Nervous System Flashcards
70-80% of all cerebrovascular accidents are?
Acute Ischemic Brain Infarct (Stroke)… 60 yr old men
Acute Ischemic Brain Infarct (Stroke) most common cause?
- **Cerebral atherosclerosis
- other causes are embolization from left cardiac chamber, thrombosis from carotid artery
Hemorrhagic infarct occurs when there is?
bleeding into the area of infarction
Most common sites of Primary Brain Parenchymal
Hemorrhage are?
Basal Ganglia (70%)
Cerebellum
Pons region of brainstem
three types of Intracranial Hemorrhage?
- Primary brain parenchymal hemorrhage
- Subarachnoid hemorrhage
- Vascular malformations
Transient Ischemic Attacks
(TIAs) caused by?
small atheromatous emboli or platelet-fibrin aggregates
Transient Ischemic Attacks
(TIAs) is an important predictor of?
subsequent infarction.
— 1/3 of patients with TIAs will develop cerebral infarcts
within 5 years.
Primary Brain Parenchymal
Hemorrhage most common cause?
Hypertension
– Associated with 50% of
cases.
—causes hyaline arteriosclerosis in small vessels making them more prone to rupture
Most common cause of
SAH is rupture of
saccular (berry) aneurism
– 80% in internal carotid artery (circle of Willis)
– 20% in vertebrobasilar
artery system
What is seen secondary to reperfusion of ischemic tissue or after dissolution of intravascular occlusions?
Hemorrhagic infarct
** Acute Ischemic Brain Hemorrhagic Infarct (Stroke)
Epidural (Extradural) Hemorrhage (Hematoma) cause?
tearing of the middle meningeal artery
Contusion
Hemorrhages in superficial brain parenchyma caused by blunt trauma
Subdural Hemorrhage (Hematoma) tears occur where?
in bridging veins of meninges, NOT an artery as in epidural hematoma
Subdural Hemorrhage (Hematoma) often associated with?
brain atrophy – greater vein mobility
define Concussion
A clinical, not pathologic entity
- *ANATOMIC LESIONS NOT SEEN
- temporary damage to the reticular activating system
Subdural Hemorrhage (Hematoma) between?
dura mater and arachnoid mater
1) Epidural (Extradural) Hemorrhage (Hematoma) commin in?
2) Acute Ischemic Brain Infarct (Stroke)
3) Subarachnoid Hemorrhage
Saccular or “berry” Aneurism
4) Subdural Hemorrhage (Hematoma)
5) Multiple Sclerosis
1) children
2) 7th decade and in males
3) Women before 50
4) older peeps on anticoagulants and infants with thin walled veins
5) female 20-40
What may have a “lucent” period followed by rapid clinical deterioration cerebral edema and herniation?
Epidural (Extradural) Hemorrhage (Hematoma)
*** neurosurgical emergency!
Coup contusion vs Contrecoup contusion
Coup contusion – site of
blow
Contrecoup contusion –
opposite the site of impact
Aseptic meningitis
Lymphocytic (Viral) Meningitis
Acute Pyogenic Meningitis vs Lymphocytic (Viral) Meningitis spinal fluid
acute= Neutrophils increased, glucose decreased
Lymphocytic (Viral)= glucose normal, no bacteria, no neutrophiles, lymphcytes increased
true or false… Lymphocytic (Viral) Meningitis is self-limiting
true
*Usually self-limiting as opposed to those caused by bacteria and fungus
Chronic Meningitis caused by normally? what is HIV present?
Mycobacterium tuberculosis
*immunodeficiency present= Crytococcus
Viral Encephalitis examples?
- Arboviruses - short for arthropod-borne virus.
- West Nile virus, a flavivirus, best known
- St. Louis & California encephalitis, western andeastern equine encephalitis
Herpes simplex I (HSV)
- most common cause of sporadic viral encephalitis in USA
- Causes hemorrhagic
- necrotizing encephalitis
- treat with antiviral agents * * 1/3 of infections
Herpes simplex 2 (HSV)
- neonates born to women with active genital lesions
- Devastating encephalitis
- 2/3 of infections
Anencephaly
hypoplastic or absentcranial vault
Sina Bifida
incomplete closure of embryonic neural tube
in Neural Tube Defects what is elevated in respect to gestational age?
Maternal alpha fetoprotein
One of the most malignant
of all tumors, but rarely metastasizes?
Astrocytoma – “Glioblastoma Multiforme”
Arises from nerve sheath cells?
Acoustic Schwannoma (Neuroma)
-Schwann cells of cranial nerve VIII within the external
auditory canal
- dizzy, hearing loss, NF-2
most common demyelinating
disease? involves what?
Multiple Sclerosis
** Autoimmune disease involving T-cell mediated injury to myelin sheaths
Demyelinated areas called
plaques
most common cause of
dementia in the elderly?
Alzheimer’s Disease
(HIV most common cause in young adults in the USA)
Involves dopamine
secreting neurons of the
substantia nigra
Parkinsonism
Lou Gehrig’s disease
Progressive degenerative disorder involving the upper & lower motor neurons of the pyramidal system. *** Motor neuron disease
Lou Gehrig’s death from?
respiratory insufficiency and infections
most common life-threatening diseases of the
peripheral nervous system?
Guillain-Barre Syndrome
“Pill rolling” tremor
Parkinsonism
1) Type I (NF-1) aka?
2) Type 2 (NF-2) aka?
1) von Recklinghausen disease
2) bilateral acoustic or central
neurofibromatosis
Hyperphosphorylated “Tau”
protein and extracellular Beta Amyloid plaques?
Alzheimer’s Disease
Neurofibromatosis Type 1
- most common
- chromo 17
- cafe-au-lait spots
- overactivity of the RAS oncogene
- oral neurofibromas, enlarged fungiform papillae and mandibular foramina
Lisch Nodules
Dendritic Melanocytic Hamartomas
Neurofibromatosis Type 1 (NF-1)
Neurofibromatosis Type 2
-chromo 22
- disrupts normal tumor
suppressor function
- affects merlin
- Neurofibromas rarely found
- Bilateral acoustic neuromas (schwannomas) involving VIII nerve leading to hearing loss
- Café au lait spots and Multiple meningiomas
(benign tumors of the meninges)
