53454ournal ofNeurology, Neurosurgery, and Psychiatry 1994;57:534-543 J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.57.5.534 on 1 May 1994. Downloaded from NEUROLOGICAL MANAGEMENT Stroke and transient ischaemic attacks Peter Humphrey The management of stroke is expensive and ANATOMY accounts for about 5% of NHS hospital costs. Carotid v vertebrobasilar arterial territory Stroke is the commonest cause of severe Carotid-Classifying whether a stroke is in the physical disability. About 100 000 people territory of the carotid or vertebrobasilar suffer a first stroke each year in England and arteries is important, especially if the patient Wales. It is important to emphasise that makes a good recovery. Carotid endarterec- around 20-25% of all strokes affects people tomy is of proven value in those with carotid under 65 years of age. The annual incidence symptoms. Carotid stroke usually produces of stroke is two per 1000.' About 10% of all hemiparesis, hemisensory loss, or dysphasia. patients suffer a recurrent stroke within one Apraxia and visuospatial problems may also year. The prevalence of stroke shows that occur. If there is a severe deficit, there may there are 250 000 in England and Wales. also be an homonymous hemianopia and gaze Each year approximately 60 000 people are palsy. Episodes of amaurosis fugax or central reported to die of stroke; this represents retinal artery occlusion are also carotid about 12% of all deaths. Only ischaemic events. heart disease and cancer account for more Homer's syndrome can occur because of deaths. This means that in an "average" dis- damage to the sympathetic fibres in the trict health authority of 250 000 people, there carotid sheath. This especially follows carotid will be 500 patients with first strokes, with a dissection. prevalence of about 1500. After an internal carotid occlusion, there Transient ischaemic attacks (TIAs) are may be exaggerated pulsation in the branches defined as acute, focal neurological symp- of the external carotid artery (especially the toms, resulting from vascular disease, which superficial temporal artery). Increased collat- eral bloodflow through this artery shunts resolve in less than 24 hours; most settle in http://jnnp.bmj.com/ less than 30 minutes. The incidence of TIAs blood via the orbital vessels into the ophthal- is a quarter that of stroke. mic artery and then into the circle of Willis in Over the past 20 years, mortality from an attempt to compensate for the internal stroke has fallen both in the United Kingdom carotid occlusion, patients thus performing and United States by about a quarter. There their own extracranial-intracranial anastomo- has also been a fall in the incidence of stroke.2 sis. This is an almost universal finding on This is probably real but may be partly ultrasonography in internal carotid artery accounted for by the reclassification of stroke. occlusion. Sometimes the collateral flow is so on September 24, 2021 by guest. Protected copyright. The more successful treatment of hyperten- marked that an orbital bruit is heard and the sion is also likely to be relevant, but is superficial temporal artery on the side of the unlikely to be a complete explanation as this occlusion becomes tender and painful. This improvement had also been seen during can mimic temporal arteritis. It is particularly 1950-60, before the treatment of hyper- important that the temporal artery is not tension was widely practised. biopsied or a major collateral source of blood Stroke is not a diagnosis. It is merely a supply will be obliterated. description of a symptom complex thought to Vertebrobasilar-The terminal branches of this have a vascular aetiology. It is important to system are formed by the posterior cerebral classify stroke according to the anatomy of artery. Ischaemia of its territory usually pro- the lesion, its timing, aetiology, and patho- duces unilateral field defects. Bilateral symp- genesis. This will help to decide the most toms are not uncommon, with complete appropriate management. blindness or bilateral visual hallucinations, such as an impression of frosted glass or water running across the whole field of vision. Classification of stroke Sometimes amnesic symptoms may be Walton Centre for seen. In most patients, however, transient Neurology and Many neurologists have described vascular Neurosurgery, Rice syndromes in erudite terms. Most of these are global amnesia is no longer thought to be a Lane, liverpool of little practical use. A broadbased anatomi- TIA.3 L9 1AE, UK cal knowledge is important, however, as this The posterior cerebral artery also supplies P Humphrey part of the thalamus: infarction here produces Correspondence to: has significance in pathogenesis and manage- Dr Humphrey ment. sensory impairment over the contralateral Stroke and transient ischaemic attacks 535 side of the body. This may be accompanied Sometimes multiple lacunar infarcts occur. J Neurol Neurosurg Psychiatry: first published as 10.1136/jnnp.57.5.534 on 1 May 1994. Downloaded from by a very unpleasant pain which may be In such patients, there is often, but by no spontaneous or induced by light touch (thala- means always, a history of preceding minor mic pain) and often only reaches its peak stroke. The resulting syndrome is of a pseudo- some months after the stroke. bulbar palsy with dementia, dysarthria, small The brainstem signs after vertebrobasilar stepping gait (marche a' petits pas) unsteadi- ischaemia depend on the level of the lesion.4 ness, and incontinence. Midbrain ischaemia may result in pupillary Bamford and colleagues6 have used the changes with impaired vertical gaze or oculo- Oxford Community Stroke Data to classify motor nerve dysfunction. Damage to the strokes clinically into-(a) lacunar infarcts; pons produces horizontal gaze palsy with (b) total anterior circulation infarcts; (c) par- facial weakness or sensory loss. In either case tial anterior circulation infarcts; and (d) pos- a tetraparesis or hemiparesis may occur. terior circulation infarcts (vertebrobasilar)- A wide range of other syndromes is (a) and (b) are classified as carotid artery reported to follow ischaemia of localised areas territory stroke. of the brain. The basic pattern is one of ipsi- Total anterior circulation infarct (TACI) lateral cranial nerve palsies and cerebellar dis- presents with a combination of higher cere- turbance combined with contralateral paresis bral dysfunction deficit (dysphasia, dyscalcu- or sensory loss which may affect the face, arm lia, and visuospatial disorder), homonymous and leg, or arm and leg, depending on the visual field defect and motor or sensory level in the brainstem at which this occurs. deficit, or both, of at least two areas of the Homer's syndrome may be seen. face, arm, and leg. Partial anterior circulation In the "locked-in" syndrome, patients infarcts (PACI) present with only two of the appear to be unconscious but are actually three components of the TACI syndrome fully conscious. They can only move their with higher cerebral function alone or with a eyes vertically; sometimes they can move their motor/sensory deficit more restricted than eyelids. It is good practice to introduce one- those classified as lacunar infarcts-for self to patients who appear to be uncon- example, confined to one limb, or to face and scious, and immediately ask them to move hand but not to the whole arm. their eyes before accepting that they are truly Patients with posterior circulation infarct unconscious. (POCI) present with any of the symptoms One word of caution-carotid artery dis- described in the section on vertebrobasilar section often presents with ipsilateral disease. Horner's syndrome and contralateral hemi- Using these simple clinical criteria, it paresis. It has also been described with ipsi- proved possible to classify most strokes into lateral cranial nerve palsies (especially one of these four different categories. This affecting nerves IX-XII) because the may be important as the prognosis, aetiology, expanded carotid artery damages these nerves and risk of recurrent strokes varies in the dif- in the neck. Classical teaching would have ferent groups. The TACI group had a very mistakenly put this vascular syndrome in the poor prognosis, with high mortality but a low vertebrobasilar territory. recurrence rate, presumably as most of the http://jnnp.bmj.com/ carotid territory had been destroyed by the Lacunar infarct. The PACI group had a good progno- These small, deep microinfarcts described by sis but a high early recurrence rate, as this Fisher are commonly seen in hypertensive type of stroke is frequently embolic, probably and diabetic patients.5 They rarely occur in from internal carotid artery atheroma. These patients with carotid artery stenosis. It is patients have much to lose if a second stroke important to recognise these lacunar syn- occurs. The lacunar group had an intermedi- dromes because of their good prognosis and ate prognosis but a low risk of recurrence. on September 24, 2021 by guest. Protected copyright. different pathogenesis. Lacunar infarcts com- This type of stroke is rarely due to embolic monly present as pure motor stroke, pure disease but follows microvascular thrombosis sensory stroke, sensorimotor stroke, or ataxic or haemorrhage, often as a result of hyper- hemiparesis (table 1). Acute focal movement tension with or without diabetes. disorders may also be lacunar. Patients must The POCI group had a good prognosis but have either complete face, arm and leg or high early recurrence rate. This Oxford major face and arm or leg involvement. Community study dispels the notion that Those with more restricted deficits-for brainstem strokes in general have a poor example, weak hands only-are not included. prognosis in the acute phase: it also empha- These are considered to be partial, anterior sises the significant risk of recurrence and the circulation infarcts in the cortex. need to give advice about risk factors, and offer early medical treatment to those with posterior circulation infarcts.