Week 4 Neurology Flashcards
Describe the parts of the brain supplied by the anterior, middle and posterior cerebral arteries?
What is the difference between the anterior circulation and the anterior cerebral artery?
The anterior circulation is everything going to the aterior brain and includes both the anterior cerebral artery and middle cerebral artery.
For example an occlusion in the internal corotid artery would affect the anterior circulation whereas if it was higher up in the anterior cerebral artery it would just be the anterior cerebral artery
What are the effects of a stroke depending which cerebral artery is affected?
What is the bamford classification of strokes? What are the four strokes and what defines them?
Thinking of the anatomy what is brainstem syndrome based on the part of the brain stem affected?
Generally: Contralateral motor and sensory symptoms for parts innervated by spinal nerves with ipsilateral cranial nerve problems with cranial nerves asscosiated with that area.
- Weber’s Syndrome
Location: Midbrain.
Symptoms:
Ipsilateral oculomotor nerve palsy (drooping eyelid, dilated pupil, and inability to move the eye).
Contralateral hemiparesis (weakness of the opposite side of the body). - Locked-In Syndrome
Location: Pons.
Symptoms:
Complete paralysis of voluntary muscles except for the eyes (blinking and vertical eye movements may remain intact).
Preserved consciousness and cognitive function. - Medial Medullary Syndrome
Location: Medulla.
Symptoms:
Contralateral limb weakness.
Contralateral loss of proprioception and vibration sense.
Ipsilateral tongue weakness (tongue deviates toward the affected side).
All have effects on motor and sensory below. Pons is total as lesion is often bilateral. They have localised effects on the corresponding cranial nerves.
What is a TIA?
Symptoms of ischemic stroke but resolved in 24h
First thing you do with a stroke?
CT scan without contrast to differentiate between haemorrhagic and ischaemic stroke
First line of treatment for an ischaemic stroke?
Perform/ Do/ Give/ Administer/ Gift / Enforce/ Oversee Thrombolysis - Usually alteplase.
Within 4.5h of symptoms
What are the contraindications to thrombolysis?
Basically anything that increases risk of bleeding.
Contraindications:
recent surgery
recent trauma to the head
taking anti-coagulant
systolic bp >185
Raised INR
What is the treatment for ischaemic stroke if it is 6-24h after symptom onset?
Mechanical thrombectomy
Mid length treatment for ischaemic stroke between 24h-2weeks?
Aspirin
Long term treatment after an ischaemic stroke >2weeks
- Clopidogrel 75mg daily (patient with AF requires warfarin or DOAC, this is initiated 2 weeks after stroke)
- Statin (atorvastatin 20-80mg daily)
- Lifestyle modification (diet, physical activity, alcohol intake, smoking)
Treatment for a haemorrhagic stroke?
Surgical intervention to releive cranial pressure if needed.
Aim to decrease BP to 120-139 systolic after 24h and maintain for 7 days
What layers of the brain will blood fill in between in a subarachnoid haemorrhage?
Underneath the arachnoid mater.
Above the pia mater.
What is the presentation of a subarachnoid haemorrhage?
Thunderclap headache (sudden onset and “worst headache they’ve ever had”)
Other symptoms may include reduced consciousness, seizures, focal neurological signs, meningism
Diagnosis of a sub arachnoid haemorrhage?
Most are visible on a CT, however this diminishes after 12h.
If appropriate history for SAH and negative CT brain, lumbar puncture (LP) performed to test for evidence of bleeding into CSF space: xanthochromia.
Need to do this 12 hours after onset (allows time for blood breakdown products)
If using a lumber puncture to detect SAH what are you looking for?
Xanthochromia: a medical condition that causes cerebrospinal fluid (CSF) to appear yellow
Order of management of a SAH
- Acute supportive care:
- basic resuscitation measures (e.g. airway support, ventilation)
- management of complications (e.g. seizures, intracranial pressure) - Nimodipine: prevents development of delayed cerebral ischaemia (which increases mortality) by preventing arterial vasospasm
- Secure aneurysm
- typically coiling (via endovascular procedure) or clipping (neurosurgical) - Ongoing rehabilitation and long-term care (including psychological support)
What drug might you use in SAH?
Nimodipine: prevents development of delayed cerebral ischaemia (which increases mortality) by preventing arterial vasospasm
What is the definition of meningitis?
Invasion of bacteria intot he meninges
What is the pathophysiology of meningitis?
- Invasion by bacteria leads to inflammation - Immune reaction; neutrophils (pus)
- Elevated intracranial pressure
- Inflammation and thrombosis in arteries
- can lead to ischaemia/stroke
- Damage to cranial nerves
- can lead to deficits (e.g. deafness)
3 most common microbial causes of meningitis?
1.Neisseria meningitidis (‘meningococcus’)
- Epidemic outbreaks (e.g. student halls)
- Streptococcus pneumonia (‘pneumococcus’)
- Haemophilus influenza
If there is an outbreak of meningitis in somewhre like student halls what is it likely to be caused by?
Neisseria meningitidis (‘meningococcus’)
If there is trauma what microbe might cause the meningitis?
Staphylococcus aureas (skull fractures)
Common environmental microbe.
Clinical features of meningitis?
- Acute headache – typically developing over hours
- Meningism: neck stiffness, photophobia
- Fever
- Non-blanching rash (meningococcus)
- Confusion, reduced consciousness
- Sometimes seizures
Exam:
Stiff neck
Kernig’s & Brudzinski’s
These lack sensitivity; often not be present
Think meningitis in anyone with fever and headache tbh