Is it a stroke? What kind of stroke is it?

Making the diagnosis of stroke on the basis of the history, either from the patient or a relative, and the examination is usually straightforward. The differential diagnosis that needs to be considered has been discussed previously (Box 1, p. 67). The clinical classification is considered on page 66. Haemorrhagic and ischaemic strokes cannot be reliably distinguished clinically.

The diagnosis of stroke can be confirmed by CT or MRI scanning, which will indicate whether the stroke is haemorrhagic. Early CT scans can be normal, indicating that the stroke is ischaemic and not haemorrhagic. MRI diffusion weighted images (DWI) can be used to distinguish new from old ischaemic lesions. The distribution of any abnormality will indicate the affected vascular territory (Fig. 1).

Fig. 1 Vascular supply of the brain in the projection commonly used for scanning.

CT and MRI scans are recommended though are not yet performed in all patients.

Why did the stroke occur?

The likely aetiology of an ischaemic stroke can usually be determined from the history and examination. The range of investigations that may be used is given in Box 1.

Which investigations are used in a particular patient will depend on the clinical picture. For example, a patient with a history suggesting a possible cardiac source (e.g. previous rheumatic fever) will require full cardiac investigation. A patient without risk factors for atheroma, mainly younger patients, would have a wider range of investigations. The investigation of the cause of a complete anterior circulation dominant hemisphere stroke is going to be tempered by the clinical condition of the patient.

In any patient with a small completed stroke in the anterior circulation, or one that could have come from the anterior circulation, a carotid Doppler scan should be performed to look for operable stenosis (see later).

A patient with a haemorrhagic stroke will usually be hypertensive and often have other risk factors for atheroma. In addition, consider whether there is a bleeding tendency (usually warfarin or thrombolytics). In younger patients who are not hypertensive, there may be a vascular abnormality that caused the haemorrhage, and cerebral angiography may be helpful.

Are there any factors that could make it worse?

Systemic metabolic disturbances, especially hypoxia and hyperglycaemia, will affect the function of the ischaemic brain and worsen the stroke. Stroke patients will frequently require hydration, either enterally or parenterally. Inappropriate fluid balance, particularly overhydration, may be detrimental and it is often helpful to monitor urea and electrolytes.

Treatment

The treatment of patients with strokes aims to:

give general medical support of the patient

minimize stroke size

prevent complications of stroke

optimize recovery

prevent recurrence of stroke.

Much of the advice given below is based on clinical trial data. However, there are still many areas where current practice has not been formally proven to be of benefit.

Prognosis

The outcome after a stroke depends primarily on the type of stroke and the clinical stroke syndrome. Primary intracranial haemorrhage carries a 50% mortality, with 50% of survivors dependent at 6 months. Total anterior circulation ischaemic strokes have a similar mortality but a higher (90%) level of dependent patients at 6 months. Partial anterior circulation strokes, lacunar strokes (Fig. 2) and posterior circulation strokes have a 10–15% mortality with 20–40% of survivors dependent at 6 months. Ischaemic heart disease is the most common cause of death following a stroke or TIA.

Fig. 2 Diffusion weighted MRI showing a lacunar infact.

Stroke III

Investigation of a stroke aims to confirm diagnosis, define the stroke type and pathogenesis and uncover any factors that could make it worse.

Acute treatment of stroke aims to protect the patient from complications of stroke, minimize stroke size and optimize recovery.