1. Clarify the history first (a witness is the most useful "test")

• Duration: Who timed 5 to 7 minutes? Faints usually last under a minute or two. Longer estimates are often wrong. If the duration is real, think arrhythmia, a seizure with a fast recovery, or pseudosyncope.
• Circumstances: Was he just up from bed or the toilet? Was he passing urine, straining, or coughing? Was it on standing or lying? Was it on exertion?
• Prodrome: Look for sweating, nausea, tunnel vision, palpitations, chest pain, breathlessness, headache, vertigo, diplopia or focal weakness. A sudden event with no warning, or one on exertion, points to arrhythmia or structural heart disease (Tintinalli's Emergency Medicine).
• The incontinence: Did he pass urine during the episode, or was it a full bladder? Urinary incontinence does not reliably separate seizure from syncope (Tintinalli's; Harrison's 22E).
• Seizure clues: Lateral tongue bite, head turning, unusual posture, and confusion lasting more than a few minutes favour seizure. Tongue laceration, head turning and posturing are the most specific features (Symptom to Diagnosis).
• Brief jerks: Short myoclonic jerks (under 20 seconds) can occur in syncope ("convulsive syncope") and do not mean epilepsy (Rosen's).
• Other history: Ask about recovery time, injuries, and whether he was pale, blue or flushed. Ask about drugs, alcohol, OTC or herbal products, and any alpha-blocker, 5-ARI or antihypertensive started by another doctor. Ask about melena or other bleeding, poor intake, previous episodes, and a family history of sudden death or fits.
• BPH-specific: Ask about nocturia, straining, retention and UTI symptoms.

2. Differentials

3. What else to do now

1. 12-lead ECG now. This is the single most important next test, and the initial ECG is part of syncope risk stratification. Look at:
   • rate, PR interval, AV block, bundle branch block
   • QTc, Brugada pattern, pre-excitation
   • Q waves, LVH or HCM pattern, epsilon waves
2. Continuous telemetry while he is in the department or ward.
3. Fingerstick glucose (do not rely on the VBG alone), plus repeat vitals.
4. Orthostatic BP and HR: lie for 5 minutes, then measure at 1 and 3 minutes standing. A fall of 20 mmHg systolic or 10 mmHg diastolic, or systolic below 90, is positive. Avoid doing this alone if he is unstable.
5. Examination:
   • Look for head or body injuries and a tongue bite.
   • Check BP in both arms and listen for murmurs (AS, HCM) and carotid bruits.
   • Examine for signs of heart failure and do a neurological exam, including gait and cranial nerves.
   • Do a rectal exam: DRE gives the prostate, and you also look for melena.
   • Palpate the bladder and do a bladder scan for retention.

• Check Hb for anaemia or bleed.
• Renal function, sodium, calcium and magnesium.
• Troponin if there is any chest pain, ECG change, or no clear reflex explanation.
• BNP/NT-proBNP if you suspect cardiac disease. Recent reviews do not give a clear role for cardiac biomarkers, so use them selectively.
• Urinalysis, plus a culture if symptomatic.
• CK and lactate if a seizure is considered.
• D-dimer or CTPA only if PE is clinically plausible.

• Echocardiogram if the ECG is abnormal, there is a murmur, known heart disease, or an exertional or no-warning event.
• CT head only if there is trauma, headache, a focal deficit or persistent altered mentation.
• EEG and MRI brain only if the history suggests seizure (tongue bite, postictal state, aura, or witnessed focal onset).
• Carotid sinus massage under monitoring if he is over 40 and the cause is still unclear. Avoid it with a carotid bruit, recent stroke or TIA.
• Prolonged rhythm monitoring (Holter, event recorder, or implantable loop recorder) and tilt table testing are done later or by cardiology if the cause is still unclear.

4. Risk stratification and disposition

• San Francisco Syncope Rule (CHESS: heart failure history, Hct below 30%, abnormal ECG, shortness of breath, SBP below 90).
• Canadian Syncope Risk Score.
• ESC high-risk features.

• abnormal ECG
• exertional syncope or no prodrome
• structural heart disease
• palpitations or chest pain
• significant anaemia or electrolyte disturbance
• injury, or age with comorbidity

5. Management by cause

• Reflex or micturition syncope: Counsel him to sit to pass urine, rise slowly, and keep up fluids and salt. Treat the BPH (bladder outflow) and avoid straining. Alpha-blockers can cause orthostasis, so start them carefully, at night.
• Orthostatic: Correct volume, stop offending drugs, use compression stockings, and teach counter-manoeuvres.
• Arrhythmia: Refer to cardiology for pacing, an ICD or ablation.
• Seizure: Do EEG and MRI and involve neurology. Do not start antiseizure drugs after a single unprovoked event that is unclear.
• Metabolic: Correct the cause, such as glucose or sodium.
• Retention or obstructive uropathy with AKI: Catheterize and watch for post-obstructive diuresis.
• For all patients: No driving until a cause is clear and the regulations allow it, and give safety counselling.

6. Recent evidence check

1. Differential diagnosis (MND-specific, in priority order)

2. Investigations

1. 12-lead ECG: check QTc, AV block, bundle branch block, Brugada pattern, ischaemia. Start continuous telemetry.
2. Pulse oximetry and RR, plus ABG if the VBG is doubtful. Look at serum bicarbonate on your electrolytes. A raised HCO3 suggests chronic hypoventilation.
3. Bedside spirometry: FVC sitting and supine. A fall of more than 20 percent supine suggests diaphragmatic weakness. Add SNIP/MIP and peak cough flow if available.
4. Fingerstick glucose.
5. Orthostatic BP and HR (lying 5 minutes, then standing at 1 and 3 minutes). A drop of 20/10 mmHg or more is positive.
6. Examination: injuries, tongue bite, murmurs, calf tenderness, bulbar signs (pooled saliva, cough strength), bladder palpation. Do a bladder scan and a rectal exam.

• Troponin, urea/creatinine, Na, K, Ca, Mg, LFT (baseline before riluzole), albumin, CK, urinalysis.
• Chest X-ray (aspiration, atelectasis, elevated hemidiaphragm).
• Echocardiogram if ECG is abnormal, there is a murmur, or the event had no warning.
• D-dimer or CTPA only if PE is clinically plausible (Wells).
• CT head only for trauma, headache or focal deficit. EEG and MRI if the history suggests seizure.
• Overnight oximetry or capnography (or polysomnography) if hypoventilation is suspected.
• Swallow assessment (bedside, then videofluoroscopy or FEES) and nutritional status (BMI, weight loss).
• Holter or event monitor, or loop recorder, if the cause is still unclear. Tilt test and carotid sinus massage are second line.

3. What the findings would mean

4. Treatment with doses

• ABC, monitoring, IV access.
• If hypoglycaemia: 25 percent dextrose 100 mL IV (or 50 percent 50 mL), then repeat glucose.
• If hypovolaemic or orthostatic: 0.9 percent saline 500 mL bolus over 15 to 30 minutes, then reassess. Be cautious if respiratory or cardiac function is poor.
• Oxygen: titrate to SpO2 88 to 92 percent. Avoid high-flow oxygen without ventilatory support, because he may retain CO2.
• Avoid sedatives, opioids and benzodiazepines.

• NIV (BiPAP): typical start EPAP 4 to 5 cmH2O and IPAP 10 cmH2O, titrated to comfort and gas exchange. NIV relieves hypercarbia and hypoxia (Harrison's 22E). Do not delay it if CO2 is rising.
• Mechanical cough assist to clear secretions and prevent aspiration pneumonia (Harrison's 22E).
• Gastrostomy when swallowing is unsafe (Harrison's 22E).
• Discuss goals of care and long-term ventilation early.

• Symptomatic bradycardia: atropine 1 mg IV (repeat every 3 to 5 minutes, max 3 mg). If it fails, use dopamine 5 to 20 mcg/kg/min or adrenaline 2 to 10 mcg/min, or transcutaneous pacing. Call cardiology for pacemaker.
• VT or long QT: correct K to above 4 and Mg to above 2 mmol/L. Magnesium sulphate 2 g IV over 10 to 20 minutes for torsades. Stop QT-prolonging drugs.

• Non-drug: slow rising, high fluid and salt intake, head of bed raised 30 degrees, compression stockings.
• Midodrine: start 2.5 to 5 mg three times a day, up to 10 mg three times a day. Give the last dose before about 6 to 7 pm to avoid supine hypertension (Adams and Victor's; Cecil).
• Fludrocortisone: 0.05 to 0.1 mg daily, titrate to a maximum of about 0.3 to 0.4 mg daily. Monitor K and watch for fluid overload.

• Sit to pass urine, avoid straining.
• If retention or AKI: catheterise and watch for post-obstructive diuresis.
• Tamsulosin 0.4 mg at night can worsen orthostasis. In a patient with orthostatic hypotension, consider finasteride 5 mg daily first, or start tamsulosin cautiously.
• Avoid anticholinergic drugs (glycopyrrolate, hyoscine, amitriptyline). They are used for drooling in MND but can precipitate retention in BPH. Consider botulinum toxin to the salivary glands instead.

• Riluzole 50 mg twice daily (Cecil). Check LFT and blood count at baseline, then monthly for 3 months. It prolongs survival by about 3 months and can cause nausea, dizziness, fatigue and raised liver enzymes.
• Edaravone: IV 60 mg daily for 14 days, then a 14 day break; subsequent cycles are 10 days of dosing in each 14 day period, followed by 14 days off. An oral formulation is also available (105 mg per dose in the same cycle pattern). Evidence is modest and based on a selected group (Harrison's 22E).
• Tofersen only for SOD1-mediated ALS (genetic testing needed).

• Levetiracetam 500 mg twice daily, increasing as needed. Do not start empirically after one unclear event.

• If PE is confirmed: therapeutic anticoagulation per local protocol.
• Anaesthetic caution: succinylcholine is contraindicated in lower motor neuron disease because of the hyperkalaemia risk (Morgan and Mikhail's). Flag this in his notes.

5. Disposition

6. Recent evidence