Neuro Flashcards
What is hydrocephalus
Enlargement of the cerebral ventricles due to excessive accumulation of CSF
What are the 2 types of hydrocephalus and where are the blockages
Non communicating - obstruction in ventricles / aqueduct
Communicating - arachnoid villi (where CSF absorbed)
Causes of non - communicating hydrocephalus
Brain tumour, inter ventricular haemorrhage, congenital malformation, dandy walker syndrome, Arnold - chiari malformation
Causes of communicating hydrocephalus
sub arachnoid haemorrhage, tuberculous meningitis, duct stenosis
Features of hydrocephalus
Head circumference - disproportionally large & rapid growing
Increased pressure on ant fontanelle - sutures separate, scalp veins prominent
What can increased pressure in hydrocephalus lead to if untreated ? What’s this sign called
Eyes deviate downward - setting sun sign
Features of hydrocephalus in older children
features of raised ICP
Headache, vomiting, respiratory abnormalities, pupil size / reaction, papilloedema, decerebrate (extended) / decorticate (flexed arms)
Diagnosis of hydrocephalus
Uss - if sutures still open can assess level of ventricular dilation
CT/MRI - establish diagnosis and cause
Treatment of hydrocephalus
Ventriculoperitoneal (VP) shunt
Complications of vp shunts
Obstruction, infection
What is craniosynostosis? Cause?
Premature fusion of skull sutures.
Part of syndrome in 30% - rest idiopathic
Features of craniosynostosis
Abnormal head shape - fused sutures cause over expansion of other sutures to compensate
Most common craniosynostosis and shape?
Sagittal -> long thin head
Raised ICP in craniosynostosis treated with?
Cranioectomy
Egs. Of neural tube defects
Spina bifida Meningocele Myelomeningocele Encephalocele Anencephaly
What causes spina bifida occulta ? Sign?
Vertebral arch fails to fuse
Hairy patch on skin over birth
What happens in meningocele
Meninges herniate through a vertebral defect -> outpouch
Difference between myelomeningocele and menigocele
Myelo - meninges & spinal cord herniate
Most severe form of spinal dysplasia
What is encephalocele
Extrusion of brain and meninges though a mid line skull defect
What is anencephaly
Brain and cranium fail to develop (detected an antenatal USS & TOP usually performed )
What is cerebral palsy
Disorder of motor function (movement +/- posture) due to a non-progressive static lesion of the developing brain
Why does cerebral palsy evolve with time even though the lesson is static
Manifestations evolve as CNS develops - due to CNS plasticity in young children
Does cerebral palsy just affect movement
No, often have other problems reflecting more widespread Brain damage
When is most cerebral palsy caused? Egs?
Antenatal 80% - cerebral dysgeneis, congenital infections (rubella, cmv, toxoplasmosis)
Intrapartum cause of cerebral palsy
Birth asphyxia / hypoxia -> ischemic brain injury
Post natal causes of cerebral palsy
Preterm birth - interventricular haemorrhage, hypoxic-ischemic encephalopathy, periventricular leukomalacia Hyper bilirubinaemia Hypoglycaemia Intracranial infections Head trauma
Features of CP
Delayed motor milestones
Abnormal tone and posture
Asymmetric hand function before 1 year old
Feeding difficulties (decreased oromoter coordination)
Speech and language delay
Diagnosis of cp
Examination - tone 👆/👇, power (eg. Hemiparesis), reflexes (brisk -> UMN)(prolonged primitive reflexes) abnormal movements / posture / gait
When should primitive reflexes disappear
4-6/12
Classes of cp
Spastic -70%
Ataxic - 10%
Dyskinetic 10%
Mixed 10%
Where is damage for spastic cp? Associated with?
UMN (pyramidal / corticospinal)
Brisk deep tendon reflexes & extensor plantar response
Why might hypotonia still be spastic cp
Turns spastic with age
What type of spastic cp is associated with birth asphyxia
Quadriplegic
Other types are hemi/para
What does spasticity of bulbar muscles cause
Dysphasia and dribbling
What is the clasp knife response
Increased limb tone suddenly gives way under increasing pressure (UMN)
What causes ataxic cp
Damage to cerebellumans pathways
Early / late signs of ataxic cp
Early - uncoordinated movements, trunk and limb hypotonia, delayed motor development, poor balance
Late - intention tremor and ataxic gait
What causes dyskinetic cp? Other name?
Damage to basal ganglia / Extrapyramidal pathways (eg by kernicterus)
Choreoathetoid
What is causes kernicterus
Bilirubin
Presentation of dyskinetic cp
Hypotonia & delayed motor development
Abnormal movements often don’t appear until 12 months
Abnormal movements in dyskinetic cp
Chorea - abrupt, jerky
Athetosis - slow, writhing, continuous
Dystonia - sustained abnormal posture
Intellect impairment in dyskinetic cp
Completely / relatively unimpaired
Problems associated with cp
mental retardation, opthalmic & auditory abnormalities, seizure, GOR, recurrent LRTI/pneumonia
Feeding problems / failure to thrive
Members of MDT for cp
Paediatrician, carers / parents, gp, health visitor, SALT, physio, OT
Management of cp
Motor function - physio, muscle relaxants (hypertonia), Botox injections to specific muscles
Treat associated features eg. Epilepsy, constipation, malnutrition, behavioural
Eg of muscle relaxants for cp
Diazepam, baclofen
Definition of epilepsy
A chronic disorder of the brain characterised by recurrent, unprovoked seizures
Egs of epilepsy mimics (funny turns)
Breath holding attacks
Reflex anoxic seizures
Syncope
What is a breath holding attack? Demographic?
Provoked by temper / frustration in 6/12 - 6years
Child holds breath, goes blue, then limb, then makes rapid recovery
What are triggers for reflex anoxic seizures?
Physiology?
What does it look like ? Possible ->?
Prognosis ?
Pain (usually mild head injury), fear, cold food.
Increased Vagal tone -> cardiac asystole.
Child becomes pale & falls to floor - hypoxia may cause GTC seizure.
Brief and child rapidly recovers
Usual triggers for syncope?
Prodromal Sx?
What happens?
Recovery?
Emotion / hot environment.
Nausea & dizziness
Loss of consciousness & posture
Rapid recovery
Egs of generalised seizures
Absence, myoclonic, clonic, tonic clonic, atonic
Difference between simple and complex partial seizures
Consciousness is retained in simple
Lobe in motor seizure
Frontal
Somatosensory / special sensory Sx seizure lobe?
Temporal (smells/ taste), parietal (sensations)
Usual lobe for complex partial seizure
Temporal
Usual cause of epilepsy
Idiopathic 75%
Egs of secondary causes of epilepsy
Cortical dysgenesis / malformations / tumours, neurocutaneous syndromes, downs, fragile X, inborn errors of metabolism (eg PKU), cerebral damage
Eg of neurocutaneous syndromes
Neurofibromatosis, tuberous sclerosis
Eg of causes od cerebral damage
Non accidental injury, birth asphyxia, hypoxia-ischemia following meningitis / encephalitis
Egs of generalised epilepsy syndromes
Infantile spasms (west syndrome), Lennox-gastaut syndrome, childhood absence epilepsy, juvenile myoclonic epilepsy
When are infantile spasms (west syndrome) most common? What happens in the seizures ?
4-6/12 Myoclonic seizures (salaam attacks) - violent flexion of head, trunk and limbs followed by extension of arms
What are infantile spasms often misdiagnosed as ?
Colic
Seen on EEG for infantile spasms ?
hypsarrhythmia - chaotic, large-amplitude slow waves with spikes & sharp waves
Usual cause of infantile spasms
Secondary - tuberous sclerosis / hypoxic-ischemic encephalopathy
Treatment for infantile spasms
ACTH
Vigabatrin (TS)
Important side effect of vigabatrin
Permanent visual field defects
Usual age for Lennox-gastraut syndrome?
Usual seizure and frequency ?
Other key feature?
2-6 years.
Daily seizures - nocturnal tonic most common (90%), myoclonic drop attacks next.
Slowed / arrested psycho-motor development
Usual age for childhood absence epilepsy?
What are the seizures like?
How common are the seizures ?
4-12 years (peak at 6-7).
Transient 5-15s, - unaware blank spells without loss of body tone.
Can be up to several hundred / day
How can absence seizures be induced ? What is this useful for? What’s seen ?
Hyperventilation for EEG.
*Generalised bilaterally synchronous 3Hz (3/sec) spike and wave *
Juvenile myoclonic epilepsy presentation
After a GTC seizure, often with Hx of *clumsiness in morning * (“cornflake / toothbrush epilepsy”)
What causes clumsiness in morning in juvenile myoclonic epilepsy
Brief myoclonic seizures usually after waking up
What can often progress into juvenile myoclonic epilepsy
Childhood absence epilepsy
Prognosis of Juvenile myoclonic epilepsy
Persist into adulthood - need to advise girls re pregnancy and medication
Non pharmacological Management of epilepsy
Supervision during baths , don’t lock doors, wear cycle helmets, avoid climbing rocks / trees, supervision when swimming
Pharmacological management of epilepsy ? Generalised ? Partial?
Aim for monotherapy.
G- sodium valproate
P- carbamazepine
What should be used for girls of child bearing age with generalised epilepsy
Lamotrigine
What is a febrile seizure
Seizure associated with fever in a child (6/12 - 6 years) in the absence of intracranial infection or an identifiable neurological disorder
Features of febrile seizure
Rapid increase in temp -> brief (1-2 minute) GTC seizure
What is the usual cause of fever -> febrile seizures ? What is another cause and needs to be ruled out? How?
Viral infection
Bacterial meningitis
LP
When are febrile seizures more worrying
In the presence of developmental delay
Prognosis of febrile seizures
30% will have a recurrence - more likely if first seizure before 18/12
Management of febrile seizures
Septic screen - identify source
Keep patient cool - antipyretics (paracetamol / ibuprofen), tepid sponging
What to be done in prolonged febrile seizure (>10mins)
Terminate using rectal diazepam
Which is more common , NF type 1 or 2
Type 1 (1/4000) 2 - 1/40000
Genetics of type 1
Autosomal dominant - 50% have no family Hx
Features of NF1 ? When seen?
>6 cafe-au-lait spots >5mm (before puberty
What characterises NF2 ? What does this lead to?
Bilateral acoustic neuroma -> deafness & sometimes cerebellopontine angle syndrome (CN VII palsy & Cerebellar ataxia)
Mutations for NF type 1 / 2
1- chromosome 17
2- chromosome 22
Genetics of tuberous sclerosis
Autosomal dominant - 75% new mutations
1/7000 births
Cutaneous features of TS
De-pigmented “ash leaf” shaped patches which fluoresce under woods light
Roughened patches of skin (shagreen patches) usually over lumbar spine
Facial *angiofibromas in butterfly distribution *
Neurological features of TS
West syndrome & developmental delay
Focal epilepsy
Intellectual impairment
What else is affected in TS
Multi system - heart, lungs, kidneys also
What type of syndrome is sturge - Weber syndrome
Neurocutaneous (like TS / NF)
Characteristic of sturge Weber syndrome
Unilateral facial naevus (port wine stain) in the distribution of the opthalmic division of CN V
Angiomas involving the leptomeningeal vessles in the brain (->seizures)
Haemangiomas in the spinal cord
Where are there abnormal blood vessles in sturge Weber syndrome and what do they cause?
Surface of the brain -> seizures, hemiplegia & learning difficulties.
Ocular involvement -> glaucoma
What’s seen in CT head in sturge Weber syndrome
Calcification of gyri in characteristic rail road track pattern
Egs of muscular dystrophies
Duchenne, Becker, myotonic
Genetics of duchenne? How many new mutations? Gene codes for what?
X linked recessive (1/4000), 1/3 new mutations.
Gene encodes dystrophin - sarcolemmal membrane protein
When does duchenne present? Do they ever walk ?
Sx at 2-4 years
Independent walking tends to be delayed and these children never run
Features of duchenne
pseudohypertrophy of calf muscles & proximal muscle weakness
positive Gowlers sign
Scoliosis
Dilated cardiomyopathy
Mild learning difficulties
What is Gowlers sign
3-5 years - hands used to push on legs to achieve upright posture (weakness of lower back and pelvic griddle muscles)
*Diagnosis of duchennes *
Serum creatinine kinase (10-20x increased)
Muscle biopsy and EMG
DNA analysis to identify dystrophin gene mutations (+ve in 65%)
Management of duchennes ?
Supportive
Walking prolonged using orthoses
Scoliosis helped by truncal brace
Genetic counciling for female carriers
Prognosis of duchennes
Cardiomyopathy worsens with age -> death
What is Becker muscular dystrophy ? How does it compare to duchenne
Milder than duchenne but caused by a mutation in same gene.
Onset is later (second decade) with prolonged survival
Genetics of myotonic dystrophy ? What does it affect?
Acquired autosomal dominant .
Muscle, endocrine, cardiac function, CNS & immunity
Features of myotonic dystrophy
Hypotonia
Progressive muscle wasting
Typical facial features
Myotonia
Typical facial features in myotonic dystrophy
Inverted v shaped upper lip, thin cheeks, high arched palate
What is myotonia ? When is it seen?
Seen beyond 5 years
Slow relaxation of muscle after contraction
How can you test myotonia
Ask to make tight fists then quickly open hands
Diagnosis of myotonic dystrophy
DNA -> CTG repeat
Serum Creatine kinase usually normal (unlike duchennes)
Treatment of myotonic dystrophy
Supportive
What is spinal muscular atrophy ? Genetics?
Autosomal recessive.
Degeneration of anterior horn cells -> progressive weakness & wasting of skeletal muscles
What’s seen in spinal muscular atrophy
Wasting & weakness
Hypotonia and weak tendon reflexes
Fasiculations in tongue, deltoids / biceps -> characteristic & sign of denervation
What is ataxia ? Cause?
Incoordination of movement, speech and posture.
Cerebellar / posterior sensory pathway problems
Egs of cause of Cerebellar ataxia
Acute - drugs / medications (alcohol and solvent abuse)
Post viral - usually after varicella infection
Posterior fossa lesions - medulloblastoma
Genetic / degenerative disorders - ataxic CP, freidrich ataxia, ataxia- telangiectasia
Cause of freidrichs ataxia ? How does it present ? Sensory impairment ?
Autosomal resseive mutation in frataxin gene .
worsening ataxia, distal wasting in legs, absent lower limb reflexes pes cavus & dysarthria.
Impairment of proprioception and vibrosence
What is ataxia-telangiectasia ? How does it present ?
Autosomal recessive disorder of DNA repair.
Ataxia with developmental delay. Telangiectasia develop in the conjunctiva, neck and shoulders from 4 years.
What must be ? In acute strabismus
Raised ICP
What does no red light reflex indicate ? What needs to happen ?
Cataracts / retinoblastoma . Repair to avoid ambylopia in affected eye
