Neurology I: Demyelination, Facial Pain & Cerebrovascular Disease Flashcards
What is neurology?
The branch of medicine or biology that deals with the anatomy, functions, and organic disorders of nerves and the nervous system.
What do the different parts of the brain control?
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
What do we mean when we say the cranial & spinal nerves all decussate?
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
What is tested in a neurological examination?
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
What is a stroke?
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
How can you measure a patient’s consciousness levels?
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
How can you identify a stroke?
FAST:
Face- asymmetry of the face, unilateral palsy
Arms- weakness in the arms
Speech- slurring of speech (dysarthria)
Time- phone for help
What are some symptoms of strokes?
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
What is a transient ischaemic attack (TIA)?
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.
What are the risk factors for a stroke?
-Diabetes
-Cigarettes
-Obesity
-Oestrogen OCP
-Excess EtOH
-Polycythaemia (Raised haemoglobin)
-Atheroma (hypercholesterol/lipid aemia)
-Hereditable nature (family history of stroke)
-Hypertension
How can someone be affected by a stroke depending on which side was damaged?
slide 17
What are the common lesions and outcomes of a stroke? (hemiplegia)
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
What are the common lesions and outcomes of a stroke? (hemisensory)
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
What should you do in case of an acute stroke?
-Thrombolysis (Within 4 hours)- not for haemorrhagic stroke
-Clot retrieval
-Maintain BP
-ECG
-Nil by mouth- till SALT assessment
What should you do in case of a chronic stroke?
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
What is a subarachnoid haemorrhage?
Uncommon type of stroke caused by bleeding into the brain - arterial
What are the classic signs and symptoms of a subarachnoid haemorrhage stroke?
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)
Why do you have to act rapidly in cases of subarachnoid haemorrhage?
There’s a fast onset and it’s a high pressure bleed because it’s arterial so you have to act quickly.
How do you treat subarachnoid haemorrhage?
First MRI scan and then often neurosurgery
Clip & tie bleeder if not stopped spontaneously - this is when blood vessel is clipped and tied off
Who is typically affected by an extradural haemorrhage?
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.
Who is typically affected by subarachnoid haemorrhages?
older women
What happens to people with extradural haemorrhage following the injury?
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
What type of bleed is an extradural haemorrhage?
Arterial bleed, usually middle meningeal artery damage
How does an extradural haemorrhage present in a CT/MRI?
As a convex blood mass
What is a subdural haematoma and where is it located?
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’
When does a subdural haematoma typically occur?
Typically after a fall or if they’re on anti-coagulants
Where do the different brain haemorrhages happen?
slide 24
What is epilepsy?
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
What are the different types of epilepsy?
General, focal (simple partial)
Do all types of epilepsy involve having seizures?
no
When can you start having epilepsy?
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
Describe the characteristics of a tonic-clonic (grand mal) seizure.
-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”
What is epilepsy managed with?
Anti-convulsants
What are some characteristics of a simple partial seizure?
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
What happens to you during a complex partial seizure?
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
What are the characteristics of a complex partial seizure?
-Smacking of lips
-Rubbing of hands
-Making random noises
-Moving arms around
-Picking at clothes or fiddling with objects
-Chewing or swallowing
What is an absence (petit mal) seizure?
An absence seizure, is where you lose awareness of your surroundings for a short time.
Mainly affects children, but can happen at any age.
What might a person do during an absence seizure?
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
What are the other types of epileptic seizures?
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
What are triggers for seizures?
-Stress
-Fatigue
-Lights (Photosensitive 3%)
-Alcohol
-Missing medication
-Coffee
-Nicotine
What investigations do you do for epilepsy?
CT scan- first seizure
MRI
EEG- electroencephalogram
Blood tests- to investigate underlying electrolyte cause e.g. low glucose (hypoglycaemia), low sodium (hyponatraemia)
What are the aims of epileptic treatment?
To minimise or stop seizures completely
What are the different epileptic treatments?
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
How effective are AEDs (anti-epileptic drugs)?
They control seizures in ~70% of people
How do AEDs work and how often do you have to take them?
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)
What are a few examples of AEDs?
-Phenytoin
-Sodium valproate
-Carbamazepine
-Lamotrigine
-Levetiracetam
-Oxcarbazepine
-Ethosuximide
-Topiramate
What is a drawback of AEDs?
They have a significant teratogenic profile (birth defects).
What is the relevance of epilepsy to dentistry?
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)
How common and prevalent is multiple sclerosis (MS)?
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
What is MS characterised by and what is its aetiology?
By areas of demyelination in CNS
Unknown cause (is it viral or autoimmune mechanism?)
Describe the pathology of MS.
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
What does MS NOT involve?
Does not involve/attack peripheral nervous system (PNS) so peripheral nerves are not involved.
What are the symptoms of MS?
Highly variable
Symptoms start rapidly evolving over few days and sometimes resolves partially.
Associated with chronic fatigue
What investigations do you do for MS?
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.
What are the different types of MS?
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.
How can you tell if someone has optic neuritis?
Use ophthalmoscope- you’ll see disc swelling of the optic nerve head.
What is optic neuritis in MS characterised by?
Blurred vision with associated stabbing eye pain and fading of colours (red in particular).
What is the significance of optic neuritis?
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
What are the different definitions of different pain?
slide 46
What are the differential diagnoses of facial pain?
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.
What is trigeminal neuralgia?
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
Are there any associated sensory changes or facial weakness with trigeminal neuralgia?
No
What age groups are typically affected by trigeminal neuralgia?
> 50yrs
Younger than this consider MS or space occupying lesion as a cause
What is the cause of trigeminal neuralgia?
Majority have no cause identified
A number of patients can have vascular compression of the trigeminal nerve as it leaves the skull base
How can you treat trigeminal neuralgia?
Medication (carbamazepine, oxcarbazepine, lamotragine)
LA injections (temporary)
Nerve ablation (gamma knife, thermo, chemical destroy the nerve)
Vascular decompression
What is glossopharyngeal neuralgia?
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
What can trigger glossopharyngeal neuralgia?
Chewing, swallowing, talking, yawning, and coughing
What is post-herpetic neuralgia and who does it typically affect?
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
How can post-herpetic neuralgia present?
Erythema and typical herpetiform rash
What are trigeminal autonomic cephalgias?
Trigeminal neuralgia like history
Localised to V1/2 (ophthalmic and maxillary)
Recurrent episodic headaches
Common in males 20-50
Fast onset
Red eye
Tearing
What is trigeminal neuropathic pain and how is it managed?
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
What is persistent idiopathic facial pain and how is it managed?
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
What is burning mouth syndrome and how is it managed?
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
what is the management of burning mouth syndrome?
Psychology
Symptomatic relief (Difflam/lidocaine
Anti-depressants
