated with antiplatelet drugs and anticoagulation




Submitted by T. Boyd.



Reference(s): Shea et al. Carotid and Vertebral Artery Dissections in the Emergency Department. Emergency Medicine Practice.14;4. April 2012; picture


epileptic vs. non-epileptic seizure: what are the signs?

7 May

WHAT ARE THE SIGNS?

review by Avbersek & Sisodiya in J Neurol Neurosurg Psychiatry (link below)
–looked at 34 studies
–tried to tease out what signs distinguish epileptic vs. non-epileptic seizure

WHAT DID THEY FIND?

–signs that favor psychogenic non-epileptic seizures (specificity)

  • fluctuating course (96%)
  • asynchronous movements (93-96%)
  • pelvic thrusting (96-100%)
  • side-to-side head/body movement (96-100%)
  • closed eyes (74-100%)
  • ictal crying (100%)
  • memory recall (96%)

–signs that favor epileptic seizures (specificity)

  • occurance from sleep (100%)
  • post-ictal confusion (88%)
  • stertorous (snoring) breathing (100%)

FYI:
–the sensitivities for all of these signs were horrible, so can’t use them to rule anything out
–sometimes excluded frontal lobe partial seizures
–insufficient evidence: gradual onset, flailing/thrasing, opisthotonus, tongue biting, urinary incontinence

Reference(s): review article, picture

Spontaneous Cervical and Intracranial Arterial Dissections

26 Apr

(scroll to bottom for quick hits)

Background
-Arterial dissections can cause stroke in both young in old populations, and is the most common cause of stroke in the young

-Extracranial dissection is more common than intracranial dissection

-Stroke is generally caused by either diminished blood flow from intraluminal thrombus or embolized clot

Pathogenesis (stick with it)
-Dissection are believed to begin with a tear in the media of the vessel wall, leading to bleeding in the wall itself

-partially coagulated intramural blood can enter the lumen which activates platelets and
the coagulation cascade leading to intraluminal thrombus.

-Intramural blood can accumulate leading to compression of the lumen



Risk Factors
Connective tissue and vascular disorders are thought to be main risk factors:
(e.g. Ehlers-Danlos Syndrome (type IV), Marfan Syndrome, Polycystic kidney disease, cystic medial necrosis, Fibromuscular dysplasia)

-many are caused by trauma




Diagnosis
-based on radiologic criteria taken from the Strategies Against Stroke Study for Young Adults in Japan (SASSY) using CTA or MRI/MRA

-Primary rules are based on finding an intimal flap or double lumen on Angiogram or MRI/MRA, or repeated non-specific findings associated with dissection on multiple studies.



Symptoms
Head or neck pain

Horner Syndrome occurs when the sympathetic fibers on the ICA are stretched. It is usually just partial with ptosis and miosis but no anhidrosis.

Difference between Carotid and Vertebral Dissections
-Transient monocular blindness occurred only with internal carotid dissection

-Ischemic stroke is more common in vertebral dissections

Neck pain and recent minor cervical trauma are more common in vertebral dissections

-Proportion of men and a recent infection are more common in ICA

Treatment
Antithrombotic therapy (antiplatelet or anticoagulation) is the primary initial treatment for ischemic stroke and TIA caused by arterial dissection

-For intracranial dissection, antiplatelet therapy is often the treatment of choice

-For extracranial dissection, anticoagulation initially followed by 6 months of warfarin therapy as opposed to antiplatet therapy is often chosen

Endovascular and surgical therapy are generally only reserved for recurrent ischemic events

BOTTOM LINE:
arterial dissection is more common cause of stroke in the young
extracranial (vertebral, carotid) more common than intracranial dissection
-sx: headache, neck pain, stroke-like symptoms, Horner’s syndrome (for ICA)
-risk factors: connective tissue disorders, trauma
-dx: angiography, MRI/MRA
-tx: antithrombotics/anticoagulation (aspirin, heparin, coumadin, etc.); surgical/endovascular for recurrent events

Submitted by J. Grover.


Reference(s): Caplan, LR and Biousse V. “Cervicocranial Artery Dissections.” J Neuro-Opthalmol. 2004; 24:299-305. Maruyama, H et al. “Spontaneous Cervicocephalic Arterial Dissection with Headache and Neck Pain as the Only Symptom.” J Headache Pain (2012) 13: 247-253. “Spontaneous Cerebral and Cervical Artery Dissection: Treatment and Prognosis”. Uptodate.  “Spontaneous Cerebral and Cervical Artery Dissection: Clinical Features and Diagnosis”. Uptodate., picture

decision rule for subarachnoid hemorrhage?

12 Apr

THOSE CANADIANS ARE AT IT AGAIN:
–study by Ottawa docs, Perry et al. reviewed nicely in an AAEM/Common Sense article (see reference)
–tried to identify a set of clinical characteristics to make a decision rule for those who need SAH workup

BASIC STRUCTURE:
–1,999 patients, 130 diagnosed with SAH
–SAH diagnosis defined by +CT, xanthrochromia, or >5 x 10^6/L RBCs + aneurysm/AVM on cerebral angiography

–included:

  • adults (>16 yo)
  • chief complaint = headache
  • GCS 15
  • non-traumatic
  • peak intensity of HA within 1 hr

–excluded:

  • >2 wks after symptom onset
  • prior SAH
  • previous CT and/or LP workup
  • 3 similar HA’s within past six months
  • papilledema/focal neuro symptom
  • prior hydrocephalus or cerebral neoplasm

RULES THEY CAME UP WITH:
–all have sensitivity 100%, but specificity sucked (28-39%)

the rules (each set works to help rule-out SAH):

  • age >40, neck pain/stiffness, witnessed LOC, DBP > 100mmHg
  • arrival by EMS, age>45, vomiting, DBP > 100
  • arrival by EMS, age 45-55, neck pain/stiffness, SBP > 160

BOTTOM LINE:
–nice study, helps think about why we do what we do, but isolated population
–the extra H&P details (age, BP, vomiting, neck pain/stiffness, etc.) are not very specific for SAH, but together might be sensitive (reminds me of appendicitis)
not ready for primetime just yet, but food for thought

Submitted by S. Lee.

Reference(s): AAEM/RSA review, picture

migraine headache treatment

13 Mar

Submitted by E. Hawkins.

Simple Partial Status Epilepticus

9 Mar

Submitted by E. Hawkins.

Do steroids prevent post-herpetic neuralgia in shingles?

6 Mar

Submitted by E. Hawkins.