Makindo Medical Notes

Related Subjects: |Status Epilepticus (Epilepsy) |Coma management |Lorazepam |Phenytoin |Levetiracetam |Epilepsy - General Management |First Seizure |Epilepsy in Pregnancy |Febrile seizures

A seizure is a brief disturbance of cerebral function, lasting from seconds to a few minutes, caused by an abnormal electrical discharge. Epilepsy is the tendency to have seizures on a chronic, recurrent basis, not resulting from a temporary condition.

About

• Always ask about driving and give appropriate advice with a first fit
• Focal seizures can suggest focal pathology and need imaging.
• Generalised seizures less likely to be a focal lesion.

Incidence

• Epilepsy affects around 456,000 people in the UK.
• This means that about 1 in 130 people has epilepsy

Aetiology

• Idiopathic, Genetic
• Physical: post-stroke, head injury brain abscess, head trauma, arteriovenous malformation, tumour , sarcoid, vasculitis
• Metabolic: hyponatraemia, hypocalcaemia, hypoglycaemia, drug overdose e.g. TCAs
• Infection: Encephalitis, meningitis, brain abscess

Clinical

• Acute onset over seconds. May become instantly generalised with fall to the floor with a suddenly increased tone which may cause tongue biting or incontinence or a yell followed by jerking. This is the typical generalised tonic-clonic seizure.
• Partial/focal seizure may start out with focal paraesthesia in a limb, jerking movements "positive phenomena". Temporal lobe originating seizures may start with auditory hallucinations, feelings in the pit of the stomach, lip-smacking and other automatism and deja vu feeling.
• Full survey top to toe assess and record GCS check pupils - small suggests pontine haemorrhage or opiates, large - cocaine. Look for head injury and other trauma. Look for evidence of drug abuse or Infection, check fundi, skin for petechiae
• Focal seizures can be generalised with a loss of consciousness or amnesia to the event.
• A witness report is invaluable when the diagnosis is unclear. If an attack is unwitnessed it becomes more difficult. Useful comments to consider that favour seizure as the diagnosis is (1) Unconsciousness for more than five minutes (2)Amnesia for more than five minutes (3) Injury (4) Motor jerking lasting for more than 30 seconds (5) Tongue biting - usually, the lateral edge is not diagnostic but very suspicious (6) Urinary Incontinence can be seen with syncope (7) Remains conscious but with confusing behaviour (8) Headache post-attack

Differential - not all that jerks is a seizure

• Vasovagal syncope: There is a famous video of hyperventilating German medical student video on youtube who induce syncope and have "jerks"
• Pseudoseizures : Often in those with seizures. Usually when someone is around.
• Arrhythmias: Many cases of syncope with jerks diagnosed as seizures which are found to be syncope to heart block. Can be v difficult to diagnose unless monitoring captures it. Needs reveal device.
• Hypoglycaemia
• Rigors : causes generalised shaking.

Clinical classification

• Partial : Simple partial e.g. jerking of fingers from motor seizure, Complex partial. All may be followed by secondary generalisation.
• Generalised : Absence (petit mal), Tonic-clonic (grand mal), Myoclonic seizures, Atonic seizures, Tonic seizures

Semiology of seizures

Management of an acute seizure

• If the patient is fitting on the street protect the head, move objects away, allow the fit to finish and place the patient in the recovery position always assessing and reassessing ABC. If a known epileptic the patient can often sleep off seizure at home. Often the patient will be brought to A&E and can go home when awake with advice not to drive and outpatient follows up and imaging if a new fit. There is no need to give any IV benzodiazepines or AEDs unless the seizures persist for more than 5 or 10 minutes. If available give oxygen and consider a cannula and fluids. Get an accurate past medical history and just check no signs of other pathology e.g. head injury. If the patient does not recover within hours and there are concerns of intracranial pathology or the history suggests this is more than a normal seizure then CT scan head and consider LP if indicated. If fits continue see [Status epilepticus]
• Absence seizures (Petit Mal) - Sodium Valproate*, Ethosuximide
• Myoclonic seizures - Sodium Valproate*, Clonazepam, Clobazam
• Temporal lobe epilepsy - Medical therapy, Consider surgery

Lifestyle Issues

• Before discharge lifestyle advice on alcohol and drug usage as well as just ensuring a healthy lifestyle is important. Especially if alcohol or tiredness or drug abuse has precipitated the seizure.
• Patient should be advised to avoid cycling in traffic, prefer a shower to baths
• Avoid locking doors so that help can be summoned
• Not to swim or bathe unsupervised.
• It is important to advise not to drive for one year if the first fit and that they must inform the DVLA and Car Insurance and you should document it.
• A fit whilst driving will primarily injure the driver, passengers and whomever they hit.

Specific issues

• SUDEP (SUDEP = Sudden unexplained deaths in Epilepsy). Seen in 0.1-1% of patients. Results in about 500 deaths per year in the UK. Commoner in those with more uncontrolled epilepsy, especially if nocturnal and compliance/treatment issues. It is a sensitive subject that needs careful handling when discussing with patients and their families
• Contraception and epilepsy Fertile sexually active women need to take particular care with contraceptive usage when on enzyme-inducing AEDs e.g. carbamazepine, phenytoin and topiramate. For instance, higher dose oestrogen pills may be needed or IUCD
• Pregnancy and epilepsy Most pregnancies in those with epilepsy are entirely normal but it is wise to follow the above advice regarding folate and choices of AEDs. Even in those not on drugs, there is a 2-3% risk of malformation which is just slightly higher than those without epilepsy. Phenobarbital, phenytoin and carbamazepine raise that to 4-5%. Valproate should be avoided. Increased risks are seen with polypharmacy and high doses. Newer drugs such as lamotrigine may be safer. None are completely safe. Take expert advice. Also, give Vitamin K post-delivery as a concern over the haemorrhagic disease of the newborn. Only 5% of the children of those with epilepsy will go on to have epilepsy too. Folate should be taken by anyone planning pregnancy and through pregnancy and reduces the incidence of birth defects.

Special cases

• Idiopathic Generalised epilepsies: This is primary generalised epilepsy. Usually have a genetic basis with a low threshold for fits. There is no macroscopic abnormality. JME discussed below is a subtype. There is often a family history. People with IGE have normal intelligence, normal neurological examination and normal MRIs. Seizures may be myoclonic (very brief isolated body jerks that tend to occur in the morning), absence (brief staring unresponsive spells often with eye fluttering lasting seconds) and generalized tonic-clonic seizures and may have more than one type. EEG often normal or may show various combinations of generalized spike-wave complexes, spikes, or polyspikes, sometimes triggered by flashing lights. Usually, respond well to medication and patients can grow out of their epilepsy later in life except for JME. IGE patients do best on Valproate and do not do well on phenytoin or carbamazepine. The alternative is lamotrigine and some of the newer agents.
• Juvenile Myoclonic epilepsy (JME) Commoner in the morning - easily remembered as one neurologist called it "cornflake epilepsy" as patients can be imagined having jerky movements whilst eating breakfast or dropping the soap in the shower. Patients may have different types of fits and as well as myoclonic epilepsy patients have generalised tonic-clonic seizures and absence seizures. EEG shows a very characteristic pattern called generalized polyspikes, often with generalized 3 Hz spike-wave complexes. Appears in adolescence that why it's called Juvenile and can be brought on by sleep deprivation, stress, alcohol. Drug treatment is Valproate or lamotrigine. Avoid drugs such as Phenytoin, gabapentin, carbamazepine, or phenobarbital as can help some patients but worsen others. There is a high rate of recurrence on any attempts to stop AED's. Patients diagnosed with JME usually need to remain on AEDs for life due to the high rate of recurrence
• Mesial temporal lobe epilepsy syndrome: Presents with complex partial seizures which may respond poorly to AED's (Antiepileptic drugs). It is best diagnosed using high-resolution MRI which may show hippocampal sclerosis. Responds well to surgery which is why its diagnosis is important. Usually, the onset is in childhood. An aura is common. May be complex automatisms, memory loss, dysphasia (dominant side). Hypometabolism on PET/SPECT between fits. Neurology referral.

Introduction

• All patients with a suspected first seizure should be seen by a specialist and a plan of care made with the patient. Advice should be given on lifestyle. A decision on whether to start an AED discussed. Special attention to driving, pregnancy and contraception.

Investigations

• EEG should be performed only to support a diagnosis of epilepsy in adults in whom the clinical history suggests that the seizure is likely to be epileptic in origin.
• MRI should be used to identify structural abnormalities that cause certain epilepsies. It is particularly important in those who develop epilepsy in adulthood who have any suggestion of a focal onset on history, examination or EEG (unless clear evidence of benign focal epilepsy) and in whom seizures continue in spite of first-line medication. Neuroimaging should not be routinely requested when a diagnosis of idiopathic generalised epilepsy has been made. MRI can be done following discharge.
• Measurement of serum prolactin is not recommended for the diagnosis of epilepsy
• Blood tests e.g. plasma electrolytes, glucose, calcium to identify potential causes and/or to identify any significant co-morbidity should be considered
• A 12-lead ECG should be performed in adults with suspected epilepsy.

Drug Management

• AED therapy usually requires more than one seizure to make a diagnosis of epilepsy. AED therapy after a single seizure may be considered if the individual has a neurological deficit or the EEG shows unequivocal epileptic activity or the individual considers the risk of having a further seizure unacceptable or brain imaging shows a structural abnormality suggesting a high risk of recurrence.
• Individuals should be treated with a single antiepileptic drug (monotherapy) where possible. If unsuccessful, then monotherapy using another drug can be tried. Caution is needed during the changeover period. Combination therapy (adjunctive or 'add-on' therapy) should only be considered when attempts at monotherapy with AEDs have not resulted in seizure freedom. If trials of combination therapy do not bring about worthwhile benefits, treatment should revert to the regimen (monotherapy or combination therapy) that has proved most acceptable to the individual, in terms of providing the best balance between effectiveness in reducing seizure frequency and tolerability of side effects
• If an AED has failed because of adverse effects or continued seizures, a second drug should be started (which may be an alternative first-line or second-line drug) and built up to an adequate or maximum tolerated dose and then the first drug should be tapered off slowly
• Vagus nerve stimulation is indicated for use as adjunctive therapy in reducing the frequency of seizures in adults who are refractory to antiepileptic medication but who are not suitable for resective surgery. This includes adults whose epileptic disorder is dominated by partial seizures (with or without secondary generalisation) or generalised seizures.

Specific Drug therapy* know these as useful first line treatments

• Drug of choice to treat generalised seizures - Sodium Valproate*, Lamotrigine
• Partial seizures - Carbamazepine*, Lamotrigine, Oxcarbezepine, Sodium Valproate

Links

• Sign Guidelines on epilepsy
• NICE guidance on epilepsy