Week 5 - Lecture 3 - Clinical Models Flashcards
Cerebral Palsy Pathophysiology
encephalopathy : a pathology involving the brain, general category of syndromes
encephalopathies can be divided into non progressive type (static) and progressive type (acute or slowly progressive
cerebral palsy is a non-progressive static encephalopathy
group of neuromuscular disorders (movement, muscle tone, posture)
- associated with intellectual disability, seizures and other problems
cause : event during the antenatal or postnatal periods damaging upper motor neurones (before, during, after birth up to 1 year of age)
Clinical manifestations of CP
genetic, teratogenic, and early pregnancy influences on the development of CP
- multifactorial
- not yet fully understood
most common factors in the perinatal period
- anoxia/hypoxia
- trauma
- infections
most common factors during birth
- low birth weight
- birth asphyxia
- metabolic acidosis detected in umbilical cord
the severity of the damage depends on the gestational age at the time of the injury and the type and degree of injury sustained
CP patho
CP is one of the most common crippling disorders of childhood in Australia
variable severity from mild motor dysfunction to severe disability
- limited fine motor skills
- lack of coordination and balance
- impaired cognitive function
- speech disorders
- seizure disorder
-CP is not a progressive disease
worsening of disabilities and deterioration of neural function are not expected
clinical manifestions CP #2
development of seizures are common
- especially if the triggering event/injury is related to hypoxia and excitation injury
- neonatal brain is very sensitive excitation injury
seizure disorder or epilepsy : result of impaired chemical and electrical neurologic transmission
sudden, transient alteration of brain function cause by an abrupt explosive, disorderly discharge of Cerebral neurons
- motor, sensory, autonomic or psychic signs
- convulsions with some seizures
Seizure activity in the brain
partial (focal) seizures
- begin locally in a small group of neurones
- spread to same or other hemisphere
- short lived
- simple partial seizures
- limited to originating hemisphere
- either motor or sensory
- no altered state of consciousness - complex partial seizures
- both hemispheres
- loss of consciousness
- lack of memory of the event during and after
Generalised seizures : more generalised electric transmission
- absence seizures : brief change in level of consciousness (LOC), rapid eye and mouth movements
- myoclonic : involuntary muscle movement, no change in the LOC
- tonic-clonic seizures : convulsive seizures, loss of consciousness, postictal state : fatigue, headache, muscle pain
tonic state : continuous muscle contraction
clonic state : rapid succession of alternating muscle contraction and relaxation
status epilepticus : life threatening state
- continuous tonic - clonic seizure ‘
- recovery from seizure activity is incomplete
- any seizure activity can progress into SE
- hypoxia development
Classification of CP
motor dysfunction classifications
- pyramidal : spastic - inability of muscles to relax ( 70-80%)
-extrapyramidal non spastic - athetoid or dyskinetic - inability to control muscle movement (20-25%)
extrapyramidal non spastic : ataxic - inability to control balance and coordination (5%)
anatomic classifications
- hemiplegia : involving one arm and one leg on the same side of the body
- diplegia : involving both legs
- quadriplegia : involving all four extremities, the trunk and neck muscles
Diagnostic criteria CP
defining specific event/time that result in CP is often difficult
no blood or diagnostic test can definitively diagnose CP
Diagnosis of exclusion
- Hx
- PE
- neuro
- motor skills
-reflexes
- presence of abnormal movements /reflexes
- developmental milestones
- reaching for toy, 3-4 months
- sitting 6-7 months
- walking 10-14 months
children are often 18 months old before diagnosis can be made
CP treatment
no known cure
supportive treatment for signs and symptoms
1. pharmacologic
- control seizures
- reduce muscle spasms
2. assistive devices
- enhance ability to complete activities of daily living
-physical, occupational, emotional, speech therapy
brain injury is static
chemical picture may change with growth and development
effective treatment requires ongoing assessment, evaluation and revision of treatment
MS pathophysiology
MS is a demyelinating disorder (damage to myelin nerve sheet) which occurs in the CNS
chronic inflammatory disease and is a progressive disease: ultimately leads to permanent disability after 20 years of onset
characterised by CNS demyelination : destruction of previously normal myelin of axons in CNS
- scarring, formation of plaque, loss of axons
leading cause of neurological disability in early adulthood
3x more female than male, high in caucasians
Prevalence of MS in Australia
2.4/100,000
US prevalence of MS
400,000
World MS
2.1 million
clinical manifestations of MS
related to impaired and slowed nerve conduction
1. relapsing remitting (RR)
periods of acute neurologic symptoms (flare ups, exacerbations, relapses) alternating with
periods of symptom relief or return of neurologic function (remission)
2. primary progressive
slow, chronic deterioration of neurological function
not associated with exacerbations or remissions
3. secondary progressive
initially presenting with RR characteristics of exacerbations and remissions
followed by a pattern of slow, chronic deterioration as seen in primary progressive
4. progressive relapsing
steady progression of a decline in neuro function
associated with exacerbations and possible remissions
Common effects of MS
cognitive loss
bladder and bowel dysfunction
altered mobility - disabled after 20 years
spasticity, paresthesia, slurred speech, fatigue, pain
impaired vision due to optic neuritis or impaired extra ocular eye movement
-loss of visual field, unilateral vision loss, altered colour perception, nystagmus, pain
rare effect of MS
pseudobulbar effect (uncontrolled laughing, crying) – indicating cerebral involvement, altered emotional responsiveness
diagnostic criteria MS
S&S Hx P/E -neuro Imaging -MRI: to detect plaques, lesions Evoked potentials (EP) -testing electrical activity in special sensory nerve pathways -visual EP (checkerboards), brainstem auditory EP (click sound), sensory EV (arm, leg)
diagnosis
- combine subjective, objective and diagnostic testing
- based on the number of flare ups, number of objective lesions and number of clinical attacks
MS treatment
no cure
pharmacologic
-disease modifying drugs that target symptoms, delay progression of the disease as well as immunosuppressants and immunomodulators
Hydrocephalus
hydrocephalus is characterised by the imbalance of CSF being produced and reabsorbed. It leads to increased ventricular accumulation of CSF which leads to ventricular enlargement and increased ICP. Long term consequences of this disease are motor disability (3/4 of children with HC) and intellectual disability
classifications of the disease are based on underlying cause
noncommunicating means that there is a CSF obstruction between ventricles and communicating means impaired absorption within the subarachnoid space
Causes of hydrocephalus
Hydrocephalus can be caused by neural tube defect (congenital >50% of cases) such as spina bifida and altered cerebral aqueduct or choroid plexus
Hydrocephalus can also be acquired secondary to another disease such as a brain tumour, intraventricular haemorrhaging, meningitis or traumatic injury
increase ICP is a common consequence of hydrocephalus and may lead to impaired perfusion leading to ischemia and cells death and atrophy can occur due to impaired circulation
Clinical manifestations of Hydrocephalus
Clinical manifestations of hydrocephalus are dependant on the age of onset, underlying pathology/cause, and the severity of brain tissue compression
an example of this is the skull of a newborn is less restrictive, so increased head circumference (cardinal sign) and fontanels and unfused sutures of skull bones are affected
Age dependancy of clinical manifestation of hydrocephalus
in infancy, manifestations incude enlarged head with bulging fontanels, scalp vein distention, difficulty feeding and a high shrill cry
in older children/adults, manifestations include impaired motor and cognitive function and incontinence
impaired neurological function and death can be a result of unresolved hydrocephalus and increased ICP
ICP
ICP is dependant on three things; brain tissue volume, CSF volume and blood volume
an increase in volume of and of the three components (according to Monro-Kellie doctrine) leads to increased ICP and compensatory decrease in other
cerebral perfusion pressure (CPP) = mean arterial pressure (MAP) -intracranial pressure (ICP)
CPP =MAP-ICP
S&S of ICP
signs and symptoms of ICP include increased blood pressure (which promotes perfusion to cerebral blood vessels), altered heart rate (initial tachycardia - increased blood flow – followed by bradycardia – by stimulation of baroreceptors, headaches (caused by stretching of vessel walls of meninges), vomiting (pressure on vomiting centre) , decreased level of consciousness (LOC), and papilledema
