Makindo Medical Notes

Related Subjects: |Acute Stroke Assessment (ROSIER&NIHSS) |Atrial Fibrillation |Atrial Myxoma |Causes of Stroke |Ischaemic Stroke |Cancer and Stroke |Cardioembolic stroke |CT Basics for Stroke |Endocarditis and Stroke |Haemorrhagic Stroke |Stroke Thrombolysis |Hyperacute Stroke Care |Hypertension

Introduction

• The Oxford Community Stroke Project classification, developed by Bamford and colleagues, is a valuable system for classifying stroke subtypes. It provides both prognostic and etiological insights that aid in clinical decision-making.
• Using data from the Oxford Community Stroke Project, Bamford and colleagues identified four main sub-categories of cerebral infarction based on presenting symptoms: Lacunar Infarcts (LACI), Total Anterior Circulation Infarcts (TACI), Partial Anterior Circulation Infarcts (PACI), and Posterior Circulation Infarcts (POCI). These classifications are determined by bedside clinical features.
• The classifications are anatomically descriptive, helping localize the infarction site. Patients with POCI have a relatively good prognosis, while LACI is associated with higher survival rates. Although initially used for infarcts, the classification applies to hemorrhagic strokes once imaging identifies the stroke type.

Anterior vs Posterior Circulation

• The anterior (front) part of the brain is supplied by the right and left internal carotid arteries, known as the "anterior circulation." Conversely, the posterior (back) part of the brain, including the brainstem, cerebellum, occipital lobes, and thalamus, is supplied by the vertebral arteries, referred to as the "posterior circulation."
• This circulation system division underlies the Bamford classification. Anterior circulation strokes exclude the vertebrobasilar system, while posterior circulation strokes indicate no involvement of the carotid arteries.

Classification

• Lacunar Infarcts (LACI): Characterized by any of the following:
• Pure motor stroke
• Pure sensory stroke
• Sensorimotor stroke
• Ataxic hemiparesis
• Note: Absence of higher cortical function loss (e.g., dysphasia or neglect) is required.
• Total Anterior Circulation Infarcts (TACI): Must have all three of the following:
• Higher cerebral dysfunction (e.g., dysphasia)
• Homonymous visual field defect
• Ipsilateral motor and/or sensory deficit in at least two areas (face, arm, or leg)
• Partial Anterior Circulation Infarcts (PACI): Characterized by two of the three TACI components or higher cerebral dysfunction alone, or a motor/sensory deficit more restricted than LACI (e.g., confined to one limb).
• Higher cerebral dysfunction (e.g., dysphasia)
• Homonymous visual field defect
• Ipsilateral motor and/or sensory deficit in at least two areas (face, arm, or leg)
• Posterior Circulation Infarcts (POCI): Any of the following symptoms:
• Ipsilateral cranial nerve palsy with contralateral motor and/or sensory deficit
• Bilateral motor and/or sensory deficit
• Disorder of conjugate eye movement
• Cerebellar dysfunction
• Isolated homonymous visual field defect

Summary Table

Assessment

The Bamford classification approach can be simplified by assessing the presence or absence of four main stroke features:

• Hemiparesis or hemisensory loss affecting face, arm, and leg
• Higher cortical dysfunction, including language problems
• Homonymous hemianopia
• Brainstem signs: vertigo, dysphagia, diplopia, cerebellar signs

Stroke type can be coded after imaging confirms the cause:

• I - Infarct (e.g., TACI)
• H - Hemorrhage (e.g., TACH)
• S - Syndrome; intermediate diagnosis before imaging (e.g., TACS)

References

• A prospective study of acute cerebrovascular disease in the community: the Oxfordshire Community Stroke Project 1981-86. 1. Methodology, demography, and incident cases of first-ever stroke. J Neurol Neurosurg Psychiatry. 1988 Nov; 51(11): 1373-1380.