Neurologic Infections, Seizures, Brain Injury, CVD

Question 1

What are the two locations of neurological infections?

Answer 1

1. Within the brain tissue. 2. Within the Meninges and Spinal Cord

Question 2

What is the meninges?

Answer 2

The meninges are the three membranes that envelop the brain and the spinal cord.

Question 3

What are the three layers of the meninges?

Answer 3

Pia Mater: the innermost layer of the meninges. Arachnoid Mater: the middle layer. The Dura Mater: the outter most layer

Question 4

What are the two classifications of nerological infections?

Answer 4

Viral or Bacterial

Question 5

Name four different routes of entry for nerological infections?

Answer 5

1. Microbe entry via compromised blood brain barrier.
2. Fracture in the skull.
3. Direct spread from adjoining area (middle ear extends to brain)
4. Along an axon that goes into the brain. (cranial nerve)

Question 6

What is bacterial meningitis?

Answer 6

Bacterial meninigitis is a bacterial inflammation of the meninges.

Question 7

What are the causes of bacterial meningitis?

Answer 7

Any bacterium that is able to enter and infect the meningies. Some bacteria are more likely to cause meningies.

Question 8

What are the three most common bacteria seen in meningitis? What age groups do they most commonly affect?

Answer 8

1. Streptoccus pneumonia: most common in adults.
2. Neisseria meningitides: causes meningococcal meningitis in youth.
3. Haemophilus influenzae: cause in those less that 5 yrs old.

Question 9

What are several predisposing factors of bacterial meningitis? (protals of entry).

Answer 9

Head trauma, infection in sinus or middle ear (congruent infection), post surgery infections, decreased immunity.

Question 10

What is the pathophysiology of bacterial meningitis?

Answer 10

Once entry occurs, microbial prliferation and lysis occurs. Cell lysis releases inflammatory agents resulting in inflammation. Because there is inflammation, purulent exudate develops and gets into the CSF. Pus accumulates around the meningies, subarachnoid space, ventricles and blood vessels are all affected. The space needed by the exudate puts pressure on the brain surface and CSF.

Question 11

What are the manifestations of bacterial meningitis?

Answer 11

There are several manifestations of bacterial meningitis.
Fever because of bacterial infections (Systemic manifestatons of infection), Headache/Neck/Back Pain, Nausea/Vomiting (centers in brain that regulate are affected), Nuchal Rigidity (nape of neck).

Question 12

What are the two physical test we can conduct for bacterial meningitis diagnosis?

Answer 12

Brudzinski’s Sign and Kernig’s Sign. Both will be positive.
Brudzinski’s is raising the head, and the knees flex at the hip.
Kernig’s is extension of knee flexion at hip and results in back pain.

Question 13

What is a diagnostic test we can complete for diagnosis of bacterial meningitis?

Answer 13

Body fluid collection and CSF. Purulent, proteins, neutrophils and decreased glucose will all show up in diagnostics due to inflammation. This will also allow for the indentification of microbes.

Question 14

Why will tests show a decreased glucose level when diagnosing bacterial meningitis?

Answer 14

Bacteria will be using the glucose as an energy source.

Question 15

What is the treatment for bacterial meningitis?

Answer 15

Indentify the bacteria and treat with antibiotics. Will also be given steroids to reduce inflammation (Anti-inflammatory)

Question 16

What is viral meningitis?

Answer 16

Viral meningitis is usually a self limiting condition which is less severe than bacterial meningitis. Most cases are due to mumps virus. Complications can still be serious, such as intercranial pressure which must be treated.

Question 17

What is the purpose of CSF tapping in viral meningitis?

Answer 17

CSF can tell us several different things: The presence of lymphocytes which come to fight viral infection. Moderately elevated levels of proteins which demonstrate inflammation, compromised brain/blood barrier, and autoimmunity. It will also show normal glucose levels.

Question 18

Why will there be a normal glucose level in viral meningitis, but not bacterial?

Answer 18

Viruses do not utilize glucose for energy, so glucose levels will remain normal.

Question 19

What is encephalitis?

Answer 19

Encephalitis is the inflammation of the brain or spinal cord parenchyma. It is usually caused by a virus.

Question 20

What is parenchyma?

Answer 20

Parenchyma is the bulk of a substance. In the case of encephalitis we are speaking about the brain tissue, or spinal column.

Question 21

What are several common viruses implicated in encephalitis?

Answer 21

1. Arbovirus Encephalitis - virus from tics.
2. Hepes Simplex 1 Virus Encephalitis - cold sore.

Question 22

What is the pathophysiology of Encephalitis?

Answer 22

Initially localized damage like necrosis and hemorrhage becomes generalized inflammation leading to edema. Eventually, the cell bodies get destroyed. The course of encephalitis follows an unpredictable course.

Question 23

What are the manifestations of Encephalitis?

Answer 23

Typically, several of the manifestations will present.

Neurological disturbances (lethargy, seizures, coma). Fever. Headache. Nuchal rigidity. Manifestations usually subside in about 2 weeks if Arbovirus. If caused by Herpes Simplex the manifestations are more serious and should be treated agressively. Antivirals like Acyclovir IV. Severe neuro impairment is possible. There is a 30% mortality rate and those that do survive may have neuro impairment like dementia or seizures.

Question 24

What is a seizure?

Answer 24

A seizure is a sudden, uncontrolled neural discharge characterized by altered movements, sensation, and altered behaviour. Manifestations will vary according to the site of discharge.

Question 25

Is a seizure a disease?

Answer 25

Nope, certainly not. It a manifestation of another disease.

Question 26

What is epilepsy?

Answer 26

Epilepsy is when one experiences recurrent seizures.

Question 27

There are two types of seizures. What are they called?

Answer 27

Primary and Secondary seizures.

Question 28

What is a primary seizure? What is it’s etiology?

Answer 28

A primary seizure is unprovoked. It is idiopathic. There is a suspected genetic component.

Question 29

What is a secondary seizure?

Answer 29

A secondary seizure is known as a provoked seizure. There is an underlaying cause that triggers a discharge. In children seizures can be caused by febrile (fever caused seizure). Any thing that injures the the CNS, called an insult, can lead to seizures. Secondary seizures can also be metabolizim related such as in hypoglycemic state, hypoxia, and electrolyte imbalances.

Question 30

What are three metabolic related reasons for secondary seizures?

Answer 30

1. hypoglycemia 2. Electrolyte imbalance (changing the resting membrane potential) 3. Hypoxia

Question 31

Seizures are classified according to where they ________?

Answer 31

Originate

Question 32

What is the difference between generalized and partial seizures?

Answer 32

Generalized - originates in both hemispheres. Partial - focal origin in one hemisphere.

Question 33

What is the difference between partial simple and partial complex seizures?

Answer 33

Partial simple - there is no loss of consciousness. Partial complex - there is loss of consciousness.

Question 34

What is the pathophysiology of seizures?

Answer 34

Seizures are a small group of hyperresponsive neurons. Known as epileptogenic focus in the cerebral cortex and hippocampus. The neurons discharge (action potential) with increasing amplitude and frequency and spread to other areas of the brain. Normal neuronal inhibition is blocked resulting in abnormal muscle action and LOC. Inhibitory neurons eventually gain control of discharge and stop the seizures. There is a period of intermittent contraction and relaxation phase. Finally, the epileptogenic cells become completely inhibited, compressing of the CNS called the post ictal state.

Question 35

The increased brain actiivity and demand for ATP has several consequences on the body, what are they?

Answer 35

A greater demand for oxygen and glucose acidosis.

Perfusion to brain not adequate leading to hypoxia and lactic acid.

Brain damage.

Question 36

How are seizures diagnosed?

Answer 36

History. Neuro Exam (PERRLA, cranial nerves, reflexes). Underlying cause (labs, scans, EEG).

Question 37

What is the treatment for seizures?

Answer 37

During seizure: protection from injury. Stat after seizure: preserve brain function. Later: underlying cause, anticonvulsant drugs, surgery if drugs fail.