cerebral vascular accident

aka "stroke" -- the sudden appearence of of neurological Sx as a result of the interuption of blood flow

The most common cause of death worldwide

Infarct

an area of dead or dying tissue resulting from an obstruction of the blood vessels normally supplying the area; often caused by a stroke

What is the main predictor of prognosis after a cerebral vascular accident?

If a stroke occurs in a small area (such as a capillary) the prognosis is usually good. However, if a major (i.e. large) vessel is blocked, devastating damage can occur, resulting in serious disability or death.

Name 5 of the most common vasular disorders that affect the CNS.

Ischemia

Migraine stroke

Cerebral hemorage

Angiomas

Artiovenous aneurysms

Ischemia

any of a group of disorders in which the Sx are caused by a vessel bloackage preventing a sufficient blood supply to the brain

Thrombosis

a type of ischemia where some of the blood vessel has coagulated to form a plug or clot that has remained at the place of its formation

Embolism

a type of ischemia where a clot or other plug brought through the blood from a larger vessel is forced into a smaller one, creating an obstruction

can be a blood clot, bubble of air, deposit of oil or fat, or a small mass of cells detached from a tumor

usually affect the middle cerebral artery of the left hemisphere

cerebral artiosclerosis

a thickening and hardening of the arteries

often results in an ischemia due to blood flow constriction

cerebral vascular insufficiency (transient ischemia)

a temporary ischemia that is usually not harmful (e.g. "blood-choke")

What is a migraine stroke (definition and Sx)?

an ischemia resulting from a migraine attack which is a common source of stroke in ppl under 40, eps. women

an immeditate constriction of the blood vessels (i.e. a vasopasm) is thought to be responsible, but the cause of the vasopasm is unknown; commonly affected area is the posterior (rear) cerebral artery

Sxs include impaired sensory function (esp. vision), numbness of skin (esp. arms), difficulties in moving, and aphasia

What is cerebral hemorrhage? What is the most common cause? Is it deadly or relatively benign?

Massive bleeding into the brain; most commonly caused by hypertension

Often fatal, esp. when patient is unconscious more than 48 hrs

What is an angioma? What can happen when they form in the brain?

Angiomas are lesions formed by malgnant collections of blood vessels in some stage of hemorraging. Thus, they have a dark red or blue color like mulberries. Often referred to as "spider viens", they are often removed using cosmetic procedures, esp. in the legs.

In the brain, angiomas can be deadly because they can result in ischemia. They can also rupture, resulting in dead as a result of cerebral hemorrhaging (although this is rare).

Aneurysm

A problem within the blood vessel due to deficits in vessel elasticity.

Basically the vessel swells up like a balloon. Aneurysm "balloons" are weak and are likely to burst.

They often cause intense pain in the head because the swelling pushes against the dura matter (outer covering of brain) which contains many pain receptors.

Edema

the accumulation of fluid in and around damaged tissue

What are the main treatments for vascular disorders?

No specific Tx, but surgery and psychotherapies can help if delivered within 3 hrs after a vascular emergency

Rx can be given to dissolve clots, dialate vessels, and/or reduce cerebral edema

Surgeries can be performed but are not always practical (e.g. an aneurysm in the middle of the brain could not be removed do to its location)

What are the two most important factors in the incidence of head injury?

age and sex

Children and the elderly are likely to occur TBIs from falls

Males ages 15-30 are likely to occur TBIs through automobile and motorcycle accidents (although sports also account for about 20% of TBIs)

Two types of head trauma

Open-head injuries, where the skull is penetrated

Sx tend to be specific and often undergo rapid and spontaneous recovery, thus these ppl make good research participants

Closed-head injuries, where the skull isn't penetrated -- result from a blow to the head

Closed-head injuries from traffic accidents are particuarly bad b/c the head is often moving forward when the blow is struck

What is a coup? A countercoup? A hematoma?

A coup is a bruise (contusion) at the site of the blow when the skull is pushed into the brain.

A countercoup is contusion where the brain is pushed against the opposite side of the skull from where the blow occurs.

A hematoma is a collection of blood outside the blood vessels, usually resulting from damage to the blood vessel -- in the brain, hematomas can cause serious problems because there is no where for the blood to go and pressure increases inside the skull

Name two types of injuries that result from closed-head injuries.

1) Discrete impairment of the specific functions mediated by the cortex at the site of the coup or countercoup lesion

2) More generalized impairments from widepsread trauma throughout the brain -- commonly associated with damage to the frontal and temporal lobes (these areas are most susceptible to damage)

In our textbook author's opinion, who seems to be affected most by closed-head injuries: smart ppl or dumb ppl?

Smart ppl because they are more aware of cogntive deficits

What are the 2 primary brain injuries that result from closed-head injuries?

1) Macroscopic lesions

Coup, coutercoup (usually in the frontal and temporal lobes), and lacerations (tearing wounds) of the brain resulting from depressed skull fracture

2) Microscopic lesions

widespread tearing of fibers in the brain resulting from the stress of the TBI

Name 6 secondary consequences of closed-head brain injuries ("HE PISS")

1) Intracranial Hemorrhaging (bleeding)

2) Edema (fluid build-up) in white matter (mylinated axons) adjacent to lesion

3) Raised intracrannial Pressure

4) Ischemic (blood-flow restriction) brain damage

5)Diffuse brain Swelling  -- hyperemia

6) Brain Shift and herniation

"HE PISS"

Are closed-head injuries always accompanied by visible neurological Sxs?

No; Sxs may not appear, and this makes assessment very important.

However, ppl with head injuries are more suscrpitble to subsequent head injuries b/c they continue doing things that result in damage. Further, damage is cumulative (as in the "punch-drunk syndrome" documented with boxers)

What is the purpose of the Glasgow Coma Scale (GCS)? What are the three domains therein?

To objectively measure the degree of unconsciousness and of recovery from unconsciousness.

The three domains are eye opening (E), motor response (M), and verbal response (V)

Despite the objectivity of the GCS, it has been criticized for missing up to 50% of ppl with brain injuries. What is an alternative way to measure the severity of head trauma?

The length of posttraumatic amnesia (PTA). The length of PTA is correlated (unperfectly) with subsequent memory disturbance.

This method has been criticized because there is no consensus on how to measure the length of an individual's PTA.

How long does recovery from head trauma usually take? When does the bulk of cognitive recovery take place? Which areas tend to have the best overall prognosis? The worst?

Recovery may continue for 2-3 years, but most cognitive improvements occur within 6-9 months.

Prognosis for the recovery of cognitive functioning is generally good.

There is less optimism about recovery concerning social skills and personality. Thus, the quality of life for ppl with closed-head injuries is significantly reduced and the reduction is chronic.

What are the characteristics of epilepsy? What are symptomatic seizures? What are idiopathic seizures?

Epilepsy is charactersized by seizures of various types that register on an EEG and are asscoaited with disturbances of consciousness.

Symptomatic seizures can be identified with a specific cause.

Idiopathic seizures appear spontaneously and in the absence of other diseases in the CNS

What is the most remarkable clinical feature of epileptic disorders? Name three Sx found in many types of epilepsy.

The varying length of time between attacks -- from minutes to years.

1) An aura, or warning of impending seizure

2) Loss of consciousness

3) Movement

How is Dx confirmed for epilepsy? What are the limitations of this method?

Dx is made by EEG scans of the brain. This method is inexact b/c some ppl have abnormal EEGs and do not have seizures.

Name and characterize four types of seizures

1) Focal seizures -- begin in one place ("focus") and then spreads. Jacksonian focal seizures begin in the part of cortex representing the region of the body where the movement first began.

2) Generalized seizures -- bilaterally symtremical without a focal onset (include grand mal seizures and petit mal seizures)

3) Akinetic seizures are ordinarliy only seen in children; they usually result in falling down for a brief period of time (football helmet recommended)

4) Myoclonic spasms are massive seizures that consists of a sudden extension of the body and often begin with a cry

What are the two methods used to treat epilepsy?

Anticonvulsant drugs are the treatment of choice; these drugs inhibi the discharge of abnormal neurons by stabilizing the neronal membrane.

If Rx fail, focal seizures can be alleviated by surgery.

Tumor

A mass of cells that grows independent of surrounding cells and has no physiological use.

Brain tumors grow from glia or other support cells, not neurons.

Benign tumors are not likely to regrow after removal.

Malignant tumors are likely to regrow.

The type of tumor may not be as important as how accessible it is to surgery.

Differentiate between encapsulating and infiltrating tumors

Encapsulating tumors develop as a distinct entity in the brain; some are cystic, which means they offer the bonus of a fluid-filled cavity in the brain.

Infiltrating tumors are not distinct from the brain; they get in and destroy normal cells (including neurons) and cause general disruption.

Name some Sxs of brain tumors

1) Increased intracranial pressure

2) Headache

3) Vomiting

4) Swelling of the optic disk (called papilledema)

5) Slowing of the heart rate (called bradycardia)

6) Mental dullness

7) Double visions (called diplopia)

8) Convulsions

9) Other functional impariments as result of location

What are three type of brain tumors?

Distinguished based on where they originate:

1) Gliomas (45%) arise from glial cells and inflitrate the brain -- severity and response varies

2) Meningiomas are growths attached to the meninges (the outer covering of the brain) and are the most benign because they are encapsulated outside the brain

3) Metastic tumors (from the word metastasis, which is the transfer of a disease from one part of the body to another) are tumors from other organs of the body, usually the lungs or breasts.

Metastic tumors usually travel in packs, making removal difficult and the prognosis poor.

Where are headaches produced (specifically)?

1) dura matter

2) large arteries of the brain

3) the venous sinuses (venous channels between layers of dura matter)

4) Branches of the 5th (trigeminal -- chewing, face and mouth touch and pain), 9th (glossopharyngeal -- taste, senses carotid pressure) , and 10th (vagus -- senses aortic pressure, slows heart rate, stimulates digestive organs, and taste) cranial nerves and the 1st (olfactory -- sniffer) and 3rd (occulormotor -- eyelid and eyeball movement) cranial nerves

The point is there is a lot of stuff that can cause a headache@