STROKE

After getting hooked publising my first blog last week and spending the rest of the week checking the number of blog "hits" with a similar level of enthusiasm that I showed towards my Tamagotchi years ago, I am continuing my medical undergraduate education blog; What I Taught Today (WITT) on the most frequent cause of severe adult disability in Scotland.  STROKE

We started by looking at the WHO definitions of stroke

"a clinical syndrome consisting of rapidly developing clinical signs of focal (or global in case of coma) disturbance of cerebral function lasting more than 24 hours or leading to death with no apparent cause other than a vascular origin"

This differs only in duration from a TIA which is defined as <24 hours.  Despite the fact that clinically a TIA typically resolves within a few hours, you have to be careful as just because the symptoms have gone and signs are no longer present patients should not just be brushed aside and discharged.  The ABCD2 scoring system is used to stratify patients into 2 day risk of stroke (0-3 = 1% 4-5 = 4% and 6-7 = 8%).  Our ED and acute medics use a score of 4 or greater as an admission criteria.

The risk factors for stroke are almost identical to coronary heart disease with the important addition of EMBOLI Sources. AF, Cardiac Valves and Carotid Plaques.

Neurological examination is reputedly the most difficult of all OSCE stations taking into account:

•Pronator Drift  •  Tone  •  Power•  Reflexes•  Coordination •  Cranial Nerves  •Gait•  Visual Fields  Cerebellar Signs Speech 

 

 Everybody has their own mnemonic for the cranial nerves many of which have become out dated.  Keeping down with the kids here is one they've been using and I've been encouraging.  (It a Harry Potter reference for those potterphobes out there)
 

On                          OLFACTORY    
On                          OPTIC
On                          OCCULOMOTOR
They                       TROCHLEAR
Traveled                 TRIGEMINAL               
And                        ABDUCENS
Found                     FACIAL
Voldemort              VESTIBULOCOCHLEAR
Gathering                GLOSSOPHARYNGEAL
Very                       VAGUS
Ancient                   ACCESSORY
Horcruxes               HYPOGLOSSAL

Click HERE to see how to carry out a succinct cranial nerve examination for OSCE examinations.

Following on from examination we covered how to classify our findings initially into the very useful UPPER vs LOWER motor neuron lesions then further developing into the Oxford Classification of Stroke.  This is a useful classification based upon function rather than anatomy that is widely used UK wide.  These can both be found in my STROKE PRESENTATION. 

Once we have clinically diagnosed stroke it's time to get on with the investigations and CT Brain.  Remember in the acute setting the purpose of CT brain is to RULE OUT HAEMORRHAGE rather than rule in infarct!  I'm sure every department has a different time window on stroke but we use to 4.5 hours door to thrombolysis cut off.  Thrombolysis or not, treatment is with 300mg of Aspirin for 2 weeks then 75mg of Clopidogrel and a high dose Statin is then given and the patient is transferred to a Stroke Unit to improve outcomes.  More on treatment and mimics can be found in the online presentation above.

So here are a few things to think about for next time:

What are the risks of thrombolysis, does this outweigh the benefits.  See the latest study IST-3 and a great summary by The NNT.com

A lady with confirmed small cell lung cancer develops left leg pain and then sudden onset upper motor neuron symptoms on her right side. How are these connected?