Headache refers to any pain in the head or neck area due to irritation of the sensitive meninges and cranial endooseum. The brain itself is non-sensitive to irritation or inflammation.
Headache is considered a protective mechanism like any other pain in the body, that may indicate an underlying serious pathology. It can be primary with no pathological predisposition e.g. migraine and cluster headache or secondary to other disorders e.g. sinusitis, hypertension emergencies or brain tumors.
Evaluation of patients with headache is directed towards elimination of serious life threatening condition, then conclusion to the right diagnosis.
Possible causes of subacute headache include brain tumors, CNS infections, CNS hemorrhage, hypertension and systemic inflammatory diseases.
Chronic headache is usually caused by tension headache, migraine, cluster headache, sinusitis, refractive errors and tempromandibular joint dysfunction. Patient history is the first diagnostic tool for primary and secondary headache as well as subtypes of primary and possible etiological factors of secondary headaches.
For exclusion of danger signs during evaluation, the mnemonic “snoop” is used. Presence of any of these manifestations prompts further investigations to know the exact pathology.
- Systemic disorders (fever, HIV state or pregnancy)
- Neurological deficit may suggest brain hemorrhage or meningitis. Conscious level, vision and cranial nerves should be checked in details.
- Onset headache (new or sudden) that needs to be fully investigated.
- Other associated conditions e.g. head trauma or intoxication.
- Previous change of present headache can be a sign of progression or another pathology. The most common type of headache among populations is tension headache but the most presentable type of headache to primary care physicians is migraine.
Giant cell arteritis
This is also called temporal arteritis and is a type of vasculitis of large and medium sized arteries above 50 years. The headache is usually in the temporal or frontal area with tenderness over the temporal muscles. It is important to early diagnose temporal arteritis based on clinical suspicion and initiation of treatment to avoid visual complication, which may progress to visual loss. Systemic inflammatory symptoms of fatigue, fever, jaw claudications and weight loss may also be present.
Elevated blood pressure with end organ damage can be presented with headache but further investigation is life saving to prevent brain hemorrhage, retinal hemorrhage, renal failure and pulmonary edema. Sodium nitroprusside is used for rapid lowering of blood pressure in hypertensive emergencies.
Subarachnoid hemorrhage refers to blood in the subarachnoid space due to rupture of brain aneurysm or arteriovenous malformation. It can be spontaneous or traumatic with severe headache that can be described as the worst headache the patient has experienced.
Clinical presentation also includes altered mental status, focal neurological lesions according to the location of hemorrhage, meningeal irritation and sometimes coma. CT scan is the first step for the diagnosis specially in patients with altered mental status.
Lumbar puncture with CSF analysis can be done following CT to exclude any brain space occupying lesions. Management of subarachnoid hemorrhage varies according to clinical presentation with ABC for comatose patients. Lowering intracranial tension with mannitol and diuretics will improve the mental status of the patients. Blood pressure control, hydration, supportive measures and antiepileptic prophylaxis are indicated.
Venous sinus thrombosis
Cerebral sinus thrombosis manifestations can vary according to the sinus affected. It usually presents with acute onset headache, visual abnormalities, nausea, vomiting and cranial nerve palsies.
Brain infarction or hemorrhage can both be complications of sinus thrombosis due to blood congestion. It can be a complication of sinusitis, hypercoagulable states, lumbar puncture, brain surgery or medications e.g. steroids, oral contraceptives, tamoxifen and Epsilon-aminocaproic acid.
Treatment includes thrombolytic therapy, analgesics, lumbar puncture and antiepileptics.
Both refer to CNS infection. While meningitis is inflammation of the brain meninges due to viral, bacterial or fungal CSF infection, encephalitis is inflammation of the brain itself due to viral or autoimmune disorder. Clinical manifestations include fever, headache, photophobia, nuchal rigidity and sometimes focal neurological symptoms.
Blood cultures, lumbar puncture and CSF analysis are used for confirming the diagnosis. According to the etiology, CSF sample differs in glucose content, WBCs infiltration, proteins and lactate concentration. Treatment is directed against the causative agent.
Glaucoma is a common cause of headache due to elevated intraocular pressure. It can lead to optic atrophy and subsequent blindness. Angle closure glaucoma is acute in onset with eye pain, conjunctival injection, nausea and vomiting. Management is directed to urgent lowering of the intraocular pressure.
Migraine is paroxysmal attacks of throbbing unilateral headache that is accompanied with nausea, vomiting, phonophobia and photophobia. It can be precipitated by many factors including visual stimuli, environmental factors, wine, stress, sleep disturbances, nitrites and aspartame.
The pain can be moderate to severe lasting from 4 to 72 hours and localized to one lobe or an area of the head mainly the frontotemporal or the ocular area. It can be accompanied also with conjunctival injection, cardiovascular manifestations of hyper/hypotension, neurological symptoms of Horner syndrome, sensory abnormality or cranial nerve abnormality.
Migraine is usually proceeded by an aura which might be sensory or motor and usually lasts for less than one hour. Visual aura of scotoma is the commonest with an arc or band of absent vision in the visual field.
Chronic migraine is defined as 15 or more headache attack days occur every month or sometimes even daily.
Diagnosis of migraine is usually clinical diagnosis with no need for imaging studies in patients with typical recurrent attacks. The patients avoid sudden movement, which can precipitate the attacks unlike patients with cluster headache which is severe enough to make the patient restless and irritable.
Management is mainly abortive for the acute attacks and prophylaxis for prevention of future attacks. Acute managements include triptans, ergot alkaloids and NSAIDs. Preventive management includes beta blockers, tricyclic antidepressants, antiepileptics, calcium channel blockers, SSRIs and NSAIDs.
Tension type headache is usually bilateral featureless pain which is mild to moderate in severity and lasts few minutes to several days. It can be associated with pericranial muscle spasm or tenderness in the neck and scalp.
The pain starts in the back of the head and neck, then spreads as tightness or pressure band. It is not associated with nausea or vomiting and no disability of the affected patients.
Chronic tension headache is defined when the attacks occur for 15 or more days every month. It is usually triggered by stressful events, depression and abnormal head posture. There is no aura or prodrome with tension headache and the neurological exam should be normal except for some tenderness or spasm of the neck muscles.
Management of tension headache is mainly to avoid the triggering stressors. Relaxation techniques, cold or hot packs, ultrasound, acupuncture, NSAIDs e.g. acetaminophen, Ibuprofen, naproxen and also diphenhydramine and finally barbiturates are helpful in relieving the symptoms.
Cluster headache (Horton’s syndrome)
This is a form of severe unilateral periorbital headache in the trigeminal distribution with conjunctival injection, lacrimation, nasal congestion and rhinorrhea. Sometimes it can be associated with miosis and ptosis. The pain usually lasts few minutes to hours.
The attacks are commonly recurrent at the same time every night and awake the patient from sleep. The pain is severe and the patient is restless and irritable. Heavy smoking and alcohol use are risk factors for development of cluster headache as well as histamine and head trauma.
Chronic cluster headache occurs when the headache free interval is less than one month or when it lasts for more than one year. Abortive management of cluster attacks include oxygen inhalation therapy, triptans e.g . sumatriptan, ergot alkaloids, caffeine and instillation of local anesthetics into the nostrils.
Prophylactic management includes calcium channel blockers e.g. verapamil & diltiazim, lithium, prednisolone and antiepileptics.
New daily persistent headache
It is a primary headache that is unremitting daily for more than 3 months. It is usually bilateral, mild to moderate headache, tightening in quality and can be associated with photophobia, phonophobia and mild nausea.
The etiology is unknown but most of the patients report infection or flu-like illness and sometimes stressful life event. Patients usually remember the exact date it started.
Diagnosis is made by exclusion of all other causes which may precipitate the headache and other life threatening conditions. Various medications have been tried for management of new daily persistent headache including propranolol, amitriptyline, gabapentin and pregabalin.
It is a primary unremitting persistent headache that can have severe exacerbations. The pain is unilateral as the name implies and is associated with miosis, ptosis, conjunctival injection or rhinorrhea. It responds well to indomethacin.
Idiopathic/benign intracranial hypertension
Also called pseudotumor cerebri, this is a known cause of chronic headache characterized by symptoms of increased intracranial tension i.e. headache, vision loss, nausea, vomiting and papilledema without any evidence of space occupying lesion in neuroimaging.
The symptoms can also include pulsatile tinnitus, and abducens nerve and other neurological deficits. The symptoms are relieved after lumbar puncture to relieve the pressure, or medications which lower CSF pressure.
The disease is common in women of child bearing age. Lumbar puncture should be proceeded with MRI to avoid brain stem herniation in case of space occupying lesion.
Elevated CSF opening pressure with normal CSF composition is both diagnostic and therapeutic. Carbonic anhydrase inhibitors, acetazolamide is used effectively to lower the CSF production.
Headache with increased intracranial tension can also be present with space occupying lesions including tumors, CNS abscess or hemorrhage.
Pheochromocytoma is characterized by intermittent hypertension with headache, palpitations and sweating. It is due to hypersecretion of the adrenal medulla.
Morning headache is more due to sleep disturbances and obstructive sleep apnea.
Chronic subdural hemorrhage is chronic hemorrhage localized within the subdural space specially in old age due to brain atrophy and minor head trauma. The blood accumulates over a long period with symptoms of headache, cognitive disability and focal neurological abnormality. Treatment is usually surgical evacuation of the hematoma.
Acute and chronic sinusitis can be associated with headache which mimics migraine or tension headache. Other sinus symptoms include fever, nasal congestion and rhinorrhea. The headache is usually pressure-like and periorbital and lacks other manifestations of migraine or tension headache. Treatment involves decongestant, antibiotic and analgesics.
Medication overuse headache is chromic headache with repeated analgesic use, which will lead to temporary relief followed by rebound of the headache.
Cranial neuralgias include poetherpetic neuralgia and trigeminal neuralgia, which are stabbing sharp pain at the nerve distribution. Medical management with gabapentin or pregabalin and surgical management can be done to decompress the nerve origin to prevent the attacks.
- Blood draws e.g. CRP, CBC, ESR are first indicated to exclude systemic inflammatory conditions which might precipitate the headache.
- Brain imaging using CT and MRI for brain tumors or lesions, hemorrhage, stroke, trauma and benign intracranial hypertension.
- Lumbar puncture and CSF analysis in case of infection, subarachnoid hemorrhage and benign intracranial hemorrhage.
- Fundal examination for cases of headaches due to brain tumor, hypertension, benign intracranial hypertension glaucoma and HIV.