SDMH EMC 2015 Acute Headache

Objectives Key assessment features to ascertain in acute headache – differential causes When to consider neuroimaging Become familiar with subarachnoid haemorrhage (SAH) workup Understand the features of infective headaches Features that may suggest uncommon but important diagnoses

Broad differential causes

Assessment History EXAM ABCD – primarily GCS BP and T Acuity of onset Prodromal features – fever, ‘flu’, nausea, visual problems Syncope, meningism, eye pain, focal neurology, facial pain, seizures Headache pattern Family history – Migraine, SAH Medications – immunosuppressant's, recent antibiotics ABCD – primarily GCS BP and T Neck rigidity/photophobia Detailed neurological exam Facial sinuses Eyes Temporal artery tenderness

Investigation Pathology – largely unhelpful. Serum Na, BSL and ESR/CRP may assist with some differentials Imaging – CT head test of choice if indicated Invasive – Lumbar puncture if SAH, meningitis, encephalitis or Idiopathic intracranial hypertension considered

Imaging algorithm

More detail Historical EXAm

About migraine… Classic – unilateral, throbbing, nauseating. Common – generalized headache, deteriorating with time Headache preceded by aura and/or nausea Family history. Onset in adolescence or young adulthood Stereotypical – patient can recognise it. Migraine sufferers can also suffer other neuropathology eg SAH

Management 1st line - NSAID – PO/PR and Paracetamol 2nd line – Metoclopromide 10mg IM/IV OR Prochlorperazine 12.5mg IM/IV OR Droperidol 1-5 IM/IV 3rd line – Chlorpromazine 12.5 mg IV in IV fluids. Repeat x 1 if ineffective Rehydrate – fluids often helpful If failing to settle, consider alternate diagnosis, senior input Triptans – expensive, frequently ineffective in ED population Ergotamine unavailable

Case scenario 44 yr old female Smoker Sudden onset severe R sided headache whilst sitting reading a book 3 hrs earlier Associated nausea, vomited x 2 Otherwise well BUT…. 4 x sisters with ‘bleeds into brain’ – 2 deceased from aneurysms in NZ

Subarachnoid haemorrhage 80% due to aneurysm Median age 50 Smoking 4-5 x risk Typically ‘worst ever’ headache Reaching maximal severity immediately Nausea/vomiting/syncope/seizure raise suspicion May only have headache Headache may dissipate within hours-days Causes 12-25% of thunderclap headaches

Subarachnoid haemorrhage Exam – often normal Photophobia/nuchal rigidity Decreasing level of consciousness , worse outcome Thus need to avoid missing the ‘sentinel bleed’ Re-bleed - 1 day to 1 month later

Investigation CT head First line test – non contrast CT head Positive result on CT  CT angiography Will help to determine neurosurgical plan

To LP or not to LP? CT sensitivity traditionally quoted as ~ 90% at 4-12hrs after headache, falling with time CSF testing for RBC breakdown (xanthochromia) - gold standard ‘Standard practice’ – if CT negative do LP 12 hrs from onset headache Perry et al 2011 – 100% CT sensitivity < 6hrs headache  no LP needed if presenting under 6 hrs LP may find alternate pathology

Management Definitive treatment - interventional neuroradiology or neurosurgeon – transfer Analgesia Antiemetic Avoid hypertension and hypotension (?140>BP>100) ?Seizure prophylaxis Nimodipine PO within 96 hrs

Bacterial meningitis Headache +fever +meningism Frequently following URTI May deteriorate quickly, or have persistent headache for days Altered LoC significant feature – drowsiness Vomiting common. Seizure 25% patients Rash in meningococcemia; may not be present in isolated meningitis

Management Meningitis considered likely THEN Dexamethasone 10mg IV then Ceftriaxone 2g IV AND Penicillin 2.4g IV IF immunocompromised, age >50, alcoholic, pregnant or debilitated Steroid BEFORE antibiotics. Avoid antibiotic delay 10% all-comer mortality (20% pneumococcus) 25% neurological morbidity

To LP or not to LP? Theoretical concerns about cerebral herniation Considered contraindicated in high ICP (e.g. low GCS) If signs ICP  CT head Ideally LP within 2 hrs of antibiotic administration PCR still possible after this CT SIGNS OF HIGH ICP Ventricle size Slit-like or none Basilar cistern size Mildly effaced or effaced Sulci size Effaced or none visible Transfalcine herniation (midline shift) Loss of gray-white matter differentiation

Viral meningitis Typical meningitis symptoms May have viral syndrome OR thunderclap onset NO altered LoC, seizures or focal neurology Often appear ‘well’ (but miserable!) Stable symptom course 85% enterovirus LP confirms diagnosis Treatment supportive

Encephalitis Viral infection of brain parenchyma Headache and fever common, but not reliably present. Meningism mild or absent Focal neurology signs – higher functions Due to grey matter inflammation – aphasia, behavior change, lethargy, movement disorder, ‘psychiatric’ phenomenon, memory loss Seizures/confusion Varying viral aetiologies HSV potentially most damaging – 20% mortality 25-40% neurological morbidity

Encephalitis Diagnosis made by CSF PCR CTB required before LP MRI/EEG supportive LP findings similar to viral meningitis Treatment: institute early – Aciclovir 10mg/kg IV tds

Temporal arteritis Vasculitis of medium-large arteries Classic symptoms of headache and temporal artery tenderness. Jaw claudication common. May only have weakness, lethargy, headaches , +/- fever +/- anaemia Strongly associated with PMR Occurs age >50 Only useful investigation ESR > 50 Need to prevent visual loss If suspected – treat Prednisone 50mg daily AND Aspirin 100mg daily Refer for biopsy and rheumatology f/u

Intracranial tumour Fear of brain tumour far outweighs actual brain tumours in ED presentations Classic early morning headaches, with positional change not common Non-specific headache 70% pts Often few other findings Suspect with hx of Vomiting Neurological changes (often subtle) Personality changes New onset seizure (esp. focal) Background hx Ca.

Idiopathic Intracranial Hypertension Pseudotumor cerebri, Benign intracranial hypertension Uncommon –younger, overweight, women age 15-50 Persistent headaches, consistent with high ICP Due to abnormal CSF production/excretion Papilloedema characteristic feature Risk of visual field loss Diagnosed by LP CSF pressure >25 cm LP therapeutic ! Treat with acetazolamide 250mg bd Refer for follow up Opthalmology/Neurology review

Questions?

Summary Take a good headache history ; ensure to check eyes, temporal arteries on exam Not everyone needs a scan (but many will get one!) and bloods not usually helpful Migraine stereotypical; don’t diagnose 1st ever migraine if age>30 CT +/- LP for sudden onset headaches Don’t delay antimicrobials if meningitis/encephalitis considered likely Temporal arteritis only occurs age > 50 LP both diagnostic and therapeutic if IIH considered