A TIA is an episode of transient focal neurological defi cit of vascular origin lasting <24hr. A TIA gives major warning for the development of stroke (5 % within 48hr, up to 50 % in 5 years). Even in patients with resolution of symptoms/signs, most have evidence of infarction on CT/MRI.
Presentation
Carotid territory involvement produces unilateral weakness or sensory changes, dysphasia, homonymous hemianopia, or amaurosis fugax.
Vertebrobasilar territory involvement produces blackouts, bilateral motor or sensory changes, vertigo, and ataxia.
Causes
Most TIAs result from thrombo-embolic disease involving either the heart (AF, mitral stenosis, artifi cial valves, post-MI) or extracranial vessels (carotid artery stenosis). Other causes include:
• Hypertension.
• Polycythaemia/anaemia.
• Vasculitis (temporal arteritis, polyarteritis nodosa, SLE).
• Sickle cell disease.
• Hypoglycaemia.
• Any cause of hypoperfusion (eg arrhythmia, hypovolaemia).
• Syphilis.
Assessment
To diagnose a TIA, the symptoms must have resolved within 24hr.
Document vital signs and perform a thorough neurological examination.
Look for possible sources of emboli eg arrhythmias (especially AF), heart murmurs, carotid bruits, MI (mural thrombus).
Investigations
• Check BMG.
• Send blood for FBC, ESR, U&E, blood glucose, lipids (INR if on anti-coagulants).
• Record an ECG to search for MI, arrhythmia.
Management
• Calculate the ABCD 2 score (Table 3.10 ).
• Admit to a stroke unit patients scoring 4 or more points, or anyone with more than one TIA in the previous week.
• Patients scoring 3 or less points, or who present one week after symp-toms have resolved, may be suitable for discharge with stroke team follow-up in the next week.
• Start the patient on daily aspirin 300mg immediately.
• Admit patients with continuing symptoms or residual defi cit (by defi ni-tion, not a TIA).
See http://www.nice.org.uk
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TRANSIENT ISCHAEMIC ATTACKS
Table 3.10 ABCD 2 score for TIAs
Criteria Points
Age Age 60 or over 1
BP at assessment Systolic > 140mmHg or diastolic > 90mmHg at assessment
1
Clinical features Speech disturbance 1
Unilateral weakness 2
Duration of symptoms 10–59min 1
60 min or more 2
Diabetes 1
Patients scoring > 4 points are at increased risk.
Seizures and status epilepticus
First fi t
A fi rst fi t has enormous consequences — do not diagnose without good evidence
A detailed history from both the patient and any witnesses is crucial to the diagnosis. The presence of jerking movements or incontinence does not necessarily refl ect epilepsy. Carefully document what was seen, in order to avoid confusion with vasovagal syncope or other types of collapse. Full rapid recovery suggests a syncopal event. Always consider alcohol/drug use, withdrawal states, hypoglycaemia, arrhythmia, head injury, subarach-noid haemorrhage, stroke/TIA, infection (including meningitis) or metabolic disturbance.
As part of the general examination, carefully examine the CNS, documenting:
GCS, confusion, focal abnormalities, fi ndings on fundoscopy. Examine the cardiovascular system and check for signs of aspiration.
Todd’s paresis may follow seizures — focal defi cit or hemiparesis may persist for up to 24hr and indicates a high chance of structural lesion.
Investigations BMG, glucose, FBC, U&E, blood cultures if pyrexial, ECG, and if there are chest signs, a CXR. Check urine pregnancy test if of child-bearing age. All patients with new onset seizures need brain imaging at some stage: a signifi cant number have structural CNS abnormalities.
Arrange emergency CT scan for patients with focal signs, head injury, known HIV, suspected intracranial infection, bleeding disorder (including anticoagulants), or where conscious level fails to improve as expected.
Disposal A patient presenting with a fi rst seizure may be discharged home, accompanied by an adult, if they have normal neurological and cardiovascular examinations, the ECG and electrolytes are normal, and there is an appointment with an epilepsy specialist in the coming week. Admit any patient with more than one seizure that day or who does not fi t the above criteria. Ensure clear documentation of follow-up arrangements, including booked clinic appointment. Meantime, advise the patient not to drive or use machinery and to take sensible precautions, with supervision when performing activities, such as swimming/bathing until reviewed. Document this advice in the notes.
Seizures in known epileptics
Ask about any change from the patient’s normal seizure pattern. Possible causes of poor seizure control include: poor compliance with medica-tion, intercurrent illness/infecmedica-tion, alcohol, or drug ingestion. Examine to exclude any injury occurring from the fi t, especially to the head. Occult dislocations (eg shoulder) may occur. Check vital signs, BMG and anticon-vulsant levels if toxicity or poor compliance is suspected. Refer patients with a signifi cant change in seizure pattern to the medical team. Discharge to the care of a responsible adult those patients who are fully recovered with no injuries, symptoms or other concerns.
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SEIZURES AND STATUS EPILEPTICUS
Status epilepticus
This is continuous generalized seizures lasting > 30min or without inter-vening recovery. Cerebral damage i with duration. Precipitants include cerebral infection, trauma, cerebrovascular disease, toxic/metabolic dis-turbances, childhood febrile seizures. Mortality is 8 10 % (due to underlying pathology). Although seizures typically start as generalized, tonic/clonic, these features may gradually diminish, making diagnosis diffi cult (coma with virtually no motor evidence of seizure, eg minimal twitching of ocular muscles only). Complications include hypoglycaemia, pulmonary hyper-tension, pulmonary oedema and precipitous i ICP can also occur.
Treatment of status epilepticus
• Establish a clear airway (a nasopharyngeal airway may help).
• Give high fl ow O 2 .
• Monitor ECG, SpO 2 , T ° , pulse rate, and BP.
• Obtain IV access, check BMG and correct hypoglycaemia if present (50mL of 20 % glucose IV).
• Give IV lorazepam 4mg slowly into a large vein (diazepam 10mg is an alternative). Repeat IV lorazepam 4mg slowly after 10min if seizures continue.
• Buccal midazolam 10mg (can be repeated once) or rectal diazepam solution 10–20mg (can be repeated up to total 30mg) are alternatives if there is no venous access.
• If alcohol abuse or malnutrition is suspected, give slow IVI thiamine in the form of Pabrinex ® 2 pairs of ampoules in 100mL of 0.9 % saline (this occasionally causes anaphylaxis; be prepared to treat — see BNF ).
• Consider the possibility of pregnancy-related fi ts (eclampsia) in women of childbearing age and treat accordingly (with IV magnesium sulphate—
— as outlined on b p.592).
• Check ABG and save blood for cultures, FBC, U&E, glucose, calcium, magnesium, LFTs, clotting, drug levels (and toxicology screen if poi-soning/overdose is suspected).
• Search for features of injury (especially head injury) and infection (look for a rash).
• If seizures continue despite above therapy, call ICU and consider the use of phenytoin (18mg/kg IV, 50mg/min) with ECG monitoring, or fosphenytoin (20mg/kg phenytoin equivalent IV, <150mg/min). A 70kg patient would require 1400mg phenytoin equivalent of fosphenytoin (28mL Pro-Epanutin ® ) diluted in 100mL 0.9 % saline or 5 % glucose, given over 10–15min.
• After 30min, contact ICU and proceed without delay to rapid sequence induction (ideally with thiopental), tracheal intubation, and continue anticonvulsant medication.