Neurology

Compression 1. Intraventricular or periventricular tumour, causing transient obstructive hydrocephalus,

colloid cyst of 3rd ventricle, craniopharyngioma, pinealoma, brainstem tumour PC: Paroxysmal headaches, drop attacks, acute blindness

2. Posterior fossa lesion: tumour, AVM, Arnold-Chiari malformation, platybasia PC: Paroxysmal headaches, drop attacks, acute blindness

3. Pituitary enlargement: apoplexy, due to infarction of pituitary macroadenoma; post-partum hypophysitis

Intracranial pressure t or 1 1. Primary intracranial hypertension:

PC: Headache worse on stooping or lying flat; visual disturbance (obscurations; 3rd cranial nerve palsy); tinnitus, triggered by weight gain

2. Spontaneous intracranial hypotension, due to CSF dural leak. PC: Headache worse on standing initially, but may become posture-independent later

1. 'Thunderclap headache' - variant of migraine (commoner in migraineurs): • Mimics subarachnoid haemorrhage

2. Situational: cough, exertion, coitus: • Mimics posterior fossa or ventricular lesion, sinusitis or dental abscess

Systemic 1. Hypertensive crisis: vasculitis, preeclampsia, phaeochromocytoma 2. Infection, e.g. sinusitis, tonsillitis, dental abscess, UTI, atypical pneumonia (e.g. mycoplasma):

• May all cause meningism and encephalopathy, esp. in children and elderly 3. Toxins: carbon monoxide

H E A D A C H E 261

Bloods • WBC Neutrophils: bacterial meningitis, abscess, LyMe disease (Lymphocytes in Meninges)

Lymphocytes: Listeria (Lymphocytes in Serum) Monocytes: TB Meningitis • ESR, CRP

Urine • MSU, glucose, protein

Microbiology • Blood cultures • Serology: bacterial meningitides, enterovirus, HIV, syphilis, cryptococcal (serum CRAG) • CSF: do brain scan before performing lumbar puncture to exclude mass-lesion or manifest haemorrhage

Radiology • CT head

• MRI

1. Subarachnoid haemorrhage: blood in sulci, cisterns - sensitivity = 90% in first 24 hrs 2. Mass lesions: intracerebral haemorrhage, abscess, tumour 1. MRI: posterior fossa lesion, ADEM, CSF dural leak (brain and spine MRI with contrast) 2. MRA: aneurysm, AVM, dissection, vasculitis; sensitivity for aneurysms > 5 mm = 90% 3. MRV: cerebral venous thrombosis

• Angiogram: If aneurysm or AVM suspected, sensitivity

90% (but risk of stroke due to procedure = 0.5%)

• Opening - Normal: 5-20 cmH20 pressure - Raised: subarachnoid haemorrhage, primary intracranial hypertension, meningitis

- Depressed: spontaneous intracranial hypotension (avoid LP if history is suggestive!) • Appearance - Normal: clear

- Xanthochromic (yellow): traumatic tap, subarachnoid haemorrhage, high protein - Bloody: traumatic tap, subarachnoid haemorrhage: .*. if subarachnoid haemorrhage is a

possibility, send for immediate centrifugation and spectrophotometry on supernatant for bilirubin (+ve between 12 hours and 2 weeks) and CSF ferritin {+ ve in SAH)

• Microscopy, - Normal: RBC count raised if traumatic tap, but should see decrease from bottles 1 to 3 culture and WBC count 0-4 (lymphocytes); deduct 1 WBC for every 700 RBCs sensitivity - Neutrophilia: meningococal, pneumococcal, listeriosis, fungal; OR early viral or TB

- Lymphocytosis: viral (enteroviruses, HIV), TB, Lyme, syphilis; OR partially treated bacterial autoimmune vaculitis, SLE, Behcet's syndrome; sarcoidosis

- Stains: Gram - bacteria, some fungal; Ziehl-Nielsen - TB; Indian Ink - Cryptococcus

• Chemistry - Normal: Protein 0-0.45 g/l; deduct 0.01 g/l for every 1000 RBCs; Glucose 2.8 - 4.2 mmol/l, or > 50% serum glucose

- Protein > 1 g/l: bacterial, TB or fungal meningitis, or subarachnoid haemorrhage - Glucose < 40%: bacterial, TB, fungal or mumps meningitis

• Other • Cryptococcal antigen (CSF CRAG), herpes class PCR, ACE, oligoclonal bands, cytology

Migraine Autonomic (trigeminal-autonomic cephalgias or TACs)

1. Cluster headaches 2. Paroxysmal hemicrania / SUNCT: briefer attacks relative to cluster headaches 3. Hemicrania continua: continuous hemicranial pain with autonomic signs

Tension Cervical disease / other surrounding structures: neck, eyes, ears, TMJ, teeth Head injury / other triggers: cough, exercise, coitus, ice cream Intracranial pressure t or 4

1. ICP raised: • Tumour or meningeal infiltration; aneurysm or AVM • Primary intracranial hypertension: assoc. with cerebral venous thrombosis

2. ICP low: • Spontaneous intracranial hypotension (due to CSF dural leak) Neuralgia, trigeminal, paratrigeminal Giant-cell, temporal arteritis

Systemic 1. Organ failure: • Hypercapnia (e.g. obstructive sleep apnoea), hypoxia (e.g. mountain sickness)

• Uraemia, hepatic failure 2. Anaemia; hyperviscosity 3. Severe hypertension: accelerated-phase, preeclampsia, phaeochromocytoma

Inflammation 1. Chronic infection, neoplasia 2. Autoimmunity: SLE, vasculitides, Behcet's syndrome 3. Sarcoid

Toxins 1. Analgesics: excess opioids, caffeine, NSAIDs, paracetamol, triptans; or withdrawal from these 2. Vasodilators: calcium antagonists, nitrates, monosodium glutamate (Chinese food) 3. Others: anticonvulsants, sulphasalazine, steroids (corticosteroids, pill, HRT), alcohol

Endocrine 1. Cortisol t or i (Cushing's or Addison's) 2. Thyroxine t or I 3. APUDoma: phaeochromocytoma, carcinoid, mastocytosis - episodic headaches, with flushing 4. Hypoglycaemia

Seizures - post-ictal Morning headaches if nocturnal fits

H E A D A C

Temporal: Attack duration = 4-72 hrs; may also develop background continuous headache ('transformed migraine')

Character: Throbbing, unilateral but may cross midline, severe; worse with movement; pt lies down Assoc: N + V, photophobia, phonophobia, osmophobia:

• Premonitory symptoms in 50% (e.g. change in appetite, arousal, mood) • Aura in 20% (preceding focal neurological sx, esp. visual)

Epi: • Age: begins in childhood (as cyclical abdominal pain or motion sickness) or teens • Sex: females > males; family history common • Triggers: carbohydrates (cola, citrus, chocolate, alcohol); premenstrual; exertion; lying-in

Autonomic: trigeminal-autonomic cephalgias (TACs) 1. Cluster headaches

Temporal: • Attack duration = 5 mins-3 hr • Onset typically same time every night-day • Cluster length = 2-12 weeks; remission length = 3 months-3 years

Character: non-throbbing; strictly unilateral peri-or retro-orbital pain; pt. paces room Assoc: ipsilateral Horner's syndrome, lacrimation, nasal congestion or rhinorrhoea, sweating

2. Paroxysmal hemicrania / SUNCT Paroxysmal hemicrania:

• Attack duration =5-45 mins • Recur 5-30 x /day, usually chronic, may be episodic (i.e. in bouts) • Respond well to indomethacin (also SUNCT and hemicrania continua)

SUNCT (short-lasting unilateral neuralgia with conjunctival injection and tearing): • Attacks last 15-60 s, recur 5-30 x /hr

3. Hemicrania continua Temporal: Continuous symptoms of cluster headache-like symptoms

Tension Temporal: Attack duration = 30 min - continuous ('chronic daily headache' > 15 days / month) Character: Tightness, pressure, heaviness, ice-pick pains, vertex-bitemporal; mild (pt works through) Assoc: Mild photophobia, nausea, depression; dizziness (due to hyperventilation) Epi: middle-aged men; triggered by alcohol

Cervical Worse with head movements; TMJ - preauricular, temple pain; associated crepitus

Head injury Assoc: Poor concentration, insomnia, irritable or depressed mood

Intracranial Raised: worse with stooping; visual obscurations; obese women (primary intracranial hypertension) Low: worsens on sitting or standing; associated with previous trauma, often minor

Neuralgia, trigeminal Temporal: Attack duration = sudden, momentary pain, repeated in bursts:

• Triggered by touching trigger zone or action e.g. chewing, swallowing, talking Character: Lancinating, in distribution of V2 or V3 dermatome typically

Giant-cell, temporal arteritis Character: Unilateral temple pain and tenderness; worse at night; anorexia and weight loss; myalgia Assoc: law of 60' = > 60 years; ESR > 60; responds within days to prednisolone 60 mg od:

• Jaw claudication; anterior ischaemic optic neuropathy (blindness); ophthalmoplegia

Acute Confusional State Def 1. Impairment in the level of consciousness (GCS), with a secondary global impairment in

the content of consciousness (i.e. cognition) over hours, days or weeks (cf. dementia, which refers to primary impairment in cognition, with preserved alertness).