Clin Med Exam 3 Flashcards
Bipolar I
Manic episode + hypomanic or major depressive episode
Bipolar II
Hypomanic episode + major depressive episode
Membrane potential - net __ charge inside cell
Negative
Sodium concentration is greater where?
Outside cell
Potassium concentration is greater where?
Inside cell
Cell membrane is more permeable to which ion?
Potassium
How is resting membrane potential maintained?
- Na-K pump –> K in and Na out of cell
2. K passively leaving cell
In the presence of a chemical or electrical stimulus that reaches threshold…
- Membrane permeability to Na increases
- Na rushes into cell due to electrical and chemical gradient
- Depolarization of cell
ALS
Increased glutamate
Extremities affected first
Eye movement, sensation, B&B preserved
Huntington’s Disease
Autosomal dominant
Random involuntary movements, dysdiadochokinesia
Atrophy of basal ganglia
Multiple Sclerosis
Progressive demyelination (CNS)
Relapsing/ remitting
2 neurological lesions
Exercise helps function, avoid excess fatigue
Parkinson’s Disease
Disease of basal ganglia, increased dopamine produced
Characterized by tremor, rigidity, bradykinesia
Festinating gait, cogwheel
PT: big movements
Alzheimer’s disease
Slow decrease in memory, cognition, and behavior
Neurofibrillary tangles, amyloid plaques
Charcot Marie Tooth Disease
Hereditary PNS disease
Demyelination, often of peroneal nerve –> foot deformities
Guillan-Barre Syndrome
Progressive weakness due to infection that progresses from extremities up, may eventually lead to respiratory issues
Lesions in motor and sensory fibers –> demyelination
Post-polio strength
Declining muscle strength in previously affected muscles
Never exercise to point of fatigue
Myasthenia Gravis
Disease of neuromuscular transmission, decreased numbers of ACh receptors.
Generalized proximal weakness, especially eyes
Close monitoring for fatigue is important
Acute pain
Chronic pain
Pain that continues after noxious stimulus is gone
Allodynia
Interpretation of pain in response to a typically non-painful stimulus
C fibers
Most common nociceptors Unmyelinated and small Transmit dull, throbbing, aching pain Slow onset, long lasting Respond well to opioids
A-Delta fibers
Myelinated and small
Transmit sharp, stabbing, pricking pain
Quick onset, shorter duration
Do not respond well to opioids
Sensitization of nociceptors
Activation threshold is decreased –> hypersensitive
Achieved via chemical mediators e.g. histamines, bradykinins, prostaglandins
Peripheral sensitization
Takes place at tissue site, nociceptors are hypopolarized
Central sensitization
Brain interpretation center is hypopolarized
Includes both specific and wide-dynamic range
wide dynamic range respond to both noxious and non-nonxious stimuli
A-beta fibesr
Larger fibers that activate SG (inhibit T cells and pain transmission)
Where do a-delta fibers synapse?
More dorsal laminae (lower numbered laminae)
Where do a-beta fibers synapse?
Deeper, higher numbered laminae
What do T-Cells do?
Communicate with anterior horn cells –> muscle spasm –> compression of nerve endings –> physical stimulus –> pain –> spasm –> repeat
SG is inhibited by…
A-delta and C fibers
Ascending method of pain modification:
Gate theory
Descending method of pain modification:
Endogenous opioids block pain modulators (e.g. substance P) –> blocks peripheral sensitization
3 Mechanisms of seizure disorder drugs
- Increase activity of GABA (CNS inhibitory neurons)
- Decrease activity of CNS excitatory neurons (glutamate, aspartate)
- Stabilize opening and closing of neuronal Na and Ca channels, prolonging absolute refractory period
Barbiturates
Increase effect of GABA
Benzodiazepenes
Potentiate inhbitory effect of GABA
Valproates
Limit sodium entry into excited neurons
2nd generation drugs compared to 1st generation
2nd generation drugs have more favorable pharmacokinetics, but use same mechanisms and are not necessarily more effective
Adrenocorticotropic Hormone
Used for infants who do not respond well to usual seizure medications
Side effects of seizure meds
Sedation
Lack or change of coordination/ cognition
Cerebral arteriography
Radiopaque contrast injected to map abnormalities in brain. Used for identification of ischemic and hemorrhagic stroke
Carotid duplex scan
Ultrasound of carotid to assess obstructions. Adds blood flow velocity to imaging. Used for TIA
Computed Tomography
Used for CNS diseases
MRI
Better than CT for contrast between normal and abnormal tissue, better for congenital malformations
Used for CNS diseases
PET
Used for CNS diseases (decreased activity with AD)..highly radioactive
Myelography
X-ray image of subarachnoid space of spinal canal, used for SCI
Electroencephalogram
Used for dx of seizures
Electromyography
Used in muscle diseases and to differentiate between neurological conditions
Nerve conduction tests
Used to identify and document severity of peripheral nerve damage
Lumbar puncture
Used to diagnose infections
