Neuropathology COPY Flashcards
REVIEW:
What are the three layers
of the meninges and
what spaces lie between them?
Skull
Epidural
Dural
Subdural
Arachnoid
Subarachnoid
Pia
Brain
Review:
What are the primary functions
of each lobe of the cerebrum?
Frontal: Motor functions,
behavior, emotions, higher intellect
Parietal: sensory
Temporal: hearing, speech
Occipital: Visual
REVIEW;
What are the three components
of the brainstem and
what do they do?
Midbrain: visual & auditory reflex centers
Pons: connection between cortex, cerebellum and medulla
Controls chewing, biting, swallowing, facial expressions, sensation
Medulla Oblongata: cardiac, vasomotor and respiratory centers
REVEIW:
What does the Cerebellum do?
Major regulator of motor activities
Integration of:
Sensory impulses from spinal cord and vestibular organ
Motor impulses of Cerebral Cortex
REVIEW
Where is the gray matter
and white matter
in the brain and spinal cord?
Brain: generally gray on the outside, white on the inside (but some gray on the inside as well.
Spinal Cord: gray on the inside, white on the outside
REVIEW:
What are key differences
between neurons and glial cells?
Neurons:
Nondividing, postmitotic, permanent cells
Glial Cells:
facultative, mitotic (labile), capable of dividing
What are the six types of cells in the nervous system,
what do they do,
and what do you call their tumors?
Neurons: signalling/information, neuroma
Glial Cells: support, glioma
Astrocytes: support, blood brain barrier, astrocytoma
Oligodendrocytes, myelination in brain, oligodendroma
Ependymal Cells: lining ventricles, ependymoma
Schwann cells: peripheral myelination, Schwannoma
Microglia, immune response, NO tumors!
What are the nine major types of diseases
of the nervous system?
- Developmental, genetic diseases
- Malformations
- Trauma
- Circulatory (vascular) disorders
- Infectious diseases
- Autoimmune diseases
- Metabolic, nutritional diseases
- Neurodegenerative and demyelinating diseases
- Brain tumors
What is a dysraphic disorder?
Incomplete closure
of the embryonic neural tube
What are three types of
dysraphic disorders
occuring at the hind end?
Spina bifida: incomplete closing of the backbone and membranes around the spinal cord. Three types:
Spina bifida occulta: outer part of vertebrae slightly open
Myelomeningocele: spinal cord and meninges protruding
Meningocele: meninges protruding
What happens
when the head end of the neural tube
does not close properly?
Anencephaly: absense of a major part of the brain and skull
Encephalocele: protursions of the brain through the skull that are coverered with membrane
What are four types of
CNS hemorrhages
and their causes?
Epidural Hematoma: middle meningeal artery rupture
Subdural Hematoma: bridging vein rupture
Subarachnoid Hematoma: 1. Trauma, 2. Aneurism
Intercerebral Hemorrhage: 1. Trauma, 2. HTN
What is the fifth leading cause of death in the US?
Hint: it used to be number 3!
Cerebrovascular Disease
What are the two types of stroke and their incidence?
Ischemic (85%)
atherosclerosis, occlusion of blood vessels
Hemorrhagic (15%)
often a complication of HTN
REVIEW:
What are the three large cerebral arteries?
What part of the brain to they perfuse?
Where do they originate?
Anterior Cerebral Artery (ACA) from Internal Carotid,
perfuses medial surface of frontal and parietal lobes
Middle Cerebral Artery (MCA) from Internal Carotid
perfuses lateral surfaces of frontal, temporal, parietal lobes
Posterior Cerebral Arteries (PCA) from Vertebral Artery
perfuses posterior aspect of temporal, occipital lobes
A patient has an MRI
showing an intracerebral hemorrhage
in the basil ganglia.
What is the likely cause?
Hypertension
(Trauma is most common cause
of intracerebral hemorrhage though)
What causes cerebral herniations?
Cerebral Edema
Where are the four most common locations
for cerebral herniations?
Which is most serious?
Tonsillar Herniation (most serious)
(cerebral tonsil exits skull through foramen magnum)
Transtentorial (uncinate) herniation
(cerebral uncus at cerebral-pontine angle)
Subfalcine herniation
(cingulate gyrus at falx)
Herniation through opening in broken skull
Which is more serious,
a concussion or a brain contusion?
A contusion is more serious.
Concussion: transient loss of consciousness
Contusion: disruption of blood supply, can lose consciousness later, produce neurological deficit
What is Coup and Counter Coup?
Coup (a “blow” in French) is the damage to your brain near where your head is hit
Counter Coup (on Contre Coup) is the damage where your brain hits the opposite side in response to the coup
What are three ways
an infection can get inside the brain?
Penetrating trauma
Hematogenous Spread (blood vessels)
Nearby infections (otitis media, sinuses)
NOTE: if you squeez a pimple, it drains into your sinuses!
What are the four most common organisms
causing as infection
in the nervous system?
Bacteria
Viruses
Fungus
Protazoa
What bacteria
can cause an infection
in the nervous system?
Neisseria meningitidis,
S. pneumo,
E. coli,
H. influenza,
Treponema pallidum
(Hematogenous Route or Septic Emboli)
What viruses
can cause an infection
in the nervous system?
Measles
Rubella
Adenovirus
Herpesvirus
Cytomegalovirus
Rabesvirus
(via Hematogenous Route)
What fungi
can cause an infection
in the nervous system?
Candida albicans
Aspergillus flavus
Cryptococcus neoformans
(Hematogenous route)
What protazoa
can cause an infection
in the nervous system?
Toxoplasma gondii
(Hematogenous route)
Name four types of infections
of the Nervous System
Encephalitis:
inflammation of the brain parenchyma, usually viruses
Myelitis:
inflammation of the spinal cord, usually viruses
Cerebral Abscess:
suppurative cavitary lesion
from pyogenic bacteria, fungi or both
Meningitis:
Inflammation of meninges, viral or bacterial
What is Multiple Sclerosis?
What is its incidence,
signs/Sx and
disease course?
Chronic, degenerative demyelinating disease
Incidence: women 2x men, genetic factors
Signs/Sx: loss of sense of touch, muscle weakness, unsteady gait, sphincter abnormalities
Course: exacerbation and remission
What is the difference
between and early and late lesion
in MS?
Early: Lymphocytes attack myelin,
macrophages consume the debris.
Late: Astrocytes and surviving axons
What are two congenital metabolic disorders
of enzymatic deficiency?
Tay-Sachs Disease
Neimann-Pick Disease
What is a common cause
and result
of a Vitamin B1 defiency?
Vitamin B1 (Thiamine) deficiency:
excessive, chronic alcohol intake can cause
Wernicke-Korsakoff Syndrome
(uncoordinated movements, progressive mental deterioration, memory and concentration loss, irritability, confusion)
What are the signs and symptoms
of Vitamin B12 (Cobalamin) deficiency?
Uncoordinated movements
Sensorimotor peripheral neuropathy
spinal cord disease
abnormal gait
psychiatric sx
What are the signs/sx
of nicotinic acid deficiency?
Dermatitis
Diarrhea
Delirium
(The three “D”s)
What are the effects of alcholism and B1 deficiency?
Wernicke Korskoff Syndrome
Subdural hematomas from falling
Pontine myelinolysis
Delirium tremens upon withdrawal
Degenerative changes to hypothalmus and mammillary bodies
Neuropathy
Myopathy
Name four neurodegenerative Diseases
Alzheimer’s disease
Parkinson’s Disease
Huntingon’s Disease
Amyotrophic Lateral Sclerosis (ALS)
Of the four key neurogenerative disorders,
what parts of the brain do they impact?
Alzheimer’s disease: diffuse (all over)
Parkinson’s Disease: substantia nigra
Huntingon’s Disease: cortex and subcortical nuclei (caudate, putamen)
Amyotrophic Lateral Sclerosis (ALS): motor neurons in the cerebral cortex, midbrain and spinal cord (lateral cerebrospinal pathways)
What is Alzheimer’s Disease?
Progressive loss of cognitive functions and memory due to diffuse cortical atrophy caused by deposits of beta-amyloid. Genetic factors include Chromosomes 19 and 21
(Recall that Down’s Syndrome is Trisomy 21)
Note: serious diagnosis with no cure
so be sure to rule out other causes of Sx.
What are the gross and histologic changes
in the brain of
an Alzheimer’s patient?
Gross: atrophic, narrowing gyri, widening sulci
Histologic: neuritic plaques, neurofibrillary tangles, granovacuolar degeneration, amyloid deposits
What is Parkinson’s Disease?
Subcortical neurodegenerative disorder
affecting mainly the elderly
Decreased dopaminergic neurons in the substantia nigra
What are the Signs/Sx
of Parkinson’s Disease?
Tremor/twitchin muscles
Cogwheel rigidity
Unstable walking
Depression
Dementia (10%)
What are the gross and histologic changes
to the brain
of a patient with Parkinson’s
Gross: substantial nigra is pale (not black)
Histologic: loss of melanin rich neurons,
presence of Lewy bodies
What is Huntington’s Disease?
Autosomal dominant neurodegenerative disease
affecting men more than women
What are the signs/sx of
Huntington’s Disease?
Involuntary, gyrating movements
Progressive dementia
First Sx do not appear until midlife
Most are mentally incapacitated by 50-60 yo
What are the gross and histological changes
to the brain
of a patient with Huntington’s
Gross: Atropy of cortex and subcortical nuclei,
especially the caudate and putamen
Enlarged and rounded ventricle
Histological: atrophy, degeneration, loss of neurons, reactive gliosis
What is
Amyotrophic Lateral Sclerosis (ALS)
Rare neurodegenerative disease
of motor weakness and
progressive wasting
affecting older men and women
What are the symptoms of ALS?
Motor weakness
progressive wasting in extremities (small hand muscles)
fasciculations
slurred speech
intact intellect!
Death in a few years.
What are the gross and histological changes
in the nervous system
of someone with ALS ?
Loss of motor neurons in the
cerebral cortex,
midbrain and
spinal cord
(loss of lateral cerebrospinal pathways)
Brain tumors occur at what age range?
Any age
What are the most common malignant
and benign
brain tumors
in children?
Malignant: Medullablastoma
Benign (low grade): pilocytic astrocytoma
What are the most common malignant
and benign
brain tumors
in adults?
Malignant: Glioblastoma
Benign: Meningioma
What are the primary locations
of brain tumors in
adults and
children?
Adults: supratentorial
Children: infratentorial
What is the difference in the impact on the brain
of gliomas versus
meningiomas?
Gliomas invade brain tissue
Meningiomas compress brain tissue
What is a glioblastoma?
Most common CNS tumor
Peak: 65 y.o.
Lateral hemispheres
Crosses corpus collosum!!
Highly variegated appearance (yellow, red, white, irregular shape)
What are the histologic characteristics of a
glioblastoma?
Anaplastic astrocytic cells
Enlarged, multinucleated cells w abundant cytoplasm
Mitoses
Necrosis
What is the AMEN criteria
for staging CNS tumors?
A - nuclear Atypia
M - mitosis
E-endothelial proliferation
N - necrosis
What is an oligodendroma?
Occurs in cerebral hemispheres
Middle-aged adults
Well circumscribed
Well differentiated
Can progress to glioblastoma
What is an ependymoma?
From ependymal lining of ventricles
Tumor cells form “pseudo-rosettes”
around papillary structures
What is a meningioma?
Arises from meninges
Can be benign or malignant
Compression can cause seizures or motor deficits
Excellent prognosis if benign
What is a Medulloblastoma
Most common malignant tumor in children
Cerebellum
Poor prognosis
What is the difference between a
Schwannoma and a
Neurofibroma?
Both can be solitary or multiple.
Neurofibromas are infiltrative.
Schwannomas are compressive (easy to resect)
Bilateral Schwannoma think Neurofibromatosis Type II
What is the most common
malignant tumor in the brain?
Metastasic
(so look for the primary tumor!)
Commonly from: lungs, breast, melanoma
What are the five most common PRIMARY brain tumors?
Glioma (75%)
Meningioma (15%)
Cranial/Spinal Tumors (neuroma/schwannoma)(5%)
Neural Cell Precursors (Medulloblastoma)(2%)
Others (3%)
(Hemangioma, cerebral lymphoma, pinealoma)
50% of ALL brain tumors are metastatis
