Neurology Flashcards
What is epilepsy?
Common neurological condition characterised by recurrent seizures
Epilepsy is not the only reason people have seizures
What are febrile convulsions?
Typically occur in children between the ages of 6 months and 5 years
Around 3% will have at least one febrile convulsion
Usually occur early in a viral infection as the temperature rises rapidly
Seizures are typically brief and generalised tonic/tonic clonic in nature
What are alcohol withdrawal seizures?
Occur in pts with a hx of alcohol excess who suddenly stop drinking ie
Chronic alcohol consumption enhances GABA mediated inhibition in the CNS (similar to benzos) and inhibits NMDA type glutamate receptors
Alcohol withdrawal leads to the opposite
Peak incidence of seizures is around 36 hrs following cessation of drinking
Pts are often given ben os following cessation of drinking to reduce the risk
What are psychogenic non epileptic seizures?
Previously termed pseudoseizures, this term describes ots who present with epileptic like seizures but do not have characteristic electrical discharges
Pts may have hx of mental health problems or a personality disorder
What are focal seizures?
Previously termed partial seizures
These start in a specific area, on one side of the brain
The level of awareness can vary in focal seizures
Focal aware of focal impaired
Further to this, focal seizures can be classified as being motor, non motor or having other features such as aura
What happens in generalized seizures and what are the specific types?
Consciousness is lost immediately
The level of awareness classification is not needed
All patients lose consciousness
They can be subdivided into motor eg: tonic clonic and non motor (absence)
Specific types;
Tonic clonic (grand mal) Tonic Clonic Typical absence (petit mal) Myoclonic- brief, rapid muscle jerks Atonic
What are infantile spasms (wests syndrome)?
Brief spasms beginning in the first few months of life
You get flexion of head, trunk, limbs —> extension of arms (salaam attack); last 1-3 secs, repeat up to 50 times
Progressive mental handicap
EEG; hypsarrythmia
Usually 2nd to serious neurological abnormality
Poor prognosis
What is lennox gastaut syndrome?
May be extension of infantile spasms (50% have hx)
Onset 1-5 years
Atypical absences, falls, jerks
90% have moderate to severe mental handicap
EEG shows slow spike
Ketogenic diet may help
What is juvenile myoclonic epilepsy?
Typical onset in the teens, more common in girls
1. Infrequent generalized seizures, often in morning
2. Daytime absences
3. Sudden, shock like myoclonic seizure
usually good response to sodium valproate
What are the symptoms and signs of epilepsy?
Generalised seizures may bite their tongue and experience incontinence of urine
Asking about such features can be useful way of detecting epileptic seizures when taking a hx from a patient who presents with blackout or collapse
Following a seizure, pts typically have a postictal phase where they feel drowsy and tired for around 15 mins
What IX do you do for seizures?
EEG and neuroimaging (MRI)
How do you treat epilepsy?
Most neurologists now start antiepileptics following a second epileptic seizure…
As a general rule
Sodium valproate is used first line for pts with generalised seizures
Carbamazepine is used first line for pts with focal seizures
What is the acute management of seizures?
Most seizures terminate spontaneously
When seizures don’t terminate after 5-10 mins then it is appropriate to administer medication to terminate the seizures
Benzodiazepines such as: diazepam are typically used and they may be administered rectally or intranasally/under the tongue
What are the causes of UMN lesions?
Stroke
Tumour
Raised ICP
MS
What is MS?
Multiple sclerosis (MS) is a chronic and progressive condition that involves demyelination of the myelinated neurones in the central nervous system. This is caused by an inflammatory process involving the activation of immune cells against the myelin.
MS typically presents in young adults (under 50 years) and is more common in women. Symptoms tend to improve in pregnancy and in the postpartum period.
What is charcots marie tooth?
Inherited disease that affects the peripheral motor and sensory nerves
They cause dysfunction in the myelin of the axons
Autosomal dominant
What should you do with blood pressure in stroke?
Should not be lowered in the acute phase unless there are complications- hypertensive encephalopathy
What should you do with regards to atrial fibrillation and anticoagulants in regards to stroke?
with regards to atrial fibrillation, the RCP state: ‘anticoagulants should not be started until brain imaging has excluded haemorrhage, and usually not until 14 days have passed from the onset of an ischaemic stroke’
What is haemorrhagic transformation and what are the symptoms?
It is where an ischaemic stroke transforms into haemorrhagic stroke around 2 weeks after a stroke
The symptoms= confusion, one sided facial weakness and headache
When should you start a statin after stroke?
if the cholesterol is > 3.5 mmol/l patients should be commenced on a statin. Many physicians will delay treatment until after at least 48 hours due to the risk of haemorrhagic transformation
What are Cerebrovascular accidents?
Ischaemia or infarction of brain tissue secondary to inadequate blood supply
Intracranial haemorrhage
What can cause a stroke?
Thrombus/embolus formation in patients with AF
Atherosclerosis
Shock
Vasculitis
What is TIA?
Transient ischaemic attacks often precede a full stroke. A crescendo TIA is where there are two or more TIAs within a week. This carries a high risk of developing in to a stroke.
What is the presentation of stroke?
In neurology, suspect a vascular cause where there is a sudden onset of neurological symptoms.
Stoke symptoms are typically asymmetrical:
Sudden weakness of limbs
Sudden facial weakness
Sudden onset dysphasia (speech disturbance)
Sudden onset visual or sensory loss
What are the risk factors for stroke?
Cardiovascular disease such as angina, myocardial infarction and peripheral vascular disease Previous stroke or TIA Atrial fibrillation Carotid artery disease Hypertension Diabetes Smoking Vasculitis Thrombophilia Combined contraceptive pill
What is the immediate management for stroke?
Admit patients to a specialist stroke centre
Exclude hypoglycaemia
Immediate CT brain to exclude primary intracerebral haemorrhage
Aspirin 300mg stat (after the CT) and continued for 2 weeks
How do you manage TIA?
Start aspirin 300mg daily. Start secondary prevention measures for cardiovascular disease. They should be referred and seen within 24 hours by a stroke specialist.
What imaging is used once a stroke is diagnosed?
The aim of imaging is to establish the vascular territory that is affected. It is guided by specialist assessment.
Diffusion-weighted MRI is the gold standard imaging technique. CT is an alternative.
Carotid ultrasound can be used to assess for carotid stenosis. Endarterectomy to remove plaques or carotid stenting to widen the lumen should be considered if there is carotid stenosis.
What is the secondary prevention of stroke?
Clopidogrel 75mg once daily (alternatively dipyridamole 200mg twice daily)
Atorvastatin 80mg should be started but not immediately
Carotid endarterectomy or stenting in patients with carotid artery disease
Treat modifiable risk factors such as hypertension and diabetes
What type of dementia is motor neurone associated with?
Frontotemporal dementia
What is motor neurone disease?
Neurological condition of unknown cause which can present with both upper and lower motor neurone signs. It rarely presents before 40 years and thee are various patterns of disease- amyotrophic lateral sclerosis most common.
What are the features of motor neurone disease?
Fasciculations
The absence of sensory signs and symptoms
Mixture of lower motor neurone and upper motor neurone signs
Wasting of the small hand muscles, tibialis anterior is common
How can you diagnose motor neurone disease?
It is a clinical diagnosis
Nerve conduction studies will be normal and hep exclude a neuropathy
Electromyography shows a reduced number of action potentials and increased amplitude
What are the features of temporal lobe seizures?
Hallucinations (auditory/gustatory/olfactory), Epigastric rising/Emotional, Automatisms (lip smacking/grabbing/plucking), Deja vu/Dysphasia post-ictal)
What is the symptoms of frontal lobe seizures?
Head/leg movements, posturing, post-ictal weakness, Jacksonian march
What are the features of parietal lobe epilepsy?
Paraesthesia
What are the features of occipital lobe seizures?
Floaters and flashes
What is Myaesthenia Gravis?
Auto immune disease characterised by antibodies against the nicotinic acetylcholine receptors on muscle fibres
This limits the ability of acetylcholine to cause muscle contraction
What are the clinical features of myaesthenia gravis?
Weakness affecting limb musclds
Extra ocular muscles (drooping eyelids, diplopia), facial muscles (difficulty smiling or chewing)
Bulbar muscles (change in speech or difficulty swallowing)
On examination there may be fatiguable muscle weakness, bilateral ptosis, myaesthenic snarl, head drop, bulbar features- nasal speech, dysarthria, dysphagia
What are the investigations done for myaesthenia gravis?
Blood tests for serum acetylcholine receptor antibody
Muscle specific tyrosine kinase antibodies
CT chest to look for thymoma
Repetitive nerce stimulation (fall in muscle action potential between 1st and 4th action potential)
What extra test is done during a myaesthenic crisis?
Serial pulmonary function tests (spirometry) should be carried out
If Forced vital capacity is 15mL/kg or less then the pt should be considered for mechanical ventilation
What id the management of myaesthenia gravis?
Regular review and involvement of MDT’ OT/PT/SALT
Medical management is with immunosuppressive agents (steroids given acutely) and anticholinesterase inhibitors (neostigmine/pyridostigmine) these inhibit the breakdown of acefglcholine
Thymectomy is considered in some pts
What are the SES of anticholinesterase inhibitors?
Salivation
Lacrimation
Diarrhoea
Urinary frequency
What is the first line treatment of focal seizures?
Lamotrigine or carbamazepine
What is status epilepticus?
Any seizure which lasts more than 5 minutes or if the pstient experiences more than one seizure and does not regain consciousness between the two.
What is the management of status epilepticus?
A-E
Oxygen
IV access
ABG
Glucose, FBC, UES, CRP Calcium phosphate and magnesium if the patient is on anti epileptics
Anaesthetic review to ensure airway is managef
IV lorazepam 4mg (second dose can be given if no response)
In the absencd of IV access then PR diazepam or buccal midazolam can br given
If initial benzos fail;
Leviteracetam
Phenytoin
Valproate
If seizures continue then intubation and general anaesthesia is necessary
What is wernickes encephalopathy?
What are the clinical features
What is the treatment
Wernickes encephalopathy is due to thiamine (B1 deficiency)
This can be caused by; chronic alcohol abuse, malnutrition, bariatric surgery, hyperemesis gravidarum
Clinical features= nystagmus, broad based gait
Triad= ataxia, confusion and ocular abnormalities
Treatment= IV pabrinex
Left untreated if can become korsakoffs
What is a total anterior circulation infarct defined by?
Contralateral hemiplegia/hemiparesis AND Contralateral honomunous hemianopia AND Higher cerebral dysfunction (aphadia, neglect)
A TACI involves the antetior AND middle cerebral arteries on the affected sign
What is a partial anterior circulation infarct defined by?
2 of
Contralateral hemiplegia/hemiparesis
Contralateral honomynous hemianopia
Higher cerebral dysfunction
OR
Higher cerebral dysfunction alone
PACI involves the anterior OR middle cerebral artery on the affectdd side
What is a lacunar infarct?
Pure motor stroke
Pure sensort sfrike
Sensiromotor stroke
Ataxic hemiparesis
There is no visual field defect, higher cerebral dysfuctiin, brainstem dysfunction
A LACI affects the small deep perforating arteries, typically supplying the internal capsule or thalamus
What are the signs of posterior infarct?
Nystagmus Vertigo Ipsilateral Horner’s syndrome Ipsilateral facial sensory loss Dysarthria & dysphagia Diplopia Dysarthria & dysphagia Contralateral pain and temperature loss
what are the causes of foot drop?
weakness or paralysis of dorsiflexion and eversion
L5 root lesion (Radiculopathy)- also have sensory loss over the L5 dermaotype, sciatic burning type pain
Distal motor neuropathy- glove and stocking sesnroy disturbance and loss of all movements of the foot
Small cortical lesions
Uncommonly- intrinsic cord disease, partial sciatic nerve disease and myopathy
What are fasciculations a characteristic of?
motor neurone disease
