Images
When will you start to see ischemic brain changes on MRI?
30 min from onset stroke symptoms
What is the flow of CSF?
Produced by choroid plexus in ventricles, Flows from lateral ventricles into 3rd ventricle via inter ventricular foramen (of monroe), 3rd ventricle to the 4th ventricle via the cerebral aqueduct, 4th ventricle into the subarachnoid space via median aperture and lateral apertures (of Luschka), around outside of brain to the arachnoid granulations, filter CSF into superior sagittal dural venus sinus, back into the blood stream
What are the 3 primary vesicles that form as expansions of the neural tube during the 4th week?
forebrain (prosencephalon), midbrain (mesencephalon), and hindbrain (rhombencephalon)
Will a CN VIII lesion (at the vestibulocochlear nerve) cause ipsilateral or contralateral deficits? What are the expected deficits?
ipsilateral, vertigo, nystagmus, tinnitus, and sensorineural hearing loss
NCV helps diagnose.....
severity and location of nerve injury
What is the difference between CT and MRI?
CT use radiation and contrast media and MRI use magnet, CT scans take a fast series of X-ray pictures, which are put together to create images of the area that was scanned. An MRI uses strong magnetic fields to take pictures of the inside of the body.
When does the neural tube form?
End of third week of gestation
When does the neural tube form?
End of third week of gestation
Will a CN X lesion (at the vagus nerve) cause ipsilateral or contralateral deficits? What are the expected deficits?
ipsilateral dysphagia, dysphonia, dyspnea
Limits of NCV
can only test large nerves, can only test nerves in PNS
What type of stroke is CT ruling out, making it a good first step in emergency medicine?
hemorrhagic
causes of congenital hydrocephalus
failure of 4th ventricle foramina to open, blockage of the cerebral aqueduct, cysts in the fourth ventricle, Arnold-Chiari malformation, intraventricular hemorrhage, subarachnoid hemorrhage, meningitis
What happens if rostral end of neural cord doesnt close
anencephaly, non compatible with life
explain the different types of spina bifida from least to most extreme case
Spina bifida occulta - malformation of the bony spinal canal, the deformity of the vertebral arch is not apparent from the surface
Meningocele - protrusion of the meninges and CSF
Menigomyelocele - protrusion of the spinal cord, CSF, and meninges through a defect in the vertebral arch of one or more vertebre
what is being measured during NCV, what is the graph interpretation
all contracting units, conduction time is stimulus to beginning of M wave (peak - composite of all axons in nerve and contracting fibers), conduction time varies depending on stimulation site and how close to the motor end plate
When will you start to see ischemic brain changes on CT?
12 to 18 hour post stroke
What is the flow of language information during conversation included cortex and function
happens in left hemisphere, primary auditory cortex (loud/pitch of sound), secondary auditory cortex (classifies it as language vs. sounds), Wernicke's area (comprehend words being heard), subcortical connections (link Wernicke's to Broca's), Broca's area (instruction for language output), oral and throat region of sensorimotor cortex (speech muscles). this happens in left hemispheres
What happens if caudal end of neural cord doesnt close
Spinda Bifida
lesion to arcuate fasciculus manifestations
a white matter tract that runs between Broca's and Wernicke's areas, and thus is considered a disconnection syndrome because a lesion in the arcuate fasciculus is assumed to interrupt communication between the sensory and motor modules of the classically defined speech-language system
what is the difference between NCV and EMG?
NCV detects a problem with the nerve, whereas an EMG detects whether the muscle is working properly in response to the nerve's stimulus.
what is the purpose of EMG (electromyography)?
measures electrical potential of the muscles and nerves
What structure allows CSF to exit the subarachnoid space and enter the superior sagittal sinus?
arachnoid granulations
What develops from the mesoderm?
skeletal muscles, smooth muscle, blood vessels, bone, cartilage, joints, connective tissue, endocrine glands, kidney cortex, heart muscle, urogenital organ, uterus, fallopian tube, testicles and blood cells from the spinal cord and lymphatic tissue
internal capsule lesion manifestations
internal capsule stroke is caused by interruption of blood supply in the middle cerebral artery (MCA) or one of its small branches.
Pure Motor Hemiplegia. When the posterior limb of the internal capsule is affected by stroke, it generally affects movement and coordination, Facial Weakness, Cognitive Impairments, Sensory Loss, Hearing Impairments, Visual Impairments
what is Motor Unit Potential (MUP)
reading from EMG, bi or tri phasic, highest peak is activity of muscle fiber closest to electrode, smaller peak is other fibers join in