{"id":1012,"date":"2018-01-16T16:42:05","date_gmt":"2018-01-16T16:42:05","guid":{"rendered":"https:\/\/drcrunch.wordpress.com\/?p=1012"},"modified":"2018-01-16T17:19:48","modified_gmt":"2018-01-16T17:19:48","slug":"brain-no-functioning","status":"publish","type":"post","link":"http:\/\/drcrunch.co.uk\/blog\/2018\/01\/16\/brain-no-functioning\/","title":{"rendered":"Brain no functioning"},"content":{"rendered":"

Based on Year 3 Imperial, Week One teaching at Hillingdon<\/p>\n

\"mo_tourist-01\"
\nA 29 year old man (Mo Tourist) is BIBA (brought in by ambulance) following a motor cycle accident. His helmet has flown off. There is extensive bruising around the head.<\/p>\n

On arrival, he appears unconscious.<\/p>\n

You start with an ABCDE approach. You pay particular attention to A because you know that in patients with reduced consciousness, the airway can be at risk (because of the loss of muscle tone leading to a floppy airway, as well as the tongue falling backwards). Think of a very drunk person (i.e. someone with reduced consciousness) deeply snoring. Think of the folds of fat and soft tissue vibrating in that floppy airway. Now imagine that airway getting even more floppy to the point where it occludes. A GCS of around 8 or lower is traditionally taught as when you would get support for the airway.<\/p>\n

B and C are fine, so you move on to ‘D’. This stands for disability.<\/p>\n

Why are we assessing the patient’s disability\/handicap at this stage?\u00a0<\/strong><\/p>\n

Although the word ‘disability’ is used, I prefer to think of it as neurological ‘deficit’. When someone has reduced consciousness, the challenge is to work out if this is because of a focal problem (i.e. in the brain), or a system problem (i.e. in the body).<\/p>\n

\"brain\"<\/p>\n

Arousal comes from the\u00a0ascending reticular activating system in the brainstem. To cause reduced consciousness, there must either be extensive bilateral<\/em>\u00a0cortical damage (as if one hemisphere is working normally, this will still project to the reticular activating system as normal, so consciousness will be maintained), or damage in the brainstem. Alternatively, there may be a systemic problem with the blood supply to the brain e.g. hypoglycemia or a toxin.<\/p>\n

Focal problems<\/strong><\/p>\n

Anything that raises intracranial pressure can cause a reduced consciousness. The commonest problems are haemorrhage and space occupying lesions such as tumours\/abscesses. Reduced consciousness can also occur after brain injury without a specific space occupying haemorrhage e.g. multiple brain contusions.<\/p>\n

The patient could also be post ictal after a seizure. This seizure could have been focal or generalised to begin with, but would have had to been focal with secondary generalisation or primarily generalised to cause reduced consciousness.<\/p>\n

Raised intracranial pressure…?<\/strong><\/p>\n

Think persistent headache that\u00a0worsens<\/em> with lying flat, bending over or coughing, vomiting (especially effortless), focal neurology and seizures. Late on, you get Cushing’s reflex<\/a> and papilloedema (can you make out the optic disc margin below? Me neither. That’s a big clue for papilloedema).<\/p>\n

\"By
By Jonathan Trobe, M.D. – University of Michigan Kellogg Eye Center – The Eyes Have It, CC BY 3.0, https:\/\/commons.wikimedia.org\/w\/index.php?curid=16115920<\/figcaption><\/figure>\n

Ischaemic strokes cause sudden onset, focal, negative neurological symptoms. These almost always occur without impaired consciousness.<\/p>\n

Systemic<\/strong><\/p>\n

Now we’re talking (unless your GCS – V is less than 3). These can be split into exogenous<\/strong> problems (drugs) and endogenous<\/strong> (toxins and metabolic abnormalities):<\/p>\n

Endogenous<\/strong><\/p>\n