Neurology - part 1 Flashcards
What are two methods of investigation problems with the peripheral nervous system (2)?
- EMG
- Nerve conduction studies
What are two findings in a nerve conduction study?
- Decreased amplitude/ smaller waves = axon loss (e.g. MND, peripheral neuropathy)
- Delayed signal = demyelination (e.g. GBS)
What are two findings in electromyography?
- Myopathy = decreased action potential duration and amplitude
- Neuropathy = increased action potential duration and amplitude
What is a myopathy vs neuropathy?
- Myopathy = problem with the muscle (e.g. muscular dystrophy)
- Neuropathy = problem with the nerve (e.g. MND)
What are 3 ways of investigating problems with the CNS?
- EEG (electroencephalogram)
- MRI
- NCCT
What is NCCT first line for?
- Stroke
- ICH
- Raised ICP
What is a contrast CT useful for?
Brain abscess
What are some differences in of PNS and CNS lesions in terms of presentation (2)?
- PNS = back pain?, bi-lateral,
- CNS = headache?, uni-lateral, visual changes
What is a lateralising sign?
Lesion affecting a single hemisphere (e.g. pronator drift, homonymous hemianopia, u/l weakness)
What are 3 important tracts to know about and where do they decussate?
- (DCML) dorsal column medial lemniscal (medulla)
- Spinothalamic (1-2 spinal levels above)
- Corticospinal (medulla)
What does the DCML carry (4)?
- Proprioception
- Fine touch
- Vibration
- 2 point discrimination
What does spinothalamic tract carry (3)?
- Lateral = pain + temperature
- Anterior = crude touch
What does the corticospinal tract carry (1)?
Motor signals to muscles
What nerve roots are responsible for the key reflexes?
- Bicep = C5/6
- Tricep = C7
- Knee = L4
- Ankle = S1
What nerve roots are responsible for the key dermatomes (6)?
- C6 = thumb
- C7 = middle + palm
- C8 = little
- T10 = bellybuT-TEN
- L5 = big toe (largest of the five)
- S1 = heel + sole
think of body doing splits with arms out
What are the nerve roots responsible for the key myotomes (5)?
- C5/6 = elbow flexion + shoulder abduction
- C7 = wrist flex, elbow extend
- C8 = hand flexion
- L5 = dorsiflexion
- S1 = plantar flexion
What are two common causes of foot drop?
- Common peroneal nerve lesion = MC
- L5 radiculopathy
How could you differentiate between common peroneal nerve lesion and L5 radiculopathy (2)?
- Common peroneal = ankle jerk absent, weak eversion
- L5 radiculopathy = ankle jerk present, weak inversion
What is a stroke?
A sudden infarct in the blood supply to part of the brain with symptoms lasting more than 24 hours
What are the two categories of stroke?
- Haemorrhagic (15%)
- Ischemic (85%)
What presentation is suggestive of a stroke?
Any sudden onset neurological symptom
What is ischemia vs infarction?
- Ischemia = inadequate blood supply
- Infarction = complete blockage of blood –> tissue death
What are the causes of a stroke (7)?
- Thrombus (+atherosclerosis)
- Embolus + infective endocarditis
- Shock
- Vasculitis
- Trauma
- Aneurysm
- Anticoagulants
What might cause a stroke in young people (6)?
- ADPKD (berry aneurysms)
- Congenital heart malformations
- COCP
- Blood clotting disorders
- Cocaine
- Infective endocarditis
Which congenital heart malformations increase the risk of stroke (3)?
- ASD
- VSD
- Patent foramen ovale
allow embolus from systemic circulation to enter the left ventricle and go to brain
What type of stroke affects the deep brain structures?
Lacunar stroke
What is a TIA?
A temporary neurological dysfunction lasting less than 24 hours caused by ischemia, but without infarction
What are some typical symptoms of a stroke (6)?
- Limb weakness
- Facial weakness
- Dysphasia
- Visual field defect
- Sensory loss
- Ataxia and vertigo
What are some risk factors for an ischemic stroke (13)?
- Smoking
- Hypertension
- AF
- Previous stoke/ TIA
- Diabetes
- Obesity
- Raised cholesterol
- Family history
- Vasculitis
- Thrombophilia
- COCP
- Migraines (with aura)
- Older age
What are the Bamford/ Oxford stroke classifications (4)?
- Total anterior circulation stroke
- Partial anterior circulation strokes
- Posterior circulation stroke
- Lacunar stroke
How does a total anterior circulation stroke present (3)?
- Unilateral sensory/ motor loss
- Homonymous hemianopia
- Higher cortical function loss e.g. dysphasia
Need all 3 for this classification
How does partial anterior circulation stroke present?
2 out of 3 of the criteria for a TACS
How does a posterior circulation stroke present (3)?
- Isolated vision change
- Cerebella Sx
- Contralateral CN palsy
How does a lacunar stroke present (3)?
- Pure motor stroke
- Pure sensory stroke
- Ataxic hemiparesis
What would be the presentation of an ACA stroke (2)?
- Lower limb»_space;» upper limb
- Behavioural change
sensory and motor deficit
What would be the presentation of an MCA stroke (4)?
- Upper limb»_space;» lower limb
- Face droop (forehead spared)
- Brocca/ wernicke aphasia (in dominant hemisphere)
- Ipsilateral gaze deviation
How does PCA stroke present (2)?
- Contralateral homonymous hemianopia (with macular sparing)
- Visual agnosia
What is webers stroke?
Branches of PCA that supply the midbrain blocked
What is the presentation of webners stroke?
- Ipsilateral CN 3 palsy (down and out)
- Contralateral hemiplegia (upper + lower)
What is Wallenberg stroke?
PICA infarct
lateral medullary syndrome
What is the presentation of Wallenberg stroke (4)?
- Ipsilateral spinothalamic face loss (pain + temp)
- Contralateral spinothalamic limb/ torso loss
- Nystagmus
- Ataxia
What is a basilar artery stroke known as?
Locked in syndrome
carries blood to brain stem
How does a retinal artery stroke present?
Amaurosis fugax
transient loss of vision
How does a Benedikt stroke present?
Wallenberg + gait disturbance (red nucleus infarct)
How does an AICA stroke present?
Wallenberg + hearing loss + ipsilateral facial paralysis
no dysphasia
lateral pontine syndrome
What tool can be used to assess the likelihood of a stroke (2)?
- FAST (community)
- ROSIER tool (ED)
How is a patient presenting with a stroke managed (5)?
- BG testing (exclude hypoglycaemia)
- Immediate NCCT head
- Aspirin 300mg (for 2 weeks)
- Consider diffusion weighted MRI
- Carotid doppler USS
How is a TIA managed (3)?
- Aspirin 300mg (daily)
- Referral for specialist assessment within 24 hours (or within 7 days if > 7 days since symptoms resolved)
- Diffusion weight MRI scanning
What are the specialist treatments offered to those with an ischemic stroke (2)?
- Thrombolysis (alteplase)
- Thrombectomy
How should blood pressure be managed in those with ischemic strokes?
Only treated in hypertensive emergency or to reduce risks associated with IV thrombolysis
reducing BP can reduce perfusion to brain
What are some complications of those with ischemic stroke (5)?
- Haemorrhagic transformation
- Cerebral oedema
- Seizures
- Aspiration pneumonia
- Long-term complications
What is haemorrhagic transformation in those with ischemic stroke?
Damaged tissue during ischemic stroke allows bleeding from the brain
What underlying causes of stroke are assessed in those who have had a TIA/ stroke (2)?
- AF (using ECG)
- Carotid artery stenosis (using USS)
How can carotid artery stenosis be managed (2)?
- Carotid endarterectomy (when > 70% stenosed)
- Angioplasty (balloon dilation) and stenting
When is thrombolysis offered to those with stroke?
4.5 hours within onset of symptoms (slightly different for those who have woken up with stroke)
What are some contraindications to thrombolysis (4)?
- Previous haemorrhagic stroke
- Recent surgery
- Active internal bleeding
- Uncontrolled hypertension
When is thrombectomy offered for those with a stroke?
Usually within 6 hours, sometimes up to 24 hours if imaging is favourable
How are strokes/ TIAs managed long term (3)?
- Clopidogrel daily - P2Y12 inhibitor (or aspirin + dipyridamole)
- Atorvastatin
- BP + diabetes control
What are the 4 types of intracranial haemorrhage?
- Extradural haemorrhage
- Subdural haemorrhage
- Subarachnoid haemorrhage
- Intracerebral haemorrhage
Which intracranial haemorrhage constitute a stroke (2)?
- Subarachnoid haemorrhage
- Intracerebral haemorrhage
Where does a subdural haemorrhage bleed between?
Dura mater and arachnoid mater
Where does an extradural haemorrhage bleed between?
Skull and dura mater
What shape is a subdural haemorrhage on CT?
Banana shaped
What shape is a extradural haemorrhage on CT?
Lemon shaped
What percentage of strokes do intracerebral and subarachnoid haemorrhages account for?
10-20%
What are some risk factors for intracerebral haemorrhage (7)?
- Head injuries
- Hypertension
- Aneurysms
- Anticoagulants
- Bleeding disorders/ thrombocytopenia
- Brain tumours
- Alcoholism
What are the signs/ symptoms of intracerebral haemorrhage (5)?
- Headache
- Seizures
- Vomiting
- Reduced GCS
- Focal neurological symptoms
What values is the GCS between?
3-15
What are the scores allocated to eyes in GCS (4)?
- Spontaneous opening
- Speech
- Pain
- No response
What scores are allocated to verbal response in GCS (5)?
- Orientated
- Confused
- Inappropriate words
- Incomprehensible sounds
- No response
What scores are allocated to motor response in GCS (6)?
- Obeys command
- Localises pain
- Withdraws from pain
- Abnormal flexion to pain
- Extension to pain
- No response
What GCS score needs intubation?
8/15 or less
Damage to which blood vessel usually causes an extradural haemorrhage?
Middle meningeal artery
Damage to which region of the head often results in damage to the middle meningeal artery and therefore an extradural haemorrhage?
Temporal bone fracture
What age patient is usually affected by extradural haemorrhage?
Younger patients (20-30)
What is the typical presentation of a patient with extradural haemorrhage?
Head trauma and ongoing headache initially with symptoms improving then rapid worsening
Damage to which blood vessel usually causes an subdural haemorrhage?
Bridging veins
What age is typically affected by a subdural haemorrhage (2)?
- Older patients
- Babies (shaken baby)
What are some risk factors for subdural haemorrhage (3)?
- Head trauma
- Dementia
- Alcoholism
*both cause brain atrophy - causing arachnoid to pull away from dura
What time period do subdural haemorrhages usually come on over?
Longer time period than extradural as usually caused by bleeding from veins
How are subdural and epidural haemorrhages managed (3)?
- Correct clotting abnormalities, stabilise BP
- Craniotomy
- Burr holes
How does an intracerebral haemorrhage present?
Similar to an ischemic stroke but with a headache
What is the presentation of a patient with a SAH?
Sudden onset occipital headache ‘thunderclap headache’
What are some other symptoms of SAH other than headache (3)?
- Meningism (hhotophobia, neck stiffness, vomiting)
- Raised ICP Sx (CN3, 6 palsy, cushings triad)
- Neurological symptoms
What are some risk factors for SAH (12)?
- Hypertension
- Smoking
- Alcohol
- Cocaine
- Family history
- Sickle cell
- Connective tissue disorders
- ADPKD
- Neurofibromatosis
- Aged 45-70
- Women
- Black
How is a SAH investigated?
CT head = hyperlattenuation in SAS
most reliable within 6 hours
What can be performed if CT head is negative for SAH?
Lumbar puncture
How long after symptoms should a lumbar puncture be performed for a SAH?
More than 12 hours
What would a lumbar puncture show for those with SAH (2)?
- Xanthocromia
- Raised red cell count
How can the source of the bleeding in a SAH be located?
CT angiogram
How is a SAH managed (2)?
- Aneurysm coiling or clipping
- Neurosurgery
What are 2 complications of a SAH?
- Vasospasm
- Hydrocephalus
How is vasospasm treated in those with SAH?
Nimodipine (CCB)
How is hydrocephalus treated (in those with SAH) (2)?
- Therapeutic lumbar puncture
- Shunt (ventriculoperitoneal/ external)
How is raised intracranial pressure treated in those with intracranial haemorrhage?
Mannitol
What is the most common cause of a head injury in the UK?
-
RTA = mc
also alcohol + drugs
What criteria might suggest a patient with a head injury would need a scan (6)?
- Persistently reduced GCS (<15)
- Vomited on more than 1 occasion
- Seizure/ focal neurological deficit
- Battle sign (fluid from ear/ nose)
- > 65
- Dangerous mechanism of injury
A fracture in which part of the skull may cause CSF to leak from nose?
Basilar skull fracture (base of skull)
What are some complications of head injuries (4)?
- Epilepsy
- Mood disorders
- Personality changes
- Focal neurological deficits
What is dementia?
Progressive condition that causes irreversible impairment in memory, cognition, communication or personality
What are the main types of dementia (4)?
- Alzheimers (60%)
- Vascular dementia
- Lewy body dementia
- Fronto-temporal dementia
What term is often used to describe symptoms similar to dementia but not as severe?
Mild cognitive impairment
What age would be considered early onset for dementia?
< 65
What are some differential diagnoses for dementia (8)?
- Delirium
- Medication use
- Psychiatric conditions e.g. depression/ bereavement
- Parkinsons
- Brain tumours
- Hyper(para)thyroidism
- Cushings
- Nutritional deficiencies
What medications can cause symptoms of dementia in particular (3)?
- Anticholinergics (urological drugs e.g. Oxybutynin)
- Antihistamines
- TCA
What nutritional deficiencies may cause dementia like symptoms in particular (2)?
- B12 deficiency
- Thiamine (B1) deficiency - Wernicke-Korsakoff syndrome
What are some risk factors for developing dementia (5)?
- Sedentary lifestyle
- Lack of mental stimulation
- Obesity
- High BP
- High BG
What are 2 specific risk factors for the development of Alzheimers?
- Downs syndrome
- Family history
What are the general signs/ symptoms of dementias (4)?
- Forgetful (events/ names)
- Asking same questions
- Difficult remembering words
- Impaired decision making
What is the general progression of symptoms in dementia?
Slow and insidious worsening of symptoms and ability to function
What are the prominent features of Alzheimers?
- Agnosia - can’t recognise
- Apraxia
- Aphasia
- Dysphagia
What is the pattern of memory loss in Alzheimers?
Short term memory worse affected
What is a prominent feature of vascular dementia?
Stepwise decrease in functioning/ symptoms
symptoms vary depending on the area of the brain affected
What type of person is typically affected by vascular dementia?
Stereotypically unhealthy patient - overweight, smokes, drinks
What is a prominent feature of fronto-temporal dementia (2)?
- Frontal = thinking and memory
- Temporal = speech and language
What is a prominent feature of Lewy body dementia (2)?
- Parkinsonism
- Hallucinations
What is the pathophysiology of Alzheimers dementia?
Beta amyloid proteins accumulate as plaques and tau neurofibrillary triangles –> death of brain cells
How is Alzheimers managed with medication (2)?
- Cholinesterase inhibitors
- Memantine
What are 3 examples of cholinesterase inhibitors used for Alzheimers?
- Galantamine
- Donepezil
- Rivastigmine
What causes Lewy body dementia?
Lewy body accumulation in the cortex
What is the main constituent of Lewy bodies?
Alpha synuclein
What is Lewy body dementia an umbrella term for?
- Dementia with Lewy bodies (memory affected first)
- Parkinsons disease dementia (movement affected first)
What is the difference between Parkinson’s disease and dementia with Lewy bodies?
Likely due to the location of accumulation of Lewy bodies
considered a spectrum of disorders
The collection of which protein leads to fronto-temporal dementia?
Tau protein/ pick body
What sometimes causes frontotemporal dementia?
Autosomal dominant mutation in tau protein
What is frontotemporal dementia associated with?
ALS (15-20% of those with ALS develop FTD)
How are those with dementia initially managed in primary care (2)?
- Exclude physical cause (bloods, CXR MSU)
- Referral to memory clinic
How are those with dementia investigated in secondary care (2)?
- ACE (addenbrookes cognitive examination)
- MRI
What would an MRI show in those with dementia (2)?
- Atrophy of brain
- Lack of structural pathology
How are those with dementia managed (5)?
- Lasting power of attorney
- Advanced decisions
- Antidepressants
- Antipsychotics (risperidone)
- Benzos (for crisis management)
What are some associated behavioural and psychological symptoms of dementia (6)?
- Depression
- Anxiety
- Agressions
- Agitation
- Hallucinations
- Sleep disturbances
What is delirium?
Acute fluctuating disturbance in mental function
What are the signs/ symptoms of delirium (6)?
- Agitation
- Confusion
- Drowsiness
- Hallucinations
- Delusions
- Memory problems
What are the causes of delirium?
- Pain
- Infection
- Nutrition
- Constipation
- Hydration status
- Medications
- Environvment/ electrolytes
What medications commonly cause delirium (5)?
- Benzos
- Opioids
- Anticholinergics
- Dopaminergics
- Steroids
What might make a diagnosis of delirium more likely in terms of presentation (3)?
- Hallucinations (esp. visual)
- Altered consciousness (hyperalert/ drowsiness)
- Agitation more common (looking round room, fidgety)
What is the second most common neurodegenerative condition after dementia?
Parkinsons disease
What is the underlying cause of parkisnons disease?
Loss of dopamine producing neurones in the substantial nigra pars compacta
What protein accumulation causes the death of these neurones in PD?
Alpha synuclein aggregating to form Lewy bodies
What is the mechanism by which parkinsons makes it more difficult to initiate movement?
Decrease in nigrostriatal pathway neurones –> less GABA-ergic inhibition (via indirect pathway) –> gross cortex inhibition –> more difficult to initiate movement
What are some risk factors for PD (3)?
- Family history
- Male (2:1)
- Older age
What is protective against PD?
Smoking
What medications can cause parkinonism or exacerbate parkinsons (2)?
- Antipsychotics (especially typical)
- Metoclopramide (antiemetic)
What is a feature of drug induced parkinsonism?
Bilateral resting tremor
What are the 4 typical symptoms of parkinsons disease?
- Bradykinesia
- Resting tremor
- Rigidity
+ Postural instability (not part of the triad, but a key symptom
What is the typical feature/ presentation of symptoms in PD?
Asymmetrical symptoms with one side affected much more than the other
What are some symptoms of PD when walking (3)?
- Stooped posture
- Reduced arm swing
- Shuffling gait
What are two types of rigidity found in parkinsons disease?
- Cogwheel = jerky
- Lead pipe = smooth tremor throughout
What are some other features of PD other than the 4 main features (7)?
- Depression
- Sleep disturbance (REM sleep disorders)
- Postural instability
- Loss of sense of smell
- Cognitive impairment/ memory problems
- Constipation
- Autonomic symptoms (e.g. postural hypotension)
What are the features of a tremor in parkinsons disease (3)?
- 4-6 hertz (pill rolling)
- Asymmetrical (worse on one side)
- Resting
What is a key differential to the tremor seen in PD?
Benign essential tremor
What are the features of benign essential tremor when compared to PD?
- Higher frequency 6-12 Hz
- Intention tremor
- Symmetrical
- Improves with alcohol
