Neuro System Pathology 1 Flashcards
What is the most common cause of infant meningitis?
Escherichia coli. Bacterial causes of meningitis are usually more common (and also more life threatening) than other causative agents.
Infection with Clostridium botulinum is associated with what kind of paralysis?
Flaccid paralysis
What microbe causes Lyme disease?
Borrelia burgdorferi (in the Americas) and Borrelia afzeli and Borrelia garinii (in Asia and Europe)
A patient comes in with fever, nausea and vomiting, stiff neck and petechiae. What is a likely diagnosis?
Neisseria meningitidis infection
Clostridium tetani causes what kind of paralysis?
Spastic paralysis
In what tissue can hsv-1 become latent?
The sensory ganglion cells of the dorsal root (trigeminal) ganglion, in sensory neurones
How does polio cause paralysis?
By destroying motor neurons in anterior horn and medulla
Which polio vaccine is alive attenuated and given orally?
Sabin
Which polio vaccine is inactivated multivalent and injectable?
Salk
What are the two types of leprosy?
Lepromatous and tuberculoid leprosy
Which type of leprosy is less infectious and has less bacteria?
Tuberculoid leprosy
Which type of leprosy is more infectious and has lots of bacteria present?
Lepromatous leprosy
Which type of leprosy is associated with defective cellular immunity?
Lepromatous leprosy. Specifically the dysfunctional expression of IL-2 receptors.
What happens when a neuron in the central nervous system (cns) is damaged?
The neuron and target cell and cells targeting that neuron atrophy and die. It is not replaced and damage is permanent
What happens when a neuron in the peripheral nervous system is damaged?
The neuron will try to repair itself and restore function through a process called the axon reaction, which involves:
(1) Sealing the severed ends to prevent loss of axoplasm
(2) Phagocytosis of the axon and synapse distal to the damaged area by the Schwann cells
(3) Filling in of the synaptic spaces by the Schwann cells
(4) Sending out sprouts from the axon proximal to the cut ends which enter connective tissue and form a synapse with the target cell
What are two examples of intraneuronal bodies?
(1) Pick bodies, which are dense spherical masses seen in Pick’s disease
(2) Lewy bodies, which are densely packed fine filaments found in the brains of patients with Parkinson’s disease
Neurofibrillary tangles are a type of intraneuronal body seen in the brains of what types of patients?
Patients with Alzheimer’s disease, supranuclear palsy, and post-encephalitic Parkinsonism
What are the effects of glial cell reactions on the body?
(1) They protect neurons and facilitate rebuilding
(2) They are destructive and cytotoxic when out of physiological control
What causes increased intracranial pressure?
(1) Space-occupying lesions, tumors
(2) Hemorrhage
(3) Tumors
(4) Cerebral edema
(5) Hydrocephalus
What are the types of cerebral edema?
(1) Vasogenic edema - caused by increased vascular permeability
(2) Cytotoxic edema - increase in intracellular water after cell injury, such as ischemia
(3) Interstitial edema - fluid accumulation in white matter with hydrocephalus
What causes hydrocephalus?
Decreased absorption or overproduction of csf
What is the major constituent of the white matter in the cns?
Myelin (which contains fat that gives white matter its distinct hue).
What are the two categories into which diseases of myelin may be grouped?
(1) Acquired diseases of myelin-previously normal myelin degenerates
(2) Hereditary myelin diseases, leukodystrophies - abnormal myelin from hereditary metabolic defects
Where are inclusion bodies found that are diagnostic features of viral infection in the brain?
(1) Herpes simplex, herpes zoster, and papovavirus - found in the nucleus
(2) Rabies - found in the cytoplasm
(3) Cytomegalovirus - found in nucleus and cytoplasm
What organisms cause bacterial meningitis?
Escherichia coli, main cause in newborns
Haemophilus influenzae B
Streptococcus pneumoniae, main cause in adults
Neisseria meningitidis, epidemic meningitis
What are the symptoms of encephalitis, a condition in which bacteria infect the brain?
Fever
Nausea and vomiting with neck pain
Focal neurological abnormalities
Seizures
Cognitive changes
What are Argyll-Robertson pupils?
A small, irregular pupil occurring in neurosyphilis in which the pupil accommodates normally with convergence but does not react to light.