medicine 4 Flashcards
cerebrovascular incidents are
ischaemia or intracranial haemorrhage
TIA is defined as
symptoms of a stroke that resolve within 24 hours
a crescendo TIA refers too
two or more TIAS in a week
presentation of a TIA
Sudden weakness of limbs
Sudden facial weakness
Sudden onset dysphasia (speech disturbance)
Sudden onset visual or sensory loss
how to quickly identify a stroke in community
F – Face
A – Arm
S – Speech
T – Time (act fast and call 999)
ABCD2 for for patients with a TIA consists of
A – Age (> 60 = 1)
B – Blood pressure (> 140/90 = 1)
C – Clinical features (unilateral weakness = 2, dysphasia without weakness = 1)
D – Duration (> 60 = 2, 10 – 60 = 1, < 10 = 0)
D – Diabetes = 1
management of 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
with a stroke, once a CT scan has ruled out an intracranial haemorrhage what treatment can be used?
Thrombolysis with alteplase
what role does alteplase have
tissue plasminogen activator
what is the gold standard for vascular territory for stroke
diffusion weighted MRI
what investigation can assess carotid stenosis
carotid US
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
presentation of an intracranial bleed
Sudden onset headache
Seizures Weakness Vomiting Reduced consciousness Other sudden onset neurological symptoms
glasgow coma score for eyes
Spontaneous = 4 Speech = 3 Pain = 2 None = 1
Glasgow coma score for verbal response
Orientated = 5 Confused conversation = 4 Inappropriate words = 3 Incomprehensible sounds = 2 None = 1
Glasgow coma score for motor response
Obeys commands = 6 Localises pain = 5 Normal flexion = 4 Abnormal flexion = 3 Extends = 2 None = 1
subdural haemorrhage is caused by
rupture of bridging veins between the dura mater and arachnoid mater
extradural haemorrhage is caused by
rupture of the middle meningeal artery
rupture of the middle meningeal artery is associated with a fracture with
temporal bone
on Ct scan an extradural haemorrhage appears as
bi-convex shape
a cerebral aneurysm usually bleeds into
the subarachnoid space
the sub arachnoid space exists between
the pia mater and the arachnoid mater
what headache is associated with a subarachnoid haemorrhage
thunderclap
features of a thunderclap headache
Neck stiffness
Photophobia
Vision changes
Neurological symptoms such as speech changes, weakness, seizures and loss of consciousness
CSF signs of a SAH
red cell count and xathochromia
Ix of SAH
lumbar puncture, angiography, CT
surgical interventions for SAH
coiling the vessel or clipping
medical treatments for SAH
nimodipine is a Calcium channel blocker that can prevent vasospasms, lumbar puncture for hydrocephalus or antiepilpetics for seizures.
Multiple sclerosis typically only affects
central nervous system’s myelin sheaths (oligodrendrocytes)
a key expression to describe the pathology of MS lesions is
disseminated in time and space
signs/symptoms of MS eye disease
optic neuritis - loss of vision in one eye
double vision due to sixth cranial nerve palsy that can either be:
unilateral internuclear ophthalmoplegia
or
conjugate lateral gaze disorder (when looking laterally won’t be able to abduct)
general symptoms of MS
focal weakness (incontinence, limb paralysis) focal sensory (trigeminal neuralgia, numbness, paraethesia) Ataxia (sensory or cerebellar)
Lhermitte’s sign refers too
electric shock sensation travels down the spine and into the limbs when flexing the neck. It indicates disease in the cervical spinal cord in the dorsal column. It is caused by stretching the demyelinated dorsal column.
sensory ataxia refers too
loss of the proprioceptive sense,
cerebellar ataxia refers too
coordination problems
Dx of MS
MRI scans can demonstrate typical lesions
Lumbar puncture can detect “oligoclonal bands” in the cerebrospinal fluid (CSF)
optic neuritis presentation
Central scotoma. This is an enlarged blind spot.
Pain on eye movement
Impaired colour vision
Relative afferent pupillary defect
relapse treatment for MS consists of
methylprednisolone:
500mg orally daily for 5 days
MS spasticity may be treated through
baclofen, gabapentin and physiotherapy
most common form of motor neurone disease is
Amylotropic lateral sclerosis (AML)
pathophysiology of motor neurone disease
progressive degeneration of both upper and lower motor neurones. The sensory neurones are spared.
presentation of motor neurone disease
insidious, progressive weakness of the muscles throughout the body affecting the limbs, trunk, face and speech. The weakness is often first noticed in the upper limbs. There may be increased fatigue when exercising. They may complain of clumsiness, dropping things more often or tripping over. They can develop slurred speech (
lower motor neurone signs
Muscle wasting
Reduced tone
Fasciculations (twitches in the muscles)
Reduced reflexes
upper motor neurone signs
Increased tone or spasticity
Brisk reflexes
Upgoing plantar responses
medication that may be used in motor neurone disease
Riluzole, may slow the progression
pathophysiology of parkinsons
basal ganglia are a group of structures situated in the middle of the brain. They is responsible for coordinating habitual movements. Part of the basal ganglia called the substantia nigra produces a neurotransmitter called dopamine. Dopamine is essential for the correct functioning of the basal ganglia. In Parkinson’s disease, there is a gradual but progressive fall in the production of dopamine.
classic triad of parkinsons is
Resting tremor
Rigidity
Bradykinesia
presentation of Parkinsons
unilateral tremor (pill rolling tremor)
cogwheel rigidity
bradykinesia (shuffling gait, hypomimia, difficulty initiating movement)
depression, postural instability, loss of smell, sleep disturbance and cognitive impairment
hypomimia refers too
reduced facial movements and expressions
Parkinson’s tremor features
asymmetrical 4-6Hz worse at rest improves with intentional movement no change with alcohol
benign essential tremor features
symmetrical, 5-8Hz, improves with rest, worse with intentional movements,, improves with alcohol
Dementia with Lewy Bodies features
parkinsons, visual hallucinations, delusions, disorders of REM sleep and fluctuating consciousness.
levodopa is
synthetic dopamine
levodopa in parkinsons is usually given alongside
peripheral decarboxylase inhibitors. Examples are carbidopa and benserazide.
SE of dopamine Tx
dystonia, chorea and athetosis
COMT inhibitors example and pharmacology
entacapone. These are inhibitors of catechol-o-methyltransferase (COMT). The COMT enzyme metabolises levodopa in both the body and brain
examples of dopamine agonists are
Bromocryptine
Pergolide
Carbergoline
Monoamine Oxidase-B Inhibitors pharmacology
Monoamine oxidase enzymes break down neurotransmitters such as dopamine, serotonin and adrenaline. The monoamine oxidase-B enzyme is more specific to dopamine
examples of monoamine oxidase B inhibitors are
Selegiline
Rasagiline
differentials for a tremor include
Parkinson’s disease Multiple sclerosis Huntington’s Chorea Hyperthyroidism Fever Medications (e.g. antipsychotics)
Ix for epilepsy
EEG, MRI, ECG
generalised tonic clonic seizure description/presentation.
tonic (muscle tensing) and clonic (muscle jerking) episodes. Typically the tonic phase comes before the clonic phase. There may be associated tongue biting, incontinence, groaning and irregular breathing.
describe the post ictal phase of a generalised tonic clonic seizure
confused, drowsy and feels irritable or depressed.
Mx of generalised tonic clonic seizure is
First line: sodium valproate
Second line: lamotrigine or carbamazepine
focal seizure start in the
temporal lobe
focal seizures presentation
Hallucinations
Memory flashbacks
Déjà vu
Doing strange things on autopilot
Tx for focal seizures include
First line: carbamazepine or lamotrigine
Second line: sodium valproate or levetiracetam
absence seizure presentation
children who becomes blank, stares into space and then abruptly returns to normal. During the episode they are unaware of their surroundings and won’t respond. These typically only lasts 10-20 seconds.
Tx of absence seizure includes
First line: sodium valproate or ethosuximide
atonic seizure presentation
drop attacks”. They are characterised by brief lapses in muscle tone. These don’t usually last more than 3 minutes.
Tx for atonic seizures are
First line: sodium valproate
Second line: lamotrigine
myoclonic seizure presentation
sudden brief muscle contractions, like a sudden “jump”. The patient usually remains awake during the episode.
Tx for myoclonic seizures
First line: sodium valproate
Other options: lamotrigine, levetiracetam or topiramate
infantile spasms are also known as
West syndrome
west syndrome Tx
prednisolone or vigabatrin
sodium valproate targets
increasing activity of GABA
SE of sodium valproate
Teratogenic so patients need careful advice about contraception
Liver damage and hepatitis
Hair loss
Tremor
carbamazepine side effects are
Agranulocytosis
Aplastic anaemia
Induces the P450 system so there are many drug interactions
phenytoin SE
Folate and vitamin D deficiency Megaloblastic anaemia (folate deficiency) Osteomalacia (vitamin D deficiency)
SE of ethosuximide
Night terrors
Rashes
SE of lamotrigine
Stevens-Johnson syndrome or DRESS syndrome. These are life threatening skin rashes.
Leukopenia
status epilepticus is defined as
seizure lasting more than 5 minutes
management of status epilepticus in hospital
Secure the airway
Give high-concentration oxygen
Assess cardiac and respiratory function
Check blood glucose levels
Gain intravenous access (insert a cannula)
IV lorazepam 4mg, repeated after 10 minutes if the seizure continues
If seizures persist: IV phenobarbital or phenytoin
Tx of status epilepticus in the community
Buccal midazolam
Rectal diazepam
features of neuropathic pain
Burning Tingling Pins and needles Electric shocks Loss of sensation to touch of the affected area
what are the four first line treatments for neuropathic pain
Amitriptyline is a tricyclic antidepressant
Duloxetine is an SNRI antidepressant
Gabapentin is an anticonvulsant
Pregabalin is an anticonvulsan
first line treatment for trigeminal neuralgia
carbamazepine
facial nerve pathway
brainstem at the cerebellopontine angle. On its journey to the face it passes through the temporal bone and parotid gland.
facial nerve supplies
Temporal Zygomatic Buccal Marginal mandibular Cervical
three functions of the facial nerve
motor, sensory and parasympathetic.
facial nerve motor supplies
muscles of facial expression, the stapedius in the inner ear and the posterior digastric, stylohyoid and platysma muscles in the neck.
facial nerve sensory supplies
taste from the anterior 2/3 of the tongue.
facial nerve parasympathetic supplies the
submandibular and sublingual salivary glands and the lacrimal gland
upper motor neurone facial palsy should require
urgent referral with suspected stroke
facial upper motor neurone sign is
forehead will be spared and the patient can move their forehead on the affected side.
in a facial lower motor neurone lesion the sign is
forehead will NOT be spared and the patient cannot move their forehead on the affected side.
bilateral upper motor neurone lesions can occur in
Pseudobulbar palsies
Motor neurone disease
bells palsy is
idiopathic lower motor neurone facial nerve palsy
Tx for bell’s palsy
prednisolone as treatment, either:
50mg for 10 days
60mg for 5 days followed by a 5 day reducing regime of 10mg a day
Patients also require lubricating eye drops
Ramsay-Hunt syndrome is caused by the
herpes zoster virus
Ramsay-Hunt syndrome presents as
unilateral lower motor neurone facial nerve palsy with stereotypically have a painful and tender vesicular rash in the ear canal, pinna and around the ear on the affected side. This rash can extend to the anterior 2/3 of the tongue and hard palate.
Tx for ramsay hunt syndrome
Prednisolone
Aciclovir
Patients also require lubricating eye drops.
initial presentation of a brain tumour may be
raised intracranial pressure or focal neuro symptoms
a patient that has had an unusual change in personality and behaviour. This indicates a tumour
frontal lobe
key fundoscopy finding for raised intracranial pressure
papilloedema
presentation of raised intracranial pressure
Constant Nocturnal Worse on waking Worse on coughing, straining or bending forward Vomiting
other features of raised intracranial pressure includes
Altered mental state Visual field defects Seizures (particularly focal) Unilateral ptosis Third and sixth nerve palsies Papilloedema (on fundoscopy)
papilloedema specifically refers too
CSF under high pressure to flow into the optic nerve sheath as the sheath is connected with the subarachnoid space.
common sites of metastases for brain tumours
Lung
Breast
Colorectal
Prostate
gliomas are tumours of the
glial cells
most common glioma is
astrocytoma (glioblastoma multiforme)
pituitary tumours cause what visual defect
bitemporal hemianopia
Acoustic neuromas are tumours of the
Schwann cells surrounding the auditory nerve
acoustic tumours occur at the
cerebellopontine angle
unilateral acoustic neuromas are associated with
neurofibromatosis type 2.
symptoms of acoustic neuroma are
Hearing loss
Tinnitus
Balance problems
They can also be associated with a facial nerve palsy.
huntington’s chorea inheritance
autosomal dominant
what disorder is huntington’s chorea specifically (mutation)
“trinucleotide repeat disorder” that involves a genetic mutation in the HTT gene on chromosome 4.
huntington’s chorea displays what genetic characteristic
nticipation is a feature of trinucleotide repeat disorders. This is where successive generations have more repeats in the gene, resulting in:
Earlier age of onset
Increased severity of disease
presentation of huntington’s chorea is
insidious, progressive worsening of symptoms. It typically begins with cognitive, psychiatric or mood problems. These are followed by the development of movement disorders.
Chorea (involuntary, abnormal movements)
Eye movement disorders
Speech difficulties (dysarthria)
Swallowing difficulties (dysphagia)
medications that can be used to supress disordered movement
Antipsychotics (e.g. olanzapine)
Benzodiazepines (e.g. diazepam)
Dopamine-depleting agents (e.g. tetrabenazine)
myasthenia gravis is an
autoimmune condition that causes muscle weakness that gets progressively worse with activity and improves with rest.
myasthenia gravis has a strong link with
thymoma, tumours of the thymus
what neurotransmitter is sued at neuromuscular junctions?
acetylcholine
myasthenia gravis pathology
acetylcholine receptor antibodies bind to post synaptic receptors preventing stimulation leading to less effective stimulation with increased activity.
what other complications are there of acetylcholine receptor antibodies inappropriately binding
activation of the complement system damaging the post synaptic membrane
are there any other autoantibodies implicated in myasthenia gravis
antibodies against muscle-specific kinase (MuSK) and antibodies against low-density lipoprotein receptor-related protein 4 (LRP4). MuSK and LRP4 and important proteins for the creation and organisation of the acetylcholine receptor
presentation of myasthenia gravis is
affects the proximal muscles and small muscles of the head and neck. It leads to:
Extraocular muscle weakness causing double vision (diplopia)
Eyelid weakness causing drooping of the eyelids (ptosis)
Weakness in facial movements
Difficulty with swallowing
Fatigue in the jaw when chewing
Slurred speech
Progressive weakness with repetitive movements
examination for myasthenia gravis points
Repeated blinking will exacerbate ptosis
Prolonged upward gazing will exacerbate diplopia on further eye movement testing
Repeated abduction of one arm 20 times will result in unilateral weakness when comparing both sides
Check for a thymectomy scar.
Test the forced vital capacity (FVC).
diagnosis of myasthenia gravis is with
autoantibodies (ACh-R), CT/MRI or edophonium test
edrophonium test involves
IV dose of edrophonium chloride (or neostigmine). Normally, cholinesterase enzymes in the neuromuscular junction break down acetylcholine. Edrophonium block these enzymes and stop the breakdown of acetylcholine. As a result the level of acetylcholine at the neuromuscular junction increases. It briefly and temporarily relieves the weakness.
Tx for myasthenia gravis
Reversible acetylcholinesterase inhibitors (usually pyridostigmine or neostigmine), immunosuppression with prednisolone or azathioprine
thymectomy
rituximab or eculizumab
myasthenic crisis can lead too
respiratory failure as a result of weakness in the muscle of respiration.
myasthenic crisis requires
non-invasive ventilation, BiPAP, intubation and ventilation as well as immunomodulatory therapies such as IV immunoglobulins and plasma exchange.
Lambert-Eaton syndrome typically occurs in patients with
small cell lung cancer
the autoantibodies in lambert eaton syndrome target
voltage-gated calcium channels present in small cell lung cancer and presynaptic terminals of the NMJ
presentation of lambert Eaton syndrome is
proximal muscle weakness. It most notably presents with proximal leg muscle weakness. It can also affect the intraocular muscles causing double vision (diplopia), the levator muscles in the eyelid causing eyelid drooping (ptosis) and the oropharyngeal muscles causing slurred speech and swallowing problems (dysphagia). Patients may also experience dry mouth, blurred vision, impotence and dizziness due to autonomic dysfunction.
what key sign may be elicited in lambert eaton syndrome
patient can maximally contract the quadriceps muscle for a period, then have their reflexes tested immediately afterwards, and display an improvement in the response. This is called post-tetanic potentiation.
Tx for lambert eaton syndrome
amifampridine, Immunosuppressants (e.g. prednisolone or azathioprine)
IV immunoglobulins
Plasmapheresis
amifampridine mechanism
blocking voltage-gated potassium channels in the presynaptic cells, which in turn prolongs the depolarisation of the cell membrane and assists calcium channels in carrying out their action.
Charcot-Marie-Tooth disease effects
the peripheral motor and sensory nerves.
Charcot-Marie-Tooth inheritance is
autosomal dominant
classical features of charcot marie tooth
High foot arches (pes cavus)
Distal muscle wasting causing “inverted champagne bottle legs”
Weakness in the lower legs, particularly loss of ankle dorsiflexion
Weakness in the hands
Reduced tendon reflexes
Reduced muscle tone
Peripheral sensory loss
causes of peripheral neuropathy
A – Alcohol B – B12 deficiency C – Cancer and Chronic Kidney Disease D – Diabetes and Drugs (e.g. isoniazid, amiodarone and cisplatin) E – Every vasculitis
guillain barre syndrome is an
“acute paralytic polyneuropathy”
pathophysiology of guillain barre is with
molecular mimicry. The B cells of the immune system create antibodies against the antigens on the pathogen that causes the preceding infection. These antibodies also match proteins on the nerve cells. They may target proteins on the myelin sheath of the motor nerve cell or the nerve axon.
presentation of guillain barre is
Symmetrical ascending weakness (starting at the feet and moving up body)
Reduced reflexes
There may be peripheral loss of sensation or neuropathic pain
It may progress to the cranial nerves and cause facial nerve weakness
diagnosis of guillain barre is through
Nerve conduction studies (reduced signal through the nerves)
Lumbar puncture for CSF (raised protein with a normal cell count and glucose)
guillain barre syndrome Tx
IV immunoglobulins
Plasma exchange
Supportive care
VTE prophylaxis (pulmonary embolism is a leading cause of death)
In severe cases with respiratory failure patients may need intubation, ventilation and admission to the intensive care unit.
neurofibromatosis causes
nerve tumours (neuromas) to develop throughout the nervous system. These tumours are benign,
NF1 gene is found on chromosome
17
NF1 codes for
neurofibromin, which is a tumour suppressor protein
NF1 inheritance is through
autosomal dominant
criteria for NF1
C – Café-au-lait spots (6 or more) measuring ≥ 5mm in children or ≥ 15mm in adults
R – Relative with NF1
A – Axillary or inguinal freckles
BB – Bony dysplasia such as Bowing of a long bone or sphenoid wing dysplasia
I – Iris hamartomas (Lisch nodules) (2 or more) are yellow brown spots on the iris
N – Neurofibromas (2 or more) or 1 plexiform neurofibroma
G – Glioma of the optic nerve
Dx of NF1
genetic testing, x-rays, CT/MRI
complications of NF1
Migraines
Epilepsy
Renal artery stenosis causing hypertension
Malignant peripheral nerve sheath tumours
Gastrointestinal stromal tumour
leukaemia
NF2 is found on chromosome
22
NF2 codes for
merlin protein, a tumour suppressor
NF2 inheritance is
autosomal dominant
NF2 leads particularly too
schwannoma
Bilateral acoustic neuromas almost certainly indicate
neurofibromatosis type 2.
tuberous sclerosis characteristically leads to the development of
hamartomas
tuberous sclerosis is caused by mutations in on of two genes
TSC1 gene on chromosome 9, which codes for hamartin
TSC2 gene on chromosome 16, which codes for tuberin
how does hamartin and tuberin interact
to control the size and growth of cells.
skin signs of tuberous sclerosis
ash leaf spots, shagreen patches, angiofibromas, subungual fibromata, cafe au lait spots and poliosis
Ash leaf spots are
depigmented areas of skin shaped like an ash leaf
Shagreen patches are
thickened, dimpled, pigmented patches of skin
Angiofibromas
small skin coloured or pigmented papules that occur over the nose and cheeks
Subungual fibromata are fibromas growing from
the nail bed. They are usually circular painless lumps that grow slowly and displace the nail
Cafe-au-lait spots are
light brown “coffee and milk” coloured flat pigmented lesions on the skin
Poliosis is an
isolated patch of white hair on the head, eyebrows, eyelashes or beard
neuro features of tuberous sclerosis
Epilepsy
Learning disability and developmental delay
other features of tuberous sclerosis is
Rhabdomyomas in the heart
Gliomas (tumours of the brain and spinal cord)
Polycystic kidneys
Lymphangioleimyomatosis (abnormal growth in smooth muscle cells, often affecting the lungs)
Retinal hamartomas
Trigeminal Neuralgia presents with
intense facial pain that comes on spontaneously and last anywhere between a few seconds to hours. It is often described as an electricity-like shooting pain. Attacks often worsen over time.
Tx for trigeminal neuralgia is with
carbamazepine, followed by surgery to decompress if unsuccessful
typical migraine features
Moderate to severe intensity Pounding or throbbing in nature Usually unilateral but can be bilateral Discomfort with lights (photophobia) Discomfort with loud noises (phonophobia) With or without aura Nausea and vomiting
aura in migraine refers too
Sparks in vision
Blurring vision
Lines across vision
Loss of different visual fields
Hemiplegic migraines can mimic
stroke
features of hemiplegic stroke
Typical migraine symptoms Sudden or gradual onset Hemiplegia (unilateral weakness of the limbs) Ataxia Changes in consciousness
5 stages of migraine include
Premonitory or prodromal stage (can begin 3 days before the headache)
Aura (lasting up to 60 minutes)
Headache stage (lasts 4-72 hours)
Resolution stage (the headache can fade away or be relieved completely by vomiting or sleeping)
Postdromal or recovery phase
acute management of a migraine is with
Paracetamol
Triptans (e.g. sumatriptan 50mg as the migraine starts)
NSAIDs (e.g ibuprofen or naproxen)
Antiemetics if vomiting occurs (e.g. metoclopramide)
triptan mechanism is
5HT receptors agonists (serotonin receptor agonists).
migraine prophylaxis is with
Propranolol
Topiramate (this is teratogenic and can cause a cleft lip/palate so patients should not get pregnant)
Amitriptyline
symptoms of a cluster headache is
Symptoms are typically all unilateral:
Red, swollen and watering eye Pupil constriction (miosis) Eyelid drooping (ptosis) Nasal discharge Facial sweating
acute management of a cluster headache is with
Triptans (e.g. sumatriptan 6mg injected subcutaneously)
High flow 100% oxygen for 15-20 minutes (can be given at home)
prophylaxis with cluster headaches is with
Verapamil
Lithium
Prednisolone (a short course for 2-3 weeks to break the cycle during clusters)
30-50 year old male smoker. Attacks can be triggered by things like alcohol, strong smells and exercise. suffer 3 – 4 attacks a day for weeks or months followed by a pain free period lasting 1-2 years. Attacks last between 15 minutes and 3 hours. what is the diagnosis?
cluster headache
