Cerebral Angiography measurs what?
- Density - radio opaque fluid is injected to carotid arteries.
- Good for revealing tumors
What do Myelograms measure?
- Density - radio opaque fluid (same as Cerebral Angiography) injected into subarachnoid space
- Good for revealing spinal cord tumors
Computed Tomography scans measure what?
- Density - they are x-rays of cross sections of your body
- Makes soft tissues more visible
- Can distinguish occlusions from hemorrhages by looking at the density of the tissue (flooded with blood = hemorrhage)
Magnetic Resonance Imaging measures what?
- The electromagnetic signals from the nuclei of cells is momentarily deflected (scrambled). When they return to position, they emit a unique signal.
- Different cells have different signals, so you can tell when something is normal or pathological
B-Mode Carotid Imaging measures what?
- Composition (ultrasound)
- Reveals regions of stenosis of the the extra cranial arteries or carotids
- Not ideal for cranial arteries since the ultrasound waves cannot penetrate bone.
Carotid Phonoangiography measures what?
- Microphone listens to the blood flow of the carotids
- ex: more thrombi = noisier blood
Transcranial Doppler Ultrasound measures what?
- High frequency sound wave targets specific arteries in the cranium
- Determines blood pressure and flow
Electroencephalogram measures what?
- Activity (EEG)
- Records the electrical activity of the cerebral cortex
- If there is a focal disturbance in the electrical activity, the rhythm is off and a lesion is present
- Brain potentials are evoked by various stimuli
Electromyography measures what?
- Invasive (hook needles in muscles)
- Electrical activity in muscles at rest indicated presence of fasciculations or fibrillations
Position Emission Tomography measures what?
- Activity (PET scan)
- Glucose solution tags areas of greatest activity and blood flow
- Good for regions of hypofunction/inactivity
Single Photon Emission Computer Tomography measures what?
- Activity (SPECT scan)
- Measues the rCBF and looks for regions of inactivity
Functional MRI measures what?
- Doesn't use radioactive isotope tracers
- Detects increased hemoglobin (iron) in a magnetic field
Which pathologies are considered gradual/uninterrupted?
Dementia, degenerative diseases, and tumors (astrocytoma)
Which pathologies are considered rapid/uninterrupted?
Malignancy (glioblastoma multiforme), encephalitis, ALS
Which pathologies are considered to be rapid/plateaus (versus uninterrupted)?
Occlusive (thromboembolic) disease
Which pathologies are considered gradual/remission?
Multiple sclerosis, vasuclar disease (esp. small arteries)
Which diseases are considered familial (tendency in family)?
Arteriosclerosis, hypertension, cancer, alzheimers
Which diseases are condsidered hereditary?
Huntington's Chorea, Myotonic Dystrophy, Friedrich's Ataxia
Damage to CN5 Trigeminal can cause what?
Weakness of masseter and Temporalis muscles results in deviation of jaw to injured side
Normally has present jaw-jerk reflex (rapid downward motion elicits upward contraction)
Damage to CN7 Facial causes what?
Results in Bell's Palsy, drooping expression of affected side
Damage to CN8 Vestibulocochlear (Auditory) causes what?
Loss of acuity and equilibrium
Damage to CN9 Glossopharyngeal causes what?
Weakened gag reflex - velum deviates away from affected side due to contraction of the intact side
Contributes to afferent (sensation) component of gag reflex
Damage to CN10 Vagus causes?
Weakened palatal elevation, loss of gag reflex, vocal fold paralysis on injured side
Contributes to the efferent (motor) component of gag reflex
Damage to CN11 Accessory causes what?
Damage to CN12 Hypoglossal causes what?
Fasciculation, deviation toward side of damage (tongues is pushed across midline by "stronger" side)
Lateral retinal fields are contralateral or ipsilateral?
Ipsilateral - lateral like on your glasses stems
Light arrives finally at the ipsilateral cortex
Nasal Retinal fields are contralateral or ipsilateral?
Contralateral, and cross at point of optic chiasm
Light arrives finally at the contralateral cortex
Damage (lesion) to posterior optic chiasm results in what?
Homonymous Hemianopsia for OPPOSITE/contralateral visual field:
Left temporal lobe = right visual field cut (Wernicke's) and vice versa
Tunnel Vision is caused by a lesion where?
- Crossing fibers of the optic chiasm are destroyed
- Right and left visual fields are cut, leaving only nasal retinal fields
MCA & PCA supply what?
Macula of the retina
Damage to visual cortex results in anopia, although the watershed area of MCA and PCA means limited damage
A Dr. taking your passive arm and holding it over your head is testing for what?
Spasticity - resistance to rapid stretch
What is spastic catch hypotonia?
Abrupt increase in movement that elicits resistance
What is clasp knife phenomenon hypotonia?
movement at continuous rate leading to diminished resistance
Choreas, athetosis, dystonia, myoclonus all result because of damage to what system?
Fasciculations and Fibrillations result because of damage where?
LMN, peripheral damage
Disturbed recognition of objects through touch (due to damage in sensory cortex) is what?
Agnosias are what?
The inablility to recognize stimuli that can otherwise be recognized through another modality where the affected modality has normal sensation
Is a NEGATIVE diagnosis
Inablitity to names SEEN items
Inability to recognized HEARD items
Pt. can recognize common nonverbal sounds but has severely impaired comprehension of words (Wernicke's area is isolated from the auditory cortex)
Auditory-Verbal agnosia (Pure Word Deafness)
Inability to recognize items through touch (unseen)