Brain Damage

Front 1

Meningiomas

Back 1

(20% of primary brain tumors)-tumors forming in or between the meninges.
-grow within their own membrane
-easily identified on scans
-most are benign and slow growing

a. easily removed surgically
b. little danger of metastasizing - spreading to other tissues

4. in the brain even benign tumors are dangerous because they grow

a. limited space for expansion inside the cranium
b. function of tissue impaired due to compression - impairment might be far from the tumor

Front 2

gliomas

Back 2

gliomas (60% of primary brain tumors) - tumors of glia

1. generally diffuse or infiltrating - ie., not encapsulated by a membrane but growing diffusely through surrounding tissue, therefore, difficult to identify on a scan
2. generally malignant - not easily removed and prone to metastasizing
3. metastatic (spreading) tumors may also develop on blood vessels or other tissues in the brain, but rarely develop from neurons (which are no longer undergoing cell division)
4. treated with chemotherapy and radiation

Front 3

FACTS

Back 3

about 10% of tumors in the brain are not primary to the brain but are metastases from other organs - breast and lung cancers are esp. likely to metastasize to the brain

1. tumor cells are carried in the blood supply or lymph and are, therefore, most likely to settle in organs with rich blood supplies (lungs, kidney, liver, and brain)

Front 4

SIGNS

Back 4

headache, vomiting, edema of the optic disk (due to increased intracranial pressure), seizures and focal signs (due to irritation or compression of tissue)

Front 5

cerebrovascular disorders

Back 5

strokes (cerebrovascular accidents or CVAs, at one time called apoplexy) - loss of blood supply to an area of brain tissue due to:
1. cerebral hemorrhage (hemorrhage = bleeding)
2. cerebral ischemia - interruption of blood flow due to a blockage

Front 6

cerebral hemorrhage

Back 6

1. bursting blood vessels, perhaps due to an aneurysm (a ballooning out of a defective blood vessel wall)

Front 7

cerebral ischemia

Back 7

1. thrombosis - blockage that forms "on the spot" (the "thrombus") due to a blood clot, tumor cells, fatty deposits, etc.
2. embolism - blockage ("embolus") that is carried into a smaller blood vessel from a larger blood vessel (air bubbles, tumor cells, fat deposits that have broken loose from vessel walls, etc.)
3. arteriosclerosis - "hardening of the arteries" or thickening of blood vessel walls due to fat deposits, eventually (perhaps) resulting in embolism or even thrombosis

Front 8

BRAIN DAMAGE IN A STROKE

Back 8

may be partially or mainly due to release of glutamate due to disinhibition of excitatory neurons - it may be possible to prevent this with NMDA-blocking drugs (which are not the clot busting drugs currently used to treat many strokes)

Front 9

excitotoxicity

Back 9

The pathological process by which nerve cells are damaged and killed by glutamate and similar substances.

Front 10

SIGNS OF STROKE

Back 10

Mainly focal
-numbness, paralysis, or weakness in face, arm, or leg, especially on only one side of body.
-problems with walking or balance.
-vision changes.
-Drooling or slurred speech.
-problems speaking or understanding simple statements, or feeling confused.
-sudden, severe headache

Front 11

RECOVERY

Back 11

1. depends upon extent of tissue damage, how rapidly treatment is obtained, and ability to pay for physical therapy

Front 12

closed-head injuries

Back 12

-the skull is not fractured or opened
1. Contusions
2. Concussions

Front 13

Contusions

Back 13

- damage to blood vessels causes bleeding and hematoma (hemato = blood, oma = tumor or mass), or bruising

1. contusions result when the brain slams against the inside of the skull
2. often there are contre coup injuries
3. subdural hematomas - most common
4. epidural or extradural hematomas

Front 14

Concussion

Back 14

temporary impairment in consciousness due to a blow to the head, but with no evidence of bleeding or other structural damage (but punch-drunk syndrome resulting from repeated concussions suggests there is some damage to the brain in a concussion; there is probably some swelling, for example, and perhaps also scarring)

Front 15

Infections of the brain

Back 15

-Bacterial
1. Meningitis
2. encephalitis
*Both above can be either bacterial or viral.
-Viral
1. Neurotropic infections
a. poliomyelitis
b. rabies
2. pantropic infections
a. mumps
b. herpes
c. AIDS
-Prion diseases
a. mad cow disease
b. chronic wasting disease
-Fungal, protozoan, metazoan
a. tapeworms

Front 16

Meningitis

Back 16

infection of the meninges (may be bacterial or viral)

1. fever, malaise, headache, stiff neck resulting from protective reflex
2. college students living in a dorm are especially at risk: CDC warning

Front 17

encephalitis

Back 17

infection of the brain tissue (may be bacterial or viral)

1. mosquito-borne diseases: Incubation is 5-10 days. St. Louis encephalitis. *Fever, headache, nausea, and stiff neck. No specific treatment
2. syphilis - after many years (10-20) the bacteria can attack the CNS
1. tabes dorsalis - sesory and motor problems resulting from infection attacking the spinal cord
2. general paresis - insanity and dementia resulting from infection attacking the brain
3. tuberculosis- infections in the lungs that can move into the brain.

Front 18

Neurotropic infections

Back 18

viral infections that specifically target neural tissue

1. poliomyelitis ("polio") - virus attacks the motor areas of the spinal cord and brainstem resulting in paralysis, muscle wasting, and death
2. rabies - malaise, headache, insomnia, restlessness, delusion, hypersensitivity, and excessive salivation. Death results from respiratory paralysis.

Front 19

Pantropic infections

Back 19

viral infections that do not specifically target neural tissue but which may travel there eventually

1. mumps
2. herpes
3. AIDS

Front 20

Prion disease

Back 20

pongiform encephalopathies

1. mad cow disease (bovine spongiform encephalopathy or BSE)
2. chronic wasting disease - seen in members of the deer family
3. Creutzfeldt-Jakob disease (CJD) - in humans

Front 21

hydrocephalus

Back 21

A. enlargement of the ventricles due to accumulation of CSF - normal flow is blocked
B. can happen in infants, children, or adults - in infants it causes cranial enlargement.
C.the danger is compression of surrounding brain tissue

Front 22

neurotoxins

Back 22

1. heavy metal poisoning (mercury, lead) can affect the CNS causing toxic psychosis
2. medications and other drugs
3. carbon monoxide - deprives the brain of oxygen
4. alcohol
-Fetal Alcohol Syndrome, effect on the brains of children
-alcoholism and the adult human brain (Science)

Front 23

genetic factors

Back 23

Phenylketonuria (PKU)- A hereditary disorder caused by the absence of an enzyme that converts the amino acid phenylalanine to tyrosine; the accumulation of phenylalanine causes brain damage unless a special diet is implemented soon after birth.

Down syndrome- A disorder caused by the presence of an extra twenty-first chromosome, characterized by moderate-to-severe mental retardation and often by physical abnormalities.

Front 24

epilepsy

Back 24

causes

1. irritation from a tumor, dead tissue, a foreign object, etc.
2. infections
3. neurotoxins
4. genes - over 70 different genes have been linked to it (Pinel)
5. biochemical abnormalities - possible loss of GABA inhibition
6. idiopathic - nobody knows! (about 1% of the population is diagnosed with epilepsy at some time during their lives, and most of these cases are idiopathic epilepsy)
7. seizures secondary to some other illness or use of medication are not labeled epilepsy (so the diagnosis can be tricky)

Front 25

Seizure

Back 25

a seizure is an abnormal burst of high-amplitude EEG spikes lasting from seconds to minutes.
-if the seizure begins in a sensory area of the brain (for example), the person may experience an epileptic aura (a bad smell or some other sensation or feeling that forebodes the full blown seizure/convulsion)
-if the seizure occurs in a motor area of the brain, the person will experience a convulsion

1. clonus - trembling or shaking of the body
2. tonus - rigidity due to muscle contraction
3. loss of balance, coordination, and often consciousness

Front 26

grand mal seizures

Back 26

loss of consciousness and violent tonic-clonic convulsions accompanied by hypoxia (oxygen deficiency) and cyanosis (turning blue due to the pooling of unoxygenated blood in the tissues)

Front 27

petit mal seizures

Back 27

absences, staring, lip-smacking, fluttering eyelids, 3 Hz spike-dome discharge in EEG

Front 28

generalized seizures

Back 28

involve the "entire brain" although may originate from a specific focus and spread (grand mal and petit mal are examples)

Front 29

Partial seizures

Back 29

do not involve the "entire brain", hence resulting in a focal epilepsy (such as temporal lobe epilepsy)

1. simple partial seizures - sensory or motor or both ("Jacksonian")
2. complex partial seizures - in more "complicated" areas of the brain, resulting in more bizarre auras and signs (temporal lobe epilepsy)

Front 30

Parkinson's disease

Back 30

-unknown origin, probably environmental
-motor impairment (primarily)

1. tremor and rigidity
2. mask like face
3. shuffling gait

Front 31

Huntington's disease

Back 31

1. genetic in origin - autosomal dominant
2. severe motor impairment and dementia with onset in middle age (fidgetiness evolving into choreiform movements and progressive dementia) with a fatal outcome
3. finding in the brain - extensive degeneration, esp. in the cortex and basal ganglia

Front 32

multiple sclerosis

Back 32

a demyelinating disease

Front 33

Alzheimer's disease

Back 33

- most common cause of dementia in the elderly
- there is no definitive test for this disease, and there is no treatment
- usually strikes in people over 70, but there is also an early onset form that may occur as young as 40 and is probably genetic in origin

Front 34

progressive degenerative disease

Back 34

progressing generally as follows:
1. depression
2. cognitive decline, esp. memory
3. deterioration of speech
4. personality changes
5. motor impairment
6. death

Front 35

Findings in the brain

Back 35

1. neurofibrillary tangles - little knots and tangles of protein found in the cytoplasm of neurons and resulting from the degeneration of the microtubules
2. amyloid plaques - clumps of scar tissue created by degenerating neurons and amyloid protein (not unique to Alzheimer's disease but much more prevalent)
3. general cell loss throughout the cortex
4. these findings tend to be most severe in the temporal lobes and prefrontal cortex (although they occur to some degree throughout the cortex)