Neuro Flashcards
Discuss diagnositc criteria for febrile siezures
1) Convulsion associated with an elevated temperauter greater than 38 degrees
2) a child older than 6 months and younger than 5 years
3) absence of CN infection or inflammation
4) Absence of acute systemic metabolic abnormality that my produce convulsions
5) no history of previous afebrile seizures
Discuss simple and complex febrile seizures
Simple
- generalised tonic clonic seizure
- duration of less than 15 minutes
- complete recovery within 1 hour
- do not recur within the same febrile illness
Complex
- focal features at onset or during the seizure
- duration greater than 15 minutes
- incomplete recovery within 1 hour
- recurrence within the same febrile illness
Recurrence rate depends on the age of the child; the younger the child at the time of the initial seizure, the greater the risk of a further febrile seizure (1 year old 50%; 2 years old 30%
Discuss criteria for discharge for febrile seizures
- Returned to a normal neurological state following a simple febrile seizure
- serious bacterial infection excluded or adequetly treated
- underlying illness managed appropriately
- patients aware of first aid advise and management of possible subsequent seizures
Discuss DDX of altered mental state in children
Vascular events
- stroke
- AVM with bleed
Infection
- menigitis
- sepsis
- encephalitis
Trauma
Tox
Anatomic or structrual
-Mass or tumor
Metabolic derangements
GIT
-Intusseception
Seizures
AEIOU TIPS A- ammonia, alcohol, atypical migraine, abuse E: electrolyte, epilepsy, encephalitis I: insulin (hypo), intussusception, inborn erros of metbaolism O- oxygen (hypoxia), opiates, overdose U- uremia T- trauma, tumor I: infection P: poisoning, psych S: seziure, sepsis, subarach
Discuss IX of altered mental state in children
Bedside: BGL and ECG
Bloods: FBC, LFT, U&E , VBG
Advanced imaging based on the presence of focal neurology and history and exam
Special consideration should be made regarding the need for more invasive diagnostic procedures such as lumbar puncture
In infants under 3 months the difficulties in assessing this population often necessitates are more thorough investigation. including urine and CSF sampling
Discuss caustive pathogens by age group for meningitis
Newborns: GBS, EColi, listeria monocytogens
Infants and children: Strep pneumo, N meningitidis, H influaenzae
Adolescents and young adults: N menigitidis, s. pneumo
Discuss Empiric AB by age
0-28 days -> Amp 50mg/kg TDS + Gentamycin 5mg/kg + Cefotaxime 50mg/kg TDS
28days - 3months: Amp or vanc + cefotaxime or ceftriazxone
> 3months: ceftriaxone + vanc
Aciclovir 10mg/kg or 500mg/m2
Define seizure (provoked vs non provoked) + define epilepsy
A paroxysmal event characterized by temporary involuntary changes in the patient cuased by abnormal and excessive activity of a group of cortical neurons.
They can be classified as unprovoked or provoked. Provoked have a clear identifiable trigger such as fever, metabolic derangement and trauma
Unprovoked seizures have no clear precedent
Epilepsy is commonly defined as the occurrence of two or more unprovoked seizures
Discuss DDX of seizures in children
Fever
- viral infection, menigitis, encephalitis, brain abcess
Trauma
- Cerebral contusion, haemorrhage, impact seizure (if occuring within 1 hour of impact does not signify significant underlying injury or risk of developing epilepsy)
Tox
-Drug intoxication or withdrawal
metabolic
-hypoglycaemia, hyponatraemia, hypernatraemia, hypomagnesemia, hypophosphatemia, hepatic or renal disorders, inborn errors of metabolism
Neoplastic
Vascular
- AVM
- Sub arach, cerebral venous thrombosis
Neurocutaneous
-neurofibromatosis, tuberous sclerosis, sturge weber syndrom
neurodegen
- hypoxia
- VP shunt malfunction
- CP
- derebral dysgenesis
- primary epilepsy
Discuss episodic disorders that may mimic siezure activity
- Breath holding spells
- rigors
- GORD
- migraine
- sleep disorders
- ALTE
- Panic attack
- Psychogenic seizures
Discuss breath holding spells
Common in chlidren aged 6months to 6 years
occur when the child is frightened or distressed - minor accident or fright or when scolded
Most will have first episode of breath holding before 18 months and will grow out of them by the time they are six years old
Two main types
Blue spells ( cyanotic) - the child will
-cry and scream
-breathe out forecefully
-hold there breath and develop central cyanosis
-may become floppy and hav eLOC
Pale spells
- Open mouth as if to cry but no sound comes out
- faint and look very pale
- have period where thier arms and legs become stiff or lose contgrol of thiere bladder and bowel
Define BRUE
Brief resolved unexplained event
Occurs in an infant less than 12 months
-duration >1 minute usually 20-30 seconds
- sudden onset accompanied by a return to a baseline state
-Characterized by >1 of the following
–Cyanosis or pallor
– Absent or decreased or irregular breathing
–marked change in tone
–Aletered level of conciousness
Discuss risk stratification for BRUE
Low risk occurs when there are no concerning features on history or exam and all of the following are met
- > 60 days
- born >32 weeks of gestation and corrected gestation age >45 weeks
- no CPR
- First event
- event lasted < 1 minute
Discuss IX and disposition
Low risk BRUE does not require any investigation and can be safely discharged home with safety netting
If not low risk should be admitted for observation
- ECG
- NPA for viruses and pertusis
- BGL
- FBC and UEC if clinically indicated
Discuss management of seizure in childrenq
A: at risk of apnoea and hypoventialtion if siezure continue so prep for intubation and assistance
B: supllemental o2 should be applied aiming spo2 >94%
C: catious fluid due to risk of ICP
D: Treat hypoglycaemia with 2ml/kg of 10% dex
E: Treat hyponatraemia with 3ml/kg of 3% hypertnoic aiming to increase sodium by 3-7 mmol/l acutely and the rest slowly
Hypernatraemia is treated over 48 horus
Hypocalcaemia treated with 10% calcium gluconate 100mg/kg
Tox as per toxin – isoniazid is particualry resistant to standard anticonvulsants and should be treated with pyridoxine 1G IV for every gram of isoniazid
Discuss Treatment of status
Initial drug of choice is benzos
-Midaz 0.2 mg/kg IM, IN, buccal, 0.15mg/kg IV, can give 2 doses
After 2 doses of benzo risk of respiratory depression increases and second line should be given
Can use Levetiracetam, valproate or phenytoin as second line agent - ESETT and ConSEPT trials found all three to be equally efficacy and nil statistically signifaicnt increase in adverse effects for any of them
Levetiracetam at 40mg/kg as second line
In patient with ongoing siezures despite second line threapy preparation for continous infusions of midaz,prop or phenobarb should be readied – will need intubatuion
Use a different second line if patient already on antiepileptics and compliant
Non convulsive epilepsy is treated as above but more difficult to recognize and may need EEG for diagnosis
Discuss common causes of neonatal seizure
Hypoxic ischaemic encephalopathy CNS infection Intracranial haemorrhage Trauma (accidental and non accidental) Cerebral infarction Chromosomal or congenital brain abnormalities inborn errors of metabolism or other metabolic derangements Drugs intox or withdrawals
Discuss IX of neonatal siezures
BGL FBC U&E Metabolic testing VBG Ammonia
Because clinical assessment of rmeningitis is not reliable in young infants, lumbar punction should be performed and fluid sent for Cell, protein and glucose determinations, MCS + herpes simplex PCR
Advanced imaging should also be performed CT or MRI
In the unstable neonate a head ultrasound can be performed
Discuss management of neonatal seixzures
ABCD
Empirical antibiotics amp + gent + cefotaxime as well as acyclovir 20mg/kg TDS if herpes encephalitis is a clinical consern
Phenobarbital is the most common first line agent for neonatal seizures loading of 20mg/kg with additional 5mg/kg every 15-30 minutes to a max of 30mg/kg - can use benzo as first line particularly if there is to be a delay for phenobarb
NEOLEV2 trial showed superioty of phenobar to levirtarcetam as first line – if phenobarb failed seconda line agents are particularly poor and infants will likely progress to intubation - can use phenytoin, keprra or valproate
If refractory to all treatment pyridoxine 100mg IV should be considered
Discuss disposition for children with seizures ( non infant)
Most can be safely discharged home after appropriate invesitgation of first unprovoked seizure
2/3rds of children with a first unprovoked siezure never experience a recurrence - the risk of recurrence is increased with abnormalities in neuroimaging or EEG, family history of epilepsy, remote symptomatic seizure, first seizure occuring during sleep or Todds paralyis - if none of thees the 5 year recurrence i 21%
As such anticonvulsants are generally not started unless there are 2 unprovoked seizure
Discuss Red flags for headach presentation in children
Sudden onset severe Occurrence with straining or exertion associated with neurological symptoms change in normal headache pattern nocturnal awakening bilaterall occipital headaches
Discuss DDX of secondary headaches
Trauma
- Intracranial bleed
- concussion
- skull fracture
Structural
- neoplasm
- AVM
- Congenital malformation
- hydrocephalus
Systemic
- HTN
- Metabolic (Diabetes and ketoacidosis)
Infection -meningitis abcsess -encephalitis -sinusitis -influenza -pyelo -GAS
Toxic
- medications
- ingestion
Discuss Acute headaches
Common problem in children and adolescents and accompanies many infectious processes
In the absence of other signs of CNS involvement (nuchal rigidity, alteration in LOC, focal neurolgocial finding) headaches in febrile children usually do not constitute evidence of infection.
Although far less common AVM can be a trigger for a new severe headache - intracranail AVM are structually unstable and prone to rupture - in children with acute sudden onset headache in the absence of trauma ICH should be considered
Other DDX for acute headache include
- Opthalmogic conditions
- sinusitis
- dentition
- ottits media
Briefly discuss acute weakness in children
Challenging presentation
in the preverbal child only symptoms may be regression in motor milestones
Ataxia can be the predominate feature
Trauma can present as weakness and NAI needs to be considered in appropriate circumstanes
INsepction should be mad for bites and ticks, rashes (enteroviral rashes are usually scattered macular papular but may be petechial or hand foot and mouth) investigation for signs of NAI should be made
Describe Gowers sign
Sign indicative of proximal muscle weakness
child is lain on his or her back and asked to stand
positive sign is seen when the child does not sit up but rolls over onto her front gets up on all fours and then climbs to his or her legs using her hands
List predictors of the necessacity for ICU level care with acute weakness
Bulbar pulsy -(lower motor lesion of CN 9,10,12)
- absent gag reflex
- toungue wasted and fasciculates
- palatal movememtn absent
- jaw jerk absent
Vital capacity <20 ml/kg >30% reduction in vital capacity flaccid quadriparesis rapidly progressive weakness autonomic CVS instability
Describe GBS
Acute polyradiculopathy. Group of diseases with two main pathological mechanisms
- demyelination and axonal degeneration
- Primarily lower MND affecting the myelin sheath with variable damage to axones.
- It is a immune mediated reaction usually to a recent infection.
- Common infection include (campylobacter, mycoplasma, EBV, coxsacki, influenzae, echovirus and CMV)
Discuss clinical features of GBS
Usually present with weakness, falls regression of motor milsetones or ataxia.
Also commonly complain of muscle pain.
CN involvment in 50% of cases with 7th nerve being most common
Miller Fisher variant presents with oculomotor palsies, ataxia and areflexia.
Classic history is one of a generalised viral respiratory or GIT illness in the preceding 2 weeks. Parasethesia may be initial symptom followed by ascending and symmetrical weakness.
-papilloedema is rare but can occur in GBS
-paralysis of resp muscles is common and must be monitored for
Sympathetic nervous systme involvement can produce perfuse sweating, hypertension and disturbances of pshincter function.
Weakness may evolve rapidly wihtin hours but usually takes 1-2 weeks to reach max, then in the 2nd -4th week recovery is apparent with most having fully recovered in 2 months,
Painful ++ in children as compared to adults
Discuss DDX of GBS
Tick paralysis snake envenomation spinal cord lesions periodic paralysis infant botulism poisoning (lead, organophosphate) Vasculitis Myosisits Polio
Discuss IX of GBS
Isolated protein in CSF is the classical finding
Nerve conduction studies characteristically show increased latency and conduction block.
Discuss management of GBS
ABCD A: indications for intubation for GBS should be actively sort to avoid resp arrest and include -Vital capacity <20ml/kg -Max inspiratory pressure <30 cm h2o -max expiratory pressure <40cm h2o -tidal volume <5ml -A sustained incrase of PCo2 -A increased resp rate -increasing oxygen requirement -An increased use of accessory muscles and paraxocial diaphragm movement these reflex restrictive lung chest wall movement and low lung volumes.
Less emergent treatment include IVIG, plasma exchange
Discuss infant botulism
Caused by release of the botulinum toxin into the bloodstream from clostridium botulinum bacteria.
Part of the toxin enters the terminal bouton of chjolinregic motor nerves and enzymatically disables the mechanisms by which ACH containing vesciles attach to the cell membrane.
Risk factors include exposure to honey in the first 6 months should not be exposed in the first year of life
Diagnosis is characterised
- age group almost always less than 6 monhts
- nature of onset: infants always start wtih bulbar pasies because that is where the blood supply is greatest; this is a descending paralysis
- fatigability but lack of reversibility with edrophonium or neostigimine
- absence of fever
- absence of an altered mental status
- absence of sensory defects
- noraml CSF
Treatment is by supportive care and administartion of butulinum antitoxin. ABS are not recommended unless there is underlying secondary infection.
If ABS are used aminoglycosides should be avoided as they can make paralysis worse
Can also get botulism at a later date from consuption of food in which there is preformed toxin and from wound botulism (very rare)
Discuss spinal cord lesions causing acute weakness in children
Transverse myelitis
- Aetiology is uncertain, hypothesis include microbial antigen cross reaction with neural elements, bacterial superantigen inflammation and direct microbial invasion.
- Usually hsa a rapid onset of predominantly lower limb weakness and altered sensation. Neck stiffness and fever are present early in most cases along with low back pain.
- the sensory level is usually around the mid thoracic region below which pain light touch and temperature sensations are impaired.
- Bladder and bowel disturbance is common
- Tone is usually flaccid early in the illness with decreased reflexes
- 60% of cases will achieve full recovery
- MRI is IX of choice
- Treatment complciated
SPinal cord space occupying lesions
CNS Tumors
AVM
- usually occur in the thoracic region
- may cause symptoms via compression or stealing circulation from the nearby cord
- history is usually subacute unless a haemorrahge or ischaemia has intervened
Epidura abscess
- rare in children
- usual presentation is with back pain and rigidity, fever leucocytosis and a raised ESR
- THese may be followed by spinal neurological signs
- MRI is the investigation of choice
Describe the basic hardware of CSF shunt
Proximal tube which take CSF from the lateral ventricle through brain tissue and a small burr hole to the outer surface of the skull
At or near this point there is usually a silicone reservoir dome that can be used for sampling and/or pumping.
Then there is a subcutaneous one way valve that is set to open at a certain pressure differential in order to avoid overshunting
The distal tubing is tunneled under the skin to the drainage site which is usually the peritoneal cavity
Discuss complications associated with VP shunts
Infection Malfunction -blocked proximal catheter -blocked distal catheter -loculation of lateral ventricle -vavle dysfunction -overshunting/slit ventricle syndrome -disconnection Abdominal pesudocyst migration of distal catheter invasion of abdominal organs
List signs and symptoms that on their own warrant immediate referral to neurosurgical services
Buldging fontanelle Decreased LOC FLuid tracking around shunt tubinh Signs of local infection (usually <6 months post operative) -erythema of site -erosion or ulceration -CSF leak -purulent drainage Meingismus Peritonitis
Discus signs and symptoms that may warrant refferal to neuro
Abdominal pain Fever Nausea/vomiting irritability headache abnormal shunt pump test Accelerated head growth
Describe shunt evaluation
Hardware should if possible be palpated and inspected for signs of infection
Compressibility of the bulb should be test
- incompressibility suggest distal obstruction (less common)
- compressibility but nil refilling suggest proximal
- Should avoid multiple test
Discuss IX of VP shunt
On rare occasions needle insertion into the shunt pumping chamber is diagnostic and therapeutic- normally performed by neurosurg – May need to be done in ED for rapid deterioation in remote regions after discussion with neurosurg.
In the moribund child insertion of a 23 gauge buttfly needle at 45 degress can releive raised ICP.
Shunt series - XR of the entire shunt may demonstrate a disconnection or kinking causing blockage, Small positive studies and did not result in subsequent surgical intervention. Some ED do not do routinely
CT - preferred method of imaging.
DIscuss presentation complaints for shunt infection and ABs of choice for same
Shunt malfunction 33%
fever 26%
Localised wound or shut tract inflammation 22%
abdominal pain or pseudocyts 19%
Staph epididymis is the most common causative agent and antibiotics regime should include fluclox + gram -ve cover
Discuss briefly toxic neuopathies
Anticholinesterases
- organophosphates and carbamates
- inhibit cholinesterases allowing ach to persistently stimulate the nicotinic and muscarinic receptors which then can become refractory and thus cause weakness.
- the weakness is usually accompanied by the cholinergic toxidrome and indeed it usually the respiratory and cardiac features that predominate.
Lead
-Lead mercury and arsenic are all known to cause neuropathies often taking the form of mononeuritis multiplex.
Chemo
-Vincristine, vinblastine and cisplastin are known to cause a peripheral neuropathy.
Discuss breifly muscular disorders causing weakenss.
Infectious myositis
- Viral infections such as influenza can cause a myositis that may may in its severest form lead to rhabdo
- children may stop walking due to associated pain
- weakness is only found on close examination
Juvenile dermatomyositis
- systemic vasculitis though to be triggered by infection
- enteroviruses and GAS
- peak incidence is 6 years of age
- The child may present with rash before weakness has become apparent.
- the rash appears on sun-exposed areas especially malar region of the face and a purple discolouration of the eyelids
- weakness come on about 2 months after the rahs and is usually very slow onset.
- proximal muscles reveal weakness first.
- the vasculopathy can affect any muscle group and children may present with aspiration dysphagia or hoarse voice.
- Diagnosis is made on clinical picture associated with a raised CK. There are typical changes on biopsy and electromyogram
Metabolic/endocrine myopathies
- Most endocrinopathies can produce weakness by several mechanisms
- often this is just myalgia and fatigue but true myopathies can develop.
- weakness usually responds to treatment of the underlying endocrine disorder
Periodic paralysis
- Series of genetic ion channel disorders that leat to acute episodes of weakness lasting from 1 hour up to more than a day
- they often come on after rest during sleep or immediately following exercise but never during
- Diagnosis is made by mearsurement of electrolytes during an attack, response to metabolic challenge or by gene mutation identification.
Discuss DDX of Ataxia in children
Post viral - acute cerebellar ataxia
Poisoning/drug intoxication
Tumours
- -posterior fossa, brainstem
- -paraneoplastic syndrome
Trauma including NAI
- Haematoma
- post concussion
Metabolic
- hypoglycaemia
- hyponatraemia
- hyperammonaemia
- inborn errors of metabolism
Infections
- Meningitis - bacterial viral
- Cerebral abcess
- malaria
- labyrinthitis
- encephalitis
Vascular
- stroke
- vasculitis
Immune
- MS
- ADEM
Discuss Acute cerebellar ataxia
Most common diagnosis of acute ataxia in children particularly between the ages of 2-7 years of age.
It is a diagnosis of exclusion after consideration of more sinister causes such as tumours.
An autoimmune aetiology is likley with autoantibodies demonstrated in acute cerebellar ataxia folowing infection with varicella, EBV, mycoplasma and huan parvovirus.
Discuss clinical features of acute cerebellar ataxia
Usually present with sudden onset of severe gait ataxia though a small number of cases have an insidious onset
Most have dysarthric speech.
Mild horizontal nystagmus occurs in 50% of cases
Clinical findings of
-intention tremor
-dysdiadochokinesis, hypoptonia and decreased or pendular reflexes are seen in 2/3rds
Truncal ataxia is uncommon
-unlike MS or ADEM there are no focal neurological signs
Usually beings to improve within a few days but full recovery may take from 10 days to 2 months. Patients with slower recovery are still likley to fully recover
Discuss IX of acute cerebella ataxia
Aimed at excluding an alternative diagnosis as there is no specific dianostic test for acute cerebellar ataxia
CT scan is usually normal
MRI may be abnormal
LP - slight elevation of CSF cell count by4-50 slight elevation in protein
Discuss Toxic causes of ataxia
Anticonvulsants
- phenytoin
- carbamazepine
Alcohols
- Ethanol
- ethylene glycol
- isopropanol
Essential oils
-eucalyptus oil
Illicit substances
- PCP
- LSD
Discuss tumor as a cause of ataxia in children
Cerebella lesions may present with an acute rather than insidious onset of ataxia as a result of either haemorrhage into a tumour or as a result of hydrocephalus.
Paraneoplastic syndrome may also present as ataxia
Posterior fossa tumors including medulloblastoma, astrocytoma and ependymomom are common cases of ataxia from brain tumours.
Brainstem gliomas
Clinical features suggestive of a brain tumor include
- headache
- vomiting
- behavioural changes
- papilloedema
- CN dysfunction
Discuss other neurological conditions presenting with ataxia
1) GBS in which areflexia and opthalamoplegia (in Miller-Fisher) distinguish it from acute cerebella ataxia
2) MS/transverse myelitis - not usually seen until adolescent years - present with ataxia, optic or retinal neuritis, regional paraesthesia or weakness
3) ADEM
4) seizures
5) complex migraines
Describe ADEM
Post-infectious encephalomyelitis is a demyelinating disease of the CNS that typically presents as a monophasic disorder associated with multifocal neurological symptoms
Encephalopathy is a required diagnositc features and usually develops rapidly in asscoaited with multifocal neuroglocail deficits including
- acute hemiparesis
- cerebella ataxia
- CN neuropathies including optic neuritis and myelopathy
Severe phase of ADEM lasts from 2-4 weeks
Most children with ADEM have mean length of Hospital stay of 13-27 days
Briefly discuss common causes of chronic ataxia
CP
HEREDITARY ATAXIAS
1) Firedreichs ataxia - an autosomal recessive condition which manifest in a child less than 10 years of age with atxai and nystagmus
Usually rapid progression
2)Ataxia telangiectasia is also autosomal recessive with neurocutaneous manifestations - ataxia is predominantly truncal and becomes evident in early childhood. Occular and cutaneous telangiectasia become evident between 2-6 yeas of age
CONGENITAL MALFORMATIONS
1) cerebella aplasia/hypoplasoa
2) Dandy-Walker malforamtion
3) Arnold-Chiari malformation or vemral palsia
Discuss pertinent history and exam finding in the ataxic child
HX
- timing of ataxia
- acute, recurrent or chornic
- what is mainly affected - trunk vs limbs
- other sumptoms such as headache blurred vision altered mental status
- antecedent history such as viral illness
- other symptoms such as parasethesia - ADEM
EXAM
- Cerebella signs
- GAIT
