PRIOR TO CLASS

1. Read syllabus section on headache (below).
2. Complete the required quiz (Quiz G) on Canvas.
3. Complete pre-class case, Ms. Dupuis.
4. Prepare an answer to the below discussion topic based on the pre-class case:
   1. Using post-test probability and the threshold to test, explain why a lumbar puncture would have been the next best test had a subarachnoid hemorrhage not been seen on the CT scan.

overview

Headache is a very common symptom, affecting the vast majority of patients over the course of a lifetime. Almost 50% of patients have an active headache disorder, most commonly tension type or migraine headache.

As with many other symptoms, headache can be caused by a great number of health issues. Many of these are chronic conditions that can have a substantial effect on quality of life but are not a threat to life or neurologic function. Examples include tension type headache and migraine headache. Much less commonly, headache may be a manifestation of a process that can be fatal or associated with significant morbidity, including devastating neurologic dysfunction, if not recognized and treated early in the disease course. Examples include subarachnoid hemorrhage secondary to a cerebral aneurysm and meningitis.

Having and using an underlying framework for approaching the diagnostic process in evaluating a patient with a headache can help to provide an explanation for a patient’s symptoms in a timely and accurate manner while avoiding unnecessary testing. The “Primary Headache, Secondary Headache, Cranial Neuralgia/Facial Pain” construct facilitates both the recall of the differential diagnosis of a headache and a prompt to specially look for an underlying “secondary” cause of the headache, which may be a serious underlying process/illness.

Differential Diagnosis of Headache

Primary Headache
These are headaches that are not associated with an underlying illness other than the underlying headache disorder. They have little in the way of manifestations outside of headache. Although called “benign”, they can cause significant patient suffering and are important to diagnose early as effective treatments are available. They are also often missed or mis-diagnosed, especially migraine headaches. The three types of primary headaches are migraine headaches, tension type headaches, and trigeminal autonomic cephalgias.

1. Criteria for Migraine Headaches(without aura)

2. Criteria for Diagnosis of Tension Type Headaches

3. Trigeminal Autonomic Cephalgias

These are characterized by unilateral pain and autonomic features such as lacrimation, rhinorrhea, forehead flushing/diaphoresis, periorbital edema, and miosis. The prototypical example is cluster headaches.  This category does NOT include trigeminal neuralgia, which is rather one of the secondary causes of headache in the “cranial neuralgia and facial pain” category.

Secondary Headaches
These headaches are present as a manifestation of an underlying disease process. The disease process may be limited to the brain and surrounding structures (e.g., cerebral venous thrombosis, subarachnoid hemorrhage secondary to a cerebral aneurysm) or be a component of a systemic disorder (e.g., metastatic cancer, giant cell arteritis). Manifestations vary greatly and headache may be the primary symptom or one among many. The VINDICATE framework again helps structure the many causes of secondary headache.

***Diseases of the eyes, ears, nose, and other cranial structures are also a frequent cause of headache

Cranial neuralgias/Facial pain

These are less common disorders such as trigeminal neuralgia and occipital neuralgia.  These manifest as pain along the distribution of specific nerves and can cause debilitating pain.

Approach to Headache

1. First determine if the characteristics of the headache suggest a primary headache disorder, specifically migraine headaches, tension-type headaches, and the trigeminal autonomic cephalgias (TACs); also specifically consider the cranial neuralgias/facial pain diagnoses.

2. Screen all patients, including those with a likely primary headache disorder, for findings that suggest a secondary headache or a serious underlying disorder. The SNOOPPPP mnemonic can be helpful to ensure the right questions are asked

***A thunderclap headache is of particular concern.

3. Consider further evaluation based on the likelihood of each possibility on the differential diagnosis. Key diagnostic questions are the below.  The answer lies in considering the likelihood of disease and comparing it to the threshold to test for each individual secondary cause:

• • Is neuroimaging needed?
  • Is a lumbar puncture needed?
  • Should inflammatory markers be checked?