neuro 2

• Sir William Osler (1849-1919): 'The very first step towards success in any occupation is to become interested in it'
• Pain


  An unpleasant sensory and emotional experience which we primarily associate with tissue damage or describe in terms of such damage, or both

  
• Pain


  The perception of a noxious stimulus that begins in the dorsal horn and involves the entire spinal cord and brain
• Pain


  • Can cause many different reactions: Activate autonomic system, Muscle activity, Mood, Prevent sleep
• Mild pain


  Does not interfere noticeably with everyday life
• Moderate pain


  May cause some annoyance and perceived as unpleasant
• Severe chronic pain


  Affects a person's entire life in major ways
• The only tolerable pain is someone else's pain
• Headache affects about 90% of the general population
• The commonest causes are migraine (12-16%) and episodic tension-type headache (up to 80%)
• Sources of pain in headaches

  • Traction or dilatation of intracranial or extracranial arteries
  • Traction of large extracranial veins
  • Compression, traction or inflammation of cranial and spinal nerves (5,7,9,10,C1-C3)
  • Spasm and trauma to cranial and cervical muscles
  • Meningeal irritation and raised intracranial pressure
  • Disturbance of intracerebral serotonergic projections
• Brain parenchyma


  Brain itself is a painless organ
• Classification of headaches


  • The primary headaches
  • The secondary headaches
  • Cranial neuralgias, other facial pain and other headaches
• Migraine


  • A serious health problem which impair quality of life
  • The second most common primary headache that affects approximately more than 10% people in general population
  • A throbbing painful headache, usually on one side of the head, that is often initiated or "triggered" by specific compounds or situations
  • Occurs more often in women (75%, approximately) and may affect a person's ability to do common tasks
• In the Global Burden of Disease Survey, migraine was ranked as the third most prevalent disorder and sixth-highest specific cause of disability worldwide
• Criteria for Diagnosing Migraine Without Aura

  • At least five attacks fulfilling criteria B–D
  • Headache attacks lasting 4-72 hours (untreated or unsuccessfully treated)
  • Headache has at least two of the following four characteristics: unilateral location, pulsating quality, moderate or severe pain intensity, aggravation by or causing avoidance of routine physical activity
  • During headache at least one of the following: nausea and/or vomiting, photophobia and phonophobia
  • Not better accounted for by another ICHD-3 diagnosis
• Migraine pathophysiology is still unclear
• Migraine

  • Likely to be a brain disorder involving altered regulation and control of afferents, with a particular focus on the cranium
  • Growing number of studies using new imaging techniques show that migraine and cluster headaches are related with neuronal structures and vasodilatation
• Pathogenesis of migraine attack

  1. Abnormal nerve impulses originating mainly from the brain stem in the distribution of the trigeminal nerve and spreading to the cortex causing release of inflammatory substances and neuropeptides that stimulate pain fibres on meningeal arterioles

  2. Involves an initial spreading occipital wave of vasoconstriction (CSD, cortical spreading depression leads to oligemia) of cortical blood vessels with decreased blood flow (the aura phase) followed later by regional cortical vasodilatation (the headache phase)
• Migraine involves alterations in the sub-cortical aminergic sensory modulatory systems that influence the brain widely
• Criteria for Diagnosing Migraine With Aura

  • At least two attacks fulfilling criteria B and C
  • One or more of the following fully reversible aura symptoms: visual, sensory, speech and/or language, motor, brainstem, retinal
  • At least two of the following four characteristics: at least one aura symptom spreads gradually over 5 minutes, and/or two or more symptoms occur in succession, each individual aura symptom lasts 5-60 minutes, at least one aura symptom is unilateral, the aura is accompanied, or followed within 60 minutes, by headache
  • Not better accounted for by another ICHD-3 diagnosis, and transient ischaemic attack has been excluded
• Tension type headache is a common type of headache
• Headache History: Essential Points


  • Onset (how long has the HA been present)
  • Nature (episodic versus continuous)
  • Frequency (per week, per month, per year)
  • Duration (minutes, hours, days, etc.)
  • Severity (pain scale or documentation of loss of normal functioning)
  • Character of Pain (stabbing, squeezing, pulsatile)
  • Location (unilateral, bilateral, fronto-temporal, occipital)
  • Radiation
  • Aura (specify what type)
  • Aggravating Factors (photophobia, phonophobia, physical exertion)
  • Alleviating Factors (including medications used, sleep, position change, etc.)
  • Associated nausea or vomiting
  • Recent head injury or concussion

  
• Examination should carefully record the vital signs including BP and check particularly for signs of raised intracranial pressure, meningism, tenderness of the temporal arteries, and focal neurological signs
• Worrisome Headache Red Flags—"SNOOP"

  • Systemic symptoms (fever, weight loss) or secondary risk factors (HIV, systemic cancer)
  • Neurologic symptoms or abnormal signs (confusion, impaired alertness or consciousness)
  • Onset: sudden, abrupt, or split-second
  • Older: new onset and progressive headache, especially in middle age >50 yr (giant cell arteritis)
  • Previous headache history: first headache or different (change in attack frequency, severity, or clinical features)
• The incidence of brain tumour in general population is 0.06-0.01% per year
• 72% of brain tumours occur over age 50
• In primary care, the risk of brain tumour with headache presentation is 0.09%
• If a GP makes a diagnosis of primary headache, the risk is 0.045%
• If a GP cannot make a diagnosis, the risk is 0.15%
• Headaches in whom a brain tumour is suspected

  • Headache of recent onset accompanied by features suggestive of raised intracranial pressure: vomiting, drowsiness, posture related headache, pulse synchronous tinnitus, or by other focal or non-focal neurological symptoms: blackout, change in memory or personality
  • New, qualitatively different, unexplained headache that becomes progressively severe
• Tension type headache is present in 58-77% of brain tumours
• Migraine-like headache is present in 7-9% of brain tumours, but with atypical features
• Intermittent headache is present in 62-88% of brain tumours
• 8% of brain tumours present with headache as the only symptom
• 74% of brain tumours present within 3 months, and 90% within 6 months
• Brain tumour headache may be similar to previous headache but more frequent/severe and associated with new symptoms
• CT (or MRI) should be done as soon as possible in patients with any of the following findings: thunderclap headache, altered mental status, meningismus, papilledema, signs of sepsis, acute focal neurologic deficit, severe hypertension
• Lumbar puncture and CSF analysis should be done if meningitis, subarachnoid hemorrhage, or encephalitis is being considered
• Neuroimaging, usually MRI, should be done if patients have any of the following: focal neurologic deficit of subacute or uncertain onset, age > 50 yr, weight loss, cancer, HIV infection or AIDS, change in an established headache pattern, diplopia