Intended for healthcare professionals

Rapid response to:

Clinical Review

Diagnosis and management of transient ischaemic attack and ischaemic stroke in the acute phase

BMJ 2011; 342 doi: https://doi.org/10.1136/bmj.d1938 (Published 31 March 2011) Cite this as: BMJ 2011;342:d1938

Rapid Response:

Diagnosis of transient ischaemic attack and ischaemic stroke in the acute phase. A reappraisal

Currently the diagnosis of transient ischemic attack (TIA) and stroke
entails special medical complexity. McArthur et al. recently made a broad
and interesting clinical review about the diagnosis and management of
acute cerebrovascular events (1). Nonetheless, some drawbacks were evident
in this article, especially regarding:

1) TIA and stroke definitions are likely to change based in some
recent precisions, but not according to the one hour versus twenty four
hours duration.

2) Patients under suspicion of acute cerebrovascular event (cerebral
TIA or stroke) always require accurate assessment based in clinical
examination, brain imaging examination, vessel imaging, cardiac test, and
blood test.

Previously, TIAs were operationally defined as any focal cerebral
ischemic event with symptoms lasting more than 24 hours. However, some
recent studies have demonstrated that this arbitrary time threshold was
too open because 33% to 50% of traditional defined TIAs show brain
infarction on diffusion weighted magnetic resonance imaging (MRI). The 24-
hour symptom duration rule misclassifies up to one third of patients who
have experienced underlying tissue infarction and has the potential to
delay the initiation of effective stroke therapies (2).

Several groups have proposed a more advanced, clinical and
neuroimaging criteria of TIA such as "a brief episode of neurological
dysfunction caused by focal brain or retinal ischemia, with clinical
symptoms typically lasting less than one hour, and without evidence of
acute infarction" (3). However, the expression "typically less than one
hour" in this operational definition is not helpful because the 1-hour
time point, like the 24-hour time point, does not accurately differentiate
between patients with or without cerebral infarction. A term such as
"acute neurovascular syndrome" or "acute cerebrovascular event" can be
used until the diagnostic evaluation is completed or if a diagnostic
evaluation is not performed. Terms such as "cerebral infarction with
transient symptoms or transient symptoms with infarction" have been
recommended to describe events that last more than 24 hours but are
connected with cerebral infarction while retaining the 24-hour time
threshold in syndrome definition (2).

For the above considerations, cerebral TIA is better defined as brief
episode of neurological dysfunction resulting from focal cerebral ischemia
not related with cerebral infarction (without a fixed time criterion). In
the same perspective, the term "stroke" is applied to a sudden focal
neurologic syndrome, specifically the type due to cerebrovascular disease
(infarction or hemorrhage) (4). The acute perspective is implicit in the
term stroke, and for this reason is unnecessary some derived compound
expressions; with the word "stroke" is enough.

The accuracy of the clinical examination is relevant for stroke
specialists, emergency physicians, and for other health personnel who may
be the first responder (paramedics, nursing, medical technicians).
Information necessary for decisions must be obtained in a structured
fashion to minimize the possibility of overlooking critical information.
During the course of care, standardized assessments of stroke patients
deficits improves the reliability of the clinical history and examination
(5). Relevant historical information can be include in two groups: 1)
Present illness history (time of symptom onset, the evolution of symptoms,
convulsion or loss of consciousness at onset, headache, chest pain at
onset), and 2) Medical history (prior intracerebral hemorrhage, risk
factors, recent head trauma or loss of consciousness, recent myocardial
infarction, recent surgical procedures, arterial puncture,
gastrointestinal or genitourinary bleeding, and anticoagulant therapy).
The neurological examination should focus on determining the level of
consciousness and the presence of a gaze deviation, aphasia, neglect, or
motor deficit. These neurological examination items may be established
within minutes of the initial encounter and can be integrated with
National Institute of Health Stroke Scale (NIHSS) (6-8). With training,
this useful assessment tool can be applied reliably by stroke physicians,
non-neurologist physicians as well as nurses. The general physical
examination, specially focused on the cardiovascular system, must not be
obviated in this context because may facilitate acute cerebrovascular
event diagnosis and influence treatment decisions. In addition, the first
priority is assessment of the patients airway, breathing, and circulation
(6).

Actually computed tomography (CT) maintains a primary role in the
evaluation of patients with stroke and remains the "gold standard" for
detection of cerebral hemorrhage (9,10). The optimal magnetic resonance
imaging (MRI) protocol in patients with acute ischemic cerebrovascular
event includes diffusion-weighted imaging (DWI) to show infarction and MR
perfusion study to estimate brain perfusion. DWI is superior to
conventional MRI, initial and follow-up CT in the examination of patients
with stroke within 24 hours of presentation. Perfusion CT offers various
advantages over other cerebral perfusion imaging methods as it can be
performed with spiral or multi-detector CT scanners immediately after
unenhanced CT, CT, and that the perfusion maps can be rapidly generated. A
caveat of CT perfusion is its limited coverage. In clinical practice,
patients with TIA or stroke should undergo neuroimaging evaluation (MRI,
or CT if MRI is not available) preferably within 24 hours of symptom
onset. The best time to image these patients is as soon as possible
according to the treatments that are assessed, as well as the imaging
tests that are available (10).

CT and MR angiography, transcranial Doppler ultrasonography, carotid
duplex sonography, and catheter angiography can detect intracranial or
extracranial vessel abnormalities. Noninvasive imaging of the
cervicocephalic vessels should be performed routinely, and noninvasive
testing of the intracranial vasculature is reasonable to obtain when the
diagnosis of intracranial steno-occlusive disease will alter management.
The indication of these tests needs to be customized to the individual
patient and clinical setting (2,6,9).

Some blood and cardiac test needs to be considered in a standard way
for patients with cerebral TIA or stroke. Recently published guidelines
recommend routine laboratory testing of blood glucose, electrolytes,
complete blood count, prothrombin time, activated partial thromboplastin
time, international normalized ratio, and renal function. Undoubtedly, a
12-lead electrocardiogram is also recommended for all patients (2,9).

In conclusion, the adoption of the most recent definitions and test
protocols offers a better diagnostic accuracy and improves the quality of
management in patients with cerebral TIA and/or stroke.

References

(1) McArthur KS, Quinn TJ, Dawson J, Walters MR. Diagnosis and
management of transient ischaemic attack and ischaemic stroke in the acute
phase. BMJ 2011;342:d1938.

(2) Easton D, Saver JL, Albers G, Alberts M, Chaturvedi S, Feldmann
E, et al. Definition and evaluation of transient ischemic attack. Stroke
2009;40;2276-93.

(3) Albers GW, Caplan LR, Easton JD, Fayad PB, Mohr JP, Saver JL,
Sherman DG, for the TIA Working Group. Transient ischemic attack: proposal
for a new definition. N Engl J Med. 2002;347:1713-16.

(4) Ropper AH, Brown RH. Adams and Victors Principles of Neurology. 8
ed. New York: McGraw-Hill;2005.

(5) Garcia PA, Alarcon MC, Cordido HF, Diaz OF, Vazquez AP,
Villanueva JA, et al. El empleo de un formulario estructurado mejora la
calidad de la historia clinica de urgencias de pacientes con ictus agudos.
Neurologia 2011.doi:10.1016/j.nrl.2011.01.012

(6) Barrett KM, Levine JM, Johnston KC. Diagnosis of stroke and
stroke mimics in the emergency setting. Continuum: Lifelong Learning
Neurol 2008;14:13-27.

(7) Goldstein LB, Simel DL. Is this patient having a stroke?. JAMA
2005;293:2391-2402.

(8) National Institutes of Neurological Disorders and Stroke (NINDS).
NIH Stroke Scale. 2003. In: www.ninds.nih.gov/doctors/NIH_Stroke_Scale.pdf
[01.04.2011].

(9) Adams HP, del Zoppo G, Alberts MJ, Bhatt DL, Brass L, Furlan A,
et al. Guidelines for the early management of adults with ischemic stroke.
Stroke 2007;38:1655-1711.

(10) Majda M. Thurnher, Mauricio Castillo. Imaging in acute stroke.
Eur Radiol 2005;15:408-15.

Competing interests: No competing interests

10 April 2011
Pedro L. Rodriguez Garcia
Neurologist
E. Guevara Hospital, Las Tunas, Cuba.