Anaphylactic shock

Common triggers

• Foods: peanuts, tree nuts, shellfish, milk, egg
• Medicines: antibiotics, NSAIDs, anesthetic agents
• Insect stings
• Latex
• Occasionally, no trigger is identified

Clinical features

• Skin/mucosa: generalized hives, flushing, itch, lip/tongue swelling
• Airway: throat tightness, hoarse voice, stridor, swelling of tongue or larynx
• Breathing: wheeze, shortness of breath, persistent cough, cyanosis
• Circulation: dizziness, collapse, confusion, weak pulse, hypotension
• GI: severe crampy abdominal pain, vomiting, diarrhea

Immediate emergency management

1. Call emergency services immediately.
2. Remove or stop the suspected trigger if this can be done quickly, for example stop an IV drug infusion or remove an insect stinger.
3. Give intramuscular adrenaline (epinephrine) without delay into the mid-outer thigh. It is the first-line treatment.
   • In adults and children aged over 12 years, current Resuscitation Council UK guidance uses 500 micrograms IM of 1 mg/mL adrenaline.
   • Repeat after 5 minutes if airway, breathing, or circulatory problems persist.
   • If an auto-injector is available, use it promptly according to its labeled dose and call emergency services.
4. Position the person flat, with legs raised if possible. Do not allow them to stand or walk. If vomiting or unconscious but breathing, place them on their side. If breathing is severely difficult, they may sit with legs extended.
5. Give high-flow oxygen, establish IV/IO access, monitor ECG, oxygen saturation, and blood pressure.
6. Rapid IV isotonic crystalloid fluids are needed for shock/hypotension.
7. If persistent symptoms after two IM doses, obtain senior critical-care support. Refractory shock may require a carefully titrated IV adrenaline infusion by experienced clinicians. People on beta-blockers with refractory hypotension may require glucagon.

What should not delay adrenaline

• Antihistamines can help itch or hives but do not treat shock or airway obstruction.
• Corticosteroids act slowly and do not replace adrenaline.
• Nebulized bronchodilators may help persistent wheeze but are only adjuncts.
• There are no absolute contraindications to IM adrenaline when anaphylaxis is suspected.

Observation and prevention

• Two epinephrine auto-injectors where indicated
• Training and a written emergency action plan
• Trigger avoidance advice
• Allergy/immunology referral to identify the cause and reduce recurrence risk

Seizures

Seizure first aid

1. Stay calm and time it from the beginning.
2. Protect them from injury: move hard or sharp objects away and cushion their head.
3. Do not restrain their movements.
4. Do not put anything in their mouth. They cannot swallow their tongue, and putting objects or fingers in the mouth can cause injury.
5. Do not give food, water, or medicines by mouth until fully awake.
6. When jerking stops, turn them onto their side in the recovery position if possible, and loosen tight clothing around the neck.
7. Stay with them, reassure them as they recover, and note what happened: duration, type of movements, breathing, injury, and recovery time.

Call emergency services immediately if

• The seizure lasts 5 minutes or longer
• Another seizure starts before they fully regain consciousness
• It is their first known seizure
• They have breathing difficulty, remain unresponsive, or do not recover as usual
• They are injured, pregnant, have diabetes, or the seizure occurred in water
• You are concerned for any reason

Status epilepticus

After a seizure

Neurological seizures

Main seizure types

Examples of clinical manifestations

• Focal aware seizure: unusual smell, rising abdominal sensation, tingling, déjà vu, visual phenomena, or rhythmic twitching of one body part, with awareness retained.
• Focal impaired-awareness seizure: behavioral arrest, staring, lip-smacking, picking movements, confusion, and reduced responsiveness.
• Focal to bilateral tonic-clonic seizure: focal symptoms followed by loss of consciousness, body stiffening, then rhythmic limb jerking.
• Generalized tonic-clonic seizure: sudden loss of consciousness, tonic stiffening, then clonic jerking, often followed by confusion and sleepiness.
• Absence seizure: brief staring and impaired responsiveness, usually with rapid recovery and no post-seizure confusion.
• Myoclonic seizure: brief shock-like muscle jerks.
• Atonic seizure: sudden loss of muscle tone, sometimes causing a fall.

Causes

• Acute symptomatic (provoked): fever, low glucose or sodium, alcohol withdrawal, intoxication, infection, stroke, head injury, or medication effects.
• Unprovoked: may reflect epilepsy, an underlying structural brain lesion, genetic predisposition, or an unknown cause.

Assessment after a first seizure

• Witness description or video, including onset and recovery
• Neurologic examination
• Blood glucose and targeted blood tests
• ECG when syncope is possible
• Brain imaging when clinically indicated
• EEG, which can support a diagnosis of epilepsy and help classify seizure type

Emergency: status epilepticus

Seek urgent help now if

• Lasts 5 minutes or longer
• Repeats without full recovery
• Is the person’s first seizure
• Occurs in water, pregnancy, or diabetes
• Causes significant injury or breathing difficulty
• Is followed by persistent unconsciousness or a new focal neurologic deficit

1. Definition and basic concepts
   • Seizure versus epilepsy
   • Provoked versus unprovoked seizure
   • Ictal, postictal, and interictal states
2. Etiology
   • Genetic epilepsy
   • Structural causes: stroke, tumor, trauma, cortical malformations
   • Infectious and inflammatory causes
   • Metabolic and toxic causes: hypoglycemia, hyponatremia, alcohol withdrawal, drugs
   • Unknown cause
3. Pathogenesis
   • Neuronal hyperexcitability and hypersynchronous firing
   • Imbalance between excitation, mainly glutamate, and inhibition, mainly GABA
   • Initiation, spread, and termination of seizure activity
4. Classification
   • Focal seizures
   • Generalized seizures
   • Unknown-onset and unclassified seizures
   • Motor and nonmotor features
   • Focal-to-bilateral tonic-clonic seizures
5. Clinical features and phases
   • Aura, ictal manifestations, postictal confusion
   • Features by cortical lobe: temporal, frontal, parietal, occipital
   • Generalized tonic-clonic, absence, myoclonic, atonic, tonic, and clonic seizures
6. Diagnosis
   • Clinical history and witness account
   • EEG
   • MRI/CT when indicated
   • Metabolic tests and differential diagnosis, including syncope and psychogenic nonepileptic seizures
7. Management
   • First aid during an acute seizure
   • Status epilepticus management
   • Long-term antiseizure medication selected according to seizure type and patient factors
   • Drug-resistant epilepsy: surgery, neuromodulation, dietary therapy
8. Complications and prognosis
   • Injury, aspiration, status epilepticus, SUDEP
   • Social and safety issues: driving, water safety, pregnancy, medication adherence

Treatment of neurological seizures and epilepsy

1. Immediate treatment of an ongoing seizure
2. Emergency treatment of status epilepticus
3. Long-term prevention of recurrent seizures

1. Management of an acute seizure

First aid

• Protect the person from injury and time the seizure.
• Move dangerous objects away and cushion the head.
• Do not restrain movements.
• Do not place anything in the mouth or give oral fluids/medicines.
• After convulsions end, position on the side, check breathing, and observe recovery.
• Check blood glucose promptly when feasible.
• Treat reversible causes: hypoglycemia, hypoxia, electrolyte disorder, infection, alcohol/drug withdrawal, stroke, trauma, or missed antiseizure medication.

When to call emergency services

• Lasts 5 minutes or more
• Repeats without full return to consciousness
• Is the first seizure
• Causes injury, occurs in water, or is accompanied by persistent breathing difficulty
• Occurs in pregnancy, diabetes, or is different from the person’s usual seizure pattern

2. Status epilepticus

Initial approach: 0 to 5 minutes

• Airway positioning, suction if required, oxygen, monitoring
• IV or intraosseous access
• Check capillary glucose immediately
• If glucose is low: IV glucose, with thiamine first or alongside in people at risk of malnutrition/alcohol dependence
• Send blood for electrolytes, calcium, magnesium, renal/liver function, blood count, toxicology as appropriate, and antiseizure drug concentrations where relevant
• Look for and treat the precipitating cause

First-line: benzodiazepine

• IV lorazepam, if IV access is available, or
• IM midazolam, buccal/intranasal midazolam, or rectal diazepam if IV access is not available.

Second-line: longer-acting IV antiseizure medicine

• Levetiracetam
• Fosphenytoin/phenytoin
• Sodium valproate

• Avoid or use major caution with phenytoin/fosphenytoin in significant cardiac conduction disease or arrhythmia.
• Avoid valproate in severe liver disease, mitochondrial disease, and where pregnancy-related risks are relevant.
• Levetiracetam has relatively few drug interactions and is often convenient, but dose adjustment may be needed with renal impairment.

Refractory status epilepticus

• Airway protection and ventilation where necessary
• Continuous EEG where possible
• Anesthetic infusions such as midazolam, propofol, or barbiturate under critical-care supervision
• Intensive investigation for infection, autoimmune encephalitis, stroke, toxic/metabolic causes, or missed structural lesions

3. Long-term treatment of epilepsy

General principles

• Confirm the seizure type and epilepsy syndrome before choosing a drug.
• Monotherapy is preferred initially: start low and titrate gradually.
• If the first appropriate medicine fails because of adverse effects or lack of seizure control, use an alternative appropriate monotherapy.
• If two suitable, adequately tried antiseizure medicines fail, refer to a specialist epilepsy service for drug-resistant epilepsy assessment.
• Do not stop antiseizure medication suddenly, as abrupt withdrawal can precipitate seizures or status epilepticus.

A. Focal-onset seizures

• Lamotrigine
• Levetiracetam

• Carbamazepine
• Oxcarbazepine
• Lacosamide
• Zonisamide
• Topiramate
• Brivaracetam
• Perampanel

• Lamotrigine: risk of rash, including rare severe cutaneous reactions. Titrate slowly.
• Levetiracetam: irritability, agitation, low mood, behavioral changes.
• Carbamazepine/oxcarbazepine: hyponatremia, rash, drug interactions; carbamazepine can aggravate some generalized seizures.
• Topiramate: cognitive slowing, weight loss, renal stones, metabolic acidosis; important pregnancy-related risk considerations.

B. Generalized tonic-clonic seizures

• Sodium valproate
• Lamotrigine
• Levetiracetam

C. Absence seizures

• Ethosuximide: preferred when absence seizures occur alone
• Valproate: useful if absence seizures coexist with generalized tonic-clonic or myoclonic seizures
• Lamotrigine: alternative option

D. Myoclonic seizures and juvenile myoclonic epilepsy

• Valproate, if appropriate
• Levetiracetam
• Lamotrigine
• Topiramate

E. Atonic, tonic, and Lennox-Gastaut syndrome seizures

• Valproate
• Lamotrigine
• Clobazam
• Rufinamide
• Topiramate
• Cannabidiol in selected syndromes and settings
• Ketogenic dietary therapy
• Vagus-nerve stimulation or corpus callosotomy in selected drug-resistant cases

4. Drug-resistant epilepsy

• Video-EEG monitoring
• High-resolution epilepsy-protocol MRI
• Neuropsychological assessment
• Surgical evaluation
• Genetic or autoimmune evaluation where indicated

Non-drug options

• Epilepsy surgery: potentially curative for an identifiable, resectable seizure focus, especially temporal lobe epilepsy.
• Vagus nerve stimulation
• Responsive neurostimulation
• Deep brain stimulation
• Ketogenic or modified Atkins diet, particularly useful in selected children and some adults.

5. Treat the cause

• Hypoglycemia
• Hyponatremia or hypocalcemia
• Alcohol withdrawal
• CNS infection
• Medication toxicity
• Acute stroke or head injury

6. Lifestyle, safety, and follow-up

• Take medication consistently and avoid abrupt withdrawal.
• Identify triggers: sleep deprivation, alcohol excess, missed doses, recreational drugs, and illness.
• Discuss driving restrictions according to local law.
• Prefer showers over unsupervised baths; avoid swimming alone, heights, open flames, and hazardous machinery if seizures are uncontrolled.
• Discuss contraception, pre-pregnancy planning, and folic acid with a neurologist before conception.
• Provide a seizure action plan and educate family/caregivers on rescue medication where prescribed.