CNS Flashcards
1
Q
What is this group of cells called?
- Perform various support functions
- _____ cell types:
- Astrocytes
- Oligodendrocytes
- Microglial cells
- Ependymal cells
A
Glial Cells
2
Q
What is this type of glial cell?
- 20-40% of glial cells
- Form BBB
- Maintain appropriate chemical environment for neuronal signaling
- Proliferate in response to injury (“glial scar”)
- foot processes
A
Astrocytes
3
Q
What is this type of glial cell?
- Form myelin around axons in the CNS
- A single _______ can extend its processes to 50 axons
A
oligodendrocyte
4
Q
What is this type of glial cell?
- 10-15% of all cells
- Derived from circulating monocytes
- Resident macrophages of CNS; remove cellular debris from sites of injury or normal cell turnover
- “Scavengers of the brain”
A
Microglial cells
5
Q
What is this type of glial cell?
- Line the cerebral ventricles and central canal of spinal cord
- Form choroid plexus; secrete cerebrospinal fluid
A
Ependymal Cells
6
Q
What are two of the unique responses CNS has to injury?
A
– Liquefactive necrosis
– Gliosis
7
Q
Why is Cerebral edema worse than edema in other parts of the body?
A
• “Enclosed space”
- Brain and spinal cord surrounded by dura
- Expansion is limited
8
Q
What is this type of Cerbral edema?
• Extracellular edema
- swelling is occuring around the cells
- cells will look spread out
- BBB disrupted
- Response to trauma or tumors
A
Vasogenic Cerbral Edema
9
Q
What is this type of Cerbral edema?
- Intracellular edema
- BBB intact
- Response to ischemia or hypoxia
- Cells themself are what swells
- cells will look bigger and closer together
A
Cytotoxic Cerebral Edema
10
Q
What is this type of herniation?
- Temporal lobe has herniated across the tentorium.
- The midbrain is displaced and compressed
A
Uncal Herniation
aka Transtentorial
11
Q
What is this type of herniation?
- Displacement of cingulate gyrus from one hemisphere to the other, under falx cerebri
A
Subfalcine Herniation
Aka Cingulate
12
Q
What is this type of herniation?
Cerebellar tonsils are displaced into the foramen magnum and the medulla is compressed
- lots of respiratory problems because the medulla has the respiratory centers
A
Cerebellar Tonsillar Herniation
13
Q
What is the name of this hemorrhage?
- Secondary brainstem hemorrhages in a patient with uncal herniation
- Caudal displacement of the brainstem and stretching of its vessels
A
Duret Hemorrhages
14
Q
What is this type of hyrodcephalus?
– Obstruction of CSF flow within ventricular system
A
Non-communicating (obstructive)
15
Q
What is this type of hyrodcephalus?
– Impaired CSF resorption
A
Communicating (nonobstructive)
16
Q
What is this type of hyrodcephalus?
– Dilatation of ventricles due to loss of brain tissue
A
Hydrocephalus ex vacuo
17
Q
What is this cerebrovascular disease–type of stroke?
- Systemic: severe hypotension/shock
- blood is not reaching the brain
- Hippocampus and cerebellum most sensitive areas
- Clinical: persistent vegetative state or brain death in severe cases
A
Global Cerebral Ischemia
18
Q
What is this general term for a cerbrovascular disease where there is neuronal damage caused by a lack of blood flow (ischemia) or bleeding?
A
Stroke
- 3 causes
- Thromboembolic disease
- Hemorrhage
- Global cerebral ischemia
19
Q
What is this cerebrovascular disease–type of stroke?
- Usually due to thromboembolic vascular occlusion
- Type of ischemic stroke
- Most common in distribution of middle cerebral artery
- May be hemorrhagic (ischemia-reperfusion injury)
- blood is going to build up pressure behind occlusion
A
Cerebral Infarct
20
Q
What is this type of cerebral hemorrhage that can lead to stroke?
- Most commonly results from hypertension
- Basalganglia, thalamus, pons most common sites
- Complications include cerebral edema and herniation
A
Cerebral Hemorrhage- Intraparenchymal
21
Q
What is this type of cerebral hemorrhage that can lead to stroke?
- Usually due to ruptured aneurysm “berry aneurysm”
- Clinical: Sudden onset of severe headache, stiff neck
- Bloody CSF
- High morbidity and mortality
A
Subarachnoid Hemorrhage
22
Q
What is this type of cerebral hemorrhage that can lead to stroke?
- Malformations of one or several blood vessels
- May cause parenchymal or subarachnoid hemorrhage
A
Vascular Malformations
23
Q
What is this type of cerebral hemorrhage that can lead to stroke?
- Concussion
- Diffuse axonal injury
- Contusions:
- Edema and hemorrhage; cortical surface most affected
- Coup - beneath site of trauma to an immobile head
- Contrecoup - opposite to the site of trauma, due to a rapidly moving head that impacts an immobile surface
A
CNS Trauma
24
Q
What is this type of traumatic CNS hemorrhage?
- Usually due to artery laceration secondary to skull fracture
- May develop rapidly
- Outside dura
A
Epidural Traumatic CNS hemorrhage
25
What is this type of traumatic CNS hemorrhage?
* Tearing of “bridging veins”
* May become chronic
* beneath dura
* occurs mostly in elderly people with loss of brain tissue because brain is smaller but skull is the same size s you are at more risk to have brain move and rupture veins when you fall
Subdural
26
What kind of hemorrhage could occur after a large fall and blood accumulates quickly?
Acute Subdural Hemorrhage
27
What is this congenital malformation?
* Most common CNS malformation
* 1,500 per year in U.S.
* Due to failure of closure of embryonic neural tube at caudal (lumbosacral) end
* Symptoms
* Sensorimotor deficits in legs
* Bowel/bladder incontinence
Spina Bifida
28
What is this type of spina bifida?
* most common, least severe
* loss of one vertebrae
* tuft of hair at skin surface
Spina Bifida Occulata
29
What is this type of spina bifida?
* Fluid sac moves outside spine because of loss of one vertebrae
* but no spinal cord actually in the sac
Meningocele
30
What is this type of spina bifida?
* sac of fluid outside spine with spinal cord contents
Myelomeningocele
31
What is this neural tube defect?
– Defect of anterior end of neural tube
– Absence of the cerebrum and top of the skull
– About 1,000 per year in U.S.
– Incompatible with life- usually stillborn
Anencephaly
32
What is this neural tube defect?
* Herniation of brain tissue through a skull defect
* Posterior (most common)
* Anterior (sinonasal)
* Maybe associated with neurologic deficits
Encephalocele
33
What is this forebrain malformation?
– Failure of hemisphere/lobar development
– Associated with craniofacial anomalies
\*one large hemisphere!
• Holoprosencephaly
34
What is this forebrain malformation?
– Agyria, “smooth brain”
Lissencephaly
35
What is this forebrain malformation?
Brain is small
Microcephaly
36
What is the Most common cause of intraventricular hemorrhage in premature infants?
* Related to hypoxia, acidosis, hypercarbia
* May lead to fetal death or scarring leading to hydrocephalus
Germinal Matrix Hemorrhage
* Perinatal Injury
37
What is the perinatal injury related to poor oxygenation?
* Seen in both term and premature infants
Necrosis of White Matter
38
What is this infectious disease of the CNS?
* Due to trauma or spread from infections of adjacent structures
* Abscess formation
* Increased in patients with neural tube defects
Epidural/Subdural Infection
39
What is this infectious disease of the CNS?
* High fever, headache, stiff neck, confusion, skin rash (meningococcus)
* CSF findings
* Neutrophils
* High protein
* Low glucose
* Bacteria on gram stain/culture
Bacterial Meningitis
40
What is this type of meningitis?
* Can be seen with any viral infection, usually self-limited
* Clinical: similar to bacterial, but less severe
* CSF: lymphocytes, normal glucose, slightly increased protein; PCR
Viral Meningitis (Aseptic Meningitis)
41
What is this type of meningitis?
* TB, Cryptococcus neoformans (AIDS), syphilis
* Morphology is variable
* Can cause vascular obstruction due to proliferative changes leading to infarction in underlying brain
Chronic Meningitis
42
Identify:
* Usually bacterial
* Direct implantation, or local or hematogenous spread
* Neurologic deficits, increased intracranial pressure
* Treatment-antibiotics, surgical drainage
Brain Abscess
43
What is the most common cause of encephalitis?
* Viral encephalitis - most common cause of encephalitis
* Common causes
* Arbovirus: arthropodborne
* West Nile Virus
* Dengue
* Zika
* Herpes simplex: HSV Type I
* Hemorrhagic, necrotizing, temporal lobes
* Cytomegalovirus: CMV
* Neonates, immunocompromised
* HIV encephalitis: progressive neurologic disease
* Poliovirus, Rabies virus
44
Identify:
* JC virus, a polyomavirus; attacks oligodendrocytes
* Immunosuppressed patient
* demylinating disease
Progressive Multifocal Leukoencephalopathy (PML)
45
What is this type of menigoecephalitis?
* Usually immunosuppressed patients
* Organisms
* Candida
* Aspergillus
* Mucormycosis (uncontrolled diabetes)
* Cryptococcus
Fungal Meningoencephalitis
46
What is this parasitic CNS disease?
* Neonates (chorioretinitis, hydrocephalus, intracranial calcification)
* Immunosuppressed adults
* from cats
• Toxoplasmosis
47
What is this parasitic CNS disease?
* Encysted larvae of tapeworm, *Tenia solium*
* Inflammatory response after organism death may worsen symptoms
* Larvae grow in brain
Cysticercosis
48
What is this parasitic CNS disease?
* Organism- Naegleria fowleri- swimming in warm lakes
* kid hurts cribiform plate while swimming organisms get into brain
* cause necrosis
* Usually fatal
Amebic meningoencephalitis
49
What is this type of Encephalopathy CNS disease?
* Prion transmission, proteins **without DNA or RNA**
* Creutzfeldt-Jacob disease, Mad Cow disease, Kuru (humans in New Guinea), scrapie (animals)
* Major infection control concern in hospitals
* Prions are **not** inactivated by routine disinfectants/fixatives
* super hard to get rid of
* All of these prion diseases are characterized by:
* **Vacuoles in the gray matter**
* Clinical: progressive dementia and other neurologic abnormalities, death within 1 year after onset is typical
Spongioform Encephalopathy
Vacuoles in the gray matter (“spongiform”)
50
What is this **Primary** CNS tumor?
* **Most common type of primary CNS malignancy**
* Arise from glial cells
* Astrocytoma
* Oligodendroglioma
* Ependymoma
Gliomas
51
What is this type of Glioma?
* 80% of adult gliomas
* Diffusely infiltrating
* WHO Grade
* Grade 2 (diffuse astrocytoma)
* Grade 3 (Anaplastic)
* Grade 4 (Glioblastoma Multiforme)
Astrocytoma
52
What is this type of Glioma?
* 5-15% of adult gliomas
* Grading is related to prognosis
* Grade 2 (Well differentiated)
* Grade 3 (Anaplastic)
Oligodendroglioma
53
What is this type of Glioma?
* Fourth ventricle in children
* Spinal canal in adults
Ependymoma
54
Identify this Primary CNS tumor:
* Well-circumscribed
* Arises from meninges
* WHO grades I-III
* Location determines surgical resectability
Meningioma
55
Identify this Primary CNS tumor:
* Arises from Schwann cells of eighth cranial nerve
* Well circumscribed; benign
* Clinical: hearing loss, dizziness, mass effect
Schwannoma (Acoustic Neuroma)
56
What is the only cancer that is more common than Primary CNS tumors in peidatrics?
Leukemia
57
What is this Pediatric Infratentorial (Posterior Fossa) Primary CNS tumor?
* 60% located in posterior fossa
* Typically 5-15 years of age
* 25 year survival (90%) after resection
* Hair like processes
Pilocytic astrocytoma
58
What is this Pediatric Infratentorial (Posterior Fossa) Primary CNS tumor?
* 15-20% of pediatric brain tumors
* Occur in 4-11 year age group
* Located in cerebellum
* Blue cell tumor
* means its high grade proliferating rapidly
Medulloblastoma
59
What is this general disease type of the CNS?
* interferes with the transmission of impulses along nerve fibers
* Findings are most prominent in white matter which is composed of nerve fibers & oligodendrocytes
Demyelinating Disease
60
What is this demyelinating disease?
* Clinical
* Visual disturbances (optic chiasm), paresthesias, spasticity, gait disturbances, numbness/weakness
* Symptoms distributed in time (acute vs. chronic) & location-worse than better than worse than better
* Cause
* Likely autoimmune with genetic susceptibility and environmental factors
* Laboratory features
* CSF: increased gamma globulin (IgG)
* Oligoclonal bands of immunoglobulin
Multiple Sclerosis
61
What is this nutritional disorder?
* Subacute Combined Degeneration
* Associated with pernicious anemia
* Causes vacuolar demyelination of the long tracts of the spinal cord (corticospinal and posterior columns)
Vitamin B12 (Cobalamin) Deficiency
62
* Caused by thiamine (B1) deficiency
* Commoninchronic alcoholics
* Confusion, ataxia and abnormalities in eye movements
Wernicke’s Encephalopathy
* Korsakoff syndrome
* When memory disturbances are combined with this deficinecy!
63
* Most common cause of dementia
* Slowly progressive memory loss, behavior changes common
* Sporadic and familial cases
* Increasing incidence with increasing age
* Familial forms less common, earlier onset
* Pathology
* **Brain atrophy, neuritic plaques and tangles that contain beta amyloid**
* Death from other causes; often infection
Alzheimer Disease
64
* Movement disorder
* characterized by rigidity, tremor, and slowness of movement (bradykinesia)
* Loss of dopamine-producing neurons in substantia nigra
* Slow onset with progressive deficits
* Death usually from other causes
* Treatment
* Drugs (L-Dopa, dopamine agonists, MAO inhibitors
* Surgical (deep brain stimulation)
Parkinson’s Disease
65
* Loss of motor neurons in motor cortex, brainstem & anterior horn of spinal cord
* Results in progressive muscle weakness
* Usually insidious onset; most cases sporadic
* Little dementia or cognitive decline
* Median survival 5 years
* because of respiratory problems
Amyotrophic Lateral Sclerosis
* (ALS; Lou Gehrig’s Disease)
