neuro disorders Flashcards
common causes of stroke?
HTN atherosclerosis CAD, hyperlipidemia diabetes consequence of AF (ischaemic)
modifiable risk factors for stroke?
hypertension
hyperlipidemia
smoking
obesity
inactive lifestyle
excessive alcohol intake
non-modifiable risk factors for stroke?
age
previous history including TIAs
male
family history
ethnicity - African- American, Hispanic, and Asian-Pacific Islander population
what is ischaemic stroke caused by?
blocked artery from an emboli or thrombus
pathophysiology of ischaemic strokes?
- vascular occlusion secondary to thromboembolic disease
- ischaemia causes cell hypoxia and depletion ATP → ion channels are impaired→K+ leaves the cells and Na+ and Ca2+ enter→cerebral oedema
- overwhelming inflammatory response leads to further damage
- further neuronal cell death and irreversible damage
pathophysiology of haemorrhagic strokes?
rupture of blood vessels
bleeding occurs directly into brain parenchyma
damage in surrounding area due to increased
intracranial pressure
types of haemorrhagic strokes?
- Subarachnoid: bleeding occurs under the thin, delicate arachnoid membrane surrounding the brain
- Intracerebral: bleeding within brain itself
difference between TIA and ischaemic stroke?
in TIA, interruption of blood flow temporary (<24 hours) and thrombus/emboli resolves spontaneously
clinical manifestations of stroke in occipital lobe?
vision issues
clinical manifestations of stroke in parietal lobe?
loss of sensation
issues with spatial tasks, reading or maths
clinical manifestations of stroke in frontal lobe?
loss of emotional control, social skills
speech issues
clinical manifestations of stroke in temporal lobe?
issues with understanding and remembering language
issues with understanding and remembering non-verbal information
clinical manifestations of stroke in brain stem?
Physical and sensory problems
Autonomic regulation of BP/Resp control
clinical manifestations of stroke in cerebellum?
Physical and sensory problems
acronym associated with recognising stroke?
FAST
face, arms, speech, time
common tests for Ax and Dx of stroke?
- Brain scans: CT scan & MRI
- ECG & echocardiogram
- Transcranial Doppler
- Cerebral angiogram
- Carotid duplex
- Blood tests: international normalised ratio or INR
- Urine tests or chest X-rays
drug therapy for haemorrhagic stroke?
anticonvulsants
anti-hypertensives
osmotic diuretics
what is epilepsy?
a chronic neurological disorder characterised by recurrent seizures
increase in risk of death in epilepsy?
up to 2-3 times higher than general population
common causes of epilepsy?
stroke
head injury
genetics
infections
two main types of seizures?
focal - one side of brain, +/- impaired conscious state
generalised - both hemispheres affected, always impaired consciousness
what is a seizure?
abnormal electrical activity in the brain causes an involuntary change in body movement, sensation, awareness, or behavior
what causes a seizure?
a momentary ‘imbalance’ within electrical and chemical circuits in the brain; excitatory neurotransmitters > inhibitory neurotransmitters.
triggers for seizures?
stress
lack of sleep/fatigue
alcohol
diet and caffeine
infections and illness
febrile illness
menstruation/hormonal changes
missed medications
N+V and diarrhoea can lead to poor drug absorption
illegal drugs
photosensitivity
N+V and diarrhoea can lead to poor drug absorption
subtypes of generalised seizures?
absence - LOC sudden but transient, unresponsive, often with automa lip smacking, blank state, eyelids fluttering
tonic clonic - collapse and rigidity → violent convulsions→ unconscious and deep sleep (postictal), +/- vomiting and incontinence
manifestations of focal seizures without impaired consciousness?
variable according to affected area of brain
experiencing auras
confusion
vagueness
repetitive actions such as uttering unusual sounds or chewing movements
muscle spasms
tingling
visual, olfactory, aural without a stimulus
manifestations of focal seizures with impaired consciousness?
variable according to affected area of brain
TEMPORAL LOBE– staring
FRONTAL LOBE – impaired memory, alterations in mood (laughing, swearing)
first seizure phase?
seizure initiation
Increased AP → Persistent Na+ channels opening →Prolonged depolarisation
second seizure phase?
seizure phase
spread of AP causing associated signs and symptoms
this is dependent on the type and origin of the seizure
activity
Inhibitory neurons release to inhibit excitatory actions
third phase of seizures?
postictal phase (in tonic clonic only)
use of O2, glucose and ATP leads to deficiency Can lead to exhaustion and sleep
what is the main complication of epilepsy?
status epilepticus
generalised recurrent seizures lasting > 30 minutes without pt regaining consciousness
medical emergency → during seizures, cerebral demands increase by 200%. → if demands not met this results in a lack of O2 and glucose to brain cells → ischaemia,
hypoxia, cell death
nursing considerations during a seizure?
- keep pts afe→remove objects which can harm
- place in a recovery position
- supplemental oxygen
- suction to prevent aspiration
- time seizures
- pharmacological agents to stop seizure activity
three main ways antiepileptic drugs work?
- increase release of GABA
- decrease action of glutamate
- inhibit Na+ movement/close ion channels
general adverse effects + nursing considerations around antiepileptic drugs?
these drugs are able to cross the BBB, therefore have many CNS adverse effects
require frequent plasma level monitoring to control seizures while reducing adverse effects - constant titration!
antiepileptic drugs that inhibit the opening of Na+ channels?
phenytoin
carbamezapine
antiepileptic drugs that enhance GABA inhibitory action?
barbituates
other drug classes used to treat epilepsy?
sodium valproate (epilim)
