week 6

neurology chapter 22 keypoints

• Headache is a common condition, and patients worry that they may have something wrong with their brain. The intracranial structures are not usually sensitive to pain, however, and most headaches do not originate in the brain.

• Migraine is a very common disorder, which reduces quality of life to an extent underestimated by people who do not have it.

• By no means all migraine patients experience aura.

• There are definitions of migraine with and without aura, but these sometimes need to be applied somewhat loosely in practice.

• There are several types of migraine, which can occur at different periods of one and the same patient’s life. A migraine diagnosis should therefore not be rejected just because the patient has a history of migraine and the symptoms are now ‘completely different’.

• There is a difference between the treatment for migraine attacks and prophylactic treatment.

• Different kinds of episodic pain can occur in the head and neck region. A shooting pain is referred to as ‘neuralgia’, trigeminal neuralgia being the most familiar type.

• Trigeminal neuralgia is initially treated with sodium channel blockers. Surgery or radiosurgery to decompress the nerve is a good alternative.

• Trigeminal neuropathy can cause chronic facial pain, which requires different treatment using analgesics for neuropathic pain.

• It is not possible to diagnose all types of facial pain clearly.

• Cluster headache follows a fairly characteristic pattern and should not be missed, as it is an excruciating pain that responds well to treatment.

• A diagnosis of temporal arteritis should also not be missed in view of the risk of neurological deficit if it is not treated quickly.

• Chronic headache is often referred to as ‘tension-type headache’. Overmedication should always be considered.

• There are warning symptoms that every physician should be familiar with in cases of both chronic and acute headache.

• Acute severe headache occurring for the first time should always be assessed in hospital.

examples of primary headaches

migraines or cluster headaches

more?

when is a headache primary

if there is no obvious cause and there is a stereotypical time pattern w/ characteristic accompanying symptoms

does brain tissue feel pain

no

if the brain cannot feel pain, what does

the basal meninges and large blood vessels (both arteries and large sinuses) can feel pain

a headache can also be caused by reduced or increased CSF pressure

the pain-sensitive structures in the anterior and middle cranial fossa are innervated by…

the trigeminal nerve (CN V)

the pain-sensitive structures in the posterior cranial fossa are innervated by…

the glossopharyngeal nerve (CN IX) and vagus nerve (CN X)

if the cause of pain is intracranial…

this will generally be due to traction on or irritation of the meninges (eg. inflammation, blood breakdown products or displacement of meninges by space occupying processes such as tumours and bleeds) and blood vessels (eg. vasodilation)

migraines

• common, occurs in 25% of women and 8% of men at least once

• particularly common around 40 y/o but they usually begin at a young age (in women around the menarche)

• of those with migraines, 50% have monthly attacks, 35% have weekly and 15% a few times a year

• often a positive family history

• tends to occur around menstruation in women and may cease during pregnancy and after menopause

  however, some women get migraines for the first time during pregnancy

• attacks occur during periods of rest

• onset after 50 is uncommon, suggests other diagnoses → imagining is indicated

• a complete attack compromises a prodromal stage lasting a few hours or days

• < than ½ of patients experience aura with: positive or negative visual symptoms (95–99%), sensory symptoms (35–40%), dysphasia (15–20%) and, least commonly, motor symptoms (15%)

• an aura develops gradually over 5-20 minutes and lasts less than an hour

• aura phenomena are usually unilateral when there are hemisensory symptoms, hemimotor symptoms or dysphasia

  now just falls under ‘migraine with aura'‘

• auras usually precede the headache and there is a headache-free interval lasting 15-30 minutes, but not always

• attacks typically cause them to lie in bed and become hypersensitive to light and sound (sometimes to smells as well)

• pain is throbbing, sometimes tight

• some patients end up falling asleep and the headache is less severe when they wake up

• nausea is common → relieved by vomiting

how does a migraine present in children

abdominal pain, or hallucinations of bodily distortion, referred to as Alice in Wonderland syndrome

prodromal stage of a migraine

lasts a few hours or days:

neck pain, mood changes, a feeling of stress, tiredness, pallor, frequent yawning, blurred vision, eating sweets, craving for sweet foods, fluid retention or sensitivity to sensory stimuli

fewer than half of patients experience aura with positive or negative visual symptoms (95–99 %), sensory symptoms (35–40 %), dysphasia (15–20 %) and, least commonly, motor symptoms (15 %). Aura phenomena are usually unilateral

aura phenomenon are usually…

unilateral

develops gradually over 5-20 minutes and lasts less than an hour

migraine accompagnee is…

when there are hemisensory symptoms, hemimotor symptoms or dysphasia

now just falls under ‘migraine with aura'‘

negative vs positive aural symptoms

• Negative visual symptoms:

  • range from loss of a large part of the field of vision to homonymous hemianopia

  • or there can be scattered patches

  • another variant is where both fields of vision gradually become restricted from the outside

• Positive symptoms:

  • take on characteristic shapes eg. sawtooth lines (fortifications, tilting) or elementary shapes such as squares or triangles

  • sometimes these are clearly coloured, often move

  • there can also be a sensation as if the picture is blurred by moving hot air, as seen above a tarmac road on a hot day (scintillations)

diagnostic criteria for migraine

1. migraine w/o aura (if at least 5 attacks have occurred)

   1. headache for 4-72 hrs (untreated)

   2. at least 2 of the following

      • unilateral location

      • pulsating pain

      • moderate or severe pain intensity

      • aggravation by or cause avoidance of routine physical activity

   3. plus at least 1 of these 2

      • nausea and/or vomiting

      • photophobia and phonophobia

2. migraine w/ aura

   1. at least 2 aura attacks that meet the following criteria

   2. 1 or more of the following completely reversible aura symptoms

      • visual

      • sensory

      • speech and/or language

      • motor

      • brainstem

      • retinal

   3. at least 3 of the following 6 types of pattern

      • at least 1 aura symptom that gradually spreads over ≥ 5 min

      • 2 or more aura symptoms occur in succession

      • each individual aura symptom lasts 5–60 min

      • at least 1 aura symptom is unilateral

      • at least 1 aura symptom is positive (e.g. flashes of light or pins and needles)

      • the aura is accompanied, or followed within 60 min, by headache

are the things that occur in migraines permanent

usually not but permanent loss of function sometimes occurs especially in particular hemianopia due to infarction in an occipital lobe = migrainous infraction

what are risk factors for migrainous infarction

aura, hypertension, smoking and oral contraception

pathophysiology of migraine attacks

• a neurovascular disorder

• genetic factors are involved

• headache: reduced stimulation of vascular and neuronal serotonin receptors in the trigeminovascular system → vasodilation and a neurogenic response by the meninges → headache and other migraine symptoms

• stress, fatigue and intolerance to certain foods are often cited as trigger factors, but these probably play only a minor role

• cortical spreading depression plays a role in the case of aura

what is cortical spreading depression

a wave of sustained depolarization (neuronal inactivation) moving through intact brain tissue and associated with brain ischemia, migraine aura, and seizures

→ temporary loss of neuronal function → neurological symptoms

unusual types of migraine

1. basilar migraine → mainly found in young people, attack begins with gradual loss of vision in both eyes (sometimes w/ vertigo), followed by ataxia, dysarthria and bilateral numbness or paraesthesia then vomiting and occipital headache

   theres sometimes amnesia, very occasionally loss of consciousness

2. migraine equivalents or migraine sine hemicrania or migraine aura w/o headache → get true migraine attacks but also auras w/o headaches

3. ophthalmoplegic migraine → whos attack ends with diplopia due to dysfunction of one oculomotor nerve (85%) or abducens nerve (15%) → can persist for 1 to 8 weeks

   It is somewhat dubious whether this actually is migraine; it is nowadays often referred to as ‘recurrent painful ophthalmoplegic neuropathy’

4. familial hemiplegic migraine → autosomal dominant, aura w/ hemiparesis that can persist for many days after the attack, begins at a young age

   → mutations have been found in genes that code for neuronal ion channels (CACNA1A gene for a calcium channel, the ATP1A2 gene for a sodium-potassium channel)

   → there is also a sporadic form

5. retinal migraine → negative or positive visual aura phenomena are limited to 1 eye, possible due to spreading depression of the retina

6. status migrainosus → migraine attack that lasts >72 hrs, aura status lasting more than a week can also occur

7. chronic migraine → when there is migranous headachace more than hald the time over a period of >3 months

   this can occur w/ and w/o excessive use of analgesics

8. vestibular migraine → attacks of vertigo in those w/ a history of migraines

treatment of migraine

• taking an antiemetic as soon as an attack threatens

• after 30 minutes they can take paracetamol or an NSAID

• if antiemetics, paracetamol or NSAIDs dont work, consider triptans (serotonin receptor agonists) → orally, rectally, subcutaneously or as a nasal spray

  these must NOT be taken during the aura, only once the headache starts

• ergotamine used to be prescribed before triptans were used (i think?) → bind serotonin receptors but theyre both blockers and stimulants

  → works quite well but its vasoconstrictive action and the risk of dependency makes it used less

• some dont take medicine, they prefer to rest in a dark room or sleep for a few hours until the worst of the headache has subsided

• prophylactic treatment:

  • recommended strategy is to start with propranolol or metoprolol, possibly followed by one of the following: flunarizine, sodium valproate, candesartan, topiramate of amitriptyline

  • use of ergotamine as a prophylactic is not recommended

  • antagonists to calcitonin gene related peptide are new → play a role in pain transmission in the trigeminovascular system

    → antibodies to CGRP or the CGRP receptor are effective as prophylaxis for both episodic and chronic migraine

approximately 10% of migraine patients experience…

transient chest tightness with tingling

but true angina symptoms are rare

which 2 migraine drugs should not be used during pregnancy

triptans and ergotamine

when is prophylactic treatment of migraines considered

if the attacks occur twice or more per month or are less frequent but very protracted (lasting for days)

types of facial pain

1. trigeminal neuralgia

2. other neuralgias in the head and neck region

3. trigeminal neuropathy

4. temporomandibular disorder

5. atypical chronic facial pain

trigeminal neuralgia

• mainly found in >50 y/o

• very brief minor attacks (1-2 s), very sharp ‘electrical’ pains on one side of the face

• pain is usually felt in the area innervated by the 2nd or 3rd branch of the trigeminal nerve, rarely in the area of the first branch

• varying frequencies

• triggered by speaking, eating, local cooling or a draught and in around 50% its triggered by touching a circumscribed area of skin = a trigger point

• some patients avoid all facial movements, stop shaving or become malnourished

• sharp pains are sometimes accompanied by facial tics (tic douloureux)

• can end/start gradually or suddenly

• examination does not reveal any sensory impairments but there might be exaggerated touch sensation

• in younger people it may be caused by MS due to demyelination of the nerve root entry zone in the brainstem

treatment:

• carbamazepine is generally very effective, can be combined with baclofen if needed

• gabapentin and pregabalin are also used

• another good option is microvascular surgery (Jannetta procedure) → surgical decompression of trigeminal roots at the base of the skull

  it’s often discovered during the procedure that the root is being stretched or compressed by adjacent structures (eg. thickened or tortuous arteries)

• jannetta procedure is not suitable if the cause of the neuralgia is MS → alternative treatment is stereotactic radiotherapy to deliberately damage part of the nerve

• if none of these work or are not considered appropriate → coagulation of the gasserian ganglion can be done

  A rare but feared adverse effect is corneal anaesthesia (if the first branch of the trigeminal nerve is affected) with poor healing of any ulcers, sometimes resulting in perforation; the damage to the nerve can also cause long-term or permanent loss of sensation in the area of skin concerned and pain (anaesthesia dolorosa) in addition to the numbness

when is jannetta procedure not suitable

if the neuralgia is caused by MS

alternative treatment is stereotactic radiotherapy to deliberately damage part of the nerve

tic douloureux is also known as trigeminal neuralgia on the internet though??? or is TC = trigeminal neuralgia + spasms???

where is pain of trigeminal neuralgia usually felt

in the area innervated by the second or third branch of the trigeminal nerve, rarely in the area of the first branch

typically one sided

glossopharyngeal neuralgia

• pain is localised to one side at the back of the throat, radiating into the ear

• triggered by swallowing and sticking the tongue out

• trigger point = tonsillar fossa or the posterior pharyngeal wall

• It should be noted that the anastomosis of nerve IX with nerve X during the attack can cause bradycardia or even heart block, causing the patient to lose consciousness

• treatment → carbamazepine, decompression may also be helpful

other neuralgias***

Neuralgia of the intermediate nerve (a branch of the facial nerve) causes a shooting pain in the ear. There are also neuralgias of the occipital nerve on the back of the head (a diagnosis sometimes wrongly made when there is a continual pain in the occiput) and of the superior laryngeal nerve in the pharynx, radiating into the ear. Imaging is indicated in these cases (see e.g. case study 2.1). These neuralgias are so rare that there is no standard treatment: medication as referred to above has been tried, as has infiltration of the nerves in question

trigeminal neuropathy

• difference from trigeminal neuralgia → trigeminal neuropathy causes continuous pain which is exacerbated by touching but WITHOUT a trigger point AND sensation is impaired in the affected area

• if this occurs in the first branch of the trigeminal n. its mainly post-herpetic neuropathy (= after herpes zoster infection in this area)

• mostly clears up in the course of months or up to 2 years

• most chronic forms cause hyperapthia = a painful syndrome characterized by an abnormally painful reaction to a stimulus, especially a repetitive stimulus, as well as an increased threshold

  but its often painless, with symptoms mainly being an unpleasant unilateral or bilateral numbness → unpleasant sensations can sometimes be treated symptomatically w/ amitriptyline

• the more chronic forms are often accompanied by a malignant disease or mixed connective tissue disease

• gabapentin and pregabalin are also claimed to have an effect, but patients are often disappointed with drug treatments

trigeminal neuropathy vs neuralgia

temperomandibular disorder********

• = a group of disorders where a dysfunction of the maxillary joint and/or masticatory muscles occurs

• disc displacement (check photo) can cause acute pain, usually with restricted movement

• chronic pain in the region of the maxillary joint radiating into the temporalis that is exacerbated by chewing can be caused by discopathy and osteoarthritis

• impaired occlusion and chronic tension in the masticatory muscles can be a contributory factor or a primary cause

atypical chronic facial pain***

The pain is deep-rooted and chronic and does not have the typical characteristics of the syndromes described above. A variety of specialists have been unable to find any cause in their areas. There is sometimes a depressive disorder, and the pain clears up if this is treated, but in many cases the cause remains unknown

cluster headache

• = episodic, very severe throbbing or stabbing pain in and around an eye, radiating into the temple or the angle of the mandible

• max pain is at 5-15 minutes, persists for 15 min to a few hours and subsides in 5-15 minutes

• first attack is between 10-50 y/o

• cause is unknown but dysfunction of the hypothalamus appears to play a role

• 90% of these patients are heavy smokers, but stopping smoking has not been found to affect the frequency of attacks

• there are vegetative symptoms on the side where the pain is, e.g. lacrimation, conjunctival redness, nasal congestion or conversely nasal discharge, and a proportion of patients also have Horner’s syndrome, which can persist after the attack

• hardly ever accompanied by nausea or vomiting unlike migraines

• prodromal symptoms are rare but an aura can occur

• Unlike the behaviour displayed by patients during a migraine attack, they do not seek bed rest but roam around at their wits' end, often inventing strange manipulation techniques to suppress the headache. Many patients report suicidal thoughts during an attack

• forms

  1. in clusters lasting weeks to months (episodic form), 1 or more times per 24 hr in each cluster

     → most common form

     → tendency to occur during nocturnal sleep

     → clusters occur with an average frequency of once a year but with a large individual spread

     → during a cluster period, small amounts of alcohol can trigger an attack, as can sublingual nitroglycerin

  2. not clustered (chronic form) → no attack free periods

• attacks often respond well to treatment

  • doesnt respond to traditional analgesics (even opiates) or carbamazepine or beta blockers

  • inhaling pure O2 helps in 65% of patients within 10-15 minutes usually in the case of milder attacks

  • subcutaneous injection of sumatriptan also helps

  • verapamil hydrochloride is an effective prophylactic if started at the beginning of a cluster

  • a brief course of prednisone is sometimes therapeutic

  • chronic form may respond well to lithium treatment

  • suboccipital injections of methylprednisolone and electrical stimulation of the greater occipital nerve have also been reported to be effective

on the affected side of a cluster headache there are…

vegetative symptoms → lacrimation, conjunctival redness, nasal congestion or conversely nasal discharge, and a proportion of patients also have Horner’s syndrome, which can persist after the attack

diagnostic criteria for cluster headaches

• recurring (at least 5) attacks of severe or very severe unilateral orbital, supraorbital and/or temporal pain

• duration: 15–180 minutes (when untreated)

• frequency: from every other day up to eight times a day

Plus 1 or both of the following accompanying symptoms:

1. at least one of the following symptoms or signs on the side of the headache:

   • conjunctival injection and/or lacrimation

   • nasal congestion and/or rhinorrhoea

   • eyelid oedema

   • forehead and facial sweating

   • miosis and/or ptosis

2. sense of restlessness or agitation

during a cluster period in cluster head aches, … can trigger an attack

small amounts of alcohol can trigger an attack, as can sublingual nitroglycerin

>90% of cluster headache patients…

are smokers

chronic paroxysmal hemicrania**********

Another much rarer (a 100-fold less common) type of episodic headache, far more common in women than in men, is chronic paroxysmal hemicrania . This disorder can start at any age, but usually does so after the age of 30. The very severe unilateral headache attacks last 2–30 minutes but can recur between ten and twenty times a day. During an attack there is conjunctival injection. There would seem to be both stimulation of the parasympathetic nervous system (constricted pupil, nasal discharge, lacrimation, ptosis, swollen eyelid) and sympathetic nervous system (perspiration, reduced salivation). The attacks respond very well to indometacin, and this is a criterion for the diagnosis

short-lasting unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT)*******************

an extremely rare condition, short-lasting unilateral neuralgiform headache with conjunctival injection and tearing ( SUNCT ), which causes a stabbing pain in the area innervated by the first branch of the trigeminal nerve, usually for five seconds to two minutes. These attacks too occur in clusters, three to 200 times a day. In many cases there is not only ipsilateral conjunctival redness and tearing but also nasal congestion, nasal discharge, eyelid oedema, miosis or ptosis, sometimes facial redness and sometimes perspiration. This differs from trigeminal neuralgia, then, in the occurrence of autonomic symptoms and the duration of the attacks

temporal arteritis

• pain localised mainly in the temple where the skin and temporal artery are thickened and tender and arterial pulses are reduced or absent

• usually form part of a more general arteritis which occurs particularly in the ocular arteries and can cause sudden vision disorders

• unknown cause

• there is also often pain in the pectoral girdle muscles (polymyalgia rheumatica → but not connected to rheumatism despite the name)

• claudication of the jaw (pain when chewing) is a highly specific symptom of temporal arteritis

• raised ESR + theres often moderate anemia

• diagnosis is confirmed by biopsy from the temporal artery

• high dose prednisone clears up the pain within a few days (sometimes a few hours), but a maintenance dose has to be taken over a long period (about 2 years)

what is a highly specific symptom of temporal arteritis

claudication of the jaw (pain when chewing)

why is there no pulse in the temporal artery in temporal arteritis???***

tension type headache

• named despite there hardly ever being a connection w/ muscular or mental tension (but they also references to MUSCULE tension headache???)

• diagnosis when there is no other likely cause (??? not sure)

• its chronic and intermittent often exacerbations but there can be spontaneous remissions sometimes lasting for years

• types

  1. episodic → pain comes in fits and starts or attacks

     → the most recent diagnostic criteria (IHS, 2018) further divide the episodic form into a non-frequent and a frequent form and a form with and without sensitivity around the head

  2. chronic → virtually continuous

• The treatment consists first and foremost in explaining the mechanism responsible (which is not a brain abnormality). Analgesics are indispensable during exacerbations, but continuous treatment with painkillers or tranquillizers (benzodiazepines) is undesirable. A temporary course of amitriptyline (10–75 mg ante noctem) may be worthwhile

analgesic dependent headache

• due to long term use of various headache painkillers

• attacks occur almost daily, especially in the morning

• by definition it must be more than 14 days of headaches per month with more than 3 months of overmedication

• occurs particularly in patients using the medication for another headache syndrome (often migraine or tension-type headache) and not e.g. in the case of chronic use of NSAIDs for disorders of the musculoskeletal system

• only treatment is abstention from the medication in question for a few months

• cough headache = a coughing fit followed within a few seconds by a splitting headache that can persist for up to 30 minutes

  → in some cases its reasonable to assume there is an anomaly in the craniovertebral junction (tonsillar descent, chiari malformation etc)

• exertional headache = a diffuse headache following physical exertion that lasts between 5 minutes and 2 days

  → patients with this problem quite often have migraine or orgasmic/post-coital headache as well, so a migrainous cause is suspected

acute headache

• if a patient suffers a sudden agonizing headache (thunderclap headache), the first thing to consider should always be subarachnoid haemorrhage or some other vascular cause

• consider other possibilities once ^ are excluded (eg. cocaine use and acute hypertension (phaeochromocytoma) + the neurovascular causes in this summary)

• usually theres no structural abnormality (idiopathic thunderclap headache) especially in post coital/orgasmic headache

• post coital/orgasmic headache → occipital or diffuse pain, unilateral (33%) or bilateral (67%)

• attacks last on average 30 minutes and never more than 24 hrs

• many patients also have a type of migraine or muscle tension headache

what should firstly be considered with a sudden agonising headache (thunderclap headache)

subarchnoid haemorrhage or some other vascular cause

consider other possibilities once ^ are excluded (eg. cocaine use and acute hypertension (phaeochromocytoma) + the neurovascular causes in this summary)

warning symptoms in cases of headache

Acute headache

• acute onset of maximum-intensity headache

• fever

• neurological symptoms during the headache

• nausea and vomiting (except in the case of migraine)

• diplopia

• impaired consciousness

• meningism

• triggered by increases in pressure (cough, orgasm)

Chronic headache

• onset after the 40th year of life

• onset in the early morning

• slowly progressive over a few weeks or months

• neurological abnormalities

• diplopia

• triggered by increased pressure

• triggered by change in position

• meningeal irritation

• morning sickness

• papilloedema

• hypertension, relatively low heart rate

if a headache presents no alarming features and no abnormalities are found on physical examination…

an organic lesion is very unlikely but of course never entirely out of the question

meningitis is usually caused by…

a virus, in which case the prognosis is good and the treatment is usually symptomatic

bacterial meningitis is less common but more severe

the key symptoms of infections of the CNS and cerebral meninges…

fever and headache but it doesnt mean theyre always there

very young and very old patients generally display even fewer classic symptoms

neurology chapter 24 key points

• When treating bacterial meningitis, the first step is to administer corticosteroids. If meningitis is suspected, antibiotics should be started as soon as possible.

• A diagnosis of meningitis always involves the preparation of blood cultures.

• As a result of vaccination, meningitis has now become a disease of older adults. Pneumococci are the main pathogens in the western World.

• Infections can sometimes produce a space-occupying lesion, rather like a brain abscess. As a result, an initial diagnosis of brain tumour is often made.

• While syphilis is rare in North-West Europe, a failure to diagnose it can have serious consequences.

• Neuroborreliosis is a multifaceted infection. This is an increasingly common disease in North-West Europe, as a growing percentage of ticks are infected with the bacterium.

CNS infections caused by fungi, yeasts and parasites are…

rare, except in patients with a weakened immune system (eg. in HIV)

in meningitis, the infection is confined to…

the meninges and subarachnoid spaces

purulent meningeal inflammations are caused by…

bacterial infections

which pathogens dont adhere to the ‘purulent = bacteria’ rule

TB, syphilis and spirochaetes

what is inflamed in encephalitis or myelitis

the brain parenchyma or spinal cord

bacterial vs viral encephalitis/myelitis

• Bacterial infections are soon encapsulated, causing an abscess . When a purulent inflammation is found in the subdural space, this is referred to as a subdural empyema

• Viral inflammations of the brain parenchyma cause more diffuse changes affecting the entire cerebrum or mainly one lobe (e.g. the temporal lobe)

bacterial meningitis

• in 50% it presents as an acute illness w/ symptoms developing within 24 hrs

• 40% of adults have risk factors for bacterial meningitis = disorders that impact the immune system (immunosuppressants, HIV, alcoholism, diabetes etc) and bacterial infections elsewhere in the body

• one particular group of people who are at increased risk are those who have suffered a skull fracture in the past or who have liquorrhoea (CSF leak) from the nose or ear following an accident or operation → provides the bacteria with a port of entry to the brain

• >80% develop headache, vomiting, photophobia and high fever

• 80% have a stiff neck but the ‘classic triad’ of a stiff neck, fever and diminished consciousness is only found in 50%

• illness is often preceded by a few days of general malaise and inflammation of the ear or paranasal sinus

• 20% are in a coma on admission, some develop cerebral herniation within a few hours due to the fulminant (sudden) inflammation

• in the acute phase, 1/3 have a neurological deficit, usually aphasia, hemiparesis or cranial nerve palsy

  the most common cranial nerve palsy involves the oculomotor (III), abducens (VI), facial (VII) and vestibulocochlear (VIII) nerves

• a small proportion have an epileptic seizure, this is particularly the case in pneumococcal meningitis

• meningococcal meningitis → usually has a mixed presentation of meningitis and sepsis w/ disseminated intravascular coagulation which causes petechiae or exanthema which are small infarctions caused by embolisms containing infected material (so the meningococcus can be cultured from a skin biopsy of the petechiae or exanthema)

• symptoms of meningeal irritation and fever are often mild or absent in young infants and neonates

• !! in neonates it may present with hypothermia !!, jaundice and poor feeding

  in infants → general malaise, drowsiness, unwilling to eat, vomiting or diarrhoea, they may cry when their diapers are changed (leg pain during changing due to meningeal irritation)

in infants w/ bacterial meningitis, why may they cry when their diapers are changed

due to leg pain during changing due to meningeal irritation

how may bacterial meningitis present in neonates

hypothermia !!, jaundice and poor feeding

patients with meningococcal meningitis often have a mixed presentation of…

meningitis and sepsis, with disseminated intravascular coagulation causing small skin bleeds (petechiae or exanthema) = small infarctions caused by embolisms containing infected material. The meningococcus can, therefore, be cultured from a skin biopsy taken from these skin abnormalities

which type of meningitis is more likely to present with an epileptic seizure

pneumococcal meningitis

(if it occurs) what is the most common cranial nerve palsy in the acute phase of bacterial meningitis

palsy of the oculomotor (III), abducens (VI), facial (VII) and vestibulocochlear (VIII) nerves

what is the ‘classic triad’ in bacterial meningitis despite only being found in 50%

stiff neck, fever and diminished consciousness

80% have a stiff neck but the triad is way less

…% of adults have risk factors for bacterial meningitis

40

= disorders that impact the immune system (immunosuppressants, HIV, alcoholism, diabetes etc) and bacterial infections elsewhere in the body

other → otitis, sinusitis, liquorrhoea

what is one specific risk factor for bacterial meningitis (not immunosuppression or other bacterial infections)

those who have suffered a skull fracture in the past or who have liquorrhoea (CSF leak) from the nose or ear following an accident or operation → provides the bacteria with a port of entry to the brain

CSF leak / liquorrhoea

an abnormal communication between the intracranial compartment and the sinonasal or tympanomastoid cavities of the skull base

most patients w/ bacterial meningitis develop

headache, vomiting, photophobia and high fever

illness is often preceded by a few days of general malaise and inflammation of the ear or paranasal sinus

diagnosing bacterial meningitis

• not hard if the classic triad is there, but its only there in 50%

• DDx will always include viral meningitis or encephalitis, sepsis or influenza

• if bacterial meningitis is suspected, history taking and physical examination are generally insufficient to rule it out, so CSF testing will be needed

• a lumbar puncture can be dangerous due to risk of cerebral displacement, withdrawing CSF at lumbar level creates a pressure difference that displaces brain structures in the caudal direction, which can cause compression of the brainstem

• patients with severely diminished consciousness or focal neurological signs therefore need to undergo a brain CT scan before the lumbar puncture is carried out

  !! if a CT is needed before a lumbar puncture, start them on antibiotics and dexamethasone before being sent to radiology BUT do take a blood culture to test the bacteria for

• always correct a coagulation disorder before a lumbar puncture

• features of the CSF → markedly elevated opening pressure in a lumbar puncture, yellow and cloudy (purulent), leukocytosis, mainly granulocytes, reduced sugar and increased protein

• gram preparation of the CSF → usually positive after 1/2 days but it remains negative in around 20% especially those given an antibiotic before the puncture

  !! this is why a blood culture is taken if patients need a CT before a lumbar puncture and are therefore given antibiotics before the puncture

• PCR can also be used

what is the most common pathogen causing bacterial meningitis/meningitis in general

pneumococcus, followed by meningococcus (found mainly in children and young adults)

Other types of pathogens are often found in particular patient populations. Listeria monocytogenes is the third most common pathogen responsible for bacterial meningitis and is found mainly in the elderly and in patients with a compromised immune system. The causes of some small-scale Listeria epidemics have been traced to contaminated foods such as soft cheese and ready meals. Patients with a combination of bacterial meningitis and endocarditis are at high risk of Staphylococcus aureus Meningitis in neonates (up to the sixth week after birth) is usually caused by group B streptococci ( Streptococcus agalactiae ) or Escherichia coli

CSF gram preparation remains negative in…

around 20% especially those given an antibiotic before the puncture

this is why a blood culture is taken if patients need a CT before a lumbar puncture and are therefore given antibiotics before the puncture

features of the CSF in bacterial meningitis

markedly elevated opening pressure in a lumbar puncture, yellow and cloudy (purulent), leukocytosis, mainly granulocytes, reduced sugar and increased protein

if a CT is needed before a lumbar puncture…

start them on antibiotics and dexamethasone before being sent to radiology

what is dangerous to do while trying to diagnose (bacterial) meningitis

lumbar puncture due to risk of cerebral displacement, withdrawing CSF at lumbar level creates a pressure difference that displaces brain structures in the caudal direction, which can cause compression of the brainstem

what can cause cerebral displacement

a brain abscess, cerebral infarction, subdural empyema or hydrocephalus

and i guess a lumbar puncture

statement: Lumbar punctures, besides being diagnostic, can be used to drain CSF thus reducing the ICP. The limitation to this is raised ICP secondary to mass effect with a possible risk of herniation if the CSF pressure drops too low

pneumococcal meningitis

• most common bacterial meningitis pathogen

• pneumococcus is found in 70% of adults and a large proportion of children beyond the neonatal period

• most patients will have a predisposing factor for bacterial meningitis (eg. otitis, sinusitis, pneumonia, liquorrhoea, or an immune deficiency (in particular diabetes, alcoholism, splenectomy, cancer, and HIV infection))

• at A&E, 1/5 are already in coma and >80% have diminished consciousness

• common complications while in the hospital → cerebral infarctions, cerebral venous sinus thrombosis, epilepsy, cerebral oedema and hydrocephalus (> 1/2 develop a neurological complication of this kind while in hospital, but systemic complications such as sepsis and respiratory insufficiency are also common)

• due to the high frequency of complications about 20% of patients die

• almost ½ of those who survive have residual symptoms (eg. hearing loss, focal neurological deficit such as hemiparesis or loss of sensation, and cognitive disturbances)

  → ½ of those patients who do not apparently have any residual symptoms are found to have mental sluggishness and cognitive disorders

• to prevent reinfection from an otogenic or sinogenic focus of infection, consult an ENT specialist at an early stage to track down the focus and clean it out if needed

  also consult them if there is a hearing disorder (bc a cochlear implant surgery can only be performed at an early stage following meningitis)

treatment:

• high doses of IV penicillin, amoxicillin or a cephalosporin, depending on the resistance pattern

• temp. course of dexamethasone (prior to or at the same time as antibiotics) cuts the mortality rate from 30 to 20%

if there is a hearing disorder following meningitis…

consult an ENT as soon as possible bc a cochlear implant surgery can only be performed at an early stage following meningitis

> ½ of those w/ pneumococcal meningitis develop … in the hospital

neurological complications such as cerebral infarctions, cerebral venous sinus thrombosis, epilepsy, cerebral oedema and hydrocephalus

but systemic complications such as sepsis and respiratory insufficiency are also common

meningococcal meningitis (neisseria meningitidis)

• responsible for small scale epidemics of meningitis in places where adolescents and young adults live together in close proximity (eg. military barracks and student accommodations)

• meningococcus is found as a commensal in the nasopharynx in many people

  in a small proportion it gains access into the bloodstream and avoids the immune system → crosses the BBB

• recall that it can cause a mixed presentation of sepsis and meningitis

  If sepsis is more prominent, toxic shock syndrome can develop, causing disseminated intravascular coagulation in addition to the sepsis. Small skin bleeds (petechiae) are a manifestation of this

• ^ is referred to as waterhouse-friderichsen syndrome (check separate card)

• other complications that occur reasonably frequently are autoimmune arthritis (12%), hearing loss (20%) and cranial nerve palsy (6%)

• mortality rate is 7% in adults and 4% in children mainly due to simultaneous occurrence of sepsis

• it MUST be reported to the municipal health authority + those in the patients immediate social circle must be given a 2 day course of oral rifampicin or ciprofloxacin as a prophylactic to eliminate the meningococcus from the nasopharynx (bc its a contagious disease)

treatment:

• penicillin, because penicillin resistant meningococci are rare

• oral rifampicin or ciprofloxacin are also given to the patients before discharge from hospital if the treatment was penicillin monotherapy, not indicated for those given cephalosporin

meningococcal meningitis is a contagious disease so…

it MUST be reported to the municipal health authority + those in the patients immediate social circle must be given a 2 day course of oral rifampicin or ciprofloxacin as a prophylactic to eliminate the meningococcus from the nasopharynx

oral rifampicin or ciprofloxacin are also given to the patients before discharge from hospital if the treatment was penicillin monotherapy, not indicated for those given cephalosporin

meningococcus is found as…

a commensal in the nasopharynx in many people

meningococci can cause both…

meningitis and sepsis → mixed presentation

if petechiae are present in meningococcal meningitis / sepsis it means…

that toxic shock syndrome has developed

waterhouse-friderichsen syndrome***

defined as adrenal gland failure due to bleeding into the adrenal glands, commonly caused by severe bacterial infection. Typically, it is caused by Neisseria meningitidis

leading to massive blood invasion, organ failure, coma, low blood pressure and shock, disseminated intravascular coagulation (DIC) with widespread purpura, rapidly developing adrenocortical insufficiency and death

why is there a bleeding tendency in waterhouse-friderichsen syndrome

due to consumption of coagulation factors

treatment of meningitis of unknown origin

Targeted parenteral antibiotic treatment needs to be continued for seven to 14 days, or three weeks in the case of some pathogens such as Listeria, E. coli and staphylococci. The focus of the infection (otitis, sinusitis, empyema, abscess, endocarditis) needs to be determined in all patients with pneumococcal meningitis and meningitis caused by H. influenzae or S. aureus. Any primary focus of infection should be cleaned out if necessary. If any additional infections, such as endocarditis, are identified, this may cause antibiotic treatment to be extended by up to six weeks.

… are almost always sensitive to penicillin

meningococci, pneumococci and other streptococci

Haemophilus influenzae frequently has reduced sensitivity to penicillin, and Listeria monocytogenes is insensitive to cephalosporins

adding dexamethasone to the antibiotic treatment has substantially improved the prognosis for…

pneumococcal meningitis (at least in adults)

brain abscess

• caused by local inflammation of the brain tissue (local cerebritis)

• 40% of brain abscess cases are due to spread of an ENT infection (25% → invasion of bacteria from the blood stream, 10% → penetrating head trauma, 20% → no focus found)

• if it occurs due to metastasis of pus from elsewhere, its usually the lungs

• most common microorganisms are: streptococci, staphylococci, E. coli and Proteus mirabilis

• manifests as a space occupying lesion and/or inflammatory process

• classic triad → fever, focal neurological signs and headache but only found in 20%

  65% → headache, 60% → nausea, 50% → neurological deficits, 25% → epileptic seizures, 5% → fever

• CT or MRI is the test of choice

• 1/5 have multiple brain abscesses

• suspected? → consult with a neurosurgeon at an early stage → confirm by a puncture (open or stereotactic aspiration) and identifying the pathogen

  drain or excise (only in those who have an easily accessible superficial abscess) the abscess at the same time

• be wary with lumbar punctures due to the risk of herniation

• CRP, blood cultures and CSF testing can assist with DDx but rarely ever diagnose brain abscess or identify the pathogen

• always find the focus to treat it

  no clear focus? need to be examined by a cardiologist (including an echocardiogram), a dentist to rule out a dentogenic focus and an ENT specialist (with imaging of the mastoid process and sinuses)

• drain or excise? antibiotics for a minimum of 6 weeks

• treat cerebral oedema w/ dexamethasone

• around 30% of patients are left with focal neurological deficits due to scarring, usually in the form of focal epilepsy

excision of a brain abscess is done…

only in those who have an easily accessible superficial abscess

if there is no clear focus in a brain abscess…

need to be examined by a cardiologist (including an echocardiogram), a dentist to rule out a dentogenic focus and an ENT specialist (with imaging of the mastoid process and sinuses)

40% of brain abscess cases are due to…

spread of an ENT infection

25% → invasion of bacteria from the blood stream, 10% → penetrating head trauma, 20% → no focus found

if it occurs due to metastasis of pus from elsewhere, its usually the lungs

most common microorganisms in brain abscesses are…

streptococci, staphylococci, E. coli and Proteus mirabilis

viral meningitis

• fever, headache, nausea, NO neurological deficit, only a MILDLY stiff neck if any

• can have a fairly acute course, typically resembling severe influenza

• main pathogens in children = enterovirus, parechovirus, Coxsackie virus, and mumps virus

  herpes simplex 2 can cause recurring viral meningitis

• CSF → not much leukocytosis (they’re increased but not like bacterial), normal CSF protein and glucose levels, clear fluid

• final diagnosis is usually based on PCR

• virus remains unidentified in > ½

• mumps meningitis is accompanied by parotitis in around ½

• symptoms clear up within a few days to a maximum of 2 weeks, without specific treatment

most common causes of viral meningitis in children

enterovirus, parechovirus, Coxsackie virus, and mumps virus

viral vs bacterial meningitis?

viral has no neurological deficits and only has a mildly stiff neck if any

viral CSF → not much leukocytosis (they’re increased but not like bacterial), normal CSF protein and glucose levels, clear fluid