Epilepsy: Focal Flashcards
Definition
The recurrent tendency to spontaneous intermittent, abnormal electrical activity in part of the brain, manifesting in seizures
Seizure definition
Paroxysmal alteration of neurological function as a result of excessive, hypersynchronous discharge of neurons within the brain.
Reversible causes of seizures and features (VITAMIN DE)
Vascular
Infection
Trauma
Autoimmune - SLE
Metabolic
- hypoglycaemia,
- hyponatraemia,
- hypoxia
-alcohol withdrawal,
Idiopathic - EPILEPSY
Neoplasms
Dementia + Drugs (cocaine)
Eclampsia + everything else
- typically longer with closed eyes and mouth
- don’t occur during sleep and don’t involve incontinence or tongue biting
- pre-ictal anxiety symptoms in non-epileptic = they know what is about to happen
Epidemiology
< 20 or > 60
Inherited Risk factors
Premature birth
Brain development malformation
Genetic condition:
- Cerebral palsy: up to 30% have epilepsy
- Tuberous sclerosis
- Neurofibromatosis
- Metabolic disorders: e.g. lysosomal storage disorders
- Mitochondrial diseases: e.g. MELAS
Family history
Arterio-venous malformation
Acquired Risk Factors - think bad things that can happen to brain
Febrile convulsions as a child: particularly if complex
Traumatic brain injury
Neurodegenerative disease
Ischaemic stroke
Brain tumour
Intracerebral infection: meningitis, encephalitis, abscess
Illicit drug use: cocaine
Mixed Risk Factors
Dementia
Aetiology (STATIC)
Strokes
Tumour/space-occupying lesions
Alzheimer’s
Tremors from Alcohol withdrawal (Delirium tremors)
Idiopathic (MC)
Cortical scarring e.g. trauma, cerebrovascular disease, infection
Pathophysiology
The disrupted neurological function causing a seizure is the result of an imbalance between excitation and inhibition within the neurons of the brain.
Normal balance between GABA - and glutamate + shifts towards glutamate = more excitatory
Components of a seizure
PRODROME
- Precedes the seizures usually by hours/days
- Weird feeling e.g. mood/behaviour changes
AURA:
- Part of the seizure where the patient is aware + often precedes other manifestations
ICTAL:
- Length of seizure
- Appearance: jerking suggests tonic-clonic, behavioural arrest suggests absence
- Progression: e.g. jacksonian march - a phenomenon in which a seizure spreads from the distal part of the limb towards the face
- Consciousness
- Injury: tongue biting, head injury
- Urinary incontinence
POST-ICTAL:
- The period after a seizure
- Headache, confusion, myalgia, sore tongue (often bitten)
- Temporary weakness after focal seizure in motor cortex = post-ictal Todd’s palsy
Temporal lobe Signs
Oral automatism: lip smacking, chewing, swallowing
Manual automatisms: picking, fumbling
Automatic behaviour: running, walking
Auras (80%) : déjà vu, feeling of fear, unpleasant smells,
Auditory: buzzing, ringing, vertigo
Frontal lobe signs
Predominantly motor symptoms: pelvic thrusting, bicycling, tonic posturing
Jacksonian march = march up/down motor homunculus
Post-Ictal Todd’s palsy = starts distally in a limb and works its way upwards to the face
Sexual automatisms
Bizarre behaviour
Vocalisations
Parietal lobe signs
Parasthesias
Visual hallucinations
Visual illusions
More subjective and difficult to diagnose than other areas
Occipital lobe signs
Visual hallucinations
Transient blindness
Rapid and forced blinking
Movement of head or eyes to the opposite side
Epilepsy sensitive signs
Tongue biting
Head turning
Muscle pain
LOC- Post ictal symptoms
Cyanosis
Triggers which lower threshold for having a seizure
Non-adherence with anti-epileptic drugs (AEDs)
Fatigue
Stress
Alcohol or recreational drugs
Flashing lights
Hypoglycaemia
Febrile illness
Medication: CYP450 inhibitors/inducers, e.g. ciprofloxacin (CYP1A2 inhibitor) can lower seizure threshold
Difference between simple and and complex partial seizures
Simple:
- No affect on consciousness or memory
- Awareness unimpaired but will have focal motor, sensory, autonomic, or psychic symptoms depending on the affected lobe
Complex:
- Memory awareness is affected during or immediately after the seizure = affects speech, memory, and emotion
- Post-ictal confusion is common if temporal lobe affected, by swift recovery if frontal lobe affected
What are partial seizures with secondary generalisation
2/3 patients with partial seizures will develop generalised seizures, usually generalised tonic clonic
These start focally and spread widely throughout the cortex
Diagnostic criteria
At least 2 unprovoked seizures occurring more than 24 hours apart
One unprovoked seizure and probability of future seizures (considered >60% risk in 10 years
Diagnosis of an epileptic syndrome
- eyes open
- synchronised movements
- can occur in sleep
Diagnosis
Must have 2+ seizures more than 24 hours apart
CT head + MRI (examine HIPPOCAMPUS, check bloods, tumours)
EEG = 3Hz wave in absence
Bloods = rule out metabolic causes
Treatment
FIRST LINE = LAMOTRIGINE or CARBEMAZEPINE
SECOND LINE = SODIUM VALPORATE
Complications
Status epilepticus = epileptic seizures WITHOUT A BREAK BACK TO BACK or seizures lasting 5< minutes (LONG TIME)
Treatment = Benzodiazepines, Lorazepam 4mg, if not worked, lorazepam AGAIN then pentynyl
Conservative management
Education: triggers to avoid, safety measures
Stop driving: all patients must inform the DVLA
First unprovoked seizure without structural abnormality or epileptiform activity on EEG: 6-month suspension
First unprovoked seizure with a structural abnormality or epileptiform activity on EEG: 12-month suspension
Established epilepsy: can apply for a license if seizure-free for 12-months or 5 years if an HGV driver
