Neurology I: Demyelination, Facial Pain & Cerebrovascular Disease

Question 1

What is neurology?

Answer 1

The branch of medicine or biology that deals with the anatomy, functions, and organic disorders of nerves and the nervous system.

Question 2

What do the different parts of the brain control?

Answer 2

Frontal Lobe: Motor control, concentration, planning, problem solving, speech, smell.

Parietal Lobe: Touch and Pressure, taste, body awareness, language

Temporal Lobe: Hearing, facial recognition

Occipital lobe: Vision

Cerebellum: Coordination

Question 3

What do we mean when we say the cranial & spinal nerves all decussate?

Answer 3

Right side of the body is controlled by the left side of the brain vice versa

because the nerves cross and intersect with each other

Question 4

What is tested in a neurological examination?

Answer 4

Tone– resistance to passive movement of a joint

Power– power is tested by comparing the patient’s strength against your own

Reflex– involuntary and nearly instantaneous movement in response to a stimulus e.g using hammer

Co-ordination– voluntary/purposeful movements

Sensation– conscious experience resulting from stimulation

Question 5

What is a stroke?

Answer 5

A focal neurological deficit which lasts longer than 24 hours resulting from a vascular lesion.

Can have either Ischaemic stroke (blood supply is blocked and cut off to a particular area of the brain)

or

Haemorrhagic stroke (you end up bleeding into a particular area of the brain or skull due to weakened vessel walls and that causes the stroke)

80% of all stroke events are ischaemic

Question 6

How can you measure a patient’s consciousness levels?

Answer 6

AVPU/GCS

AVPU:

A- alert (can answer questions sensibly)

V- responds to verbal commands

P- responds to a pressure or pain stimulus

U- unresponsive to any stimulus

GCS: see attached image

Question 7

How can you identify a stroke?

Answer 7

FAST:

Face- asymmetry of the face, unilateral palsy

Arms- weakness in the arms

Speech- slurring of speech (dysarthria)

Time- phone for help

Question 8

What are some symptoms of strokes?

Answer 8

Sudden numbness or weakness in the face, arm, or leg, especially on one side of the body

Sudden severe headache with no known cause

Confusion, trouble speaking, or difficulty understanding speech (aphasia)

Sudden trouble seeing in one or both eyes (visual field defects)

Ataxia- sudden trouble walking (gait disturbance), dizziness, loss of balance, or lack of coordination

Question 9

What is a transient ischaemic attack (TIA)?

Answer 9

A focal neurological deficit which lasts less than 24 hours resulting from a vascular lesion; the deficit fully resolves

Temporary in nature

Requires active preventative treatment and investigation, indicates a stroke coming.

Question 10

What are the risk factors for a stroke?

Answer 10

-Diabetes
-Cigarettes
-Obesity
-Oestrogen OCP
-Excess EtOH
-Polycythaemia (Raised haemoglobin)
-Atheroma (hypercholesterol/lipid aemia)
-Hereditable nature (family history of stroke)
-Hypertension

Question 11

How can someone be affected by a stroke depending on which side was damaged?

Answer 11

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Question 12

What are the common lesions and outcomes of a stroke? (hemiplegia)

Answer 12

Most common lesion - hemiplegia

From infarct of contralateral internal capsule (high-risk zone of motor & sensory fibres converging on brainstem from cerebral cortex

Middle cerebral artery territory Motor - hemiplegia arm - leg
Initially hypotonic (flaccid) with reduced reflexes

Few days spasticity supervenes - arm(flexed) & leg (Extended)
hyper reflexia & upgoing plantar (indicates UMN)

Strength recovery over weeks to months UMN VII nerve

Question 13

What are the common lesions and outcomes of a stroke? (hemisensory)

Answer 13

Sensory - hemisensory (patchy if not so dense)

Hemianopic
(1 side vision loss (homonymous hemianopia)

Possibly apahasia

Smaller infarcts can give pure motor / sensory damage

Brainstem infarcts – complex
e.g. – pseudobulbar palsy (IX –XII #) – dysphagia etc Horner’s syndrome

Question 14

What should you do in case of an acute stroke?

Answer 14

-Thrombolysis (Within 4 hours)- not for haemorrhagic stroke
-Clot retrieval
-Maintain BP
-ECG
-Nil by mouth- till SALT assessment

Question 15

What should you do in case of a chronic stroke?

Answer 15

Support- Stroke unit; rehab/physio/skin care

NG feeding/laryngeal introitus care; hydration

Aids/chairs lifts/OT input/GDP OH adaptations

Look for second risk factors

Carotid atheroma (MRA/Doppler angio-flow); clotting screens (clotting syndromes/medications); hypertension

Medication- anti-platelets/anticoagulants

Question 16

What is a subarachnoid haemorrhage?

Answer 16

Uncommon type of stroke caused by bleeding into the brain - arterial

Question 17

What are the classic signs and symptoms of a subarachnoid haemorrhage stroke?

Answer 17

Classic “thunderclap headache” with neck stiffness

(caused by Circle of Willis Berry aneurysm rupture)

Sudden LOC (loss of consciousness- shortly after event)

Signs of meningism (e.g. photophobic)

Question 18

Why do you have to act rapidly in cases of subarachnoid haemorrhage?

Answer 18

There’s a fast onset and it’s a high pressure bleed because it’s arterial so you have to act quickly.

Question 19

How do you treat subarachnoid haemorrhage?

Answer 19

First MRI scan and then often neurosurgery

Clip & tie bleeder if not stopped spontaneously - this is when blood vessel is clipped and tied off

Question 20

Who is typically affected by an extradural haemorrhage?

Answer 20

Young patients, usually involved in a head strike (either during sport or a result of a motor vehicle accident) and they may/may not lose consciousness transiently.

extradural hamemorrage - a collection of blood that forms between the inner surface of the skull and outer layer of the dura, which is called the endosteal layer.

Question 21

Who is typically affected by subarachnoid haemorrhages?

Answer 21

older women

Question 22

What happens to people with extradural haemorrhage following the injury?

Answer 22

Following the injury they regain a normal level of consciousness (lucid interval)

Usually have an ongoing and often severe headache

Over the next few hours they gradually lose consciousness

Question 23

What type of bleed is an extradural haemorrhage?

Answer 23

Arterial bleed, usually middle meningeal artery damage

Question 24

How does an extradural haemorrhage present in a CT/MRI?

Answer 24

As a convex blood mass

Question 25

What is a subdural haematoma and where is it located?

Answer 25

It's a collection of blood between the dura and the brain which has a slower onset and is a venous bleed Located 'below the dura'

Question 26

When does a subdural haematoma typically occur?

Answer 26

Typically after a fall or if they're on anti-coagulants

Question 27

Where do the different brain haemorrhages happen?

Answer 27

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Question 28

What is epilepsy?

Answer 28

A neurological disorder marked by sudden recurrent episodes of sensory disturbance, loss of consciousness, or convulsions, associated with abnormal electrical activity in the brain Generally it's a lifelong condition

Question 29

What are the different types of epilepsy?

Answer 29

General, focal (simple partial)

Question 30

Do all types of epilepsy involve having seizures?

Answer 30

no

Question 31

When can you start having epilepsy?

Answer 31

Can start at any age, but usually in childhood or over 60 But if onset is at >60yrs, it is likely to be secondary to other neurological pathologies- tumours/strokes

Question 32

Describe the characteristics of a tonic-clonic (grand mal) seizure.

Answer 32

-Muscle Contractions -Stiff, jerking muscular movements -Unable to communicate- blank stare/aphasic -Vomiting or loss of bladder/bowels -Cheek and tongue biting -Breathing difficulties -Loss of consciousness -Recovery- variable but 5 minute duration not unusual -"Feels like I ran a marathon"

Question 33

What is epilepsy managed with?

Answer 33

Anti-convulsants

Question 34

What are some characteristics of a simple partial seizure?

Answer 34

A general strange feeling that's hard to describe A feeling that events have happened before (déjà vu) A sinking feeling in your abdomen- like when on a fairground ride Unusual smells or tastes; tingling in your arms and legs; stiffness or twitching in part of your body, such as an arm or hand but you remain awake and aware while this happens Considered as "warnings" or "auras" as they can be a herald of another type of seizure

Question 35

What happens to you during a complex partial seizure?

Answer 35

You lose your sense of awareness and make random body movements Patient won't be able to respond to anyone during seizure & won't have any memory of it

Question 36

What are the characteristics of a complex partial seizure?

Answer 36

-Smacking of lips -Rubbing of hands -Making random noises -Moving arms around -Picking at clothes or fiddling with objects -Chewing or swallowing

Question 37

What is an absence (petit mal) seizure?

Answer 37

An absence seizure, is where you lose awareness of your surroundings for a short time. Mainly affects children, but can happen at any age.

Question 38

What might a person do during an absence seizure?

Answer 38

Stare blankly into space Look like they're "daydreaming" Flutter their eyes Make slight jerking movements of their body or limbs The seizures usually only last up to 15 seconds and you won't be able to remember them They can happen several times a day

Question 39

What are the other types of epileptic seizures?

Answer 39

Status epilepticus : name of any seizure that lasts a long time or a series of seizures when the person doesn't regain consciousness in between. Medical emergency and needs to be treated ASAP

Question 40

What are triggers for seizures?

Answer 40

-Stress -Fatigue -Lights (Photosensitive 3%) -Alcohol -Missing medication -Coffee -Nicotine

Question 41

What investigations do you do for epilepsy?

Answer 41

CT scan- first seizure MRI EEG- electroencephalogram Blood tests- to investigate underlying electrolyte cause e.g. low glucose (hypoglycaemia), low sodium (hyponatraemia)

Question 42

What are the aims of epileptic treatment?

Answer 42

To minimise or stop seizures completely

Question 43

What are the different epileptic treatments?

Answer 43

Anti-epileptic drugs-the main treatment Surgery to remove a small part of the brain that are causing the seizures (rarely) A procedure to put a small electrical device inside the body that can help control seizures- (Vagus nerve or deep brain stimulation) A special diet (ketogenic diet) that can help control seizures If triggers are known & can be avoided, treatment may be avoided

Question 44

How effective are AEDs (anti-epileptic drugs)?

Answer 44

They control seizures in ~70% of people

Question 45

How do AEDs work and how often do you have to take them?

Answer 45

AEDs work by changing the levels of chemicals in your brain They don't cure epilepsy, but can stop seizures happening Must be used EVERY day- sudden cessation can provoke a seizure (cessation is slow withdrawal)

Question 46

What are a few examples of AEDs?

Answer 46

-Phenytoin -Sodium valproate -Carbamazepine -Lamotrigine -Levetiracetam -Oxcarbazepine -Ethosuximide -Topiramate

Question 47

What is a drawback of AEDs?

Answer 47

They have a significant teratogenic profile (birth defects).

Question 48

What is the relevance of epilepsy to dentistry?

Answer 48

Trauma that occurs from seizures Broken restorations that may occur from seizures Diet (may not be able to control it well if they're losing consciousness a lot) Oral hygiene compliance Drug side effects (phenytoin can induce gingival hyperplasia)

Question 49

How common and prevalent is multiple sclerosis (MS)?

Answer 49

It's a common neurological condition (1:1000) Higher female prevalence and there's also a geographic variance in prevalence (common in Europe) More common in family members, but no known inheritance pattern

Question 50

What is MS characterised by and what is its aetiology?

Answer 50

By areas of demyelination in CNS Unknown cause (is it viral or autoimmune mechanism?)

Question 51

Describe the pathology of MS.

Answer 51

You get peri-venular plaques of demyelination Areas that can be affected: -Optic nerves- (first presentation can be optic neuritis) -Periventricular white matter -Brainstem & cerebellar connections -Cervical spinal cord- corticospinal and dorsal columns

Question 52

What does MS NOT involve?

Answer 52

Does not involve/attack peripheral nervous system (PNS) so peripheral nerves are not involved.

Question 53

What are the symptoms of MS?

Answer 53

Highly variable Symptoms start rapidly evolving over few days and sometimes resolves partially. Associated with chronic fatigue

Question 54

What investigations do you do for MS?

Answer 54

MRI- look at brain & spinal cord to see if there's evidence of demyelination plaques, white lesions etc. Electrophysiology: Visual evoked potentials (light flash- record on optic cortex- ? slowed/decreased amplitude) Auditory evoked potentials (sound evoked version) Somatosensory– touch, smell etc.

Question 55

What are the different types of MS?

Answer 55

Primary progressive - Relentless progressive neurological deficit accumulation Secondary progressive - One episode followed by period of remission before latter resurgence and decline Benign MS - One episode followed by full recovery, no return.

Question 56

How can you tell if someone has optic neuritis?

Answer 56

Use ophthalmoscope- you'll see disc swelling of the optic nerve head.

Question 57

What is optic neuritis in MS characterised by?

Answer 57

Blurred vision with associated stabbing eye pain and fading of colours (red in particular).

Question 58

What is the significance of optic neuritis?

Answer 58

It's often the first presentation of MS in young females so it's something to be very mindful of Also, optic neuritis can suggest brainstem demyelination which can also result in cranial nerve defects

Question 59

What are the different definitions of different pain?

Answer 59

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Question 60

What are the differential diagnoses of facial pain?

Answer 60

Dental Pain Temporomandibular disorder Sinus pain Trigeminal Neuralgia Facial Migraines Trigeminal Neuropathic Pain Trigeminal Autonomic Cephalgia Temporal Arteritis Persistent idiopathic facial pain Post herpetic neuralgia History taking is important and helps identify the cause of facial pain.

Question 61

What is trigeminal neuralgia?

Answer 61

Nerve disorder where you get recurrent, brief, lancing pain lasting approximately 30 seconds The characteristic trigger zones are identified on the skin Picture shows how patients described the pain

Question 62

Are there any associated sensory changes or facial weakness with trigeminal neuralgia?

Answer 62

No

Question 63

What age groups are typically affected by trigeminal neuralgia?

Answer 63

>50yrs Younger than this consider MS or space occupying lesion as a cause

Question 64

What is the cause of trigeminal neuralgia?

Answer 64

Majority have no cause identified A number of patients can have vascular compression of the trigeminal nerve as it leaves the skull base

Question 65

How can you treat trigeminal neuralgia?

Answer 65

Medication (carbamazepine, oxcarbazepine, lamotragine) LA injections (temporary) Nerve ablation (gamma knife, thermo, chemical destroy the nerve) Vascular decompression

Question 66

What is glossopharyngeal neuralgia?

Answer 66

Paroxysmal pain in ear, base of tongue, tonsillar fossa or angle of jaw It affects sensory areas of the glossopharyngeal nerve and has similar treatment modalities as trigeminal neuralgia

Question 67

What can trigger glossopharyngeal neuralgia?

Answer 67

Chewing, swallowing, talking, yawning, and coughing

Question 68

What is post-herpetic neuralgia and who does it typically affect?

Answer 68

Steady, sustained pain, which persists for several months and has paroxysmal shooting pain as well Typically affects elderly & immunosuppressed Caused by reactivation of herpes virus

Question 69

How can post-herpetic neuralgia present?

Answer 69

Erythema and typical herpetiform rash

Question 70

What are trigeminal autonomic cephalgias?

Answer 70

Trigeminal neuralgia like history Localised to V1/2 (ophthalmic and maxillary) Recurrent episodic headaches Common in males 20-50 Fast onset Red eye Tearing

Question 71

What is trigeminal neuropathic pain and how is it managed?

Answer 71

Pain caused by insult to the peripheral nerves Following removal of painful stimulus, the pain or altered sensation persists Some patients report burning sensations Managed with anti-depressant therapy

Question 72

What is persistent idiopathic facial pain and how is it managed?

Answer 72

Nagging dull throbbing / persecuting pain Doesn’t conform to anatomical boundaries – typically crosses midline Management techniques include -pychology – CBT -Self management – meditation, stress and lifestyle modulation -Relieved by relaxation / rest -Antidepressants: Nortryptyline, Amitryptiline

Question 73

What is burning mouth syndrome and how is it managed?

Answer 73

Idiopathic burning sensation on the tongue. Can also include unusual tastes. More common in females Age over 40 Stress and anxiety can modulate the level of burning Must exclude low Ferritin, B12, Candida Often subjective dry mouth

Question 74

what is the management of burning mouth syndrome?

Answer 74

Psychology Symptomatic relief (Difflam/lidocaine Anti-depressants