Neurology Flashcards
What substances are hypoattenuating on CT scan?
Air
Fat
Fluid
Oedema
What substances are hyperattenuating on CT scan?
Bleeds
Bone
Mineralisation
What is used for CT contrast dye?
Iodine- hyperattenuating
What is used for MRI contrast dye?
Gadolinium
What are the risks with angiography?
Stroke
Vascular damage
Give examples of nuclear medicine scans
PET-CT Scan
DAT Scan for Parkinsons
What are the signs of UMN lesion?
- Hyperreflexia: reflexes brisk
- Hypertonia: the faster you move the patient’s muscle, the greater the resistance, until giving way (clasp knife)
- Spasticity in strong muscle groups (arm flexors and leg extensors)
- Upgoing plantars (positive Babinski)
- Loss of skilled fine finger movements
Where do UMN lesions impact?
Anywhere along the pyramidal (corticospinal) tracts
Ie. Between the precentral gyrus of frontal cortex to the anterior horn cells in spinal cord
Arm- extensors affected
Leg- flexors affected
Where do LMN lesions impact?
Anywhere from anterior horn cell distally, to nerve plexuses and peripheral nerves.
What are the signs of a LMN lesion?
- Hyporeflexia: reflexes reduced or absent
- Hypotonia: limbs feel soft and floppy
- Fasciculations: spontaneous involuntary twitching
- Plantars remain flexor
What is the function of the dorsal columns?
Vibration
Proprioception
What is the function of the Lateral spinothalamic tract?
Pain
Temperature
What is the normal intracranial pressure?
7-15mmHG
Which drug decreases the activity of histamine?
Cyclizine
Which drugs are agonists/ increase the activity of dopamine?
Levodopa Pramipexole (dopamine agonist) Cabergoline (hyperprolactinaemia, acromegaly)
Which drugs are dopamine antagonists?
Chlorpromazine (schizophrenia)
Metoclopramide (nausea)
Which drugs are agonists of serotonin?
Lithium (mood)
Fluoxetine and Sertraline (SSRIs)
Sumatriptan (migraine)
Which drugs are antagonists of Serotonin?
Clozapine, Olanzapine (Schizophrenia)
Where does the anterior cerebral artery supply?
Front and mid cerebrum
Where does the middle cerebral artery supply?
Lateral cerebrum
Where does the posterior cerebral artery supply?
Occipital lobe
What are the 2 types of oedema?
- Cytotoxic- ischemia, cell damage
2. Vasogenic- abnormal vessels lead to fluid leakage. Caused by tumours (angiogenesis), infection, inflammation
What are the risks of using contrast?
Contrast reaction
Acute renal failure
Diabetic lactic acidosis
Extravasation
What primary events can occur following head injury?
- Contusions
- Traumatic axonal injury
- Haemorrhage
What secondary events can occur following head injury?
- Ischemia
- Raised intrcranial pressure
- Infection
- Post traumatic epilepsy
- Chronic traumatic encepalopathy
What is the pathophysiology of Alzheimer’s?
- Accumulation of B-amyloid peptide
- Progressive neuronal damage
- Neurofibrillary tangles (NFTs)
- Increased amyloid plaques
- Loss of Ach neurotransmitter
Which brain parts are most affected by Alzheimer’s?
Basal nuclei
Hippocampus
Amygdala
Temporal neocortex
What are the risk factors for developing Alzheimer’s?
Age Head injury 1st degree relative with Alzheimer's Down Syndrome Homozygous for ApoE4 allele Mutation in BAPP gene Smoking Vascular risk factors
The Apolioprotein E4 allele increases the risk of which condition?
Alzheimer’s
What is vascular dementia?
Dementia due to cumulative effect of multiple small infarcts
Sudden onset dementia and stepwise deterioration
Grey matter loss
What is Lewy body dementia?
Lewy bodies of alpha synuclein which are eosinophilic in the brainstem and neocortex
Often in Parkinsons
What are the key signs of Lewy body dementia?
Visual hallucinations
Parkinsonism
Fluctuating cognitive impairment
Which medications should be avoided in Lewy body dementia?
Antipsychotics
What are the key signs of fronto temporal dementia?
Personality changes Behavioural changes Emotional unconcern Disinhibition Memory preserved until later stages
What is Pick’s disease?
A subtype of fronto temporal dementia
Tau positive
PIck bodies on histology
What is delerium?
Acute confusion: hours- days
Memory loss
Global cognitive deficit
Reversal of sleep-wake cycle
What is uncal herniation?
Type of supratentorial herniation
Temporal lobe moves towards tentorium and puts pressure on brainstem
What are the clinical features of uncal herniation?
Compression of cranial nerve 3: Mydriasis (dilated pupil) Diplopia Ptosis (drooping eyelid) Eye displaced and turned out
Ipsilateral hemiparesis
What is tonsillar herniation?
Cerebellar tonsils move downward through the foramen magnum, and may compress the brainstem and cervical spine
What are the features of tonsillar herniation?
Headache
Headtilt
Decreased consciousness
Respiratory dysfunction
What are the signs of a venous sinus thrombosis?
Headache Stroke symptoms One sided weakness Difficulty speaking Seizures Abnormal vision
What are the risk factors for a venous sinus thrombosis?
Women age 20-35 Pregnancy Combined oral contraceptive Nephrotic syndrome Thrombophilia Inflammatory diseases
What is the most aggressive type of brain tumour?
Glioblastoma- originates from glial cells, astrocytes
Which cancers most commonly metastasize to the brain?
Lung
Breast
Skin
Kidney
What is the most common paediatric brain tumour?
Medulloblastoma
Originates in the 4th ventricle
Which bacteria most commonly cause meningitis in ADULTS?
Strep pneumoniae
Neisseria meningitidis
What are the clinical signs/ symptoms of meningitis?
Fever >38 or hypothermia Photophobia Neck stiffness Headache May have altered consciousness Kernig's sign- painful to extend the leg towards head when laid supine Lymphadenopathy Rash
Which antibiotics can treat bacterial meningitis?
Cephalosporins
Vancomycin and or Rifampicin for penicillin resistant
What are the complications of meningitis?
Seizures Raised intracranial pressure Infarction Venous sinus thrombosis Cerebral oedema Hearing loss
Which bacteria may cause meningitis following travel?
Tuberculous meningitis
How is tuberculous meningitis treated?
Rifampicin
Isoniazid
Pyrazinamide
Ethambutol
Which viruses can cause viral meningitis?
HIV
Enterovirus
MMR
HSV1 and 2
Which organisms cause fungal meningitis?
Candida
Cryptococcus
How is cryptococcal (fungal) meningitis treated?
Fluconazole
Amphotericin B
What is encephalitis?
Inflammation of the brain parenchyma
Which virus causes 90% of encephalitis?
HSV1
How does HSV1 infect the brain parenchyma to cause encephalitis?
Oral mucosa infection, spread along CNV to the trigeminal ganglion
How can viral encephalitis be treated?
Aciclovir IV
What are the potential causes of brain abscesses?
Bacterial meningitis
Encephalitis
Sinusitis
Ear infection
What is rabies caused by?
Rhabdovirus
What can be seen under the microscope to diagnose rabies?
Negri bodies
What are the causes of ischemic stroke?
- Large vessel disease- plaque rupture at sight of turbulence eg bifurcation of common carotid, leads to acute occluding clot (Eg. Carotid artery disection)
- Cardioembolism
- Lacunar infarct
What is the commonest cause of stroke in young people?
Carotid artery disection, usually caused by trauma
Leads to ischemic stroke
What is the classic triad of symptoms in a carotid artery dissection?
- Unilateral face/ neck pain
- Horner’s syndrome (sympathetic dysruption)
- Anterior stroke/ TIA
What are the risk factors for lacunar infarct?
Hypertension
Hyperlipidaemia
Diabetes
Which parts of the brain are affected by lacunar infarct?
Subcortical: occlusion of perforating arterioles in the deep white matter/ brain stem
How does an infarct appear on CT scan?
Hypoattenuated = dark
Difficult to see early on
Loss of grey/ white matter differentiation
Sulcal effacement (adjacent gyri pushed together)
What are the main causes of anterior circulation stroke (TACS/ PACS)?
Ischemia
Cortical intracerebral haemorrhage
What are the clinical signs of an anterior stroke?
- Contralateral UMN hemiparesis and or sensory loss
- Homonymous hemianopia
- Higher mental function problems: dysphasia (language problems)
TACS: 3/3, PACS: 2/3
What is Broca’s aphasia?
Expressive dysphasia- difficulty expressing language, but comprehension remains intact
What is Wernicke’s aphasia?
Receptive dysphasia- difficulty comprehending language
What are the clinical findings of Lacunar stroke?
- Contralateral UMN hemiparesis
- Contralateral hemisensory loss
- Contralateral positive Babinski sign
- NO cortical problems (too deep)
Which arteries are affected in a posterior circulation stroke?
Vertebral
Basilar
What are the clinical findings of a posterior circulation stroke? (POCS)
- Dizzyness, Vertigo
- Diplopia
- Dysphagia
- Dsyarthria
- Limb weakness
- Ataxia
- Cranial nerve palsies
Bilateral issues
What are the clinical findings of a cerebellar stroke?
Nausea and vomitting Headache Loss of balance Vertigo Nystagmus (involuntary eye movement)
What are the consequences of a basilar artery thrombi?
Affects brainstem and occipital blood supply
Locked in syndrome
Respiratory arrest
Coma
Which symptoms almost NEVER occur in a TIA?
POSITIVE sensory symptoms: burning/ stinging Global symptoms Seizure like symptoms Migraine Symptoms which develop over time
What is Amaurosis Fugax?
TIA in the retinal artery (due to large vessel disease of carotid)
Causes transient blindness in one eye “like a curtain drawing” which is painless
What conditions can cause stroke mimics?
Dementia Seizure Syncope Sepsis Migraine Labyrinthitis
What is dysarthria?
Difficulty articulating
What is dysphonia?
Difficulty with voice production
What can cause ACUTE weakness?
- Lacunar infarct
- Transverse myelitis
- Spinal shock
- Guillain- Barre syndrome
What can cause SUBACUTE weakness?
- Spinal cord compression
- Myasthenia gravis
- Peripheral neuropathy
Which CHRONIC conditions can cause weakness?
- Space occupying lesion
- Motor neurone disease
- Cervical spondolysis
- Myopathy
What is transverse myelitis?
Acute inflammation of the spinal cord, usually post viral infection
Usually in younger people
Pain on onset
What can cause spinal cord compression?
Disk prolapse
Secondary malignancy- breast, lung. prostate
What are the key clinical features of myasthenia gravis?
SUBACUTE onset
PROXIMAL muscle weakness- difficulty climbing stairs
Remitting and relapsing muscle fatigue
Occular, bulbar, face and neck muscles affected
Ptosis and diplopia
What is the pathophysiology of myasthenia gravis?
Autoimmune destruction of NAchR
What are the key clinical features of cervical spondolysis?
Neck stiffness
Crepitus
Specific reflexes affected
Pain/ electrical sensation in arms/ fingers at compression level
What are the key clinical features of MND?
Foot drop Spastic gait Upgoing plantars Speech affected Proximal myopathy Weak grip NO sensory loss or sphincter disturbance NO affect on eyes
Which medication taken at a low dose for long term can cause myopathy?
Prednisolone
What are the common sites of berry aneurysm rupture?
PCA junction with internal carotid
ACA with anterior communicating
Bifurcation of MCA
What does the drug Nimodipine do?
Calcium antagonist
Reduces vasospasm and morbidity from ischemia
What shape is an extra-dural haematoma on CT?
Biconvex/ lens shaped
What shape is a sub-dural haematoma on CT?
Crescent shaped
What happens to the severity of a migraine when laying down?
It improves
What are the common features of migraines?
Hemicranial Photophobia Auras Improve on laying down Nausea May have associated symptoms: Restless legs, vertigo, neck or muscle pain
What are the 4 stages of a migraine?
- Prodrome- hours
- Aura
- Migraine headache (with associated symptoms)
- Post drome
What are the best treatments for migraines?
- Avoid triggers, stop caffeine
- NSAIDs - avoid opiates
- Anti emetics
- Tryptans eg Sumitryptan (serotonin agonist)
- Prophylaxis- beta blockers, candesartan, monocloncal antibodies
What causes Trigeminal Autonomic Cephalalgias?
Autonomic activation on ONE side (hemicranial)
What are the types of TAC?
Hemicrania continua
Cluster headaches
Parxoysmal hemicrania
SUNCT
What is the treatment for Trigeminal Neuralgia?
Sodium channel blockers eg. Carbamazepine
What are the partial triggers for migraines?
C- Chocolate H- Hangovers O- Orgasms C- Cheese/ caffeine O- Oral contraceptive L- Lie-in A- Alcohol T- Travel E- Exercise
Compare Parkinson tremor to essential tremor.
Parkinson- Unilateral onset, resting, affects jaws arms and legs, alcohol has no impact, family history is usually negative, also has bradykinesia and rigidity
Essential- Bilateral onset, no associated features, affects arms, head and voice, family history usually positive, alcohol relieves symptoms
How is Essential Tremor treated?
Beta blocker- propanolol
Primidone (type of Diazepam)
Alprazolam
What are the potential causes of blackout?
- Vasovagal syncope
- Situational syncope
- Epilepsy
- Orthostatic hypotension
- Hypoglycaemia
- Stokes Adams attack
- Carotid sinus syncope
What are the potential causes of vertigo?
- Benign positional vertigo
- Labyrinthitis
- Meniere’s disease
- Ototoxicity- Aminoglycosides, Cisplatin, Loop diuretics
- Acoustic neuroma
What are the key features of a cerebellar lesion?
DANISH: D- Dysdiadochokinesis (impaired rapidly alternating movements) and Dysmetria (past pointing) A- Ataxia N- Nystagmus I- Intention tremor S- Slurred speech (dysarthria) H- Hypotonia
What are some clinical features of Bell’s Palsy?
CNVII affected: Unilateral facial weakness (LMN- cant wrinkle forehead) Numbness around ear Mouth sagging Saliva drooling Hypersensitive to sounds Decreased taste
Which class of Parkinson drugs interacts with sinus decongestants?
MAOB Inhibitors (Rasagiline, Selegiline)
What are the types of Parkinson’s drugs?
- Levo-dopa
- Carbidopa
- Dopamine agonist- Pramipexole, Ropinirole, Bromocrptine
- COMT inhibitors- Entacapone, Tolcapone
- MAOB inhibitors- Rasagiline, Selegiline
Chorea is associated with ……….
Huntington’s
Levodopa use
Hemiballismus is associated with………….
Stroke in subthalamic nucleus
Diebetes
Athetosis is associated with ……………
Cerebral palsy
Resting tremor is associated with………..
Parkinsons
Intention tremor is associated with………….
Cerebellar lesion (stroke, MS)
Postural tremor is associated with………….
Essential tremor
Bromocriptine is what type of drug?
Dopamine agonist
Pramipexole is what type of drug?
Dopamine agonist
What sensory symptoms may be seen in MS?
Dyaesthesia Pins and needles Visual disturbance Loss of vibration sensation Trigeminal neuralgia
What motor symptoms may be seen in MS?
Trunk and limb atazia
Intention tremor
Falls
Scanning speech
What sexual/GU symptoms may be seen in MS?
Incontinence
Erectile dysfunction
Anorgasmia
Urine retention
85% of patients who experience a clinically isolated syndrome go on to develop…………
Relapsing Remitting MS
in MS patients what may be found on lumbar puncture?
Oligoclonal IgG bands (not found in serum)
Lhermitte’s sign is present in which condition?
Multiple sclerosis
What is Charcot’s neurological triadf?
- Nystagmus
- Intention tremor
- Scanning speech
Found in MS
What are the visual features of idiopathic intracranial hypertension?
- Reduced visual field
- Diplopia
- Blurred vision
- Blind spot
Which drugs are used for treating idiopathic intracranial hypertension?
Acetazolamide
Topiramate
Loop diuretics
Prednisolone
Which nerves are affected by a Bulbar Palsy?
CN 9-12: Glossopharyngeal Vagus Accessory Hypoglossal
What are the signs of a Bulbar Palsy?
- Quiet / hoarse voice
- Flacid, fasciculating tongue
- Normal or absent jaw jerk
What are the signs of a PseudoBulbar Palsy?
- Increased jaw jerk
- Slow deliberate speech
- Slow tongue movement
- Giggling/ weeping
Which nerves are affected by a Pseudobulbar palsy?
UMN
Corticobulbar tract
Bilateral
What can cause a bulbar palsy? (LMN)
- MND
- Myasthenia gravis
- Gullain Barre syndrome
- Polio
- Central pontine myelinolysis
- Brainstem tumour
What can cause a pseudobulbar palsy? (UMN)
- MND
- MS
- Stroke
- Central pontine myelinolysis
Which condition is associated with cafe au lait spots, freckles in folds and Lisch nodules on the iris?
Neurofibromatosis Type 1
Which condition results in dissociated sensory loss (loss of pain and temp) with weakness/ wasting of hands?
Syringomyelia
Which nerve pathway does a syringomyelia press on?
Lateral spinothalamic
Loss of pain and temp sensation; preservation of fine touch, proprioception and vibration. Due to CSF blockage. May also get hand wasting/ claw hand.
Lambert Eaton Myasthenic syndrome affects which part of the neurone?
Voltage gated calcium channels on pre-synaptic membrane
Myasthenia Gravis affects which part of the neurone?
NAchR on post-synaptic membrane
Which AEDs block voltage gated sodium channels?
Sodium valproate
Phenytoin
Carbamazepine
Lamotrigine
Which AED blocks voltage gated calcium channels?
Phenytoin
Which AEDs increase GABA levels?
Barbiturates
Benzodiazepines
Which AED decreases glutamate levels?
Topiramate
The superior division of the middle cerebral artery supplies where?
Broca’s area