Wk11 Damage And Repair In The CNS Flashcards
Head injury facts
- in 2013-14 there were 162,544 admissions for head injury
- admissions in uk with brain injury related diagnosis increased by 10% since 2005-6
- men are 1.6x more likely than females to be admitted for head injury
Why is repair in the Injured CNS so complicated?
Cell to tissue
Proliferation and migration Contact inhibition of proliferation Loss of neighbouring cells Réactivation of neighbouring cells Réactivation of proliferation Tissue repair (damage accumulates)
From multipotent cell to neuronal networks
Proliferation and migration
Neuronal differentiation —> synapse formation
Synapse plasticity —> altered connectivity and network reorganisation
C1 to C8 functions affected
Cervical nerves Head and neck Diaphragm Wrist extenders Triceps and hand
T1 to t12 functions affected
Thoracic nerves
Chest muscles
Abdominal muscles
L1 to L5 functions affected
Lumbar nerves
Leg muscles
S1 to S5 functions affected
Sacral nerves
Bowel
Bladder
what do functional consequences of injury rely on?
Depend on the site and size of the injury not the type of injury
Energy supply - brain
– 2% of the total body mass
– consumes 15% of the energy generated in the body
– no energy stores of its own (small amount of glycogen in astrocytes)
– energy is derived exclusively from glucose metabolism.
Cerebral amyloid angiopathy and lobar hemorrhage
Alzheimer’s
Fibrous protein deposits become brittle leading to giant haemorrhage
Arterio-venous malformations
Large number of dilated blood vessels with bad walls - can form embolisms
Aneurisms
Blood coagulated over time - increased inter cranial pressure
Lacunar infarcts and white matter damage
Tissue dies and leads to liquid filled hole
Traumatic brain injury
- Impact - cerebral contusions and lacerations
- Movement of the brain inside the skull - subdural hematoma and diffuse axonal injury
Consequences:
• Hematomas (epidural and subdural ) – compression of the brain, raised intracranial pressure
• Contusions and diffuse axonal injury - structural brain damage
• Hypoxic injury, focal ischemic lesions
• Multiple lesions and different types of lesions
Hypoxia - ischemic brain injury
– Drop in cerebral perfusion (Global ischemia) - cardiac arrest or severe hypotension (shock) – Hypoxia - CO poisoning – Hypoglycemia – severe anemia – generalized seizures