Headache

Headache is one of the most common complaints encountered by neurologists and general practitioners. The International Society of Headaches (IHS) identifies more than 160 types of cephalgia.

Headache is one of the most common reasons for seeking medical attention. Most recurrent headaches can be classified as primary headache (i.e., not associated with obvious structural abnormalities). Primary headaches include migraine (with or without aura), cluster headache (episodic or chronic), tension headache (episodic or chronic), chronic paroxysmal hemicrania, and hemicrania continue. New, previously unfamiliar persistent headache may be secondary to a variety of intracranial, extracranial, and systemic disorders.

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Reasons

Pain in the cranial vault (from the eyebrows up to the back of the head) and inside the cranium is called cephalgia, cranialgia. Pain in the face - prosopalgia - is caused by neuralgia and neuritis of the cranial nerves (trigeminal, glossopharyngeal), autonomic ganglia (ciliary, pterygopalatine, auricular), cervical sympathetic ganglia, including stellate, sinusitis, arthrosis-arthritis of the temporomandibular joints, damage to the vessels of the external carotid artery, diseases of the teeth and gums (odontogenic prosopalgia).

Headache is not a separate disease, but a symptom, which is sometimes a very important sign warning of a serious pathology. Sometimes headache can be determined by laboratory testing or neuroimaging. If this cause is established, then the headache can often (but not always) be eliminated with adequate therapy of the underlying disease. If the source that causes pain is not established or its treatment does not lead to regression, then there is a need for symptomatic pharmacotherapy and concomitant disorders. Pharmacotherapy is mainly empirical in nature and involves the use of various agents. Chronic headache may require not only therapeutic measures aimed at stopping a pain attack, but also preventive therapy aimed at reducing the frequency and severity of attacks. The mechanism of action of many therapeutic agents is not well understood. Headache is a young condition and as the understanding of the pathogenesis of primary forms deepens, conditions are created for the development of more effective and safe drugs.

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What's happening?

Headache and its pathogenesis have not been sufficiently studied. It may be caused by irritation of the sensitive structures of the head and neck from tension, pressure, displacement, stretching and inflammation. Along with the nerves and vessels of the external soft parts of the head, some parts of the dura mater, venous sinuses with their larger tributaries, large vessels of the dura mater, and sensitive cranial nerves have pain sensitivity. The brain tissue itself, the soft meninges and small blood vessels do not have pain sensitivity.

Headache may be due to spasm, dilation, or traction of blood vessels; traction or displacement of the sinuses; compression, traction, or inflammation of the aforementioned cranial nerves; spasm, inflammation, or injury to the muscles and tendons of the head and neck; irritation of the meninges; and increased intracranial pressure. The severity and duration of the attack, as well as the location, may provide valuable information for diagnosis.

Headache can be functional or organic. Organic headache will usually be associated with neurological symptoms and signs such as vomiting, fever, paralysis, paresis, seizures, confusion, decreased consciousness, mood changes, visual disturbances.

Headache is familiar to everyone, starting from childhood. The only exceptions are people with congenital deficiency of sensory neurons.

Pain receptors of sensory neurons are located in the dura mater, sinuses of the dura mater, duplication of the membrane in the area of the sagittal venous sinus and tentorium cerebelli, vessels. There are no pain receptors in the pia mater and arachnoid mater of the brain, ependyma, choroid plexus, most areas of the brain parenchyma.

There are also pain receptors in extracranial tissues: skin, aponeurosis, muscles of the head, nose, teeth, mucous membranes and periosteum of the jaws, nose, delicate structures of the eyes. There are few pain receptors in the veins of the head, bones and diploe. Neurons with pain receptors in the tissues of the head make up the sensory branches of the cranial nerves (V, V, X, X) and the first three spinal root nerves.

Headache is the most common complaint with which patients seek medical attention in any specialty and is the leading or only complaint in more than 45 different diseases: organic lesions of the nervous system (inflammatory, vascular, tumor, traumatic), arterial hypertension and hypotension of various origins (nephrogenic, endocrine, psychogenic), neuroses, depression, etc., i.e. it is a polyetiological syndrome.

At the same time, detailed clarification of the characteristics of the pain syndrome helps both topical diagnostics and pathogenetic diagnosis. When complaining of headache, it is necessary to clarify its nature, intensity, localization, duration and time of occurrence, as well as provoking, intensifying or alleviating factors.

Localization and characteristics of headache

Patients often cannot independently describe the nature of pain sensations. Therefore, it is important for the doctor to correctly formulate specific questions to clarify the characteristics, using definitions such as "pressing", "boring", "brain-grinding", "gnawing", "bursting", "squeezing", "shooting", "explosive", "tense", "pulsating", etc. Headache can cause minimal psychological discomfort or lead to loss of ability to work, deterioration in the quality of life.

It is important to clarify the localization. Intense headache along the extracranial vessels is characteristic of arteritis (e.g., temporal). When the paranasal sinuses, teeth, eyes, and upper cervical vertebrae are affected, the pain is less clearly localized and can be projected to the forehead, upper jaw, and orbit. In case of pathology in the posterior cranial fossa, the headache is localized in the occipital region and can be unilateral. Supratentorial location of the pathological process causes pain in the frontotemporal region of the corresponding side.

However, the localization may not coincide with the topic of the pathological process. For example, headache in the forehead may be due to glaucoma, sinusitis, thrombosis of the vertebral or basilar artery, compression or irritation of the cerebellar tentorium (Burdenko-Kramer syndrome with a tumor, cerebellar abscess: pain in the eyeball, photophobia, blepharospasm, lacrimation, conjunctivitis, increased mucus discharge from the nose). Ear pain may indicate a disease of the ear itself or be reflected in case of damage to the pharynx, neck muscles, cervical vertebrae, structures of the posterior cranial fossa. Periorbital and supraorbital headache indicates a local process, but can also be reflected in case of a dissecting hematoma of the internal carotid artery at the neck level. Headache in the parietal region or in both parietal regions occurs with sinusitis of the sphenoid and ethmoid bones, as well as with thrombosis of the large veins of the brain.

There is a relationship between the localization and the affected vessel. Thus, with dilation of the middle meningeal artery, the headache is projected behind the eyeball and into the parietal region. With pathology of the intracranial part of the internal carotid artery, as well as the proximal parts of the anterior and middle cerebral arteries, the headache is localized in the eye and orbitotemporal region. Localization of algesia usually depends on irritation of certain sensory neurons: pain from supratentorial structures radiates to the anterior two-thirds of the head, i.e., to the innervation territory of the first and second branches of the trigeminal nerve; pain from infratentorial structures is reflected to the crown and back of the head and neck through the upper cervical roots; with irritation of the V, X and X cranial nerves, pain radiates to the ear, nasoorbital zone and pharynx. In case of dental disease or temporomandibular joint, pain can radiate to the skull.

It is necessary to find out the type of onset of pain, the time of change in its intensity and duration. A headache that suddenly appears and is intense, increasing over several minutes, with a feeling of spreading warmth (heat) is characteristic of subarachnoid hemorrhage (when a vessel ruptures). A headache that suddenly appears and intensifies over tens of minutes and an hour occurs with migraine. If the headache is increasing in nature and lasts for hours or days, it is a sign of meningitis.

Depending on the duration and characteristics of the course, there are 4 options:

1. acute headache (single, short-term);
2. acute recurring (with the presence of light intervals, characteristic of migraine);
3. chronic progressive (with a tendency to increase, for example, with a tumor, meningitis);
4. chronic non-progressive headache (occurs daily or several times a week, does not change in severity over time - the so-called tension headache).

Most often, headaches occur due to pathological processes that lead to deformation, displacement or stretching of the vessels or structures of the dura mater, mainly at the base of the brain.

It is interesting that the increase in intracranial pressure with the introduction of sterile saline solution subarachnoidally or intraventricularly does not lead to an attack until other mechanisms are activated. Headache is a consequence of dilation of intracranial and extracranial vessels against the background of their possible sensitization. This is observed with the introduction of histamine, alcohol, nitrates and other similar drugs.

Vasodilation is observed with a significant increase in arterial pressure against the background of pheochromocytoma, malignant arterial hypertension, sexual activity. In such cases, monoamine oxidase inhibitors have a therapeutic effect.

A decrease in the pain threshold of the receptors of the vessels of the base of the brain and the dura mater (vascular sensitization) and their expansion can be caused by a disturbance in the exchange of neurotransmitters, in particular serotonin receptors (5HT) in the vessels of the brain and trigeminal neurons, as well as an imbalance in the work of opioid receptors around the aqueduct of Sylvius and nuclei of the urea, which are part of the antinociceptive system and provide endogenous control over the formation of pain sensations. Headache due to vasodilation occurs with various common infections (flu, acute respiratory viral infections, etc.).

In 1988, an international classification was adopted that helps the doctor to correctly navigate during examination and treatment of the patient. According to this classification, headaches are divided into the following groups:

1. migraine (without aura and with aura);
2. tension headache (episodic, chronic);
3. cluster headache;
4. headache not associated with structural lesions (from external pressure, provoked by cold, coughing, physical exertion, etc.);
5. headache associated with head injury (acute and chronic post-traumatic headache);
6. headache associated with vascular disorders (ischemic cerebral vascular disease, subarachnoid hemorrhage, arteritis, cerebral vein thrombosis, arterial hypertension, etc.);
7. headache due to intracranial non-vascular processes (with high or low cerebrospinal fluid pressure, infection, tumor, etc.);
8. headache associated with the use of chemical substances or their withdrawal (nitrates, alcohol, carbon monoxide, ergotamines, analgesics, etc.);
9. headache due to extracerebral infectious diseases (viral, bacterial and other infections);
10. headache associated with metabolic disorders (hypoxia, hypercapnia, dialysis, etc.);
11. headache due to pathology of the neck, eyes, ears, nose, paranasal sinuses, teeth and other facial structures.

What to do if you have a headache?

In most cases, the anamnesis and results of an objective examination allow us to suggest a diagnosis and determine further tactics for examining the patient.

Anamnesis

Headache should be characterized by parameters that are important for diagnosis, including age of onset of headaches; frequency, duration, location, and intensity; factors that provoke, aggravate, or relieve pain; associated symptoms and diseases (eg, fever, stiff neck, nausea, vomiting, mental status changes, photophobia); and preexisting diseases and events (eg, head trauma, cancer, immunosuppression).

Episodic, recurrent, severe headache beginning in adolescence or early adulthood is likely to be primary. Intolerable (lightning) headache may indicate subarachnoid hemorrhage. Daily subacute and progressively worsening headache may be a symptom of a space-occupying lesion. Headache beginning after age 50 and accompanied by tenderness on palpation of the scalp, pain in the temporomandibular joint during chewing, and decreased vision is likely to be due to temporal arteritis.

Confusion, seizures, fever, or focal neurologic signs indicate a serious cause that requires further evaluation.

The presence of an underlying medical condition may explain the cause of headaches: for example, a recent head injury, hemophilia, alcoholism, or treatment with anticoagulants may cause a subdural hematoma.

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Clinical examination

A neurologic examination, including funduscopy, mental status assessment, and testing for meningeal signs, should be performed. Recurrent episodic headache in patients who appear healthy and have no neurologic abnormalities is rarely due to a serious cause.

Neck stiffness with flexion (but not rotation) suggests meningeal irritation due to infection or subarachnoid hemorrhage; elevated body temperature suggests infection, but a slight increase in temperature may also accompany hemorrhage. Tenderness to palpation of the vessels of the temporal region in most cases (>50%) suggests temporal arteritis. Papilledema indicates increased intracranial pressure, which may be due to malignant hypertension, neoplasm, or thrombosis of the sagittal sinus. Morphological changes (eg, tumors, strokes, abscess, hematoma) are usually accompanied by focal neurologic symptoms or changes in mental status.

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Instrumental examination

Imaging and laboratory tests are only necessary when history or examination findings raise suspicion of pathology.

Patients who require urgent CT or MRI to detect hemorrhage and other morphological changes causing headache include those with conditions such as:

• sudden onset of headache;
• changes in mental status, including seizures;
• focal neurological symptoms;
• optic disc edema;
• severe arterial hypertension.

Since conventional CT cannot completely exclude conditions such as subarachnoid hemorrhage, meningitis, encephalitis or inflammatory processes, a lumbar puncture is indicated if these diseases are suspected.

Immediate, but not urgent, CT or MRI is indicated if headache has changed from its usual pattern, headache is new onset after age 50, systemic symptoms (eg, weight loss), secondary risk factors (eg, cancer, HIV, head trauma), or chronic unexplained headaches are present. For these patients, MRI with gadolinium and magnetic resonance angiography or venography is preferred; MRI can visualize many important potential causes of headache that are not visible on CT (eg, carotid dissection, cerebral venous thrombosis, pituitary apoplexy, vascular malformations, cerebral vasculitis, Arnold-Chiari syndrome).

Severe persistent headache is an indication for lumbar puncture to exclude chronic meningitis (eg, infectious, granulomatous, tumor).

Other diagnostic methods are used according to the complaints and clinical picture to confirm or exclude specific causes (eg, determination of ESR to exclude temporal arteritis, measurement of intraocular pressure if glaucoma is suspected, dental X-rays if a dental pulp abscess is suspected).