Neurological disorders

What is microcirculation ?

Blood flow through arterioles, venules + capillaries

What type of membranes do capillaries have?

Basement membrane

What is an intracellular cleft ?

Small gaps between continous lining of endothelial cells

Which 3 places are intracellular clefts mostly found ?

Skeletal muscle
Lung tissue
Connective tissue

What is a fenestrated capillary?

Epithelium riddled with filtration pores = ^ permeability and has intracellular clefts

Where are fenestrated capillaries found?

Kidneys
Small intestine

What is sinusoid capillary ?

Missing / incomplete basement membrane + large fenestrations

Where are sinusoid capillaries found?

Bone morrow
Liver

What is sinusoid capillaries function ?

Allow whole blood cells out into intracellular space

What are the 3 functions of the blood / brain barrier?

Maintains stable environment

Regulates fluid + ion passage between blood + brain tissue

Regulates entry + exit of nutrients + waste

What are 3 layers blood / brain barrier ?

Endothelium
Basement membrane with pericytes + macrophages
Polarised astrocytes feet

What is different about the blood / brain barriers endothelium ?

Has tight junctions = harder to cross barrier

What do pericytes do in blood / brain barrier?

Monitors what passes through the BBB by contracting / diluting

What is the function of polarised astrocytic feet in the blood / brain barrier?

Control fluid + electrolyte balance

Where are polarised astrocytic feet found in the blood / barrier membrane?

Wrap around the basement membrane

What 2 things does a molecules have to be in order to cross the blood / brain barrier?

Small
Lipid soluble

Name 4 things that can easily cross the blood brain barrier?

Water
O2
CO2
Glucose

How does sodium cross the blood / brain barrier?

Transported in can't diffuse in

What does the blood / brain barrier not let in for pts with Parkinson's disease?

Dopamine

Name 4 bad things that can cross the blood / brain barrier?

Heroin
Alcohol
Meningitis bacteria
Nicotine

What are the two types of non-blanching rashes?

Petechial - under 2mm
Purpuric - over 2mm + can blanch initially

What is nuchal rigidity in meningitis diagnosis?

Resistance to neck flexion

What is kernels sign in meningitis diagnosis ?

Knee extension pain when hip is flexed

What is brudzinskis sign in meningitis diagnosis?

When neck is flexed, stiffness = knees and hips to flex

What does a spinal tap extract?

Cerebrospinal fluid

What are the two sites for cerebrospinal tap?

L3-5

What is meningitis ?

Inflammation of meninges + subarachnoid space

What are the risk factors of meningitis?

Under 25
Pregnancy
Working with animals
Immunodeficiency
Communal living

What are the 3 types of infections that can cause meningitis?

Viral
Bacterial
Fungal

Which is usually the most serious type of meningitis ?

Bacterial meningitis

What is the name of the bacteria that causes meningococcal septicaemia?

Neisseria meningitidis

What is the leptomeninges?

Pia mater + arachnoid mater

What are the two ways pathogens can reach the subarachnoid space?

Direct - via sinuses or skin cuts

Haemotogenous - in blood and passes through blood brain barrier into space

What are the symptoms of meningitis?

Gradual onset persistent headache not made better with painkillers
Fever
Neck stiffness
Photophobia
Hyperacusis- loud sounds = worse pain

What are the two types of neurons ?

Excitatory
Inhibitory

What occurs in result of an unbalanced excitatory / inhibitory neuronal response?

Seizure

Name 8 causes for seizures

CNS infection
Pyrexia
Cerebral hypoxia
Hypoglycaemia
Alcohol withdrawal
Brain tumour
CNS stimulating drug abuse eg ADHD + narcolepsy meds

Name 4 possible causes of epilepsy

Neurotransmitter imbalance
Previous brain injury
Genetic
Idiopathic

What are the 4 stages of having seizure?

Prodromal
Aura
Ictus
Post ictus

What is the prodromal phase of having seizure?

Time between internal symptoms (eg headache + irritability) and the seizure

What is the aura stage of having a seizure?

Altered sensation prior to seizure eg drowsy, smell / taste

What is the ictus stage of having a seizure?

The actual seizure

What is status epilepticus ?

When pt doesn't fully recover before their next seizure or seizure is more than 5 mins

What is the post-ictus stage of a seizure?

Seizure has ended but pt is not fully recovered - confused, headache, tired

What are the 6 types of generalised seizures?

Tonic - clonic
Tonic
Clonic
Absent
Myotonic
Atonic

What is a tonic seizure?

Full body stiffness - muscle contraction

What is a clonic seizure?

Rhythmic jerking

What is a myotonic seizure?

Sudden muscle contraction for a few seconds- pt have no memory of it

What is an atonic seizure?

Sudden lack of muscle tone = sudden drop

What is sudden unexpected death in epilepsy (SUDEP)?

Sudden unexpected non-traumatic death of epileptic patient

What are the risk factors of SUDEP?

Have epilepsy for over 15 years
Got epilepsy before age of 16
Young adult

What are the two types of focal seizures?

Focal aware
Focal impaired awareness

What id a focal aware seizure?

Often called the aura stage of a bigger seizure to come

No altered level of consciousness

No seizure related movement

What is a focal impaired awareness seizure?

Altered level of consciousness

Can have Alice in wonderland syndrome

Repetitive actions eg rubbing hands together or reaching for things that aren't there

What are the risk factors of seizures?

Developmental disabilties
Born undersized
Cerebral palsy
Family Hx
Autism
Alzheimers

How can seizures be treated long term?

Seizure devices in brain
Epilepsy surgery removing part of brain
Seizure medications

What are the two common ages for epilepsy to start?

Childhood or over 60

What is a stroke?

Interruption to blood supply in part of the brain

What are the two types of stroke and which is more common?

Ischemic - more common
Haemorrhagic

What is a thrombotic stroke?

Artery narrowed due to atherosclerosis

What are the two types of ischemic stroke?

Thrombotic
Embolic

What is an embolic stroke?

Blood clots from elsewhere in the body travel to brain and block BVs

What causes the ischemic cascade?

Ischemic strokes

What are the main parts of the cerebral ischemic cascade?

Mitochondrial dysfunction = anaerobic respiration

Na+, K+ pump dysfunction due to lack of ATP as not enough O2 for active transport = sodium build up = cytotoxic oedema

How does clot = mitochondrial dysfunction in the cerebral ischaemic cascade?

Not enough O2 = anaerobic metabolism

Calcium build up from Ca+ / Na+ pump = apoctic factor degrading cell membrane

How does Na+ / Ca+ pump dysfunction cause cell membrane degradation in the cerebral ischaemic cascade?

Na+, Ca+ pump. dysfunction = calcium build up in the cell = excitotoxicity (neurone firing too fast) + activates degradative enzymes + free radicals that break down cell membranes = programmed cell death = infarction + necrosis

How does Na+ / K+ pump dysfunction = cytotoxic oedema in neuron

Na+ / K+ pump dysfunction = Na+ build up = osmosis = cytotoxic oedema

What are the main 4 steps in cerebral inflammation?

Ischemia = inflammation

DAMPS (damage associated molecular patterns) = inflammation

Anti-inflammatory =

Necrosis

What stimulates DAMPs in cerebral inflammation?

Damaged / dying cells

What do DAMPs do?

Promotes inflammatory response - macrophages flood area

How do holes form in the brain from cerebral inflammation?

Necrosis of brain tissue from inflammation becomes a cyst then turns into hole

How long does it take for a brain cavity to form?

2 weeks

What are 3 issues with hemorrhagic stroke bleeding in the brain?

Blood compresses the brain tissue increasing intercrainal pressure

Tissue elsewhere now has no blood as never got there

Blood breaks down into chemicals that irritate other vessels

How can a secondary stroke be causes from hemorrhagic stroke?

Blood breaks down into chemicals that irritate other vessels = vasoconstriction = low blood supply = secondary stroke

What are the two causes of a hemorrhagic stroke?

Cerebral aneurism
Arterial venous malformation

What is a cerebral aneurism ?

Vessel in the brain bulges out + can rupture

What can cause a cerebral aneurisms?

Chronic HTN
Congenital / genetic

What is an arterial venous malformation ?

Abnormal connection between BVs and capillaries = high pressure blood flow to capillaries = can rupture

What causes arterial venous malformation ?

Congenital

What are the risk factors of arteriole venous malformation?

HTN
Oral contraceptive
Pregnancy
Substance abuse

What is a TIA?

Temporary disruption to brain blood supply

How long do TIAs last?

mins - hrs + fully resolve in 24 hrs

What are the symptoms of a TIA?

FAST symptoms
Loss of balance / coordination
Visual disturbances
Confusion

What can cause a TIA?

Clots
Air bubbles
Amniotic fluid

Name 8 risk factors of TIA?

Smoking
Drinking
Obesity
HTN
^ cholesterol
AF
Diabetes
over 55
Asia / African Caribbean

What are the treatments for TIA?

GP give low dose aspirin
Health review
Surgery to clear out artery

How long after a TIA are pts high risk for a stroke?

4 weeks

What is spina bifida ?

Defect of neutral tube (turns into spinal cord once developed)

What are the symptoms of spina bifida?

Urinary or doubly inconntinent

Paraplegia
Leg weakness
Loss of leg sensation
Learning difficulties
Hydrocephalus (fluid build up in brain)

What causes spina bifida?

Unknown

Name 3 risk factors of spina bifida?

Hereditary
Low folic acid during pregnancy
Medications

How can spina bifida be diagnosed?

Assess movement for paralysis
Ultrasound bladder to assess unreel storage
Scan brain fro fluid (Hydrocephalus)

Whats the treatment for spina bifida

Pre/postnatal surgery
Physiotherapy
OT
Mobility aids

What is Hydrocephalus?

Fluid build up in brain = ^pressure = cerebral damage

What are the 3 types of Hydrocephalus?

Congenital
Acquired
Normal pressure

What are the symptoms of congenital Hydrocephalus?

Unusually large head
Thin shiny scalp w visible veins
Poor feeding
Vomiting
Lethargy
Muscle stiffness /spasms in legs

What causes congenital Hydrocephalus?

Spina bifida
Premature babies
Genetic disorders

How is congenital Hydrocephalus diagnosed?

Ultrasound un utero
Newborn examination

How can congenital Hydrocephalus be treated?

Surgery:
Shunts to remove fluid

Drill hole to allow fluid to reabsorb

What is cerebral palsy?

Group of disorders affecting movement, posture + coordination from brain damage