Lec 3 Flashcards
What kind of complex meylin is ?
Protein lipid complex
What cells make myelin in cns , pns
Oligodendrocytes, schwann
What is the predominant component of white matter
Myelinated axons
What is the function of myelin
İnsulation of axons , quick transmission of neural signals
What is the main pattern of myelin injury in pns
Segmental demylination
Causes of demylinating neuropathies
Hereditary , immune destruction of myelin
Segmental demylination is related to which cell
Schwann , and can be primary or secondary due to axonal damge
Hypertrophic neuropathy is a complication of which disease , what is its appearance under the microscope
Due to re - demylination cycles of schwann cells in segmental demylination , onion bulb appearance
What is the clinical features of perephiral neuropathy related to segmental demylination
İmpaired function of the damaged nerve : muscle weakness and atrophy , pain , loss of sensation , parasthesia , AN dysfunction ( loss of bowel , bladder control )
What is parasthesia
Any abnormal sensation , numbness, pricking , tingling , burning sensation without real physical stimulus
What are peripheral neuropathies
Affects the function of one or more peripheral nerves , devided into: Axonal neuropathy (axonal degeneration) 90% Demyelinating neuropathy (segmental)
The most common cause of generalised peripheral neuropathy
Diabetes ( diabetic neuropathy )
All causes of peripheral neuropathy
Axonal damage :
Diabetes most common
Others : amylodosis , tumor , trauma , alcoholism , neurotoxic drugs , infections , autoimmune , vasculitis, CRF , nutritional diff
So any toxins , infections , infiltrative diseases , vascular diseases
Demylinating : immune destruction , heridetary ++ diabetes
The Risk of developing diabetic neuropathy depends on
Duration of diabetes , level of control of blood sugar
What is the most dangerous about diabetic neuropathy
(Most imp )The presence of cardiovascular autonomic neuropathy.
And loss of feeling in the lower limb is a high risk for amputation
Types of neuropathies in diabetic n
- Distal symmetric sensorimotor polyneuropathy ( most common )
- Autonomic neuropathy
- Lumbosacral
How increased glucose damages the nerves
- AGE which causes microangiopathy , ischemia to nerves
2. Polyol pathway , low nadph , low glutathione wich is an antioxidant
What cells have age receptor
Macrophages, endothelial , vascular smooth muscle cells , t lymphocytes
Rage - age interaction effects
- ros formation
- cytokines and growth factors
- Procoagulant activity
- Proliferation of smooth muscle and extracellular matrix
The effect of high sorbitol
Edema
Guillian barre syndrome after what
Autoimmune neuropathy
After infections , immunization , surgery
What microorganisms can cause gb syndrome
Cmv ebv corona-sars2 compylobacter jejuni
What lab tests can be in gb syndrome
Csf : high protein , low wbc
What kind of paralysis happen in gb
Acute symmetric ascending neuromuscular paralysis ( but can involve sensory and autonomic disturbances )
What is fisher syndrome
5% Gb syndrome patients who have ophthalmoplagia , ataxia , areflexia
What is the most dangerous about gb syndrome
Diaphragm paralysis (muscular) Cardiac arrhythmia , hypo , hypertension (autonomic)
Summerize chronic inflammatory demylinating polyneuropathy
Chronic sensorimotor poly neuropathy
Immune mediated but not after infections
Associated with autoimmune diseases and aids
Myelin diseases in pns
GB
CIDP
Segmental demyelination
Diabetic neuropathy
