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Neurological Problems
Dr Gillian Small
Consultant Paediatrician
Neurological Problems
• Congenital anomalies
• Cerebral Palsy
• Seizures
• Meningitis/encephalitis
• Encephalopathy
• Neurodegenerative Disorders
• Neuromuscular Disorders
Cerebral palsy
• Disorder of posture and movement due to non progressive damage of developing brain.
• First described 150 years ago
• Prevalence 2-3 per 1000 live births
• Slight increase in recent years due to increase in survival of sick preterms
Aetiology
Preterm babies
Perinatal cause in 90% of these
• Periventricular leukomalacia
• Intraventricular haemorrhage
Prenatal cause in 10%
• Brain malformation
Aetiology
Term babiesIn 75% cause is prenatal• Genetic• Cerebral malformation eg migration defect• Intrauterine infection eg CMV, rubella, toxo• Maternal – placental illness15% perinatal eg birth asphyxia10% postnatal eg meningitis, head injury, cardiac
arrest
Neurophysiology
Approx 40% of children with CP are preterm
Damage to extrapyramidal system causes dyskinetic CP (basal ganglia) or
ataxic CP (cerebellum)
Spastic CP results primarily from damage to
pyramidal system (motor cortex/ internal capsule)
Neurophysiology
Damage to pyramidal system causes• Loss of selective voluntary control• Dependence on primitive patterns of
mobility• Abnormal muscle tone & weakness• Agonist/antagonist imbalance – causes
fixed joint positions & contractures• Preserved primitive reflexes
Classification of CP
• Diplegia (44%)
• Quadriplegia (7%)
• Hemiplegia (34%)
• Dyskinetic (9%)
• Ataxic (6%)
Associated Problems
• Vision
• Hearing
• Epilepsy
• Feeding
• Constipation
Diagnosis
Made on follow up of at risk infants from neonatal unit in about half of cases
Parental concern
Routine surveillance
Acquired from later severe illness in first year
Diagnosis
• History
Obstetric, perinatal history
Lethargic, irritable
Feeding problems, poor weight gain
Diagnosis
• Examination
To identify motor delay/abnormality
Take gestational age into account for first 2yrs
• General
Dysmorphism, head growth, length, wt gain
DIAGNOSIS
• Tone
Hypotonia, hypertonia• Movements• Primitive reflexes
Normally Grasp gone by 4 months, Moro by 6 months
• Abnormal posture/positioning
Persistent thumb adduction, fisting, head lag
Diagnosis
• Asymmetry
If persistent, indicates hemiplegia
• Trunk control
• General developmental delay
Investigations
• MRI
• Chromosomes
• Rubella/toxo/CMV titres
• TFTs, creatine kinase
• Urine metabolic screen
Management
• Multidisciplinary team approach
Physios
Speech and language therapy
Occupational therapy
Preschool support
Dieticians
Doctors
Febrile Fits
• Fits precipitated by fever not due to intracranial infection or other CNS cause and are not preceded by afebrile fits
• Common: 2 – 5% of children under 5 yrs
Aetiology
• Genetic factors important
• Strong family history – 17-31% in first degree relatives
• Polygenic mode of transmission
• Fever usually high > 38.5 C
• Fits usually occur early in course of fever
• Perinatal factors do not play a role
Clinical Features
• Usually between 6 months and 6 years of age
• Onset before 6 months suggestive of meningitis
• Fits usually brief, bilateral, tonic clonic • Complicated febrile fits – if last more than
15 mins, if focal, those followed by Todds paresis. Higher risk of later epilepsy
Clinical Features
• Fits lasting > 30mins – Status epilepticus
• May leave sequelae if untreated eg association with hippocampal sclerosis and consequent mesial temporal epilepsy
• EEGs poorly correlate with later occurrence of epilepsy
Clinical Features
• Differential diagnosis – meningitis
encephalitis
• Consider LP in infants, especially < 6 mnths
• Herpes encephalitis may present in infants with febrile partial seizures
Prognosis
• Favourable• 60 – 70% have only 1 fit• Only 9% have more than 3 episodes• Risk of recurrence greater if family history, aged
under 1 year, had 2 or more episodes, had complex febrile fits.
• Partial epilepsy more common after long lasting focal fits
• Neurodevelopmental outcome usually excellent
Treatment
• Treat underlying illness
• Cooling measures advised but no evidence that antipyretics prevent fits
• Treat prolonged fits
• Regular anticonvulsants are not advised
Prognosis
• Risk of developing afebrile fits – 2-5% (background risk 1%)
• Risk low in simple seizures, increases with younger age, neurological/developmental abnormality, family history of epilepsy, complex febrile fits
EPILEPSY
Definition of epileptic seizure
Paroxysmal discharge of cerebral neurones sufficient to cause a clinically definable event apparent to the observer or subject
Diagnosis
• RequireEye witness accountBackground historyGeneral and neuro examination
• Causes of misdiagnosisLack of eye witnessPresence of clonic jerks/incontinencePositive family history Over interpretation of EEG
Predisposing Factors
• Genetic• Developmental brain abnormalities• Acquired structural abnormalities
- Perinatal insults
- Intracranial infections/trauma
- Prolonged febrile fits
- Cerebral haemorrhage or infarct
- Tumours or AVMs
Recurrence
• Recurrence after first seizure quoted between 71 – 82%
• Chances of remission
81% 15yrs later (Goodridge and Shorvon)
82% achieve 2 year remission after 8 years
(Elwes 1984)
Differential Diagnosis
• Syncope and related disorders
vasovagal episodes
reflex anoxic seizures blue or pallid
long QT
• Behavioural/ psychiatric disorders• Neurological disorders• Sleep related phenomenon
Types of seizure
• Focal (simple or complex)
• GeneralisedAbsenceMyoclonicAtonicTonicTonic clonicSpasms
Absence seizures
• Sudden cessation of activity with blank facial expression & eyelid flickering
• Uncommon < 5yrs• More common in girls• Rarely longer than 30 seconds• No postictal drowsiness• Precipitated by hyperventilation• EEG – 3/second spike and wave• Treat with sodium valproate or ethosuximide
Infantile Spasms
• 3 – 12 months• Aetiology
Cryptogenic (20%) normal development & CTPrenatal–Tuberous sclerosis, cong infectionPerinatal-hypoxia, birth injuryPostnatal-meningitis, encephalitis,trauma
Infantile spasms
• Flexor spasms – of neck, arms & legs on to trunk
• Extensor spasms – extension of trunk and extremities & are least common
• Mixed
• Very brief, occur in clusters, may be preceded by a cry, occur when drowsy or awakening
Infantile spasms
• EEG most commonly associated shows hypsarrythmia
• Treat with vigabatrin or steroids
• Associated with developmental delay
Floppy infant
• Marked hypotonia, lies in frog position, head lag
• CAUSES
Exclude systemic cause eg infection, hypothyroidism, inborn error of metabolism, congenital lax ligaments
Floppy Infant - Causes
• Central
Encephalopathy
Chromosomal abnormalities eg Down’s, Prader Willi
Ataxic CP
Floppy Infant - Causes
• PeripheralSpinal cord; transection, compression .Ant. horn cell; Werdnig Hoffman (acute spinal
muscular atrophy), A.R., lack of fetal movements, floppy at birth, muscle fasciculation esp of tongue. Diagnosed on EMG, muscle biopsy. Death before 18 months from resp failure.Milder forms exist.
Floppy infant - Causes
• Peripheral Nerve
Guillain Barre neuritis
• Neuromuscular Junction
Myasthenia gravis. Transient in baby of myasthenic mother, or persistent
Floppy infant - Causes
• MuscleCongenital myopathyMyotonic dystrophy; A.D., involves face and neck
muscles producing myopathic face, ptosis, open/fish like mouth. Myotonia – difficulty in relaxing grasp. Also cardiac involvement and cataracts.
Many die in newborn period, those surviving show some recovery.
Floppy infant - Causes
Metabolic myopathyGlycogen storage disease type II (Pompe Disease)Muscular Dystrophy; Duchenne MD X linked
recessive. Rarely symptoms in early infancy. Late walkers, hypertrophied calves, onset of weakness aged 2 yrs, Gower’s sign.
Elevated creatine kinaseGenetic counselling, prenatal diagnosisDeath in late adolescence, early adult life