Neurology Flashcards
What is epilepsy?
What are seizures and how can they be classified?
Disease characterised by the enduring predisposition to generate epileptic seizures and the neurobiological, cognitive, psychological and social consequences of the condition
Seizures are a transient occurrence of signs and symptoms resulting from abnormal excessive or asynchronous brain activity
May be focal (partial) - start in 1 part of the brain
Or may be generalised - more distributed affecting both brain hemispheres
What are the RF for epilepsy ?
- Genetic predisposition
- Trauma
- Perinatal asphyxia
- Structural CNS abnormalities
- Metabolic disorders
- Complex febrile seizures
How can epileptic seizures be categorised? [International League against Epilepsy 2017]
- Where they begin in the brain:
- Focal
- Generalised
- Unknown
- Focal to Bilateral (AKA secondary generalised - where starts focally then becomes generalised) - Level of awareness:
- Focal aware
- Focal impaired
- Awareness unknown (unwitnessed)
- Generalised (presumed to affect awareness) - Other features of the seizure (motor vs non-motor):
- IF Focal onset: MOTOR onset (jerking, twitching, stiffening) or NON-MOTOR (cognitive, emotional, sensory)
- IF Generalised onset: MOTOR (tonic/stiffenining and clonic/jerkining) or NON-MOTOR (absence, brief changes in awareness +/- automatic/repeated movements)
What are the signs and symptoms of:
- Absence/generalised non-motor seizure?
Absence/generalised non-motor:
- Brief impairment of consciousness (5-10 secs)
- Behavioural arrest or staring, interrupting normal activity
What are the signs and symptoms of a:
- Tonic-clonic seizure?
Tonic-clonic/’Grand Mal’:
- Patient falls unconscious and may have a preceding aura
- Violent muscle contractions and shaking
- Eyes may roll back, tongue biting, incontinence
- Post-ictal phenomena (confusion, drowsiness, headache, nausea)
What are the signs and symptoms of a:
- Myoclonic seizure?
- Different types (BRE, JME, PME)
Myoclonic:
- Brief, arrhythmic muscular jerking movements
- Last a few seconds, sudden jerking or twitching
Benign Rolandic Epilepsy (BRE):
- Most common childhood epilepsy affecting 3-12yo, but outgrow by puberty
- Seizures of face/upper limbs DURING SLEEP with hyper salivation and speech arrest (AKA sylvan seizures)
Juvenile myoclonic epilepsy (AKA ‘fly in cornflakes’):
- Begin around puberty (12-18yo)
- Usually involve neck, shoulders, upper arms occurring mostly AFTER WAKING up)
Progressive myoclonic epilepsy:
- Rare syndromes
- Combination of myoclonic and tonic-clonic
- Pt deteriorates over time
How would you manage a patient with epilepsy (Ix/Mx)?
note: think about AEDs + SEs/CI
[EEGs are not that useful so mainly clinical?/Mx]
- MDT based –> paediatrician, neurologist, epilepsy nurse, GP, schools
- Urgent referral to neurologist if 1st fit; whilst waiting for a referral then advise:
- -> how to recognise a seizure + what to do
- -> avoiding dangerous activities e.g. swimming
- -> video other seizures
- -> seek help if another event before referral
Treatment:
- Not all children require AEDs as weight vs risk of drug SE and severity/freq/type of seizures (i.e. BRE is not usually treated pharmacologically)
Appropriate AED choices:
Generalised:
–>TC - Valproate > Lamotrigine (or carbemapzepine/ oxcarbazepine)
–>Absence - Ethosuximide (girls) or Valproate, > lamotrigine (note: carbamazepine exacerbates absence seizures!)
–>Myoclonic - Valproate > levetiracetam, topimerate (note: lamotrigine + carbemazepine exacerbates myoclonic seizures!)
Focal seizures:
–> Carbemazepine, Lamotrigine (or consider adjuncts of valproate, topimerate or alternatives like levetirectam)
note:
- AEDs may be discontinued after 2y free of seizures
- monotherapy at lowest possible dose; can use adjuncts but try to limit dose
- ++ rescue therapy for status epilepticus >5 mins (buccal midozalam)
- monitoring only for carbamazepine
SE of drugs:
- Valproate (weight gain, hair loss, idiosyncratic liver failure)
- Carbemazepine - hyponatremia (SIADH), rash, neutropenia, drug-inducer
- Lamotrigine (severe skin rash - Steven Johnson syndrome)
What other treatments may be available for intractable epilepsies?
- Ketogenic diets
- Vagal nerve stimulation
- Surgery (if well localised structural cause)
What is Status Epilepticus?
1 epileptic seizure lasting >5 minutes OR at least 2/+ seizures within a 5 minute period without the person returning back to normal in-between OR 1 febrile seizure lasting >30 mins
How would you manage a child with status epilepticus?
A to E assessment:
Airway - high flow oxygen and don’t ever forget glucose
Circulation - if vascular access/can get quickly then IV/IO Lorazepam - if not then Buccal Midozalam (or rectal Diazepam) - in first 5 mins!
Then if not, try I/IO Lorazepam again and call for senior help
- reconfirm it is an epileptic seizure
- prepare phenytoin (IV/IO over 20 min)
- alert ICU and anaesthetist
- consider rectal paraldehyde
- if already on phenytoin, then give phenobarbitone IV/IO over 5mins
Final step - Anaesthetist must be present; rapid sequence induction of anaesthesia with thiopental
What are infantile spasms and who do they affect?
Epilepsy syndrome presenting in infancy (<1y, 3-8mo peak incidence)
- Characteristically part of West Syndrome (infantile spasms, developmental plateau and hypsarrhythmia - characteristic disordered brain activity on EEG)
- more common in males
Causes of infantile spasms?
- Any disorder causing brain damage
- Genetic syndromes
- Congenital infections
- Prenatal conditions
- HIE/Trauma
- Idiopathic
How would a child with infantile spasms present?
- Spasms: sudden, rapid, tonic contractions of trunk and limb muscles with gradual relaxation over 0.5-2 seconds
- ‘Salaam attacks’ - head goes down and arms up [looks like colic]
- Contractions last 5-10 seconds
- Can be gentle nodding of head –> powerful body movements
- Occurs in clusters; usually when WAKING or BEFORE sleeping
- Psychomotor delay
- Hypopigmented skin lesions (tuberous sclerosis)
- Growth restriction
How would you manage (Ix+Mx) a child with infantile spasms?
Ix:
- EEG - characteristic hypsarrhythmia (“random high-voltage spike and slow waves of varying amplitude, arising from multiple foci that vary over time. The background is asynchronous and generally chaotic” - BMJ)
- Others (glucose, Mg, Ca) to rule out other aetiology
Mx:
- Vigabatrin or corticosteriods
[Poor prognosis]
note: vigabatrin associated with visual field defects
What are Muscular Dystrophies and what is the most common one?
Progressive generalised diseases of muscles, often caused by defective/absent glycoproteins e.g. dystrophin in the muscle membrane.
–> Duchenne is the most common (DMD)
When does Duchennes normally present + continue and how is it inherited/acquired?
EXTRA: What is the pathophysiology of this mutation?
1:3000-6000 infants
X-linked recessive (males mainly affected) but 1/3 have denovo mutations (must check FHx!!)
- [dystrophin gene deletion means no connection of muscle fibre cytoskeleton to ECM through cell membrane and so Ca influx –> calmodulin breakdown + excess free radicals –> myofibre necrosis
Presents around 1-3yo with symptoms and diagnosed at 5; no longer walking by~10 with median LE ~35yo but on increase now
How may a child with DMD present?
Presents 1-3yo:
- Developmental delay (persistent waddling gait, some language delay)
- toe-walking
- decreased tone and power (flexors stronger > extensors therefore may also have lumbar lordosis, scoliosis also)
- Gower’s sign - need to turn prone to rise
- Pseudohypertrophy of calves due to fat+fibrous tissue replacing muscle
- Primary dilated cardiomyopathy
- Risk of aspiration pneumonia with infections also
What Ix would you do in a child with suspected DMD?/MD
- Plasma CK (creatine kinase) - elevated (~50-100x normal) due to myofibre necrosis
- genetic testing (Xp21),
- other: EMG, biopsy
How would you manage a child with DMD?
Note: no cure, just symptomatic treatment
- Physiotherapy (to clear lungs) + exercise (to reduce contractures)
- Psychological support
- Dietician for gastric feeding if indicated + VitD + Ca supplements
- Medical
- -> CPAP overnight for respiratory support (weakness of intercostal muscles may cause nocturnal hypoxia)
- -> Glucocorticoids to delay need for wheelchair
- -> Ataluren - drug that restores dystrophin synthesis and may be used if 5/+yo
- -> Cardio protective drugs e.g. carvedilol for preservation of LVEF
Surgery if needed (tendoachilles lengthening, scoliosis surgery)
What happens in Becker MD?
Same signs and symptoms as DMD but often LESS SEVERE and progresses SLOWER (also X-linked)
- learn to walk later than usual
- muscle cramps after exercise, struggle with sport at school
- as age increases, struggle with lifting objects
- can walk into their 40-50s but then need wheelchair
