pathophysiology Flashcards
what is delirium?
Delirium: disturbance of consciousness and cognition that develops over a short period of time (hours to days) and fluctuates over time
what type of conditions can include delirium?
o ICU psychosis
o ICU syndrome – type of organic brain syndrome manifested by variety of psychological reactions including fear, anxiety, depression, hallucinations and delirium
o Acute confusional state
o Encephalopathy
o Acute brain failure
hoe prevalent is delirium?
occurs in between 20-80% of medical and surgical patients
what is seen in hypoactive delirium?
decreases responsiveness, withdrawal and apathy
what is seen in hyperactive delirium?
agitation, restlessness and emotional lability
which type of delirium has better outcomes?
hyperactive
the pathophysiology of delirium is poorly understood, what are potential hypothesis behind it?
o Neurotransmitter imbalance: excess of dopamine and depletion of Ach, but other NT are likely to be involved
o Inflammation: abnormalities induced by endotoxin and cytokines play a role. The mediators that cross BBB in animal studies increase vascular permeability changes seen on EEG. Inflammation may also reduce cerebral blood flow via formation of microaggregates of fibrin, platelets, neutrophils and erythrocytes
o Impaired oxidative metabolism: the reduction is in oxidative metabolism
what can cause delirium?
- D: drugs
- E: eyes and ears
- L: low O2 – MI, ARDS, PE, CHF, COPD
- I: infection
- R: retention of stool/ urine
- I: ictal
- U: underhydrated and under nutrition
- M: metabolic
- S: shock, sleep deprivation
if cerebellum pathology what signs would be seen?
affects fine motor
ataxia
speech/ language deficits
dysdiachokinesia
past pointing
uncoordinated walking
what is intentional tremor?
tremor on nose to finger exam
rhythmic, oscillatory, and high amplitude tremor during a directed and purposeful motor movement, worsening before reaching the endpoint
how would an upper motor lesion present?
flexed
hypertonia
spasticity
positive toe test - flexed toe on babinski test
how would lower motor lesion present?
hypotonia
floppy
fasculitations
how is bells palsy managed?
50mg 10 day course of pred - step down
eye drops for lubrication
what are the signs of cerebellar dysfunction?
DANISH
D: dtsdiachokinesia
- A: ataxia
- N: nystagmus (coarse)
- I: intention tremor
- S: scanning speech
- H: hypotonia
what is nystagmus?
involuntary repetitive eye movements
side to side
up and down
circular motions
what is the function of the midbrain?
- Helps with sleep cycle
- Pain
- Movement
- Transmitting info about hearing
what info does the ascending tracts relay?
sensory from peripheries to brain
what are the two tracts within ascending tracts?
- Conscious: dorsal column-medial lemniscal and anterolateral
- Unconscious: spinocerebellar
the conscious ascending tract is the dorsal column-medial, what info does it carry?
tactile sensation - fine touch ]
vibration and proprioception
the anterolateral conscious tracts is split into anterior and lateral spinothalamic, what info do they carry?
anterior spinothalamic: crude touch and pressure
lateral spinothalamic: pain and temperature
what info does the spinocerebellar - unconscious tracts send?
proprioception
are tracts contralateral?
Most is contralateral opposite side (90%)
why can some people recover from spinal tract injury?
10% of info remains ipsilateral
can relearn using these tracts if not damaged
what pathology would be seen with damage to dorsal column medial tract?
affects conscious
deficits in fine touch eg cotton wool - can not feel
can not feel vibration
proprioception - moving toe/ thumb up or down
