Topic 8.1 - General and Acute Neurological Dysfunction Flashcards
What structures are in the brainstem?
Medulla, pons, midbrain
What structures are in the diencephalon?
The thalamus and hypothalamus
What structures are found in the cereberum?
The basal ganglia and cerebral cortex
Which spaces does CSF flow through?
Through ventricles and subarachnoid space
What are some early signs of increase intracranial pressure?
–> LoC changes
–> Decreased PERRLA Reflex
-> Severe headache due to stretching of dura and blood vessels
–> Vomiting due to stimulation of emetic center in medulla
–> Papilledema due to swelling on optic disk
What is papilledema?
Swelling of the optic disks
–> Blurred vision, double vision, or complete loss of vision
How and why do the vitals change during increase in ICP?
ICF leads to cerebral ischemia:
Systemic vasoconstriction tries to provide more blood to the brain –> systemic BP rise
Baroreceptors respond to increase BP by slowing heart
Chemoreceptors respond to low CO2 levels by reducing RR.
How are issues with ICF diagnosed?
Specimen taken from lumbar puncture
–> Test for increased pressure
–> Presence of blood (pink)
–> Presence of WBCs (yellow)
–> Abnormal proteins (Neoplasm)
What is transtentorial hernia?
The movement of brain tissue from one intracranial compartment to another.
What is an uncal herniation?
Rising intracranial pressure due to herniation of uncus.
What are space occupying lesions?
Neurological diseases/masses/lesions that cause secondary damage by occupying space at the expense of the brain tissues and its blood supply.
Can lead to herniation
What kinds of issues can cause space occupying lesions?
Intracranial hemorrhage, increased CSF, edema, Intracranial abscess and tumors.
What is the most common brain tumour in children? How is it graded?
Astrocytoma - in cerebellum, occurs in childhood
Graded from type I-IV
What kind of brain tumors are commons in young children?
Cerebellar and brainstem tumors
What kind of brain tumors are most common in adults and emerge in mid-life?
Gliomas
What are the most aggressive and common primary tumors in the adult brain?
Glioblastoma
Where do glioblastomas usually develop? What symptoms’ do they cause? What is the prognosis?
Usually develop in the cerebral white matter - cause seizures, nausea, vomiting, headache
Infiltrates into other brain tissues, very difficult to operate on. Poor prognosis.
Why are brain tumors so difficult to treat?
–> They are resistant to conventional radiation and chemo
–> They are difficult to remove by surgery
–> At time of diagnosis they are already quite large, and have likely migrated.
Brain tumors are difficult to treat. What methods an be effective?
–> Angiogenesis inhibitors
–> Emergence of tumor treatment fields (electrical fields to disrupt tumor cell division)
–> Neutralize tumor with immune system
What percentage of cardiac output does the brain use at rest?
20%
What vessel circuit can compensate for a blocked internal carotid artery and prevent stroke?
The arterial circle of Willis
What causes Transient Ischemic Attack?
Temporary localized reduction of blood flow to brain
–> Patrial occlusion of artery
–> Atherosclerosis
–> Small embolus
–> Vascular spasm
What are the symptoms of a TIA?
Symptoms may be directly related to location of ischemia
–> Muscle weakness in arm/leg
–> Visual disturbances
–> Numbness
–> Transient aphasia or confusion
How are TIAs treated?
Thrombolytic agents
What is CVA?
A cerebrovascular accident is an infarction in the brain tissue that results in a lack of blood (stroke)
_ minutes of ischemia can lead to irreversible nerve cell damage.
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What are the three kinds of strokes?
–> Occlusion by atheroma in large artery
–> Sudden obstruction caused by embolus lodged in a cerebral artery
–> Intracerebral hemorrhage due to severe HTN
What kinds of conditions can predispose an individual to CVA?
Diabetes, hypertension, atherosclerosis, history is TIAs, aging, heart disease
What lifestyle factors can predispose an individual to CVA?
Sedentary lifestyle, oral contraceptives, nicotine/tobacco
What kind of cerebral aneurism is most common?
Berry Aneurism
–> At bifurcation point of circle o Willis
How are cerebral aneurisms treated?
Surgical treatment - high risk procedure, required early screening
What might cause cerebral edema? What are the biggest concerns with this kind of edema?
–> Infectious agents are often to blame
–> Increased pressure, disruptions in BBB and ischemic stroke are main concerns.
What is meningitis?
Infection that results in swelling on the meninges.
How can meningitis be detected in an CSF specimen?
Exudate from infection contains cell proteins, and other abnormal solid materials.
Different age groups are susceptible to meningitis due to different causative organisms. What usually causes meningitis in neonates?
E. Coli
Different age groups are susceptible to meningitis due to different causative organisms. What usually causes meningitis in young children?
H. influenzae
Different age groups are susceptible to meningitis due to different causative organisms. What usually causes meningitis in children and young adults?
N. meningitides or meningococcus
Different age groups are susceptible to meningitis due to different causative organisms. What usually causes meningitis in older adults?
S. pneumoniae
What are some symptoms of meningitis?
–> Severe headache
–> Back pain
–> Photophobia
–> Nuchal (neck) rigidity
–> Vomiting, irritability, lethargy, fever, chills
–> Progression of fever
–> Kernig and Brudzinski’s signs
What might cause brain abscesses? Where might they spread to?
Localized infection area of necrosis surrounded by edema, or the site of injury or surgery.
May spread to ear, throat, lung, or sinuses
What kind of infection usually causes encephalitis?
Usually one of viral origin
What is encephalitis?
infection of parenchymal or connective tissue in the brain and spinal cord, which leads to necrosis and inflammation.
What are the early signs of encephalitis?
Headache, neck stiffness, lethargy, vomiting, seizures, and fever
Western Equine Encephalitis:
How is it spread?
When is it more frequent?
Who does it usually affect?
Spread by mosquitos - more common in summer months
Common in young children
St. Louis Encephalitis - which demographic does it affect most?
More serious for elders than for younger individuals
What causes and spreads West Nile Fever?
A kind of encephalitis caused by flavivirus and spread by mosquitos
Lyme Disease:
Caused by which bacterium?
Transmitted by what?
Symptoms?
Spread by ticks carrying Borrelia burgdorferi.
Symptoms include sore throat, dry cough, fever, headache, cardiac arrythmias, and neurological abnormities. Also causes encephalitis.
What kind of HSV causes encephalitis?
Herpes Simplex I can cause encephalitis and extensive necrosis and hemorrhage in the brain.
Ameobic Meningeocephalitis:
Caused by which microorganism?
Where is this found?
Prognosis?
Caused by Naegleria flowleri amoeba, often found in warm water habitats.
Rare but fatal.
How does rabies reach the CNS?
By travelling up the neuron
What are are the symptoms of rabies?
Headache, fever, respiratory failure, death. The virus also causes issues swallowing.
Concussion:
Cause?
Symptoms?
Caused by sudden excessive movement of the brain from blow to head or whiplash type injury
Can lead to amnesia and headaches, but usually recover within 24 hours.
What is a contrecoup injury?
Bruising contralateral to primary concussion injury - may be secondary to accelerating or deceleration accidents.
What is an epidural hematoma? When do symptoms usually arise?
Bleeding between the dura and the skull - symptoms arise within a few hours of injury
What is a subdural hematoma?
Bleeding between the dura and arachnoid mater.
A tear in the arachnoid will results in ICP
What is a subarachnoid hemorrhage?
Bleeding between the arachnoid and pia mater - blood mixes with CSF
What kind of hematoma is associated with traumatic bleeding from BVs at the base of the brain?
A Subarachnoid hemorrhage.
What causes intracerebral hematoma?
Results from contusion or shearing injuries - may develop days after injury.
What are some common causes for hematomas?
Automobile or motorcycle accidents, sports injuries, falls.
