Migraine

Clinical features: signs and symptoms

1. Prodrome: Hours to 1-2 days before the headache
   • Fatigue, yawning, mood change, food cravings
   • Poor concentration, neck stiffness, increased urination
2. Aura: Usually develops gradually and is fully reversible
   • Most commonly visual: flashing lights, zigzag lines, blind spots or scintillating scotoma
   • Sensory: unilateral tingling or numbness that may spread
   • Speech/language disturbance
   • Less commonly, vertigo or motor weakness
     Aura often lasts under an hour and may precede or occur during headache.
3. Headache phase
   Typical features are:
   • Unilateral, though it can be bilateral
   • Pulsating or throbbing
   • Moderate to severe intensity
   • Worse with routine activity, such as walking or climbing stairs
   • Nausea and/or vomiting
   • Photophobia and phonophobia
   • Possible osmophobia, neck pain, dizziness, impaired thinking, and scalp sensitivity
4. Postdrome
   • Tiredness, “brain fog,” low mood, difficulty concentrating, or neck discomfort.

Diagnosis

Migraine without aura: practical diagnostic criteria

• Unilateral location
• Pulsating quality
• Moderate or severe intensity
• Aggravated by normal physical activity

• Nausea and/or vomiting
• Photophobia and phonophobia

Examination

• Blood pressure and general examination
• Neck assessment for stiffness
• Fundus/eye examination when indicated
• Complete neurologic examination

Red flags: investigate urgently for a secondary headache

• Sudden maximal headache, “thunderclap” onset
• New neurologic deficit, confusion, seizure, fainting, or persistent weakness
• Fever, neck stiffness, rash, or immunosuppression
• New headache during pregnancy/postpartum
• Head injury
• New onset after age 50
• Cancer, clotting disorder, markedly high blood pressure
• Papilledema or visual loss
• A clear progressive change in headache pattern
• Headache triggered by exertion, sex, coughing, or Valsalva

Treatment

1. Acute treatment

• Triptans should generally be avoided in people with ischemic heart disease, prior stroke/TIA, peripheral vascular disease, or uncontrolled hypertension. They should not be combined with ergot medicines.
• Avoid opioids and butalbital-containing products for routine migraine care. They have poorer outcomes and increase the risk of dependence and medication-overuse headache.
• Limit acute medication use to avoid medication-overuse headache. A common practical threshold is avoiding triptans, ergots, opioids, or combination analgesics on 10 or more days/month, and simple analgesics/NSAIDs on 15 or more days/month.

2. Preventive treatment

• Beta-blockers: propranolol, metoprolol
• Antiseizure medicines: topiramate, valproate
• Antidepressants: amitriptyline, venlafaxine
• CGRP-targeting prevention: erenumab, fremanezumab, galcanezumab, eptinezumab; oral atogepant or rimegepant in suitable settings
• OnabotulinumtoxinA: for chronic migraine, generally defined as headache on 15 or more days/month for over 3 months, with migraine features on at least 8 days/month

3. Non-drug measures

• Keep regular sleep, meals, hydration, and exercise routines.
• Do not skip meals or abruptly change caffeine intake.
• Identify personal triggers with a headache diary. Common triggers include stress, alcohol, fasting, hormonal fluctuations, sleep disruption, and sensory stimuli, though triggers differ between people.
• Manage stress with relaxation, CBT, mindfulness, or biofeedback where useful.
• Treat coexisting anxiety, depression, sleep apnea, or neck pain.

CT and MRI findings in migraine

Typical migraine

• CT brain is usually normal.
• MRI brain is usually normal, especially in uncomplicated migraine with a normal neurologic examination.
• Imaging does not diagnose migraine. Migraine remains a clinical diagnosis based on the history and examination. American Headache Society guidance states that imaging is not indicated for recurrent headaches with migraine features, a normal neurologic examination, and no warning signs.

Possible MRI findings

• Small punctate T2/FLAIR hyperintense white-matter foci, often in deep or subcortical white matter
• Usually nonspecific, nonenhancing, and of uncertain clinical significance
• These lesions do not by themselves mean multiple sclerosis, stroke, or a brain tumor.

Imaging during an acute migraine aura

• CT and conventional MRI are commonly normal.
• Advanced research imaging can show transient functional or perfusion changes related to cortical spreading depression, but these are not routine clinical findings and are not used to confirm ordinary migraine.

Complicated migraine and important exceptions

When CT or MRI is needed

• Sudden thunderclap onset
• First or markedly different severe headache
• Persistent focal weakness, aphasia, confusion, seizure, or reduced consciousness
• Papilledema or persistent visual loss
• Fever, neck stiffness, cancer, immunosuppression, or head injury
• New headache after age 50
• Pregnancy/postpartum headache
• Progressive worsening pattern
• Atypical aura, prolonged aura, or motor weakness

• Non-contrast CT: preferred first in emergency situations, particularly thunderclap headache, head trauma, or suspected acute hemorrhage.
• MRI brain: preferred for non-emergency evaluation of atypical, progressive, or focal neurologic presentations because it better detects tumor, infarct, inflammation, posterior fossa lesions, and demyelination.
• CTA/MRA or CTV/MRV: used if arterial dissection, aneurysm, vascular occlusion, or cerebral venous thrombosis is suspected.

Causes of migraine

Main contributing factors

1. Genetic predisposition
   • Migraine commonly runs in families.
   • Common migraine is polygenic, meaning many small genetic effects combine with environmental factors.
   • Rare familial hemiplegic migraine is linked to specific ion-channel gene mutations.
2. Hormonal changes
   • Menstruation, ovulation, pregnancy/postpartum changes, perimenopause, and hormonal contraceptives can alter attack frequency.
   • This helps explain why migraine is more common in women after puberty.
3. Brain sensitivity and nervous-system mechanisms
   • Migraine aura is associated with cortical spreading depression, a wave of altered electrical activity across the cerebral cortex.
   • Activation of trigeminal pathways produces throbbing pain, nausea, and light/sound sensitivity.
4. Individual triggers Triggers do not cause migraine in everyone and may only trigger an attack when the person is already susceptible. Common examples:
   • Stress or emotional upset
   • Poor sleep, excess sleep, shift work, jet lag
   • Skipping meals, fasting, dehydration
   • Alcohol, especially red wine
   • Caffeine excess or caffeine withdrawal
   • Bright/flickering light, loud noise, strong smells
   • Weather or barometric-pressure changes
   • Intense exercise in some people
   • Certain foods in susceptible people, for example aged cheese, processed meats/nitrates, or chocolate
5. Medication overuse
   • Frequent use of pain medicines can convert episodic migraine into chronic daily headache or medication-overuse headache.
   • Risk is especially high with opioids, butalbital-containing products, combination analgesics, and frequent triptan use.

Important point

Leptospirosis

How it spreads

• Broken skin, cuts, or abrasions
• Eyes, nose, or mouth
• Occasionally by drinking contaminated water

• Wading through floodwater
• Working in rice fields, farms, sewers, or mines
• Freshwater swimming/adventure sports
• Contact with rodents or infected animal urine

Incubation period

Clinical features

1. Mild or anicteric leptospirosis

• Sudden high fever and chills
• Severe headache
• Marked muscle pain, classically in the calves and lower back
• Weakness and fatigue
• Nausea, vomiting, abdominal pain, diarrhea
• Red eyes without pus, called conjunctival suffusion
• Rash in some patients
• Cough or sore throat

2. Severe leptospirosis: Weil disease

• Jaundice due to liver dysfunction
• Acute kidney injury, reduced urine output, electrolyte abnormalities
• Bleeding tendency, petechiae, gastrointestinal bleeding, or pulmonary hemorrhage
• Low platelet count
• Severe muscle breakdown
• Meningitis or encephalopathy
• Myocarditis or arrhythmia
• Acute respiratory distress syndrome and respiratory failure
• Shock and multiorgan failure

Diagnosis

Important history

• Recent flooding or freshwater exposure
• Rat or rodent exposure
• Farming, sewage work, animal handling, or outdoor water activities
• Travel to tropical or endemic regions
• Fever with calf pain, red eyes, jaundice, or reduced urine output

Tests

Differential diagnosis

• Dengue
• Malaria
• Viral hepatitis
• Influenza or COVID-19
• Typhoid fever
• Scrub typhus/rickettsial disease
• Acute pyelonephritis or sepsis
• Viral meningitis
• Hantavirus infection

Treatment

Mild disease

• Doxycycline 100 mg orally twice daily for 7 days for appropriate adults
• Alternatives may include amoxicillin, ampicillin, azithromycin, or oral penicillin-based regimens depending on pregnancy status, age, allergies, and local guidance

Severe disease or Weil disease

• IV penicillin G, ceftriaxone, or cefotaxime, selected according to local protocol and patient factors
• IV fluids with careful monitoring
• Management of acute kidney injury and electrolytes
• Dialysis if indicated
• Oxygen, ventilation, or ICU support for pulmonary hemorrhage/ARDS
• Blood products if clinically significant bleeding occurs

Evidence note

Prevention

• Avoid wading or swimming in potentially contaminated floodwater or freshwater.
• Wear waterproof boots, gloves, and protective clothing during flood cleanup, sewage work, or farming.
• Cover cuts with waterproof dressings.
• Control rodents and safely store food/waste.
• Do not drink untreated water from potentially contaminated sources.
• Clean wounds promptly after exposure.
• Doxycycline prophylaxis is sometimes considered for selected high-risk exposures or travelers, but it is not appropriate for routine self-medication and should follow local public-health or clinician guidance.

Seek urgent care now if