Investigations Flashcards
Cranial CT scan
computer-processed combinations of many X-ray measurements taken from different angles to produce cross-sectional images of specific areas of a scanned object - allows user to see inside without cutting into it
Magnetic Resonance Imaging (brain and spine)
strong magnetic fields, magnetic field gradients, and radio waves are used to generate images of the organs in the body
EEG
electrophysiological monitoring method to record electrical activity of the brain - typically noninvasive with the electrodes placed along the scalp
EEG clinically refers to the recording of the brain’s spontaneous electrical activity over a period of time
Lumbar puncture
a needle is inserted into the spinal canal, most commonly to collect cerebrospinal fluid (CSF) for diagnostic testing
Nerve conduction studies
medical diagnostic test used to evaluate the function and ability of electrical conduction of motor/sensory nerves
Cranial CT indications
suspected brain damage/injury
- eg intracranial hematomas, cerebral contusions, edema. foreign bodies
neurological conditions
sudden hearing loss
conditions involving the skull/sinuses
to guide surgery
Cranial CT contraindications
coronal images require the person to hyperextend their neck - avoided if any possibility of neck injury exists
exposed to ionising radiation - increased risk of brain cancer esp in children, avoid in pregnant ladies
some people can be allergic to contrast agents used n CT scans
MRi indications
neurological cancers - better than CT for visualization of the posterior cranial fossa, containing the brainstem and the cerebellum
CNS conditions - demyelinating diseases, dementia, cerebrovascular disease, infectious diseases, Alzheimer’s disease and epilepsy
(due to better tissue contrast between grey/white matter than CT)
to guide surgery
MRI contraindications
most cochlear implants
cardiac pacemakers
shrapnel
metallic foreign bodies in the eyes
used with contrast in pregnancy
EEG indications
epilepsy sleep disorders depth of anaesthesia coma encephalopathies brain death
sometimes tumours, stroke, focal brain disorders
EEG contraindications
essentially none
lumbar puncture indications
help diagnose CNS diseases eg
- meningitis/infections
- subarachnoid haemorrhage
- inflammatory/neoplastic disease
- hydrocephalus
- benign intracranial hypertension
- fever without source in children
can also be used therapeutically
- inject medication eg spinal anaesthesia, intrathecal chemo
- temporary treatment for idiopathic intracranial hypertension
- normal pressure hydrocephalus
lumbar puncture contraindications
idiopathic increased ICP - could lead to herniation
bleeding diathesis (unusual susceptibility to bleed/hypocoagulable)
infections
vertebral deformity
lumbar puncture complications
post spinal headache and N/V - give fluids and pain meds
- IV caffeine injection can abort headache
CSF leak - blood patch
paraesthesia
rare:
spinal or epidural bleeding
adhesive arachnoiditis
trauma to the spinal cord/nerve roots
nerve conduction study indications
carpal tunnel syndrome cubital Tunnel Syndrome Guillain–Barré syndrome peripheral neuropathy peroneal neuropathy spinal disc herniation tarsal Tunnel Syndrome ulnar neuropathy
essentailly investigation of paresthesias (numbness, tingling, burning) and/or weakness of the arms and legs
