14. Nervous System II - Pathologies Flashcards
Raised Intracranial Pressure: definition
Increase in pressure within the cranial cavity
Raised Intracranial Pressure: pathophysiology
Compression of blood vessels leads to reduced oxygen perfusion to the brain
Raised Intracranial Pressure: aetiology
- Tumours - gliomas (primary), metastases
- Haemorrhage - subdural (venous, slow), subarachnoid (arterial, rapid)
- Hydrocephalus - excess CSF
- Meningitis - inflammation of meninges
- Encephalitis - inflammation of brain tissue
- Intracranial abscess
Raised Intracranial Pressure: signs and symptoms
Headache - worse on awakening*, when coughing or moving head
Vomiting - often without nausea
Visual disturbance - if damage to optic nerve
Pupil fixed/dilated in one eye
Impaired mental state
Altered speech
Seizures
Papilloedema - bulging of the optic disc
Elevated blood pressure, slow irregular pulse, slow breathing
*CSF at daily peak
Hydrocephalus: definition
Abnormal accumulation of CSF in the cerebral ventricles and subarachnoid space
Hydrocephalus: pathophysiology
Impaired absorption or excessive secretion
Results in ventricular dilation
CSF permeates through the ependymal lining into the surrounding white matter
Hydrocephalus: aetiology - young children
Infection or congenital malformation
Hydrocephalus: aetiology - older children/adults
Tumour
Trauma
Meningitis
Hydrocephalus: signs and symptoms
Headache - worse on awakening - CSF doesn’t drain well whilst lying down
Infants - increase in head circumference and dliated scalp veins
Vomiting, nausea
Blurred or double vision
Neck pain
Hydrocephalus: allopathic treatment
Diuretics - inhibit CSF secretion
Shunt, ventricular drain, lumbar puncture
Emergency - to prevent white matter scarring/brain damage/death
Meningitis: definition
Infection or inflammation of the meninges
Can be life-threatening if leads to intracranial pressure
Meningitis: aetiology
Viral meningitis (herpes simplex) - most common cause (90%). Less severe
Bacterial infection - more serious
Fungal/parasitic micro-organisms
Non-infective - brain tumour
Meningitis: signs and symptoms
Can initially resemble flu:
~~~
Fever
Sudden onset of severe headache
Neck stiffness
Photophobia
Vomiting
~~~
Petechiae - small purple/red spots on skin as result of tiny haemorrhages that don’t disappear under pressure (non-blanching)
Kernigs sign - pain resistance to knee extension when lying with the hips fully flexed
Brudzinski sign - neck flexion causes flexion of hip and knee
Meningitis: diagnostics
Lumbar puncture: withdraw CSF between L4-L5
Meningitis: complications
Swelling
Raised ICP*
Septicaemia
Seizures
*Intracranial pressure
Meningitis: allopathic treatment
Antibiotics, antivirals, corticosteroids
Analgesics, antipyretics (to lower temperature)
Intravenous fluids
Concussion: definition
Temporary loss of neuronal function
Concussion: aetiology
Significant blow to the head
Concussion: signs and symptoms
Loss of consciousness
Memory loss of events surrounding the injury
Headache
Disorientation
Nausea/vomiting
Concussion: allopathic treatment
Rest
If any consciousness lost, avoid any vigorous activity for 3 months
Cerebral Contusion: definition
Traumatic brain injury that causes bruising of the brain with ruptured blood vessels and oedema
Cerebral Contusion: aetiology
Blunt blow to the head
Cerebral Contusion: signs and symptoms
Headache Confusion Dizziness Loss of consciousness Nausea Vomiting Seizures Difficulty with co-ordination/movement Impaired memory, vision, speech, hearing
Cerebral Contusion: allopathic treatment
Medical emergency
Coup injury: definition
Injury to the site of primary impact
Contrecoup injury: definition
Damage to the brain at a site contra-lateral to the site of trauma
The skull acts to stop acceleration of the brain away from the site of impact, causing damage to the opposite side
Headaches: aetiology
- Dehydration
- Cervicogenic (from the neck)
- TMJ* - jaw headache (structural)
- Tension (muscular)
- Congested sinuses
- Hypoglycaemia
- Migraine/cluster (Trigeminal nerve)
- Medication - e.g. paracetamol
- Intra-cranial - e.g. brain tumour, haemorrhage
- Organ referral
*Temporomandibular joint
Cervicogenic headache:
location, duration, severity, pain character
Occipital to frontal/temporal
1 hr to weeks
Moderate to severe
Non-throbbing pain, dull and deep
Tension headache:
location, duration, severity, pain character
Diffuse (bilateral)
Hours to days
Mild to moderate
Dull pain
Migraine headache:
location, duration, severity, pain character
Retro-orbital (behind eyes)
4-72 hrs
Moderate to severe
Throbbing, pulsating
Cervicogenic headache: aetiology
Neck movement, sustained postures
Cervicogenic headache: signs and symptoms
Reduced neck range of movement (ROM)
Cervicogenic headache: allopathic treatment
Stretching
Supporting neck
Massage
Tension headache: aetiology
Stress
Muscle tension
Tension headache: signs and symptoms
Reduced appetite
Photophobia
Tension headache: allopathic treatment
Rest
Massage
Relaxation
Migraine headache: definition
Neurological condition that results in recurrent, severe headaches
Migraine headache: aetiology
Strong links with genetics - more common in women
Food allergies
Food additives - tyramine, nitrates, MSG, aspartame, histamine, alcohol
Emotions - stress
Hormonal changes
Poor sleep
Low levels of serotonin (link with digestive function)
Complex series of intracranial vascular changes - vasoconstriction (aura) and subsequent vasodilation (headache)
Induced by cerebral depolarisation - this secretes vasodilators and pain mediators
Migraine headache: signs and symptoms
Aura - occurs hours to days before headache (tingling, changes in vision, smell)
Unilateral, pulsating headache (retro-orbital)
Moderate to severe intensity, worsened by movements
Photophobia
Phonophobia
Nausea, vomiting (which can improve symptoms)
Migraine headache: allopathic treatment
Analgesics - ibuprofen
5-HT agonists*
Bind to and activate 5-HT (serotonin) receptors in the brain.
Headaches: red flags
First onset
of headache over 50 yrs old
Thunderclap headache
(subarachnoid haemorrhage)
Signs of intracranial pressure:
Worsening morning headaches, uneven pupils, double vision, tunnel vision, papilloedema, vomiting but no nausea
Signs of meningitis:
Headache, neck stiffness, non-blanching rash, positive Kernig/Brudzinski tests