Tom Wade MD

Today, I review, link to, and excerpt from Emergency Medicine Cases‘ Ep181 Cerebral Venous Thrombosis, Idiopathic Intracranial Hypertension, Giant Cell Arteritis and Peripartum Headaches*.

*Helman, A. Shah, A. Baskind. R. Red Flag Headaches: Cerebral Venous Thrombosis, Idiopathic Intracranial Hypertension and Giant Cell Arteritis. Emergency Medicine Cases. April, 2023. https://emergencymedicinecases.com/red-flags-headache-cvt-iih-gca. Accessed 4/26/2024.

All that follows is from the above outstanding resource.

This is part 2 of our 2-part podcast on red flag headaches that do not readily appear on plain CT head. In Part 1 we covered cervical artery dissections. In this episode, Dr. Roy Baskind and Dr. Ahmit Shah answer such questions as: when is an LP opening pressure required? When should we pull the trigger on ordering a CT venogram in the patient with unexplained headache? What is the value of D-dimer to screen for Cerebral Venous Thrombosis (CVT)? Which older patients who present with headache require an ESR/CRP to screen for Giant Cell Arteritis (GCA)? How do the presentations of CVT and idiopathic intracranial hypertension (IIH) compare and contrast? When is it safe to start steroids in the ED for patients suspected of GCA; will starting steroids in the ED affect the accuracy of a temporal artery biopsy? How soon should patients suspected of GCA get a temporal artery biopsy? When should we consider posterior reversible encephalopathy syndrome (PRES) and pituitary apoplexy in the peripartum patient? How should we think about the differential diagnosis of vascular headaches? and many more…

Podcast: Play in new window | Download (Duration: 1:13:22 — 67.2MB)

Differential diagnosis of acute headache in the peripartum period

While migraine is common in the peripartum period, do not assume that all new onset headaches in this period are caused by migraine.

Life threatening causes of headache to consider in the paripartum patient

1. Pre-eclampsia/eclampsia/HELLP Syndrome – highest risk is in first 48hrs however can occur up to 6 weeks after delivery, BP can be only mildly elevated, have a low threshold to check for proteinuria (deep dive into pre-eclampsia and preterm labour on CritCases)
2. PRES – Posterior Reversible Encephalopathy Syndrome
   1. Posterior Reversible Encephalopathy Sydrome (PRES) from StatPearls. Jaime E. Zelaya; Lama Al-Khoury. Last Update: May 1, 2022. 
   2. A misnomer as it may include the parietal lobes and frontal in addition to the occipital lobes and it is not always reversible (mortality rate 15%),
   3. Presents with headache, seizures, altered mental status and visual loss
   4. Diagnosed on MRI (white matter vasogenic edema)
   5. Overlap with Pre-eclampsia/eclampsia as it is associated with acute hypertension
3. Cerebral venous thrombosis – see below
4. Pituitary apoplexy – rare abrupt severe headache (similar to SAH) with loss of visual field or diplopia, nausea, neck stiffness, altered LOA, some have underlying pituitary adenoma, incited by enlargement of pituitary in peripartum period leading to infarction/hemorrhage, may lead to adrenal insufficiency, diagnosed on MRI (may see hemorrhage on plain CT)
5. Cervical artery dissection – see Part 1 of this podcast series

Non-life threatening causes of headache to consider in the peripartum patient

1. Migraine is the most common peripartum cause of headache that presents to the ED, but do not assume that a new acute headache in peripartum period is migraine – consider it a diagnosis of exclusion
2. Post-dural puncture headache – usually within 5 days of epidural, bilateral frontal or an occipital, postural (worse in the upright position, improved in supine position), may have nausea, dizziness, neck pain/stiffness, visual changes, tinnitus, hearing loss, upper extremity radicular symptoms, treated with caffeine, pregabalin +/- epidural patch

A useful way to think about the differential diagnosis of vascular headaches

One way to think about the differential diagnosis of non-traumatic headaches that originate from blood vessels as outlined by Dr. Baskind includes:

• Clots (arterial and venous) – ischemic stroke, cerebral venous thrombosis
• Tears – cervical artery dissections
• Rupture – SAH (aneuryms, AVMs)
• Inflammation (giant cell arteritis)*
• Vasodilation (migraine)

*Giant Cell Arteritis (Temporal Arteritis) from StatPearls. Muhammad Atif Ameer; Ryan J. Peterfy; Babak Khazaeni. Last Update: August 8, 2023

*Assessment and comparison of probability scores to predict giant cell arteritis. [PubMed Abstract] [Full-Text HTML] [Full-Text PDF]. Clin Rheumatol. 2024 Jan;43(1):357-365. doi: 10.1007/s10067-023-06721-6. Epub 2023 Aug 1.

There are 111 similar articles in PubMed.

Cerebral venous thrombosis (CVT): A very challenging diagnosis

CVT (or Cerebral venous sinus thrombosis – CVST) can be thought of as ‘a DVT of the brain’, with similar risk factors. However, in addition to venous obstruction, upstream raised intracranial pressure and decreased cerebral perfusion pressure may lead to brain ischemia and subsequent hemorrhage which are often devastating. COVID infection and vaccination with Astra-Zeneca vaccine have been implicated as risk factors (See EM Quick Hits 28 on VIPIT – Vaccine-Induced Thrombotic Thrombocytopenia) as well as head and neck infections, although these causes are exceedingly rare. The challenge with COVID patients and patients with head/neck infections is that most present with headache as one of their symptoms, so unless they present with an obvious neurologic deficit it is difficult to know which of these patients require a workup for CVT. For post Astra-Zeneca COVID vaccine headache, one can safely rule out VIPIT if the platelet count is normal.

CVT* is a very difficult diagnosis to make in the ED because the clinical presentation is highly variable and non-specific, a reflection of the various syndromes/locations of the venous obstruction (superior sagittal sinus and transverse sinus being the most common) and pathophysiological changes over time. As a result, the median time to diagnosis between initial presentation and diagnosis is 7 days and return visits to the ED for the same headache should be considered a risk factor. An additional challenge is that plain CT has only a 41% to 73% sensitivity for the diagnosis of CVT, with CT venogram being the diagnostic test of choice in the ED and MRI venogram being the gold standard. An elevated opening pressure on LP is consistent with CVT.

Headache caused by cerebral venous thrombosis* has no specific characteristics: it is most often diffuse, progressive and severe, but can be unilateral and sudden (even thunderclap), or mild, and sometimes migraine-like. It can mimic migraine, cluster headache, SAH (CVT can be a cause of SAH), headache attributed to low cerebral spinal fluid and primary thunderclap headache.

*Cerebral Venous Thrombosis from StatPearls. Prasanna Tadi; Babak Behgam; Seth Baruffi. Last Update: June 12, 2023.