In Part 2 of this episode on Thunderclap Headache – Cerebral Venous Thrombosis & Cervical Artery Dissction, Dr. Stella Yiu and Dr. Anil Chopra review the presentation, work-up and management of some of the less common but very serious causes of headache including Cervical Artery Dissection (CAD), Cerebral Venous Thrombosis (CVT) and Idopathic Intracranial Hypertension (IIH). They tell us the most effective ways in which we can minimize the chance of the common Post-LP Headache. They answer questions such as:  How does a carotid artery dissection present compared to a vertebral artery dissection? What is the evidence for chiropractic neck manipulation as a cause for Cervical Artery Dissection? How do antiplatelets compare to heparin for the treatment of Cervical Artery Dissection? What is Spontaneous Intracranial Hypotension? What is the differential diagnosis for headache in the peri-partum patient? Does D-dimer have a role in ruling out Cerebral Venous Thrombosis in the low risk patient? What is the imaging modality of choice for suspected Cerebral Venous Thrombosis? What is the value of opening pressure when performing an LP? What are the key headache diagnoses that can be missed on plain CT of the head and would warrant further investigation? and many more…..

Written Summary and blog post by Lucas Chartier, edited by Anton Helman May, 2011

Cite this podcast as: Chopra, A, Yiu, S, Helman, A. Part 2: Thunderclap Headache – Cerebral Venous Thrombosis and Cervical Artery Dissection. Emergency Medicine Cases. May, 2011. Accessed [date].


Spontaneous cervical artery dissection

  • Often present after a trivial trauma such as hyperextension of the neck as a result of shaving, checking one’s blind spot while driving, chiropractic manipulation, roller coaster ride, boxing, or even coughing or vomiting, especially in the setting of connective tissue disease
  • Carotid artery dissection presents as thunderclap headache or subacute headache with unilateral facial, neck or head pain with a partial Horner’s syndrome (myosis and ptosis, but not anhydrosis), and 1/3rd of patients will have retinal or cerebral TIA within one week (neurological symptoms lag behind because it takes time to have a thrombus formed and thrown from the site of dissection)
  • Vertebral artery dissection presents with posterior neck or occiput pain and posterior circulation symptoms – ataxia, vertigo, dysarthria, diplopia and dysphagia
  • Diagnosis is made by CT‐A of the head and neck (carotid Doppler may be used if CT‐A not available, but it is not as good and therefore a CT‐A is still eventually necessary)
  • Treatment includes antiplatelet or anticoagulation therapy, except in the presence of large infarct with mass effect, hemorrhagic transformation of an infarct, or intracranial extension of the dissection, but consultants should weigh in before treatment is initiated

Cerebral venous thrombosis (CVT)

  • May present as three different entities: headache (from thunderclap headache to subacute), stroke‐like symptoms, or seizures
  • Clinical features associated with CVT are risk factors associated with thromboembolic disease, as well as papilledema, younger patients (<40yo), orbital chemosis and proptosis in cavernous CVT, dilated scalp veins and scalp edema in sagital CVT, and CNS or ENT infections such as sinusitis
  • D‐dimers are not reliable in the diagnosis of CVT, even in low‐risk patients (if you are considering the diagnosis, you need to fully investigate it with neuro‐imaging)
  • Given that the optimal test MR‐V is not readily available, diagnosis can be made with plain CT head in only 30% of cases (delta sign, hemorrhagic infarct at gray‐white junction, or hyperdense cortical vein or dural sinus – transverse sinus in image below) so CT‐venogram must be done as well if plain CT is negative (CT‐V signs: empty delta sign – see image below)
  • If LP is performed, opening pressure may be elevated; treatment includes unfractionated heparin or LMWH (despite the risk of hemorrhagic transformation, anticoagulation has been shown to reduce death and dependency
  • CVT is on the same spectrum as idiopathic intracranial hypertension (IIH), which presents as refractory headache with blurry vision and visual field defects in young, obese women on oral contraceptive pills; signs include papilledema and VERY high opening LP pressure in the face of normal CT scan; it is treated with diuretics, not anticoagulation

Extracranial causes of headache

CO poisoning (think in the setting of multiple patients or wood‐bruning stove), acute glaucoma (photophobia – do an eye exam!), temporal arteritis (systemic signs, and associated with polymyalgia rheumatica, jaw claudication blurry vision or retinal ischemia – check the ESR!), and hypertensive encephalopathy (altered mental status with papilledema and end‐organ damage in the setting of severe  hypertension)

10 serious causes of headache to consider for every ED patient with headache

  • Lesion on CT scan (blood, pus or tumor):
    • Blood ‐ Subarachnoid hemorrhage, subdural hemorrhage, or stroke – hemorrhagic or not
    • Pus ‐ meningitis or encephalitis
    • Tumor ‐ tumor – 1ry or 2ry, benign or malignant
  • Other diagnoses in the head:
    • Cervical artery dissection – carotid or vertebral
    • Hypertensive  encephalopathy
    • Pre‐eclampsia (or eclampsia)
    • Cerebral venous thrombosis or idiopathic intracranial hypertension
    • Glaucoma
    • Temporal arteritis
  •  Thinking ‘outside the box’: Carbon monoxide (CO) poisoning

emcases-update Update 2020: The strongest predictors of GCA, based on positive likelihood ratios, include limb claudication (6.0), jaw claudication (4.9), temporal artery thickening (4.7), loss of temporal artery pulse (3.3), platelet count > 400 x 1000/μL (3.8), temporal tenderness (3.1) and ESR >100 mm/h (3.1). The strongest negative predictors according to negative likelihood ratios include ESR < 40mm/h (0.18), CRP <2.5mg/dL (0.38) and age <70 (0.48). Abstract

For more on Cerebral Venous Thrombosis on EM cases
EM Quick Hits 25: When to Consider Cerebral Venous Thrombosis 2021

For more on headaches in the emergency department on EM Cases:
Episode 14 Part 1: Migraine Headache and Subarachnoid Hemorrhage
Best Case Ever 3: Emergency Headache – Importance of Opening Pressure

Dr. Chopra, Dr. Yue and Dr. Helman have no conflicts of interest to declare.

Key References

Saposnik G, Barinagarrementeria F, Brown RD, et al. Diagnosis and Management of Cerebral Venous Thrombosis: A Statement for Healthcare Professionals From the American Heart Association/American Stroke Association. Stroke 2011;42;1158‐1192

Tintinalli J, Stapczynski J, Ma OJ et al. Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, Seventh Edition (Book and DVD). Mcgraw-hill; 2010.

Hockberger RS, Walls RM. Rosen’s Emergency Medicine – Concepts and Clinical Practice, 2-Volume Set,Expert Consult Premium Edition – Enhanced Online Features and Print,7, Rosen’s Emergency Medicine – Concepts and Clinical Practice, 2-Volume Set. Elsevier Health Sciences; 2009.