Neurology Flashcards
What are UMNs and LMNs?
• The neurons that travel within the descending tracts are upper motor neurons, these synapse on neurons in the spinal cord which are lower motor neurons
• Lower motor neurons make contact with skeletal muscle to cause muscle contraction
Define spasticity? Is it UMN or LMN sign?
Spasticity: velocity dependent increase in tone, the faster you move the muscle the greater the resistance
UMN sign
Define rigidity? What is this a sign of?
Rigidity: Velocity independent increase in tone present throughout muscle movement (usually associated with lesions of basal ganglia)
What is babinski sign?
Babinski Sign (extensor plantar response): big toe bends up and back and other toes fan out
UMN sign
Define clonus? UMN or LMN sign?
sequence of rhythmic and involuntary muscle contractions
UMN sign
Define fasciculations? UMN or LMN sign?
involuntary twitching of muscles
LMN sign
Define hypo and hypertonia and reflexia? UMN or LMN?
Hypotonia - decreased muscle tone - LMN
Hypertonia - increased muscle tone - UMN
Hyperreflexia - over responsive reflexes - UMN
Hyporeflexia - under responsive reflexes - LMN
What is a bulbar palsy?
lower motor neurone lesion of cranial nerves IX, X and XII
What is a pseudobulbar palsy?
an upper motor neuron lesion of cranial IX, X and XII
List some causes of UMN signs?
• Stroke
• Multiple Sclerosis
• Cerebral palsy
• Spinal cord injury
• Huntington’s disease
• PLS
List some causes of lower motor neurone signs?
• Any kind of peripheral neuropathy
• Progressive muscular atrophy
What groups are MND more common in?
Slightly more common in males
thought to be links with C9ORF72 gene
generally presents in ages 50-75
(this gene is also linked to FTD and to an extent thought to be linked with MND)
What are the 4 types of MND and are they UMN, LMN or mixed?
ALS - mixed
PLS - upper
PMA - lower
PBP - mixed (but only muscles of head and neck)
Describe ALS?
- Most common type of MND
- Causes both UMN and LMN damage
- Progressive focal muscle weakness and wasting with muscle fasciculations due to spontaneous firing of abnormally large motor units formed by surviving axons branching to innervate muscle fibres that have lost their nerve supply
- Weakness often starts in one limb and then spreads to other parts of the body
- Cramps are common
- On exam there are UMN and LMN signs
- This has a poor prognosis
Describe PMA?
- Pure LMN presentations
- Quite rare
- There is weakness, muscle wasting, fasciculations that start in one limb and spread
- This has a variable prognosis
Describe PBP?
- Lower cranial nerve nuclei and supranuclear connections are initially involved
- Mixed bulbar and pseudobulbar signs (mixed UMN and LMN picture you see in ALS but confined to the mouth)
- Dysarthria, dysphagia, nasal regurgitation, choking
- Tongue fasciculations with slow stiff tongue movements
- Poor prognosis
- Patients with this can progress onto ALS
Describe PLS?
- Least common type of MND (very rare vs other types)
- Confined to upper motor neurons causing a slow progressive tetraparesis and pseudobulbar palsy
- Good prognosis more than 5 years, can live for much longer
Diagnosis of MND?
• Diagnosis is largely clinical, no specific diagnostic tests but investigations allow exclusion of other conditions
• Denervation of muscles due to degeneration of LMN is confirmed by EMG
Management of MND?
• There is no treatment that improves outcomes substantially
• Riluzole a Na+ channel blocker that inhibits glutamate release slows progression slightly by 3-4 months, many patients choose not to take it as the extra time added to life tends to be when you are at your most disabled
• MDT approach
• Communications aids
• Dietician advice (metabolic rate in MND is increased and weight loss is expected so needs managed)
• Gastrostomy
• Physiotherapy
• quinine, Baclofen or gabapentin for muscle spasms
• Non-invasive ventilatory support- BiPAP at night
What is the basal ganglia and what is its role?
• The Basal Ganglia refers to a number of masses of grey matter located near the base of each cerebral hemisphere. (technically, it is actually a nucleus because it’s a collection of nerve cell bodies in the CNS but the name ganglia has stuck)
3 roles are:
1. To facilitate purposeful movement.
2. Inhibit unwanted movements.
3. Role in posture and muscle tone.
What is Parkinson’s disease?
• Neurodegenerative condition caused by loss of dopaminergic neurons from the substantia nigra, and surviving cells contain inclusions called Lewy bodies
What groups tend to get parkinsons disease?
• Genetics of the condition are not fully understood but thought to play a role
• Older age is a risk factor particularly over age 70
• Prevalence is slightly higher in men
Pathology of parkinsons disease?
• Sections through the brainstem reveals loss of the normally dark black pigment in the substantia nigra
• Pigment loss correlates with dopaminergic cell loss
• A neuro-histological hallmark of PD are Lewy bodies (mainly consist of alpha synuclein) but these can be found in other conditions too
Prodromal symptoms of parkinsons disease?
- Anosmia
- Depression and anxiety
- REM sleep behaviour disorder (the atonicity of muscles in sleep is disrupted)
- Autonomic features- urinary urgency, hypotension and constipation
- Restless leg syndrome
Motor symptoms of parkinsons disease?
- Akinesia
- Tremor (typically starts in the fingers, called a pill-rolling tremor – dragging thumb across hand)
- Rigidity: can be cogwheel (jerky rigidity associated with tremor) or lead-pipe (smooth, continuous rigidity)
- Postural and gait disturbances (stooped posture, shuffling gait (festination), slow turns, freezing and reduced arm swing)
- Speech and swallowing difficulties
Mask like expression?
parkinsons
Pill rolling tremor?
parkinsons
What might you find on examination of parkinsons disease?
- Look at features of their gait
- Masked like expression due to lack of facial movement
- Micrographia (they write really small)
- Froment’s manoeuvre – rigidity increases in examined body segment by voluntary movement of contralateral body parts
Explain what is meant by extrapyramidal symptoms and parkinsons?
Parkinson’s Disease causes what is called extrapyramidal symptoms because the symptoms originate out with the pyramidal tract (which allows voluntary movement). There is extra movement that they don’t want and when they do want movement it is slow to initiate.
Diagnosis/ investigation of parkinsons?
if suspect parkinsons the person should be referred to a specialist
• No lab test that can be used to diagnose, mainly a clinical diagnosis
• Dopamine Transporter Imaging using SPECT or PET can be useful to visualise dopamine transporter levels
What is guidance for pharmacological treatment of someone with parkinsons?
• First line treatment should be L dopa to anyone who has Parkinson’s disease with motor symptoms affecting quality of life
• In those with early stage disease whose motor symptoms are not affecting quality of life could consider a choice of L dopa, dopamine agonists or MAO inhibitors
Describe use of L-dopa in Parkinsons and side effects etc?
L dopa is converted in the brain into dopamine. It provides the most improvement in motor symptoms and in activities of daily living. However, this drug causes more motor complications than dopamine agonists, but it does cause less adverse events (although still get adverse events such as excessive sleepiness and impulse control disorders)
Motor complications of L dopa include:
- Motor fluctuations
- Dyskinesias
- Need for higher doses to get same effect (because L dopa eventually causes dopamine producing cells to stop working by methylation which is why the dose keeps needing increased and dyskinesia becomes worse)
- On/off phenomena where patients go suddenly from mobile to immobile state
Describe use of dopamine agonists in parkinsons?
Dopamine agonists mimic the effect of dopamine but aren’t actually converted to dopamine like L dopa is. These provide less improvement in motor symptoms and activities of daily living. However, they have fewer motor complications but do cause more adverse events (including excessive sleepiness, hallucinations and impulse control disorders)
Describe use of monoamine oxidase inhibitors in parkinsons?
These are sometimes used and cause fewer motor complications and fewer adverse events but also less improvements.
Explain what is meant by parkinsonism vs parkinsons disease?
Parkinsonism encompasses any condition that causes TRAP (tremor, rigidity, akinesia/ bradykinesia, postural disturbances) which are extrapyramidal symptoms. Parkinsonism can be caused by anything that causes a relative dopamine deficiency in the nigrostriatal pathway. An example would be antipsychotic drugs which block the D2 receptors and therefore can cause parkinsonism as well as other extrapyramidal side effects.
Explain the difference between lewy body dementia and parkinsons disease dementia?
Parkinson’s disease dementia refers to those who develop dementia > 1 year after PD diagnosis. Dementia with Lewy Bodies is dementia as a presenting complaint or within 1 year of PD diagnosis.
Describe cogwheel rigidity vs lead pipe rigidity?
lead pipe rigidity is defined as a constant resistance to motion throughout the entire range of movement. Cogwheel rigidity refers to resistance that stops and starts as the limb is moved through its range of motion.
What is multiple sclerosis?
• Most common neuroinflammatory disorder in Western populations (note examples of other neuroinflammatory disorders are post infectious disorders, transverse myelitis etc. these aren’t covered much in curriculum to my knowledge)
• T cell mediated disorder
• Multiple plaques of demyelination are found throughout the brain and spinal cord occurring sporadically over years
What groups is multiple sclerosis more common in?
• The condition is more common in women
• Typically presents between age 20-40 years
• There is a genetic predisposition- if someone in your family has it you have an increased chance of developing the condition
Pathology of multiple sclerosis?
• Plaques of demyelination 2-10mm in size are cardinal features, only effect CNS- peripheral myelinated nerves are not directly affected (hence there are UMN signs NOT LMN)
• Plaques can occur anywhere in the CNS but there are sites which are more commonly affected: optic nerves, periventricular region, the corpus callosum, the brainstem, cerebellar connections and the cervical spinal cord
• Acute relapses are caused by focal inflammation causing myelin damage and conduction block, recovery follows as inflammation subsides and remyelination occurs
• When damage is severe, secondary permanent axonal destruction occurs
• Progressive axonal damage is the pathological basis of the progressive disability seen in the progressive forms of MS
• Grey matter damage also takes place early on and the extent of the damage correlates with the severity of disability and cognitive involvement
Describe some different presentations of MS?
depends on area affected:
- pyramidal dysfunction
- sensory nerve involvement
- cerebellar symptoms
- bladder symptoms
- optic neuritis
- fatigue
- compression of cranial nerves in brainstem e.g. 6 and 7
Describe presentation of optic neuritis in MS?
- Painful visual loss in an eye develops over 1-2 weeks
- Pain on eye movements
- Very rarely complete blindness usually loss of central vision with colour desaturation
- RAPD positive (the pupil dilates in response to swinging light test)
- Most improve
Diagnosis of MS?
• At least 2 episodes suggesting demyelination
• “Evidence of damage to the CNS that is disseminated in time and space” (i.e. damage that has occurred on different dates and different places)
• Blood tests should be done to exclude other inflammatory disorders and infections e.g. borellia, syphilis
• MRI is the definitive investigation as it demonstrates areas of demyelination with high sensitivity
• Lumbar puncture is abnormal in most patients with MS, there are oligoclonal bands in the CSF with NO corresponding bands in the serum
Four types of MS?
• RELAPSING AND REMITTING: this is the most common, symptoms occur in attacks which get fully or partially better over weeks, the patient may accumulate disability over time if they don’t fully recover from the relapses
• SECONDARY PROGRESSIVE: 75% of people with RRMS evolve into this type within 35 years of onset where they experience gradually worsening disability
• PRIMARY PROGRESSIVE: gradually worsening disability without relapses or remissions
• RELAPSING PROGRESSIVE: least common type, relapses on a pattern of progressive disability from the outset
Management of MS?
referred to specialist for treatment
symptom management e.g. bladder training, anticholinergics, physiotherapy, neuropathic pain treatment etc
acute exacerbations are treated with observation, oral or iv steroids depending on severity
spasticity - baclofen or gabapentin
disease modifying drugs: 1st line for RRMS are tecfidera, interferons, glutamir acetate, 2nd line or first for progressive are fingolimid, cladribine, monoclonal antibodies (more effective but more toxic)
Prognosis of MS?
• Although people become progressively disabled most people live similar length lives to those without MS
• Some rarer aggressive forms may cause death
Define epileptic seizure and epilepsy?
• An epileptic seizure can be defined as a sudden synchronous discharge of cerebral neurons causing symptoms or signs that are apparent either to the patient or to an observer
• Epilepsy is a tendency to recurrent, usually spontaneous epileptic seizures
How can seizures be classed? Describe what each means?
• Seizures can be classed as focal or general
• Focal seizures occur in a focal region of the brain e.g. a focal sensory seizure or a focal motor seizure
• General seizures affect the whole brain, there is simultaneous involvement of both hemispheres, always associated with loss of consciousness or awareness
What are the 2 types of epilepsy? Describe them
• Focal epilepsy is a type of epilepsy where there is a seizure focus (part of brain that doesn’t work properly) that can irritate the surrounding brain, this focus can cause a focal seizure if the irritation stays in that area or it can cause a general seizure if the abnormal electrical activity hits a cortical network allowing it to spread throughout the brain
• In generalised epilepsy the seizures happen on cortical networks so as soon as they occur they immediately propagate around the brain and generalised seizures occur
• Focal epilepsy can cause focal or generalised seizures
• Generalised epilepsy can only cause generalised seizures
What are the 5 types of general seizure?
absence, myoclonic, tonic, atonic, tonic clonic
Describe absence seizures?
• Loss of awareness and vacant expression <10 secs before returning abruptly to normal and continuing as though nothing happened
• Patients are not aware but they could have many of these seizures a day
• Patient appears like they are day dreaming/ dozing but they can’t be snapped out of it
• May have slight eye fluttering but apart from that there are no motor symptoms
Describe myoclonic seizures?
• Jerk movements
• Momentary brief contractions of muscles or muscle groups
• E.g. involuntary twitch of a finger or hand
Describe tonic seizures?
• Consists of a stiffening of the body not followed by jerking
Describe atonic seizures?
• Sudden collapse with loss of muscle tone and consciousness
Describe tonic clonic seizures?
• Often no warning before these occur
• An initial tonic stiffening is followed by the clonic phase with synchronous jerking of the limbs reducing in frequency over about 2 minutes until the convulsions stop
• When the convulsions stop there may be incontinence
• A period of flaccid unresponsiveness is followed by gradual return of awareness with confusion and drowsiness lasting 15 mins to an hour or longer, headache is common after
What are the types of primary generalised epilepsies? When do they tend to present? Is the brain structurally normal?
the brain is structurally normal
tend to present in childhood/ early adulthood
3 main syndromes: childhood absence epilepsy, juvenile myoclonic epilepsy and monogenic epilepsies
Describe childhood absence epilepsy?
absence seizures, spontaneous remission by age 18 is usual
Describe juvenile myoclonic epilepsy?
accounts for 10% of all epilepsies, typically myoclonic jerks start in teenage years (which are usually ignored) followed by generalised tonic clonic seizures that bring the teenager to medical attention, seizures and jerks can occur in the morning after wakening, lack of sleep, alcohol and strobe or flickering lights can all be triggers, this type of epilepsy has a good response to treatment but treatment is required lifelong
List some causes of focal epilepsies?
• Hippocampal sclerosis
• Genetic and developmental disorders
• Trauma, hypoxia and surgery
• Vascular disorders
• Infections e.g. encephalitis, cerebral abscess
• Alcohol and drugs
• Immunological disorders e.g. autoimmune antibody mediated encephalitis or NMDA antibodies
List some features in a history that may point to an epileptic seizure over syncope?
may have an aura or strange feeling, during the seizure they may have convulsions, after the seizure they may have a headache and confusion and take a while to recover, common triggers include strobe or flickering lighting, sleep deprivation, alcohol and drugs
Driving rules for epilepsy?
• After a single seizure must tell the patient to stop driving
• If patient continues to drive the doctor has the responsibility to inform the DVLA
• After a single seizure you are not allowed to drive a motor car for 6 months or a HGV for 5 years
• If receive a diagnosis of epilepsy you are not allowed to drive a car until you have been a year seizure free and not allowed HGV until 10 years off all medication and seizure free
• If the only type of seizure someone has ever had doesn’t affect consciousness or someone’s ability to drive and the 1st seizure was over 12 months the person can still drive
• If the person only ever has seizures at night and the 1st seizure was 12 months ago the person can still drive OR if the person has only had night seizures for the past 3 years
Management of generalised tonic clonic seizures?
• Sodium valproate is first line monotherapy for boys, men, girls under 10 unlikely to need treatment when old enough to have children, women who are unable to have children
• If first line therapy of sodium valproate is unsuccessful try lamotrigine or levetiracetam
• Lamotrigine or levetiracetam is first line monotherapy for women and girls of child bearing age or those likely to be on treatment when of child bearing age
• Only try sodium valproate for women and girls if discussed pregnancy risks etc
Management of focal seizures?
• Lamotrigine or levetiracetam as first line monotherapy, if first choice unsuccessful try the other
• Second line choices are: carbamazepine, oxcarbazepine, zonisamide
Management of myoclonic seizures?
• First line is sodium valproate but if not suitable then can consider levetiracetam or topiramate
What is important to tell woman of childbearing ages about AEDs?
• A number of AEDs are enzyme inducing and can make many forms of contraception including COCP and emergency contraception pills ineffective
What anti-epileptic drug can make some generalised epilepsies worse?
carbamazepine
What is status epilepticus?
medical emergency
• Defined as continuous seizure activity for longer than expected, generally 5 minutes is threshold although previously it was longer (can also be 2 seizures without recovery for similar length of time)
What is the risk of status epilepticus?
permanent cerebral damage, rhabdomyolysis and AKI
List some precipitants of status?
• Severe metabolic disorders
• Infection
• Head trauma
• Sub arachnoid haemorrhage
• Abrupt withdrawal of AEDs
• Treating absence seizures with carbamazepine
Management of status epilepticus?
- Provide resuscitation and immediate emergency treatment for anyone with convulsive status epilepticus (defined as seizures lasting longer than 5 minutes)
- If the patient has an individualised emergency plan use this
- If not then give a benzodiazepine (buccal midazolam, rectal diazepam or IV lorazepam if IV access)
- Wait five minutes, if not stopped give a second dose
- Wait five minutes, if not stopped, second line treatment is IV levetiracetam, phenytoin or sodium valproate
- If not stopped, consider other second line treatments
- Third line treatments are phenobarbital or general anaesthesia
You should also be looking for underlying causes and if can treat these
Do NOT give more than 2 doses of benzodiazepine as this could cause respiratory arrest
Any suggestion of hypoglycaemia give IV glucose
Any suggestion of alcoholism or impaired nutritional status give thiamine
Once status is stabalised a person should be put back on their usual anti-convulsant drugs
Most acute seizures stop themselves so it is only status epilepticus that needs treated
Lumbar puncture shows oligoclonal bands in the CSF with no corresponding bands in the serum?
MS
List some headache red flags?
• Any new onset headache in someone over 55
• Anyone with known/ previous malignancy
• Anyone immunosuppressed
• Early morning headache
• Associated with nausea and vomiting
• Headache that wakes you up
• Headache that is exacerbated by the valsava manuovre or leaning forward
• Visual symptoms
What group are migraines more common in?
females
Features of migraine? How long do they have to last for and how many episodes for diagnosis?
5 attacks lasting 4-72 hours
may experience aura
pain is unilateral
pulsating quality
moderate or severe pain intensity
aggravated by routine activities
nausea and/ or vomiting
photophobia or photophobia
What may migraine auras consist of?
visual e.g. scotomas, central fortification, hemianopia, sensory or motor disturbances, there is separate criteria for diagnosis
These auras usually last 20-60 minutes and are followed by the headache phase
What are some potential triggers of migraines?
sleep deprivation, skipping meals, alcohol, hormones (oestrogen), physical exertion
Management of migraines?
• Non-pharmacologic treatment: headache diary, education on avoiding triggers, relaxation, stress management
• Acute abortive treatments include high dose NSAIDs e.g. naproxen, triptans are specific for migraines and these can be effective where NSAIDs are insufficient e.g. sumatriptan, almotriptan. It should be noted that overuse of acute abortive treatments can lead to dependence and cause further headaches
• Suppression medication can be used when migraine episodes are frequent (more than 1-2 per month) and impacting on quality of life. amitriptyline or propranolol or topiramate
What is the name given to the classic everyday headache?
tension headache
What are features of a tension headache?
• Pain is usually mild to moderate, bilateral, tight band sensations, pressure behind the eyes, bursting sensation
• There is the absence of photophobia, phonophobia, nausea and vomiting
