Causes of Daily Persistent Headache
Primary Causes
Daily persistent headaches are primarily caused by four distinct primary headache disorders: chronic migraine, chronic tension-type headache, new daily persistent headache (NDPH), and hemicrania continua. 1
Chronic Migraine
- Defined as headaches occurring ≥15 days per month, each lasting ≥4 hours, with migraine features on ≥8 days per month 1
- Represents transformation from episodic migraine in most cases, affecting up to 3% of episodic migraine patients annually 1
- Risk factors for transformation include female sex, high baseline headache frequency, inadequate treatment, medication overuse, depression, anxiety, and obesity 1
New Daily Persistent Headache (NDPH)
- Characterized by sudden onset headache that becomes continuous within 24 hours and remains daily from onset 2, 3
- Patients can pinpoint the exact date their headache started 3
- Prevalence estimated at 0.03% to 0.1% in general population, higher in children and adolescents 3
- Potential triggers include infectious diseases (viral or bacterial), stressful life events, and cervical hypermobility 2, 3, 4
- Pathophysiology may involve neuroinflammation, pro-inflammatory cytokines, and abnormal glial activation 2, 3, 4
Chronic Tension-Type Headache
- Part of the chronic daily headache spectrum affecting 4-5% of the general population 5
- Evolves from episodic tension-type headache or may be daily from onset 5
Hemicrania Continua
- A less common primary headache disorder that presents with continuous unilateral headache 1
Secondary Causes (Critical to Exclude)
Before diagnosing a primary headache disorder, secondary causes must be ruled out through careful history and examination for "red flags." 1
Red Flag Conditions Requiring Neuroimaging
- New-onset headache in patients over age 50 6
- Morning headaches that improve with upright positioning (suggests increased intracranial pressure) 6
- Thunderclap onset or headache started with Valsalva maneuver (suggests CSF pressure abnormalities) 2
- Atypical headache features warranting MRI of the brain 6
Specific Secondary Causes to Consider
- Temporal arteritis in patients over 50 with new headache (check ESR and CRP) 6
- Obstructive sleep apnea presenting as morning headaches that resolve within hours of waking 6
- Infectious triggers particularly in NDPH cases where viral or bacterial infection preceded headache onset 2
- Cervicogenic problems which may play a role in NDPH development 3
Medication Overuse as a Perpetuating Cause
Medication overuse headache (MOH) is a critical perpetuating factor that develops in patients with pre-existing headache disorders who regularly overuse acute headache medications. 1, 7
Defining Medication Overuse
- Headache occurring ≥15 days per month developing from regular overuse of acute medications 1
- Simple analgesics (NSAIDs, acetaminophen) used ≥15 days per month 7
- Triptans used ≥10 days per month 7
- Any acute headache medication used >2 days per week 7
- Medications containing barbiturates, caffeine, butalbital, or opioids carry the highest risk 7
Clinical Significance
- Accounts for approximately two-thirds of chronic migraine cases (though this may be underestimated) 1
- Affects up to 73% of patients with chronic migraine seeking treatment 1
- Perpetuates the headache cycle and prevents preventive treatments from working 7
- Must verify over-the-counter medication use as patients often underreport this 6
Management Approach
Initial Evaluation Steps
- Ask patients: "Do you feel like you have a headache of some type on 15 or more days per month?" 1
- Maintain a headache diary tracking severity, frequency, duration, disability, medication use, and triggers 1, 7
- Assess for medication overuse patterns in all patients with chronic daily headache 6, 8
- Screen for comorbidities including depression, anxiety, sleep disturbances, obesity, and chronic pain conditions 1
Treatment for Medication Overuse Headache
- Immediate, complete withdrawal of all overused medications (abrupt withdrawal preferred except for opioids) 1, 7
- Start prophylactic therapy simultaneously with withdrawal 7
- Educate patients that symptoms will worsen before improving 1
- Avoid prescribing daily analgesics as this perpetuates the problem 7, 6
Prophylactic Treatment Options
For chronic migraine, topiramate is first-line due to being the only agent with randomized controlled trial evidence specifically in chronic migraine and its lower cost. 1
Evidence-Based Options for Chronic Migraine
- Topiramate: Only oral agent proven efficacious in randomized placebo-controlled trials for chronic migraine 1
- OnabotulinumtoxinA: FDA-approved for chronic migraine prophylaxis, proven beneficial in Phase III trials 1, 7
- CGRP monoclonal antibodies (erenumab, fremanezumab, galcanezumab): Proven beneficial when ≥2 other preventives have failed 1
Other Prophylactic Agents
- Amitriptyline (second choice, causes dry mouth, sedation, weight gain) 7, 8
- Gabapentin 1, 8
- Propranolol 8
- Valproate 1, 8
- Tizanidine 1, 8
Treatment for NDPH (Most Refractory)
- Treat based on predominant headache phenotype (migraine-like vs. tension-type) 3
- For refractory cases: IV ketamine, IV lidocaine, onabotulinumtoxinA, CGRP antibodies, nerve blockade 2, 3
- Antiviral medications if infectious trigger suspected 2
- CSF-lowering medications if started with thunderclap or Valsalva 2
- SSRIs/SNRIs or benzodiazepines if concurrent affective disorders present 2
Non-Pharmacological Interventions
- Improve diet, sleep patterns, reduce caffeine and alcohol consumption 2
- Relaxation techniques, cognitive behavioral therapy 8
- Acupuncture, osteopathic manipulation, cervical exercises 8
- Nerve blockade and nerve stimulation (more efficacious in children than adults) 2
Acute Treatment Principles
- NSAIDs (aspirin, ibuprofen, naproxen, diclofenac) are first-line for acute migraine attacks 1
- Triptans for patients not responding to NSAIDs, most effective when taken early with mild headache 1
- Limit acute treatment to no more than twice weekly to prevent medication overuse 1, 7
- Non-oral routes (intranasal, subcutaneous) when nausea/vomiting present early 1