Topic 2 - ALOC Flashcards
ALOC - 2 Categories
- Intracranial pathology (structual)
- CVA, subarrachnoid hemorrhage, intracerebral hemorrhage, DAI, meningitis, ecephalitis, status epilepticus, space-occupying injury
- Extra-cranial pathology
- Cardiovascular system - arrythmias
- Metabolic
- Endocrine
- Toxins
- Other - hyper/hypothermia, hypoxia/hypercarbia, infection, psychiatric
Stroke versus TIA
A TIA is defined as a breif episode of neurological dysfunction (traditionally 24 hours) resulting from focal temporary cerebral ischemia.
Stroke lysis time
- 4.5 hours from the onset of symptoms - time must be unambiguous
- Only to consider acute stroke referal if symptom onset was within 3.5 hours of presentation to paramedics
Stroke/TIA management
- O2
- Antiemetic
- Analgesia
- IV fluid
- Consider stroke mimics
- 45 degree semi-recumbent positioning to balance perfusion with reducing oedema
Stroke Mimics
- Hypoglycemia
- Intracerebral mass lesions
- Seizures and post-ictal states
- Hemiplegic migraine
- Electrolyte abnormalities
- Conversion disorder
Focal seizures - definition and types
- A focal seizure is where abnormal neuronal activity originates and is limited to one hemisphere of the brain
- Focal dyscognitive seizures are another type of focal seizure where conciousness is affected however full conciousness is not completely lost
Generalised seizures and types (Absence, Atonic, Tonic, Myoclonic)
A generalised seizure is one where the abormal neuronal activity rapidly engages both hemispheresof the cerebral cortex. Several types include:
- Abscence - breif loss of awarness and responsiveness (usually 10 seconds) with no post-ictal phase
- Atonic - sudden loss of muscle tone (<2 seconds) which results in a fall
- Tonic - sudden increased muscle tone that most often oxxure in clusters during sleep
- Myoclonic - a breif sudden jerking action of a muscle or group of muscles that may occur in a series leading to a tonic-clonic seizure
- Tonic clonic - abrupt LOC with involuntary muscle contractions (tonic phase) followed by symmetrical jerking movements (clonic phase)
Phsycogenic non-epileptic seizures management
- Where doubt to cause exists, Midazolam is appropriate
Provoked seizure definition
A seizure resulting from a recognised cause including hypoxia, hypotension, pregnancy eclampsia, drugs, cerebral pathology etc.
Complications of prolonged seizure activity
- Hypoxia
- Hypercarbia
- Progressive lactic and respiratory acidosis
- Hyperthermia
- Hypertension
- Hypo/perglycemia
- Hyperkalemia
- Physical injury
Focal dyscognitive seizure management
- Manage as per generalised seizure if GCS 12 or less
Midazolam (Pharmacology)
- Enhances the action of inhibitory neurotrasmitter GABA. Binds to GABA-A receptors which potentiates the effects of GABA by increasing opening of chloride channels
Midazolam (ACP Indications)
- Generalised seizure/focal seizure (GCS 12 or less)
Midazolam (Contraindications)
KSAR or hypersensitivity to midazolam
Midazolam (Precautions)
- Reduced dosages should be used in elderly, renal failure, CCF and shock
- Respiratory depression in COPD
- Myasthenia gravis
- MS
