Clinical diagnosis in the acute phase of stroke –
quite a challenge!
Peter Sandercock
Edinburgh
11 am. Wife notices husband speech a bit odd and right hand clumsy.
Is it a stroke?
Clinical diagnosis in the hyperacute phase (< 6hrs)
• Need to be quick: ‘Time is brain’
• Need to triage in A&E as potential thrombolysis / IST 3 candidate if:– known time of onset– onset less than 5 hrs ago– definite focal neurological deficit still present (use
FAST or LAPSS for screening)
• NIHSS and OCSP classification if FAST +ve
Harbison. Stroke 2003;34;71-76;
Face Arm Speech Test (FAST) screening for paramedics/nurses
‘Acute brain attack with’ +ve FAST screen?
CT Scan Non-stroke pathology
Stroke: Infarct, intracerebral bleed, SAH
Clinical assessment
Conditions that mimic acute stroke
3.1%
3.6%
18.2%
0.0% 5.0% 10.0% 15.0% 20.0% 25.0% 30.0%
seizures
toxic/metabolic
PN palsy
tumour
SDH
confusional state
migraine
psychogenic
dementia
syncope/presyncope
MS
vertigo
TGA
SAH
miscellaneous
% of all stroke mimics (n=670)
Acute brain attack
If NO evidence of ‘mimic, e.g.: fits/migraine
Hypo/hyperglycaemia
Other obvious metabolic cause
DO CT
CT Scan Non-stroke pathologySubdural, tumour
Stroke: Infarct, intracerebral bleed, SAH
Non-stroke: bilateral subdural haematoma
Acute brain attack
Exclude: fits/migraine
Hypo-hyperglycaemia
Other metabolic causes
CT Scan Non-stroke pathology:Subdural, tumour, etc
CT Normal or evidence of acute ischaemic stroke
Do you need a neurologist?• Approximately 75% of conditions mimicking stroke are
neurologicalHow many of these can be identified by CT?• ~15% of non-stroke disorders (eg subdural) found by CT• rest diagnosed clinically/with other tests• CT < 6hrs of ischaemic stroke often normalIf CT is normal • Often need stroke specialist or neurologist to confirm clinical
diagnosis of stroke before thrombolysis:• avoid thrombolysis for migraine, focal epilepsy, ‘functional
weakness’, ischaemic deficit after subarachnoid haemorrhage!
Problems of clinical diagnosis within 6 hours of onset
CT NormalMRI DWI abnormal
-but DWI not widely available
2hrs ago right hemiparesis: thrombolyse?
Edinburgh ‘brain attack’ study
Aim • Identify the ‘brain attack’ patients most likely to
have acute cerebral ischaemia, potentially for thrombolysis
Patients• 350 admissions (336 patients)• Age: 76.3 yrs (67 - 83)• Source of referral to stroke team: A&E triage in
92%• Time from onset to A&E: 4.7 hrs (2 - 14)
Hand PJ. Stroke 2006; 37: 769-775.
Primary analysis• ‘Thrombolysis eligible brain attacks’
(n=241) = definite stroke, probable stroke, definite TIA
• Mimics (n=109) = definite non-stroke, all possible stroke/TIA with a plausible non-stroke explanation
Pointers to ‘rt-PA/ist3 eligible:’ past history
Pointer to ‘more likely NOT for thrombolysis/IST3’
Pointer to ‘more likely eligible’
Pointers to ‘rt-PA/ist3 eligible:’ History of this event
NIHSS training website
http://asa.trainingcampus.net/uas/modules/trees/windex.aspx
Note: works best with a high-speed (broadband) connection!
Clinical pointers: summary
To ‘likely eligible for thrombolysis/ist3’• Known time of onset • Abnormal vascular signs (AF, PVD)• Unilateral neurological signs • Can assign an OCSP classification• Increasing NIH scoreTo ‘likely not eligible’• prior cognitive impairment• LOC early • seizure• can walk now ( too mild)
• The time of onset of stroke symptoms is known precisely
• You have an experienced stroke physician/stroke neurologist able to see the patient urgently in A&E or at CT scan room
• Urgent non-contrast CT scan is interpreted by someone with expertise in acute stroke CT
• -> MRI not essential; its place in routine acute stroke care yet to be determined
Can you diagnose ‘acute ischaemic stroke suitable for thrombolysis’ without
DWI MR? Yes, if: