Neuro Diseases Flashcards
Define dementia.
A set of symptoms that may include memory loss and difficulties with thinking, problem solving or language. There is a progressive decline in cognitive function with no impairment of cognition
Describe the epidemiology of dementia.
10% of people over 65 and 20% of people over 80 have dementia.
Rare below the age of 55
Give 3 causes of dementia.
- Alzheimer’s disease (65%).
- Fronto-temporal.
- Vascular.
- Lewy bodies.
Frontal and temporal lobe atrophy is seen on an MRI. What kind of dementia is this patient likely to have?
Fronto-temporal.
Give 3 symptoms of fronto-temporal dementia.
- Disinhibition
- Personality and behavioural change
- Early memory preservation
- Progressive aphasia
What is the pathology of frontotemporal dementia
Pick bodies
Which disease is fronto-temporal dementia often associated with?
Motor neurone disease.
Give 3 functions of the temporal lobe.
- Hearing.
- Language comprehension.
- Memory.
- Emotion.
What lobe of the brain is affected in Alzheimer’s disease?
Medial Temporal lobe atrophy
Give 4 symptoms of Alzheimer’s disease.
- Global Memory/cognitive decline
- Behavioural change
- Hallucinations
- Delusions
- Depression
- Visual spatial changes
What is often the first cognitive marker of AD?
Short term memory impairment.
Give 2 histological signs of AD.
- Beta Plaques of amyloid.
2. neurofibrillary tangles §
What are the risk factors for AD
ApoE4 allele
Preseniliin 1/2 mutations
Down’s syndrome
What is the treatment for AD
Cholinesterase inhibitors (Rivastigmine)
25% of all patients with AD will develop what?
Parkinsonism.
What is the pathology of vascular dementia
Multiple infarcts or major strokes
What are the symptoms of vascular dementia
Sudden onset, stepwise deterioration with patchy deficits
What might you see on MRI for someone with vascular dementia
Extensive infarcts or small vessel disease
What is the treatment for vascular dementia
Manage predisposing factors
What is the pathology of Lewy body dementia
Lewy bodies in the occipital-parietal cortex
What are the symptoms of Lewy body dementia
Fluctuating cognitive dysfunction, visual hallucinations and Parkinsonism
What is the treatment for Lewy body dementia
Cholinesterase Inhibitors
What are the treatable causes of dementia
Infection (HIV, HSV) Vascular (Subdural haematoma) SLE and Sarcoid Nutritional (Thiamine deficiency, B12 and folate deficiency) Hypothyroid Hypercalcaemia Hydrocephalus
What are the risk factors for dementia
Family history Age Down's syndrome Alcohol, obesity and increased BP Hypercholesterolaemia Diabetes Atherosclerosis Depression
What investigations can you do in primary care to determine whether someone might have dementia?
- Good history of symptoms.
- 6CIT.
- Blood tests.
- FBC, LFTs, Thyroid, B12 and folate - Mini mental state exam
What questions are asked in 6CIT?
- What year is it?
- What month is it?
(Give an address). - Count backwards from 20.
- Say the months of the year in reverse.
- Repeat the address.
Why might you do a blood test in someone who you suspect has dementia?
To look at the vitamin levels that may suggest a reversible cause e.g. dementia due to B12 deficiency.
Dementia: what secondary care investigation could you do to look at brain structure?
MRI of the brain.
What secondary care investigation could you do to look at the pathology of dementia?
Amyloid and tau histopathology.
What score on the MMSE indicates serious impairment
<17
Name the staging system that classifies the degree of pathology in AD.
Braak staging.
Describe Braak staging.
- Stage 5/6 - high likelihood of AD.
- Stage 3/4 - intermediate likelihood.
- Stage 1/2 - low likelihood.
What is functional memory dysfunction?
Acquired dysfunction of memory that significantly affects a person’s professional/private life in the absence of an organic cause.
How could you determine whether someone has functional memory dysfunction or a degenerative disease?
When asked the question ‘when was the last time your memory let you down?’, someone with functional memory dysfunction would give a good detailed answer whereas someone with degenerative disease would struggle to answer.
Give 5 ways in which dementia can be prevented.
- Stop smoking.
- Healthy diet.
- Regular exercise.
- Healthy weight.
- Low alcohol intake.
- Education decreases the risk
What medication might you give someone with dementia
- Acetylcholine esterase inhibitors. (Rivastigmine and Donepezil)
- Anti-glutamate (Memantine)
- Blood pressure control to reduce vascular damage in vascular dementia
Define subarachnoid haemorrhage
Spontaneous arterial bleeding into the subarachnoid space (Between arachnoid and Pia)
Describe the epidemiology of subarachnoid haemorrhage
35-65 years
What are the causes of subarachnoid haemorrhage
- Rupture of saccular aneurysms (Berry aneurysms) (80%)
2. Arteriovenous malformations (15%)
Where are berry aneurysms most likely to form
Junction between the posterior communicating artery and the internal carotid
Anterior communicating artery and the anterior cerebral artery
Bifurcation of the middle cerebral artery
What diseases are berry aneurysms associated with
Adult polycystic kidney disease
Co-arcation of the aorta
Ehlers Danlos Syndrome
What are the risk factors for subarachnoid haemorrhage
Smoking Hypertension EtOH Bleeding diathesis Mycotic aneurysms Family history Disease that predisposes to aneurysms (PCKD, Ehlers Dnalos) Cocaine
What are the symptoms of subarachnoid haemorrhage
Sudden, severe occipital headache (Thunderclap)
Collapse and vomiting
Meningism (Neck stiffness, N/V, photophobia)
Seizures
Drowsiness and coma
How would you describe the headache associated with sub-arachnoid haemorrhage?
Thunderclap headache - maximum severity within seconds.
What are the signs of subarachnoid haemorrhage
Kernigs - cant straighten leg past 135 degrees
Retinal or subhyaloid haemorrhage
Focal neuro @ presentation suggest aneurysm location
Brudzinski’s = when neck is flexed, hip and knees flex
What is a sentinel headache
6% of patients experience a sentinel headache from small warning bleeding before subarachnoid haemorrhage
What investigations might you carry out in someone with subarachnoid haemorrhage
- CT - star shaped lesion - blood in sulci
- LP - Bloody in early stages and then xanthochromia due to breakdown of bilirubin
- Cerebral angiography
How long do you wait for before doing a lumbar puncture in someone with a suspected SAH?
If CT-ve and no CIs and At least 12 hours! You need to wait for the Hb to break down and then CSF will become yellow, this is a sign that there is bleeding in the sub-arachnoid space - xanthochromia.
What are the treatment options for someone with subarachnoid haemorrhage
- Nimodipine for 3wks to decrease cerebral vasospasm
- Endovascular coiling to stop rebleed
- Bed rest and BP control
What are the complications of subarachnoid haemorrhage
- Rebleeding
- Cerebral ischaemia (Due to vasospasm)
- Hydrocephalus (Due to blockage of the arachnoid granulations)
- Hyponatraemia
What is the management for unruptured aneurysms
Young patients with unruptured aneurysms >7mm in diameter may benefit from surgery
Define stroke.
Rapid onset of focal neurological deficit which is the result of a vascular lesion and is associated with infarction of central nervous tissue lasting >24hr
What can cause a stroke?
Infarction either due to cerebral ischaemia (80%) or intracerebral haemorrhage (20%)
What are the causes of Ischaemia
Atheroma (Large ie MCA or small vessel perforator)
Embolism (Cardiac from AF, endocarditis, MI) (Atherothromboembolism from carotids)
What are the causes of intracerebral haemorrhage
increased BP Trauma Aneurysm rupture Anticoagulants Thrombolysis Carotid artery dissection Watershed stroke (Sudden drop in Bp ie Sepsis) Vasculitis Venus sinus thrombosis Anti-phospholipid syndrome
Give 5 risk factors for stroke.
- Hypertension.
- Diabetes mellitus.
- Cigarette smoking.
- Hyperlipidaemia.
- Obesity.
- Alcohol.
- Family history or previous history of TIA
- Cardiac (AF, valve disease)
- Ethnicity (Increased in blacks and asians)
What investigation could you do to determine whether someone has had a haemorrhagic or an ischaemic stroke?
A CT scan of the head.
How might you identify HTN as a risk factor for stroke
Retinopathy
Nephropathy
Big heart on CXR
How might you recognise cardiac emboli as a risk factor for stroke
ECG to identify AF
Echo to identify septal defects
How might you recognise carotid artery stenosis as a risk factor for stroke
Doppler ultrasound with angio
How might you recognise hyper viscosity as a risk factor for stroke
Polycythaemia
Give 5 signs of an ACA stroke.
- Lower limb weakness and loss of sensation to the lower limb.
- Gait apraxia (unable to initiate walking).
- Incontinence.
- Drowsiness.
- Decrease in spontaneous speech (Akinetic mutism)
Give 5 signs of a MCA stroke.
- Contralateral arm and leg weakness and contralateral sensory loss
- Hemianopia.
- Aphasia.
- Dysphasia.
- Facial drop.
Give 5 signs of a PCA stroke.
- Contralateral homonymous hemianopia
- Cortical blindness.
- Visual agnosia.
- Prosopagnosia.
- Dyslexia, anomic aphasia
- Unilateral headache.
What is visual agnosia?
An inability to recognise or interpret visual information.
What is prosopagnosia?
An inability to recognise a familiar face.
A patient presents with upper limb weakness and loss of sensory sensation to the upper limb. They also have aphasia and facial drop. Which artery is likely to have been occluded?
The middle cerebral artery.
A patient presents with lower limb weakness and loss of sensory sensation to the lower limb. They also have incontinence, drowsiness and gait apraxia. Which artery is likely to have been occluded?
The anterior cerebral artery.
A patient presents with a contralateral homonymous hemianopia. They are also unable to recognise familiar faces and complain of a headache on one side of their head. Which artery is likely to have been occluded?
The posterior cerebral artery.
What is a lacunar stroke
Small infarcts around the basal ganglia, internal capsule, thalamus and pons
What are the symptoms of a lacunar stroke
Higher cortical dysfunction
Homonymous hemianopia
Drowsiness
Brainstem signs
What is the treatment for an ischaemic stroke?
Thrombolysis e.g. alteplase - IV infusion to break up the clot.
Aspirin 300mg PO once haemorrhagic stroke excluded
May coil bleeding aneurysms
Decompressive hemicraniotomy for some forms of MCA
When is thrombylosis and appropriate treatment for stroke
If pt between 18-80 and <4.5 hours since onset of symptoms
What non pharmacological treatment options are there for people after a stroke?
- Specialised stroke units.
- Swallowing and feeding help.
- Physiotherapy.
- Home modifications.
What are the secondary preventative measures for strokes
Statin
Aspirin and clopidogrel
Warfarin instead of aspirin or clopidogrel if cardioembolic stroke
Define TIA
Sudden onset focal neurology lasting <24hr due to temporary occlusion of part of the cerebral circulation
What are the signs of a TIA
Symptoms are brief and location dependent
If Carotid
- Amaurosis Fugax - retinal artery occlusion leading to vision loss like a descending curtain due to reduction in retinal, ophthalmic or cilliary blood flow leading to temporal retinal hypoxia
- Aphasias, hemiparesis and hemisensory loss
If vertebrobasilar
- Double vision, Vomiting, vertigo, ataxia, hemisensory losss, hemianopia vision loss, Loss of consciousness
What are the causes of TIA
Atherothromboembolism from carotids
Cardioembolism (Post MI, AF, valve disease)
Hyperviscosity (Polycythaemia and Sickle cell disease)
What are the signs of the causes of TIA
Carotid Bruit
Increased BP
Heart murmur (Suggestive of valve disease)
AF
What investigations might you carry out in someone with suspected TIA
Bloods - FBC for polycythaemia - U and E - ESR CXR ECG Echo Carotid doppler and angiography
What is it essential to do in someone who has had a TIA?
Assess their risk of having a stroke in the next 7 days - ABCD2 score.
What is the ABCD2 score?
It is used in patients who have had TIA’s to assess their risk of stroke in the next 7 days.
- Age > 60.
- BP > 140/90mmHg.
- Clinical features: unilateral weakness, speech disturbance.
- Duration? >1hr or 10-59min
- Diabetes?
What is the management of someone with TIA
- Antiplatelet therapy/anticoagulants (Aspirin and clopidogrel
- Cardiac risk factor control (Statin, ACE-I, Exercise, decrease salt)
- Assess subsequent stroke risk (ABCD2 score)
- Specialist referral to TIA clinic
>4 = referral within 24hr
<4 = referral within 1wk
Define and describe the pathophysiology of subdural haemorrhage
Bleeding from bridging veins between the cortex and venous sinuses (Sagittal sinus) which creates a haematoma between dura and arachnoid leading to increased ICP and shifting of midline structures away from clot
What are the causes of subdural haemorrhage
Often due to minor trauma that occurred a long time ago - especially deceleration injuries
Latent period after the head injury. 8-10 weeks later the clot starts to break down and there is a massive increase in oncotic pressure, water is sucked up into the haematoma -> signs and symptoms develop. There is a gradual rise in ICP.
Name 3 groups of people who are at increased risk of a sub-dural haematoma.
- Elderly people due to brain atrophy
- Alcoholics and epileptics (More likely to fall)
- Shaken babies.
- People on anticoagulants
Why are elderly people and alcoholics at increased risk of a sub-dural haematoma?
Both of these groups have cerebral atrophy which leads to an increased tension on cerebral veins.
What are the symptoms of subdural haemorrhage
Headache Fluctuating consciousness Sleepiness/drowsiness Gradual physical and mental slowing Unsteadiness Confusion and personality changes
What are the signs of a subdural haemorrhage
increased ICP leads to tentorial herniation and coning where the brain herniates through the foramen magnum
What are the investigations for someone with suspected subdural haemorrhage
Crescenteric haematoma over one hemisphere
Midline shift
Clot goes from white to grey over time
What is the management for someone with subdural haemorrhage
Irrigation and evacuation via burr hole craniostomy
Craniotomy
Address causes of trauma
Mannitol to decrease ICP
Give 3 differences in the presentation of a patient with a subdural haemorrhage in comparison to an extradural haemorrhage.
- Time frame: extra-dural symptoms are more acute.
- GCS: sub-dural GCS will fluctuate whereas GCS will drop suddenly in someone with an extra-dural haematoma.
- CT: extra-dural haematoma will have a rounder more contained appearance.
Define extradural haemorrhage
Often due to fracture of the temporal or parietal bone leading to laceration of the middle meningeal artery and vein resulting in blood between the bone and dura
When should you suspect extradural haemorrhage
Suspect if after head injury GCS falls, is slow to improve or there is a lucid interval
Describe the presentation of extradural haemorrhage
Lucid interval - deterioration of GCS after head injury that causes no loss of consciousness
Increased ICP leading to
- Headache
- Vomiting and nausea
- Confusion –> COma
- Fits/Seizures
- Ipsilateral blown pupil
Brainstem compression
- Deep irregular breathing
- Death by cardiorespiratory arrest
What tests would you do in someone with suspected extra-dural haemorrhage
Lens-shaped haematoma and
Skull frature on CT
LP contra-indicated
What is the management of extradural haemorrhage
Neuroprotective ventilation
Mannitol to decrease ICP
Craniectomy for clot evacuation and vessel ligation
Will GCS drop rapidly or slowly in someone with an extra-dural haematoma?
GCS will drop suddenly - there is a rapid deterioration in consciousness with focal neurological signs.
A 60-year-old man has just had surgery on his carotids and is complaining of difficulty speaking and swallowing. OE his tongue is deviated to the right. Which nerve has most likely been damaged during the operation?
Right hypoglossal.
What is meningitis
Inflammation of the meninges (usually the inner meninges = leptomeninges)
What are the risk factors for meningitis
Intrathecal drug administration Immunocompromised Elderly and pregnant Crowding Endocarditis DM IVDU
What are the meningitic symptoms of meningitis
Headache and fever Neck stiffness - Kernigs - Brudzinskis Photophobia Nausea and vomiting
What are the neurological symptoms of meningitis
Decreasing GCS –> Coma
Seizures
Focal neuro ie. CN palsies
Increased ICP = Papilloedema, irritaility, drowsiness and decreased pulse
What are the symptoms of septic meningitis
Fever
Decreased BP and increased HR
Purpuric rash = petechial non blanching
DIC
Name the viral causes of meningitis
Enteroviruses (Coxsackie and echovirus
HSV2
CMV
VZV
What are the bacterial causes of meningitis
Neisseria meningitidis
Streptococci Pneumonia
Name 3 organisms that can cause meningitis in adults.
- N.meningitidis (g-ve diplococci).
- S.pneumoniae (g+ve cocci chain).
- Listeria monocytogenes (g+ve bacilli).
Name 3 organisms that can cause meningitis in children.
- E.coli (g-ve bacilli).
- Group B streptococci e.g. s.agalactiae.
- Listeria monocytogenes.
Name a fungi that causes meningitis
Cryptococcus
How would you describe the rash that is characteristic of meningitis?
Non-blanching petechial rash.
What investigations might you do in someone who you suspect has meningitis.
- Blood cultures.
- Bloods: FBC, U+E, CRP, serum glucose, lactate.
- Lumbar puncture.
- CT head.
- Throat swabs.
What antibiotic is commonly given for the treatment of meningitis?
Cefotaxime.
What is the treatment of meningitis?
Cefotaxime.
+ amoxicillin if L.monocytogenes infection.
+ steroids to reduce inflammation in S.pneumoniae infection.
What is the treatment if viral meningitis is suspected
Aciclovir
What are the contraindications for LP
Thrombocytopaenia Lateness Pressures (Increased ICP) Unstable (Cardio and resp) Coagulation disorder Infection at LP site Neurology
CSF from an LP of someone with bacterial meningitis will show what
Be turbid, contain PMNs and have increased protein and low glucose
CSF from an LP of someone with TB meningitis will show what
Fibrin Web
Lymphocytic/mononuclear with massive increase in protein
CSF from an LP of someone with Viral meningitis will show what
Clear
Lymphocytic and mononuclear
Mild increase in protein
When is a child vaccinated against meningitis C?
At 12 weeks and 1 year.
When is a child vaccinated against meningitis ACWY?
At age 14.
At what vertebral level would you do a lumbar puncture?
L4/5.
Give 4 potential adverse effects of doing a lumbar puncture.
- Headache.
- Damage to spinal cord.
- Paraesthesia.
- CSF leak.
When is a child vaccinated against meningitis B?
At 8 weeks and 16 weeks.
You see a patient who you suspect has meningitis. It is noted that they have raised ICP. Would you do a lumbar puncture?
NO! You would not do a lumbar puncture in someone with raised ICP due to the risk of coning.
Give 4 signs of raised intra-cranial pressure.
- Papilloedema.
- Focal neurological signs.
- Loss of consciousness.
- New onset seizures.
Define encephalitis
Inflammation of brain parenchyma
What are the symptoms of encephalitis
Infectious prodrome (Fever, rash, cold sores, conjunctivitis, meningeal signs) Behaviour and personality change Decreasing GCS and coma Fever Headache Seizures Hx of travel or animal bite
What are the causes of encephalitis
Viral
- HSV1/2
- CMV, EBV, VZV
- HIV
Non Viral
- Any bacterial meningitis
- TB
- Malaria
- Lyme disease
What investigations would you carry out in someone with suspected encephalitis
Bloods (Cultures, viral PCR, malaria film)
Contrast CT (Focal bilateral temporal involvement)
LP (Increased protein, lymphocytes and PCR)
EEG
What is the treatment for encephalitis?
Acyclovir.
Encephalitis without the fever is what
Encephalopathy
In what group of people is encephalitis common?
The immunocompromised.
A lumbar puncture is done and a CSF sample is obtained from someone who is suspected to have encephalitis. Describe what the lymphocyte, protein and glucose levels would be like in someone with encephalitis.
- Lymphocytosis (raised lymphocytes).
- Raised protein.
- Normal glucose.
Give 4 symptoms of rabies.
- Fever.
- Anxiety.
- Confusion.
- Hydrophobia.
- Hyperactivity.
Name the organism responsible for causing tetanus.
Clostridium tetani (gram positive anaerobe).
Give 3 symptoms of tetanus.
- Trismus (lockjaw).
- Sustained muscle contraction.
- Facial muscle involvement.
Name the organism responsible for causing botulism.
Clostridium botulinum.
Give 3 symptoms of botulism.
- Diplopia (double vision).
- Dysphagia.
- Peripheral weakness.
Define epilepsy
Recurrent tendency to spontaneous, intermittent, abnormal electrical activity in part of the brain that manifests as seizures
Define seizure.
A convulsion caused by paroxysmal discharge of cerebral neurones.
Abnormal and excessive excitability of neurones.
Give 5 causes of transient loss of consciousness.
- Syncope.
- Epileptic seizures.
- Non-epileptic seizures.
- Intoxication e.g. alcohol.
- Ketoacidosis/hypoglycaemia.
- Trauma.
Give 5 causes of epilepsy.
2/3 are idiopathic Congenital (Tuberous sclerosis) Acquired (Vascular CVA, SLE Non epileptic (EtOH, Opiates,) Increased ICP Infection (Meningitis, encephalitis) Eclampsia
Define aura
A simple partial seizure which may proceed other manifestations experienced as epigastric rising, deja vu, automatisms, smells, lights and sounds
What is a partial (focal) seizure
Features referable to one hemisphere, often associated with structural brain abnormality
What is a primary generalised seizure
No warning/aura
Discharge throughout both hemispheres w/o localising features and loss of consciousness
What is a simple seizure
Awareness unimpaired
What is a complex seizure
Awareness impaired
What is a secondary generalised
Focal seizure = generalised
Aura –> tonic clonic
Describe the presenting features of simple partial seizures
Doesn’t affect consciousness or memory
Focal motor, sensory, autonomic and psychic symptoms
Describe the presenting features of complex partial seizures
Aura
Autonomic (Change in skin colour, temperature, palpitations)
Awareness lost (Motor arrest and motionless stare)
Automatisms (Lip-smacking, fumbling, chewing, swallowing)
Amnesia
Describe the presenting features of absence (Petit Mal) seizures
Often seen in childhood - child ceases activity, daydreaming and stares - stop talking mid sentence then carries on where left off
Abrupt onset and offset Short <10sec Eyes (Blank stare and glazed) Normal intelligence, Clonus or automatisms EEG: 3Hz spike and wave Stimulated by hyperventilation and photics
Describe the presenting features of tonic clonic seizures (Grand Mal)
Loss of consciousness
Tonic = limbs stiffen and person falls to floor if standing
Clonic = Rhythmic jerking of limbs (Contract and relax)
Incontinence
Tongue biting
Post-ictal confusion and drowsiness
Describe myoclonic seizures presenting features
Sudden jerk of limb, face or trunk and stiffening
Movement cessation/falling + convulsants
Describe the presenting features of atonic seizures
Sudden loss of muscle tone –> Fall forwards
No loss of consciousness
Describe the presenting features of tonic seizures
Increase in muscle tone + stiffening causing patient to fall backwards
What features localise a seizure to the temporal lobe
Automatisms (Lip smacking, chewing, fumbling)
Deja vu
Delusional behaviour
Abdominal rising/N and V
Emotional disturbance - terror, panic, anger
astes and smells
What features localise a seizure to frontal lobe
Motor features: Arrest, Jacksonian march, Todd’s palsy
What features localise a seizure to the parietal lobe
Sensory disturbance = tingling and numbness
What features localise a seizure to the occipital lobe
Visual phonomenon = spots, lines and flashes
What investigations would you cary out in someone with epilepsy
Basic blood products (FBC, U + E’s and glucose)
Urine toxicology
ECG
EEG - helps classification and prognosis
Neuroimaging = MRI
What are the treatments for tonic clonic seizures
Valproate and lamotrigine
What are the treatments for absence seizures
Valproate and lamotrigine
What are the treatments for tonic, atonic and myoclonic seizures
Valproate and levetiracetam
What is the treatment for a focal or 2 generation seizure
Lamotrigine nd CBZ
What treatments are used in acute seizure management
Diazepam and lorazepam
What are the surgical treatment options for epilepsy
Neurosurgical resection
Vagal nerve stimulation can decrease seizure frequency
What are the side effects of lamotrigine
Skin rash associated with hypersensitivity, fever
Diplopia and blurred vision
Vomiting
What are the side effects of valproate
Appetite = increase wt Liver failure Pancreatitis Reversible hair loss Oedema Ataxia Teratogenicity Encephalopathy
What are the side effects of carbamazepine
Leukoapenia Skin rashes Diplopia, blurred vision SIADH Impaired balance
What are the side effects of phenytoin
Ginigival hypertrophy Hirstuism Cerebellar syndrome Peripheral sensory neuropathy Diplopia Tremr
Which anti-epileptics should pregnant women avoid
Avoid valproate and take lamotrigine instead
CBZ and PHE are enzyme inducers so reduce the effectiveness of OCP
What is the mode of action of lamotrigine and carbamazepine
Inhibit pre-synaptic Na+ so prevents axonal firing
What is the mode of action of sodium valproate
Inhibits voltage gated Na+
Give 5 signs of an epileptic seizure.
- 30-120s in duration.
- ‘Positive’ symptoms e.g. tingling and movement.
- Tongue biting.
- Head turning.
- Muscle pain.
Define syncope.
Insufficient blood or oxygen supply to the brain causes paroxysmal changes in behaviour, sensation and cognitive processes.
Give 5 signs that a transient loss of consciousness is due to syncope.
- Situational.
- 5-30s in duration.
- Sweating.
- Nausea.
- Pallor.
- Dehydration.
Give a definition for a non-epileptic seizure.
Mental processes associated with psychological distress cause paroxysmal changes in behaviour, sensation and cognitive processes.
Give 5 signs of a non-epileptic seizure.
- Situational.
- 1-20 minutes in duration (longer than epileptic).
- Eyes closed.
- Crying or speaking.
- Pelvic thrusting.
- History of psychiatric illness.
Which is likely to last for longer, an epileptic or a non-epileptic seizure?
A non-epileptic seizure can last from 1-20 minutes whereas an epileptic seizure lasts for 30-120 seconds.
A patient complains of having a seizure. An eye-witness account tells you that the patient had their eyes closed, was speaking and there was waxing/waning/pelvic thrusting. They say the seizure lasted for about 5 minutes. Is this likely to be an epileptic or a non-epileptic seizure?
This is likely to be a non-epileptic seizure.
A patient complains of having a seizure. An eye-witness account tells you that the patient was moving their head and biting their tongue. They say the seizure lasted for just under a minute. Is this likely to be an epileptic or a non-epileptic seizure?
This is likely to be an epileptic seizure.
A patient complains of having a ‘black out’. They tell you that before the ‘black out’ they felt nauseous and were sweating. They tell you that their friends all said they looked very pale. Is this likely to be due to a problem with blood circulation or a disturbance of brain function?
This is likely to be due to a blood circulation problem e.g. syncope.
What 2 categories can epileptic seizures be broadly divided into?
- Focal epilepsy - only one portion of the brain is involved.
- Generalised epilepsy - the whole brain is affected.
Give 3 examples of focal epileptic seizures.
- Simple partial seizures with consciousness.
- Complex partial seizures without consciousness.
- Secondary generalised seizures.
Give 3 examples of generalised epileptic seizures.
- Absence seizures.
- Myoclonic seizures.
- Generalised tonic clonic seizures.
Describe a generalised tonic clonic seizure.
Sudden onset rigid tonic phase followed by a convulsion (clonic phase) in which the muscles jerk rhythmically.
The episode lasts up to 120s and is associated with tongue biting and incontinence.
Give 2 features of absence seizures.
- Commonly present in childhood.
2. Child ceases activity and stares for a few seconds.
Describe a myoclonic seizure.
Isolated muscle jerking.
What is the treatment for focal epileptic seizures?
Carbamazepine.
What is the treatment for generalised epileptic seizures?
Sodium valporate.
What is the major side effect of sodium valporate?
It is teratogenic!
Give 4 potential side effects of AED’s e.g. sodium valporate and carbamazepine.
- Cognitive disturbances.
- Heart disease.
- Drug interactions.
- Teratogenic.
What is status epilepticus
Seizure lasting >30min or repeated seizures w/o intervening consciousness
What is the management for status epilepticus
Lorazepam
Phenytoin
Diazepam
Dexamethasone
What are the causes of Parkinsonism
Parkinson's disease Infection (Syphilis, HIV, CJD) Vascular = multiple infarcts Drugs = antipsychotics Genetic = Wilson's disease
What are the three cardinal signs of parkinsonisms
Tremor
- worse @ rest, exacerbated by distraction, 4-6hz, pill rolling
Rigidity
- Increase tone in all muscle groups = lead pipe rigidity
- Rigidity + tremor = cog-wheel rigidity
Bradykinesia
- Slow initiation of movement and reduction of amplitude and speed of repetition
- Expressionless face
- Monotonous voice
- Micrografia
Gait
- Decreased arm swing
- Festinance (Short, shuffling steps with flexed trunk)
- Freezing esp in doorways
- Decreased blinking
What is dopamine produced from?
Tyrosine -> L-dopa -> dopamine.
Describe the pathophysiology of parkinson’s disease.
There is a loss of dopamine producing neurones in the pars compacta region of the substantia nigra.
Where does the substantia nigra project to?
The striatum.
Describe the epidemiology of PD
Mean onset 65 years
2% prevalence
Describe the pathophysiology of PD
Destruction of dopaminergic neurones in the pars compacta of substantia migrant
B-amyloid plaques
Neurofibrillary tangles: Hyperphosphorlated tau
Describe the clinical features of PD
Asymmetric onset - side of onset remains worse
Tremor = increased by stress and decreased by sleep
Rigidity
Akinesia = Slow initiation, micrographia, monotonous voice
Postural instability = stooped gait
Postural hypotension and autonomic dysfunction
Psychosis = visual hallucinations
Sleep disorders
Depression/Dementia
Describe the autonomic dysfunction in PD
Postural hypotension Constipation Hypersalviation Urgency, frequency and nocturia ED Hyperhiridrosis