Neurology - 1 Flashcards
What are risk factors for cerebral palsy?
Maternal illness during pregnancy: DM Infection - rubella, herpes, CMV, toxoplasmosis Fever Hypothyroidism Seizures Proteinuria
Rh or ABO incompability
Exposure to toxins such as methyl mercury in thermometers. Drugs, alcohol, tobacco.
Birth RF: pre-term (before 37weeks), low birth weight
Multiple pregnancy
Respiratory distress syndrome at birth or heart problems
In infancy: Kernicterus Postnatal meningitis, encephalitis NAI Symptomatic hypoglycaemia Hyperbilirubinaemia
Trauma either during labour or after is one of the commonest causes
What are the types of cerebral palsy?
Spastic cerebral palsy
Dyskinetic cerebral palsy
Ataxic (hypotonic) cerebral palsy
Which factors may be indicative of cerebral palsy in the neonatal period?
There is usually abnormal tone, delayed development. Feeding difficulties (oromotor incoordination, slow feeding, gagging, vomiting).
Abnormal gait once able to walk
Asymmetrical hand function before 12 months
What are the characteristics of spastic cerebral palsy?
Damage to UMN (corticospinal and pyramidal tract)
Persistently increased limb tone (spasticity) which is velocity dependent (may be neonatally present)
Brisk deep tendon reflexes
Extensor plantar response
3 types:
Hemiplegia
Quadriplegia
Diplegia
Describe Hemiplegic spastic cerebral palsy
unilateral involvement of arm and leg (NOT face)
Arm > leg
At 4-12 months:
Fisting of the affected hand, flexed arm, pronated forearm.
Asymmetrical reaching/function
Then, toe-heel gait
May initially have lower tone, but then becomes hypertonic.
Sometimes caused by neonatal stroke
Describe quadriplegic spastic cerebral palsy
All limbs affected, often severely.
Extensor posturing (opisothonus) Poor head control
Often: seizures, microcephaly, >moderate intellectual impairment
Possible history of perinatal hypoxic-ischaemic encephalopathy
Describe diplegic spastic CP
All 4 limbs affected, but legs much more than hands (almost normal - noticed with functional hand use)
Walk abnormal
associated with preterm birth due to periventricular brain damage
What are the characteristics of Dyskinetic CP?
Involuntary, uncontrolled movements. Muscle tone variable. Primitive motor reflexes pre-dominate.
Chorea - irregular, sudden, brief, non-repetitive movements
Dystonia - simultaneous contraction of agonist and antagonist muscles of the trunk and proximal muscles, giving a twitching appearance
Athetosis - slow writhing movements distally (eg. fanning of fingers)
Often unaffected mentally.
poor motor development in infancy
floppiness in infancy
involuntary movements after 1st year of life
Caused by kernicterus and hypoxic-ischaemic encephalopathy at term (most common)
What are the characteristics of ataxic (hypotonic CP)?
Most are genetic and thus symmetric. Sometimes acquired brain injury, and thus ipsilateral.
Early trunk and limb hypotonia.
Poor balance.
Delayed motor development.
Later, incoordinate movement.
Intention tremor.
Ataxic gait
MDT involvement in CP
Primary therapist does 90% of the therapy
Paediatrician
Health visitor
Social worker
Physio (movement and coordination)
Orthotis (specialized in the use of devices to correct deformities)
OT - skills and abilities
Teacher specialized in visual impairment
Orthopaedic surgeon
Neurologist
What are important parts of long-term management of posture and movement in CP
Posture and movement:
Improve symmetry, joint ranges, muscle length and power
-stretching exercises
-Orthoses: ankle foot
Wheelchair for mobility
Sleeping and standing systems
Botox to gastrocnemius
Surgery is last resort
Factors in long-term management of CP
Posture and movement
Communication (speech therapy and aids)
Independece with a tailored education program
Cognition and learning support
General medical: watch for seizures, constipation and behavioral/psychiatric disturbance
Aim of physio in CP
Encourage movement and improve capability (eg. walking aid or orthotics)
Build of strength and prevent weakening of unused muscles
Prevent muscles shortening and losing their normal range of movement (contracture)
Which medications are used in CP
Diazepam (short term for muscle pain/stiffness)
Baclofen (long-term for muscle pain and stiffness) - pump which is implanted under skin and connected to spinal cord
Botox - targets specific muscles that are stiff - lasts 3-6 months
Dyskinetic CP medications (trihexyphenidyl, Gabapentin, Clonidine)
Orthopaedic surgery in CP
Soft tissue - tendon release or muscle lengthening
Bone surgery - eg. hip dislocation
Generalized seizure characteristics
Always loss of consciousness
No warning
Symmetrical seizure
Bilaterally synchronous seizure discharge on EEG
What are absent seizures
Transient loss of consciousness
Abrupt onset and termination
No motor phenomena, apart from some flickering of the eyelids
What are myoclonic seizures
Brief, often repetitive jerking movements of the limbs, neck or trunk
Tonic seizures
Generalised increase in tone
Describe tonic-clonic seizures
Rhythmical contraction of muscle groups, following the tonic phase
In tonic (rigid) - child falls to the ground. Breathing stops - cyanosis.
Clonic. Jerking of limbs. Irregular breathing. Cyanosis persists and saliva may accumulate in the mouth.
Biting of tongue.
Incontinence of urine.
Seizure usually lasts seconds-minutes. Followed by unconscious or deep sleep for several hours.
Describe atonic seizures
Often with myoclonic jerk.
Transient loss of muscle tone with a sudden fall to the floor
Describe focal seizures
Begin in one hemisphere
Aura may be present which reflects site of origin
There may or may not be a change in consciousness
Frontal - motor phenomena
Temporal - auditory or sensory phenomena
Occipital - positive or negative visual phenomena
Parietal - contralateral altered sensation (dysasthesia)
What is status epilepticus
Convulsive with tonic/clonic movements or it can be non-cpnvulsive with impairment of consciousness and often subtle twitching
Technically, a seizure lasting >30 minutes
Or repeated seizures lasting >30 minutes without recovery of consciousness
Which syndromes are associated with epilepsy?
West syndrome Lennox-Gastaut syndrome Childhood absence epilepsy Benign epilepsy Early onset benign childhood occipital epilepsy Juvenile myoclonic epilepsy
What is West syndrome
Age 4-6 months
EEG shows hypsarrhythmia (chaotic bakcground of slw wave acitivity with sharp mulfitfocal components)
Violent flexor spasms of the head, trunk and limbs followed by extension of the arms
Spasms occur for 1-2 seconds and repeat 20-30 times
What is Lennox-Gastaut syndrome
Age 1-3 years
Mostly drop attacks and atypical absences
What is childhood absence epilepsy
Age 4-12 years
EEG shows 3/second spike and wave discharge which is bilaterally syncrhonous
What is benign epilepsy
Tonic clonic seizures in sleep or simple focal seizures with awareness of abnormal feelings
EEG shows focal sharp waves
What is early onset benign childhood occipital epilepsy
Periods of unresponsiveness in young children and hallucinations/visual disturbance in older children
EEG shows occipital discharge
What is juvenile myoclonic epilepsy
Myoclonic, but generalised tonic-clonic seizures or absences may also occur
characteristic EEG
What things can be detected on EEG
Asymmetry or slowing - suggest underlying structural abnormality
Neuronal hyperexcitability - sharp waves or spike-wave complexes
However, children with epilepsy may have normal EEG and vice versa
Seizure needs to be captured with EEG - otherwise it is just supportive evidence
When is structural imaging indicated in epilepsy?
MRI
CT
If there are neurological signs between seizures
If seizures are focal
Can identify tumour, vascular lesion or area of sclerosis
When are functional scans used in epilepsy?
Detect area of abnormal metabolism suggestive of seizure foci
PET scan
SPECT
They use isotopes and ligands taken up by metabolically active cells
Both can be used between seizures to detect areas of hypometabolism in epileptogenic lesions
First line investigation for suspected epilepsy
EEG
Role of genetic studies in epilepsy
Increasing
Certain epilepsy syndromes are due to genetic deletions causing abnormalities of sodium and other ion channel - eg. SCN1A mutation in severe myoclonic epilepsy
Principles of antiepileptic drug use
Not all seizures require AED therapy and treatment should be based on seizure type, frequency and the social and education circumstances
Choose the appropriate drug for the seizure
Monotherapy at the minimum dose is desired
All AEDs have unwanted side effects that need discussing
Drug levels are not measured routinely
Children with prolonged seizures are given rescue therapy (usually rectal or buccal diazepam)
AED can usually be discontinued after 2 seizure free years
First line in tonic-clonic
Valproate
Carbamazepine
First line in Absence
valproate
Ethosuximide
First line in myoclonic
Valprote
First line in focal seizures
Carbamazepine
Valproate
Lamotrigine (most effective)
Treatments in epilepsy that are not AED
Ketogenic diet may help some children
Vagal nerve stimulation - external programmable wire or magnet
Surgery - last resort, only if localised with useful EEG and MRI findings
Side effects of valproate
Weight gain
Hair loss
Rare idiosyncratic liver failure
Side effects of carbamazepine
Rash Neutropenia Hyponatraemia Ataxia Liver enzyme induction
Side effects of lamotrigine
Rash
Side effects of Ethosuximide
Nausea and vomiting
Side effects of Gabapentin
Insomnia
What is SUDEP
Sudden unexpected death in epilepsy
Occurs in very small proportion
Cause often unknown: not due to injury, drowning or prolonged seizure causing hypoxia
In which epilepsy is SUDEP commonest and what can be done
Generalised tonic-clonic
Especially in young adults
RF:
Poor seizure control
Seizures in sleep
Try to minimize through medication and surgery
How often do febrile seizures occur? When
4% of children
Usually between 6 months and 6 years
Genetic predisposition: 10% risk if first-degree relative had febrile seizures
They usually occur in viral illness when the fever is rapidly rising
Management of febrile seizure
Safety - move any danger away
Assistance - call for help
Treatment - if >10 min, treat for status epilepticus. Afterwards, assess for source of fever.
Meningitis? consider if stiff neck, extreme lethargy post seizure, abundant vomiting or less than 12 months old
Seizure prevention - give early anti-pyretics in early febrile illness and get expert advice if seizure lasts >10 minutes
First aid advice in febrile seizure
Place in recovery position on a soft surface
Place in a safe location, away from objects that could cause injury
Stay with child
Call for help if seizure lasts >5 min
Relationship between febrile seizures and convulsions - aka prognosis
Temperature may be >39°C
Seizure usually during first days of fever
Children prone to febrile convulsions are not considered to have epilepsy (up to 98% will not develop epilepsy)
25% recurrence risk in the next 12 months
Vast majority of febrile convulsions are harmless: bad prognostic factors for subsequent epilepsy are:
lengthy seizure
recur in 24 hrs
Neurological abnormalities
Categorise febrile seizures
simple (typical): generalised tonic-clonic activity lasting <15 minutes without associated fever
Complex febriles seizure (atypical): 15% of cases - focal seizure activity, prolonged seizure (>15min) or multiple seizures within 1 day
