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Flashcards in Case 10 Deck (40):

What are the two phases of sleep?

Rapid Eye Movement (REM) sleep and Slow wave sleep (non-REM).


What is non-REM sleep?

Muscle tension and movement reduced, although movement is still possible for changing position. Increased parasymapthetic activity causes decreased HR, respiration and kidney function. Idling brain in moving body.


What is REM sleep?

Active hallucinating brain in paralysed body. Brain activity has fast and low voltage EEG and higher oxygen consumption than an awake and concentrating brain. Body incapable of movement except for respiratory muscles, eye mscles. Stimulated by acetylcholine secretion and inhibited by serotonin.


What percentage of sleep is spent in REM phase?

about 25%.


What is consciousness defined as?

Alert cognitive state in which you are aware of yourself and your situation


What is a coma?

State of unarousable unresponsivness, caused by damage to either the diencephalon/midbrain or the hemispheres.


What is toxic-metabolic encephalopathy?

Acute brain dysfunction with symptoms of delirium or confusion, usually reversible, causes systemic illness, infection, organ failure, and other conditions.


What is locked-in syndrome?

Awareness, sleep-wake cycles meaningful behaviour (eye movements) but quadripelgia and pseudobulbar palsy.


Minimally Conscious State?

Intermittent periods of awareness and wakefullness, display some meaningful behaviour.


Persistant vegetitive state?

Sleep wake cycles, lacks awareness, only displays reflexes and non purposful behaviour, classified as permanent after 1 year.


Chronic Coma?

Patient lacks awarneness and sleep-wake cycles, only displays reflective behaviour, classed as a coma after 6 hours.


Brain death?

Patient lacks awareness, sleep-wake cyclesand brain-mediated reflexive behaviour, irreversible end of brain activity.


Medically induced?

Used to protect brain from swelling after an injury, patient receives controlled dose of anesthetic causing lack of feeling or awareness.


What is a neurophysical assessment?

used to examine cognitive consequences of brain damage or similar. Test includes ability areas such as memory attention, processing speed, reasoning, judgment, problem-solving, spatial and language functions.


What is the Glascow coma scale?

Indicator of head injury severity, calculated on a patients eye opening verbal and best motor responses. Scors range from 3-15, less than 8 indicates coma, 9-12 indicates moderate head injury and above 12 mild head injury.


What is a compound fracture?

Outside environment is in contact with the cranial cavity.


What is a linear fracture?

Most common, traverse the full length of the skull from the outside to inside, usually fairly straight without bone displacement


What is a depressed fracture?

Part of the skull bones press inward, present a high risk of increased pressure on the brain, or a haemorrhage to the brain that crushes delicate tissue.


What is a diastatic fracture?

When the fracture line transverses one or more sutures of the skull causing a widening of the suture.


What is a basilar fracture?

Linear fracture that occur on the floor of the cranial vault (skull base), which require more force so are rare.


What is a laceration?

When the arachnoid mater and brain are damaged usually at the site of fracture.


What artery is commonly damaged during extradural haemorrhage and why?

Middle meningeal artery, lies beneath the pterion where the skull is thinnest.


How might patients with extraldural haemorrhage (EDH) present?

Lucid immediatley after a head injury only to become unconscious.


What causes a subdural haemorrhage?

Acceleration of brain, brain lags behind skull in accleration, causing traction on bridging veins between brain and dura mater, which get torn. Blood slowly spreads in the subdural space and symptoms can take days to months to present and often there is damage to the underlying axons.


What is a crainiotomy?

Surgical operation in which a bone flap is temporarily removed. Burr holes are drilled into the skull in several locations, these are then joined together to remove the flap and expose the dura.


What are the four types of cerebral oedema?

Vasogenic, Cytotoxic, Osmotic, Interstitial.


What is an internal herniation?

When there is a difference in pressure between two adjacent intracranial compartments (or an intracranial compartment and the spinal cord) causes the brain to be displaced into the compartment with lower pressure.


What are the three sites herniation tends to occur?

Subfalcine - herniation of the cingulate nucleus under the flax cerebri.
Tentorial - herniation of the uncus of the temporal lobe through the tentorial notch.
Tonsillar - herniation of the cerebellar tonsils through the foramen magnum and onto the respiratory and cardiac centres of the medulla.


What are post-traumatic seizures?

Seizures that result from a traumatic brain injury.


What are thought to be the causes of immediate seizures?

The force of the injury stimulates brain tissue that has a low threshold for seizures when stimulated.


What is thought to be the cause of early seizures?

Factors such as cerebral oedema, intracranial haemorrhage, cerebral contusion or laceration.


What is thought to be the cause of late seizures?

Late seizures are thought to be the result of epileptogenesis, in which neural networks are restructured in a way that increases the likelihood that they will become excited, leading to seizures.


What are the three types of partial seizures?

Simple partial seizure, complex partial seizure, partial seizure with secondary generalisation.


What are simple partial seizures?

Seizure activity is limited to a focal area, there is no loss of consciousness. The origin of focal seizures leads to symptoms that depend on the area involved. The patient may experience weakness in the affected muscle.


What are complex partial seizures?

Associated with impaired consicousness, the patient may be able to continuesimple motor behaviour.


What are partial seizures with secondary generalisation?

Focal epilepsy may sometimes spread over the cerebral cortex, first on the side of the initial focus and then to the opposite hemisphere.


what are generalised seizures and what are the two types?

Involves both hemispheres of the brain, thought to originate from midline structures like the thalamus. Absece seizures or tonic-colonic seizures.


What are absence seizures?

'Daydreaming' woth th patient staring vacantly, sometime blinking or eye-rolling.


What are tonic-colonic seizures?

3 stages: 1)patient becomes very rigid, all muscles undergo tonic, sustained contraction, there is no respiration. 2) Clonic phase during which the muscles go into strong, random conractions, may be accompanied by urinary/fecael incontinance 3) Coma, breathing becomes regular, neural activity is very high but blood oxygenation is poor..


Why might a patient with a head injury be hyperventialted?

Makes them hypocapnic, causes vasoconstriction, blood vessels take up less space decreasing intracranial pressure, less fluid goes to the brain, so oedema does not worsen. The risk of sichemia is countered by 100% oxygen supply.