According to the World Health Organization (WHO), 15 million people suffer stroke worldwide each year. Of these, 5 million die and another 5 million are left permanently disabled. The 2010 Global Burden of Disease Study suggested Stroke is the second leading cause of death globally and the third leading cause of premature death and disability as measured in Disability Adjusted Life Years (DALY).
Broadly speaking there are two types of stroke – Ischemic (85%) and Hemorrhagic (15%). Hemorrhagic strokes are divided into two further subtypes – intracerebral hemorrhage and atraumatic subarachnoid hemorrhage. The severity of ischemic strokes range greatly from mild or transient (TIA) to severe but the cause is identical. The distinction between ischemic stroke and TIA is no more than severity therefore it is not useful to divide these into two categories.
Ischemic-type strokes have many causes: 25% cardioembolic (such as atrial fibrillation), 25% arteroembolic (such as a plaque), 25% lacunar (small vessel disease in the brain) and 25% other causes, in other words arterial occlusion is a overwhelmingly common cause of ischemic strokes.
Stroke syndromes present with rapid onset and symptoms depend on the area of the brain affected, this is defined by the arterial anatomy involved. Although some features are more or less typical of hemorrhagic or ischemic stroke, none are sufficiently discriminatory to allow clinical diagnosis of stroke type. This is integral for the acute management. Therefore, imaging in the acute phase is required for all strokes.
Common symptoms of stroke in the left hemisphere include aphasia, right hemiparesis and right hemianopia, and in the right hemisphere, left hemispatial neglect, left hemiparesis and left hemianopia. The majority (90%) of strokes are supratentorial; as such, the public can be taught to recognize and act upon stroke using the acronym FAST, for facial droop, arm drop, speech disturbance and time.
4.5 hours is a crucial time deadline in the management of ischemic stroke and this is why speed is integral to diagnosis and arrival to hospital. If given within this deadline Alteplase has been proven to reduced functional disability and is the leading treatment. The problem is efficacy wanes rapidly if there is any delay in administration. This is was speed is of the essence.
To be sure that the treatment is correct (hemorrhagic strokes cannot be managed with Alteplase) diagnosis needs to be confirmed and this is often a delay in treatment. To combat this UCLA have been trialing the use of a CT-equipped ambulance. Alongside the scanner there is also a CT tech, a small blood lab, a neurologist, a critical care nurse as well as a paramedic.
This is clearly an amazing step forwards in the timeline of the management of ischemic stroke but it still relies on timely call for emergency help. As mentioned about F.A.S.T is a crucial tool in helping members of the public recognize a stroke. Qualcomm have produced a fantastic VR educational tool to help teach the importance of F.A.S.T. In the app is takes you through each step of the diagnostic process.