Symptoms, signs, pathological processes, cerebral haemodynamics Flashcards
What are the words describing different levels of loss of sensation?
loss- Anaesthesia
heightened- Hyperasthesia
altered- Parasthesia
What are the words describing different levels of sense of smell?
lost- Anosmia
diminished- Hyposmia
What are the words describing different levels of sense of taste?
lost- Ageusia
diminished- agueusie
What is the difference between monoplegia, paraplegia, hemiplegia and quadriplegia?
Muscle paralysis of:
one limb -Mono
2 limbs -Para
one side of the body -Hemi
4 limbs -Quadri
What are the words describing different types of altered movements?
Kinesia:
Hyper- excess normal or abnormal movements Dys- impairment of voluntary movement Hypo- decreased bodily movement A- lost movement Brady- slow movement
List examples of hyperkinesias
- tremors
- convulsions
- chorea
- athetosis
Convulsion
- seizure
* sudden, violent, irregular movement of the body, caused by involuntary contraction of muscles
Chorea
• jerky involuntary movements
Athetosis
- abnormal muscle contraction causes involuntary writhing movements
- ex. pill rolling in cerebral palsy
What are the words describing different types of altered speech?
Dysphasia -deficiency in the generation of speech
Aphasia -inability to generate speech
dysarthria
difficult or unclear articulation of speech that is otherwise linguistically normal
apraxia and dyspraxia
difficulty planning a movement, even though they know what it is and how to do it
What are the words describing different types of altered reflexes?
hyperreflexia
hyporeflexia
Pathologic changes in the NS can be classified in what 3 broad groups?
a) Focal lesions
b) Diffuse/generalised disorders
c) Systemic nervous diseases
What is a NS focal lesion?
causes localized disturbance of function
What is a NS diffuse/generalised disorder?
- infective, metabolic, toxic, vascular
* affect NS and supporting elements throughout NS
What is a NS systemic nervous disease?
- pathologic process shows predilection for a particular neuronal structure or group
- anterior horn cells, cerebellum, corticospinal tracts
Gliosis
Damage to brain -> multiplication and enlargement of neuroglia with increased fibril production -> cell atrophy -> dense meshwork of fibres -> scarring
Satellitosis
- oligodendrocytes increased in number and size when neurones are damaged
- microglia phagocytose damaged cells and their degradation products
What are the fundamental types of nerve injury?
a) neuropraxia
b) axonotmesis
c) neurotmesis
What is neuropraxia?
- transient iteration of nerve conduction WITHOUT loss of axonal continuity
- Schwann cells start to remyelinate the axon
What is axonotmesis?
- transection of axons (or loss of integrity) with preservation of endoneurium
- wallerian degeneration -> repair if cell body intact
- Schwann cells functional -> some scar tissue
What is neurotmesis?
- complete disruption of nerve fibre and connective tissue surrounds
- loss of normal architecture
- wallerian degeneration
- needs surgical intervention repair
What occurs following axon damage?
a) chromatolysis- nissl bodies break into finer masses
b) (distal) Wallerian degeneration- swelling, neurofilament hypertrophy, myelin sheath shrinks and disintegrates, neurolemma remains; axon disappears
c) (proximal) swelling and dispersal of Nissl substance, cell increase metabolic activity, protein synthesis, mitochondrial activity; new terminal sprouts project
What occurs during axon regeneration?
1) macrophage phagocytose debris
2) protein synthesis accelerates
3) Schwann cells multiply and connect both ends
4) regenerating axon evade Schwann tube, growing toward distal part of axon (if gap not too large)
What factors influence cerebral oxygenation?
- cerebral blood volume
- cerebral blood flow
- cerebral perfusion pressure
- intracranial pressure
What determines cerebral blood volume?
- diameter of blood vessels
- arterial blood pressure
- total blood volume
- brain activity
What determines cerebral blood flow?
cerebral perfusion pressure divided by cerebrovascular resistance (influenced by length, diameter, laminar flow, arrangement of vessels)
What is cerebral perfusion pressure? what influences it?
- pressure gradient btw arteries and veins
- influenced by mean arterial pressure and intracranial pressure
- usually constant