What is the appropriate evaluation and management for nocturnal headaches that wake a patient from sleep?

Nocturnal Headaches Waking Patient from Sleep at 11pm

This patient requires urgent evaluation to exclude secondary causes of nocturnal headaches, particularly increased intracranial pressure, obstructive sleep apnea, and arterial hypertension, before considering primary headache disorders like hypnic headache. 1, 2

Immediate Red Flags to Assess

The following features mandate urgent neuroimaging and further investigation 2:

• New or worsening headache pattern - particularly concerning in patients over age 50 2
• Neurological symptoms or abnormal signs on examination 2
• Systemic symptoms including fever, weight loss, or signs of increased intracranial pressure 2
• History of cancer or immunocompromised state 2
• Headache brought on by Valsalva maneuver or exertion 2

Essential Clinical Evaluation

Focused History Questions

Ask specific screening questions to identify underlying conditions 3:

• Sleep disorders: "Do you snore and wake up choking?" "Does your partner say you stop breathing?" "Do you wake unrefreshed or fall asleep during the day?" 3
• Cardiovascular: "Do you experience ankle swelling?" "Do you get short of breath walking?" 3
• Neurological: "Do you have problems controlling your legs?" "Have you noticed slowness of movement or tremor?" 3
• Endocrine: "Have you been feeling excessively thirsty?" 3

Medication Review

Review all medications that may contribute to nocturnal symptoms 3:

• Diuretics, calcium channel blockers, lithium, NSAIDs 3
• Medications causing xerostomia: anxiolytics, antidepressants (especially tricyclics), antimuscarinics, antihistamines 3
• Alcohol and caffeine intake due to diuretic effects 3

Physical Examination

Perform targeted examination 3:

• Careful blood pressure measurement - hypertension is a critical secondary cause 3
• Peripheral edema - suggests cardiac or renal disease 3
• Neurological examination - assess for lower limb weakness, abnormal gait, speech abnormalities, tremor 3

Baseline Investigations

Order the following tests to identify underlying conditions 3, 4:

• Blood tests: electrolytes/renal function, thyroid function, calcium, HbA1c 3, 4
• Urinalysis: albumin:creatinine ratio, protein 3
• Blood pressure assessment if not already documented 3

When to Order Polysomnography

Polysomnography is indicated when 5, 6:

• Symptoms suggest obstructive sleep apnea (snoring, witnessed apneas, daytime somnolence, morning headaches) 5
• Poorly defined nocturnal headaches without clear primary headache diagnosis 5
• No underlying psychological disorder or analgesic overuse identified 5
• 55% of patients with nocturnal headaches have identifiable sleep disorders on polysomnography, and treatment of these disorders leads to headache improvement or resolution 6

Primary Headache Considerations

If secondary causes are excluded, consider hypnic headache 1, 7:

• Typically occurs in patients over age 50 with late-onset presentation 1
• "Alarm-clock headache" that awakens at consistent times 1
• Characterized by dull pain, short duration, absence of autonomic symptoms 1
• Occurs exclusively during sleep with chronic pattern (≥15 attacks per month) 1

Other primary headaches to consider include cluster headache, chronic paroxysmal hemicrania, and migraine, which can occur nocturnally but have distinct clinical features 7, 5

Critical Management Pitfall

Do not assume a primary headache disorder without excluding secondary causes - nocturnal headaches can indicate increased intracranial pressure, sleep apnea, or hypertension, all of which have significant morbidity and mortality implications if missed 1, 2, 6