Headache

General Principles

o Headache is a common symptom arising from psychological, otological, ophthalmological, neurological or systemic disease. In clinical practice tension-type headache is encountered most frequently

Definition :

o Pain-sensitive structure are :

- Venous sinuses

- Cortical veins

- Basal arteries

- Dura of anterior

- Middle and posterior fossae

Diagnostic Approach

History :

o Most information is derived from determining :

- The first attack or previous attacks

- Whether onset is acute or gradual (days or weeks)

- Whether attacks have recurred for many years (chronic)

- Site of headache

- Accompanying symptoms

- Precipitating factors

Diagnostic Approach

Headache in children

o All causes of adult headache (except in retrobulbar neuritis, glaucoma, temporal arteritis and cervical spondylosis) may cause headache in children.

o In this age group, the commonest type of headache is that accompanying any febrile illness or infection of the nasal passages or sinuses

o The clinician must not take a complaint of headache lightly; the younger the child, the more likely the presence of an underlying organic disease.

o Pyrexia may not only represent a mild ‘constitutional’ upset, but may result from meningitis, encephalitis or cerebral abscess

o The presence of neck stiffness and/or impaired conscious level indicates the need for urgent investigation

o Although intracranial tumours are uncommon in childhood, when they occur they tend to lie in the midline (e.g. medulloblastoma, pineal region tumours)

o As a result, obstructive hydrocephalus often develops acutely with headache as a prominent initial symptom

In a child with ‘unexplained’ headache, CT scan should be performed :

o If the presentation is acute

o If the severity progressively increases

o If school performance declines, or other symptoms, e.g. personality change, develop

o If the head circumference increase

o If the child is under 5 years

Specific Causes

o The aura of migraine may take amny forms. The visual forms comprise: flashing lights, zigzags (fortifications), scintillating scotoma (central vision) and may precede visual field defects. Such auras are of visual (occipital) cortex origin

o The headache is recurrent, lasting from 2 to 48 hours and rarely occurring more frequently than twice weekly. In migraine equivallent the aura occurs without ensuing headache

Mechanism :

o Mutations in mitochondrial DNA and CA2+ channel genes may explain familial cases.

o Vascular and neuronal processes probably co-exist with changes in serotonin acitivity initiating attacks

Specific types of migraine with aura :

Basilar :

o Characterised by bilateral visual symptoms, unsteadiness, dysarthria, vertigo, limb paraesthesia, even tetraparesis

o Loss of consciousness may ensue and precede the onset of headache. This form of migraine affects young women

Hemiplegic :

o Characterised by an aura of unilateral paralysis (hemiplegia) which unusually persist for some days after the headache has settled

o Often misdiagnosed as a ‘stroke’. When familial, mendelian dominant inheritance is noted. Recovery is the rule

Ophthalmoplegic :

o Characterised by extraocular nerve palsies, usually the 3rd, rarely the 6th. These may result from dilatation of the internal carotid artery with streatching of the III or VI cranial nerve within the cavernous sinus

o Rarely migraine can present as episodic come –MIGRAINE COMA

Retinal :

o Unilateral (monocular) visual loss which is reversible and followed by headache

o Ophthalmological examination between episodes is normal

Precipitating factors in migraine :

o Dietary : alcohol, chocolate and cheese (contain tyramine)

o Hormonal : often premenstrual or related to oral contraceptive (fluctuations in oestrogen)

o Stress, physical fatigue, exercise, sleep deprivation and minor head trauma

Diagnosis :

Clinicla history with -

o Occasional positive family history

o Travel sickness or migraine variants (abdominal pains ) in childhood

o Onset in childhood, adolescence, early adult life or menopause

o Distinguish –

o Partial (focal) epilepsy (in hemiplegic or hemisensory migraine)

o Aneurysm compressing III cranial nerve, (in ophthalmoplegic migraine)

o Transient ischaemic attack (in hemiplegic or hemisensory migraine)

o Arteriovenous malformation – gives well localised but chronic headache)

o Hypoglycaemia

Management :

(i) Identification and avoidance of precipitating factory

(ii) Prophylaxis :use only for frequent and severe attacks

Pizotifen (5HT2 receptor blocker) – use with caution in view of side effects, e.g. retroperitoneal fibrosisi

In resistant cases, use calcium antagonists, antidepressants and anticonvulsants, e.g. Topiramate

(iii) Treatment of an acute attack :

Simple analge (e.g. aspirin) with metoclopramide to enhance reduced absorption during an attack

Sumatriptan (a selective 5HT1 agonist) and other triptans e.g. Naratriptan, Rizatriptan and Zolmitriptan – effectively reverse dilatation in extracranial vessels. Given orally or subcutaneously

Ergotamine – widespread action on 5HT receptors reversing dilatation. Give orally or by inmhalation, injection or by suppository

Methylprednisolone i.m. or i.v. will halt the attack when prolonged (status migrainosus)

Treatment :

o Urgent treatment, prednisolone 60 mg daily, prevents visual loss or brain-stem stroke, as well as relieving the headache. If complications have already occurred e.g. blindness, give parenteral high dose steroids

o Monitoring the ESR allows gradual reduction in steroid dosage over several weeks to a maintenance level, e.g. 5 mg daily.

o Most patients eventually come off steroids; 25% require long-term treatment and if so, complications commonly occur

Low Pressure Headache :

o (Spontaneous intracranial hypotension/post lumbar puncture headache) Due to obvious or occult CSF leak. Headache is posturally dependent (worse when erect and eased by lying flat)

o MRI shows downward displacement of midline structures e.g. cerebellar tonsils, meningela enhancement with contrast (Gd) and an elevated CSF protein

o Spontaneous improvement is usual, occasionally a dural ‘blood patch’ at the site of CSF leak (post LP or epidural anaesthesia) is necessary

Meningism

Local Causes :

Sinuses :

o Well localised. Worse in morning. Affected by posture, e.g. bending

o X-ray – sinus opacified

o Treatment – decongestants or drainage

Non-neurological causes of Headache

Occular :

o Refraction errors may result in ‘muscle contraction’ headaches

o Resolves when corrected with glasses

o Glaucoma does not produce headache without other symptoms, e.g. misting of vision, ‘haloes’. Cupping seen on fundoscopy

Dental disease :

o Discomfort localised to teeth. Check for malocclusion

o Check temporomandibular joints

Systemic Causes :

o Headache may accompany any febrile illness or may be the presenting feature of accelerated hypertension or metabolic disease, e.g. hypoglycaemia, hypercalcaemia

Many drugs produce headache –

o Through vasocilation e.g. bronchodilators, antihistamines

o On withdrawal e.g. amphetamines, benzodiazepines, caffeine