Neurology Flashcards
What is the glasgow coma scale?
When there are different motor responses on each side, the best motor response is used for scoring.
What is status elipticus?
Status epilepticus is a medical emergency that refers to a prolonged seizure or a series of seizures without full recovery of consciousness between them. Specifically, it is defined as:
A seizure lasting more than 5 minutes.
Two or more seizures occurring without the person regaining full consciousness between them.
What is the management of status elipticus?
ABC
airway adjunct
oxygen
check blood glucose
First-line drugs are benzodiazepines
in the prehospital setting PR diazepam or buccal midazolam may be given
in hospital IV lorazepam is generally used. This may be repeated once after 5-10minutes
If ongoing (or ‘established’) status it is appropriate to start a second-line agent such as levetiracetam, phenytoin or sodium valproate
NICE state ‘Take into account that levetiracetam may be quicker to administer and have fewer adverse effects than the alternative options.’
If no response (‘refractory status’) within 45 minutes from onset, then the best way to achieve rapid control of seizure activity is induction of general anaesthesia or phenobarbital
What are the complications of meningitis?
Neurological sequalae
sensorineural hearing loss (most common)
seizures
focal neurological deficit
infective
sepsis
intracerebral abscess
pressure
brain herniation
hydrocephalus
Patients with meningococcal meningitis are at risk of Waterhouse-Friderichsen syndrome (adrenal insufficiency secondary to adrenal haemorrhage).
What is the most common complication of meningitis?
Sensorineural hearing loss
What lumbar puncture results suggest meningitis?
High white cell count, high protein and low glucose which are the typical findings of bacterial meningitis.
There is also the high opening pressure and the cloudy CSF which suggest infection.
What is hoffmans sign?
Hoffmann’s sign is a pathological reflex where the thumb and index finger of the patient involuntarily flex when the examiner gently flicks or taps the nail of the middle finger (or sometimes the thumb) in a downward direction. indicate the presence of upper motor neuron dysfunction
What is Degenerative cervical myelopathy?
Degenerative cervical myelopathy (DCM) is a progressive neurological condition caused by spinal cord compression in the cervical spine (the neck region) due to degenerative changes in the spine.
What are the symptoms of DCM?
DCM symptoms can include any combination of [1]:
Pain (affecting the neck, upper or lower limbs)
Loss of motor function (loss of digital dexterity, preventing simple tasks such as holding a fork or doing up their shirt buttons, arm or leg weakness/stiffness leading to impaired gait and imbalance
Loss of sensory function causing numbness
Loss of autonomic function (urinary or faecal incontinence and/or impotence) - these can occur and do not necessarily suggest cauda equina syndrome in the absence of other hallmarks of that condition
Hoffman’s sign: is a reflex test to assess for cervical myelopathy. It is performed by gently flicking one finger on a patient’s hand. A positive test results in reflex twitching of the other fingers on the same hand in response to the flick.
Kernigs sign?
Kernigs sign refers to painful knee extension, from a position of hip flexion and knee flexion. It suggest meningeal irritation e.g. meningitis, subarachnoid haemorrhage.
Straight leg raise: this is positively associated with radicular pathology such as disc herniation. The patient feels pain in the back when the leg is raised between 30-60 degrees.
The ankle brachial pressure index [ABPI] is a simple method of assessing the peripheral circulation. It is calculated by dividing systolic blood pressure in the ankle by the the systolic blood pressure in the arm. These are equal in health (ABPI = 1). The ABPI is reduced in peripheral vascular disease.
Tinels test includes tapping over the volar surface of the wrist joint i.e. over the carpal tunnel. This can reproduce paraesthesias in patients with carpal tunnel syndrome.
Limited external rotation of the shoulder 73%
This patient is likely to have adhesive capsulitis. Patients have global restriction of shoulder movements, in at least two axes, though external rotation is classically described as the most affected and painful.
Features of Brown sequard syndrome
Unilateral spastic paresis and loss of proprioception/vibration sensation with loss of pain and temperature sensation on the opposite side
Tracts affected
1. Lateral corticospinal tract
2. Dorsal columns
3. Lateral spinothalamic tract
- Ipsilateral spastic paresis below lesion
- Ipsilateral loss of proprioception and vibration sensation
- Contralateral loss of pain and temperature sensation
How does idiopathic intercrainal hypertension present?
The patient presents with a chronic headache that worsens in the morning and upon coughing or straining, which suggests elevated intracranial pressure. A CT scan of the head rules out a mass lesion. Clinical examination confirms papilloedema. Given her multiple risk factors for idiopathic intracranial hypertension’including contraceptive pill use, age, gender, and weight’this is the most likely diagnosis.
Features
headache
blurred vision
papilloedema (usually present)
enlarged blind spot
sixth nerve palsy may be present
What are the risk factors for Idiopathic intercranial hypertension?
Risk factors
obesity
female sex
pregnancy
drugs
combined oral contraceptive pill
steroids
tetracyclines
retinoids (isotretinoin, tretinoin) / vitamin A
lithium
What is the management of Idiopathic intercranial hypertension?
Management
weight loss
whilst diet and exercise are important, medications such as semaglitide and topiramate may be considered by specialists. Topiramate is particularly beneficial as it also inhibits carbonic anhydrase
carbonic anhydrase inhibitors e.g. acetazolamide
topiramate is also used, and has the added benefit of causing weight loss in most patients
repeated lumbar puncture may be used as a temporary measure but is not suitable for longer-term management
surgery: optic nerve sheath decompression and fenestration may be needed to prevent damage to the optic nerve. A lumboperitoneal or ventriculoperitoneal shunt may also be performed to reduce intracranial pressure
What is normal pressure hydrocephalus?
Normal pressure hydrocephalus is a reversible cause of dementia seen in elderly patients. It is thought to be secondary to reduced CSF absorption at the arachnoid villi. These changes may be secondary to head injury, subarachnoid haemorrhage or meningitis.
What is the classical triad seen in normal pressure hydrocephalus?
A classical triad of features is seen
urinary incontinence
dementia and bradyphrenia
gait abnormality (may be similar to Parkinson’s disease)
It is thought around 60% of patients will have all 3 features at the time of diagnosis. Symptoms typically develop over a few months.
What is seen in imaging of normal pressure hydrocephalus?
hydrocephalus with ventriculomegaly in the absence of, or out of proportion to, sulcal enlargement
What is the management of normal pressure hydrocephalus?
Management
ventriculoperitoneal shunting
around 10% of patients who have shunts experience significant complications such as seizures, infection and intracerebral haemorrhages
What is Spastic paraparesis?
Spastic paraparesis describes a upper motor neuron pattern of weakness in the lower limbs
What are the causes of Spastic paraparesis?
Causes
demyelination e.g. multiple sclerosis
cord compression: trauma, tumour
parasagittal meningioma
tropical spastic paraparesis
transverse myelitis e.g. HIV
syringomyelia
hereditary spastic paraplegia
osteoarthritis of the cervical spine
What is amaurosis fugax?
amaurosis fugax means ‘transient darkening’ and it is used by doctors to describe a temporary loss of vision through one eye, which returns to normal afterwards. This is usually due to a temporary disturbance of the blood flow to the back of the eye.
What are the feautures of Internuclear ophthalmoplegia?
impaired adduction of the eye on the same side as the lesion
horizontal nystagmus of the abducting eye on the contralateral side
What is typically spared in motor neuron disease?
Motor neurone disease (MND), also known as amyotrophic lateral sclerosis (ALS), occurs when motor neurons in the brain and spinal cord degenerate. This typically leads to progressive weakness of limb, respiratory, and bulbar musculature.
The extraocular muscles are seemingly preserved in most MND patients, even until the terminal stage. Notably, eye movements and blinking are usually the last modes of communication available to terminal MND patients. The eye muscles appear to be better equipped to maintain their muscle-nerve contacts and are thereby less affected.
What are the clues which point towards a diagnosis of motor neuron disease?
asymmetric limb weakness is the most common presentation of ALS
the mixture of lower motor neuron and upper motor neuron signs
wasting of the small hand muscles/tibialis anterior is common
fasciculations
the absence of sensory signs/symptoms
vague sensory symptoms may occur early in the disease (e.g. limb pain) but ‘never’ sensory signs
Other features
doesn’t affect external ocular muscles
no cerebellar signs
abdominal reflexes are usually preserved and sphincter dysfunction if present is a late feature
What is motor neuron disease?
Motor neuron disease is a neurological condition of unknown cause which can present with both upper and lower motor neuron signs. It rarely presents before 40 years and various patterns of disease are recognised including amyotrophic lateral sclerosis (ALS), progressive muscular atrophy and bulbar palsy.
What is the presentation of a basilar artery infarct?
This patient is presenting with locked-in syndrome which can occur in a basilar artery infarct. This blood vessel supplies the cerebellum, thalamus, occipital lobe, and brainstem. These strokes are rare and often devastating. There are 3 main presentations of patients experiencing a basilar artery infarct:
An acute decreased GCS and advanced motor symptoms.
Insidious, gradual deterioration in GCS and motor symptoms with a subsequent sudden advanced decrease in GCS and motor symptoms.
A ‘herald hemiparesis’ with associated headache and vision changes prior to the onset of permanent symptoms of motor loss.
Draw the circle of willis
What does Anterior cerebral artery infarct cause?
Contralateral hemiparesis and sensory loss, lower extremity > upper
What does middle cerebral artery infarct cause?
Contralateral hemiparesis and sensory loss, upper extremity > lower
Contralateral homonymous hemianopia
Aphasia
What does Posterior cerebral artery infarct cause?
Contralateral homonymous hemianopia with macular sparing
Visual agnosia
What does Weber’s syndrome (branches of the posterior cerebral artery that supply the midbrain) cause?
Ipsilateral CN III palsy
Contralateral weakness of upper and lower extremity
What does Posterior inferior cerebellar artery (lateral medullary syndrome, Wallenberg syndrome) infarct cause?
Ipsilateral: facial pain and temperature loss
Contralateral: limb/torso pain and temperature loss
Ataxia, nystagmus
What does Anterior inferior cerebellar artery (lateral pontine syndrome) infarct cause?
Symptoms are similar to Wallenberg’s (see above), but:
Ipsilateral: facial paralysis and deafness
What does Retinal/ophthalmic artery infarct cause?
Amaurosis fugax
How do lacunar strokes present?
present with either isolated hemiparesis, hemisensory loss or hemiparesis with limb ataxia
strong association with hypertension
common sites include the basal ganglia, thalamus and internal capsule
What is Mononeuritis multiplex?
Mononeuritis multiplex is simultaneous or sequential involvement of individual non-contiguous nerve trunks. It typically presents with acute or subacute loss of sensory and motor function of individual nerves. The pattern of involvement is asymmetric, however, as the disease progresses, deficit(s) becomes more confluent and symmetrical, making it difficult to differentiate from polyneuropathy.
What lesion is Homonymous hemianopia
incongruous defects
lesion of optic tract
What lesion is Homonymous hemianopia congruous defects:
lesion of optic radiation or occipital cortex
What lesion is Homonymous macula sparing:
lesion of occipital cortex
Homonymous quadrantanopias*
superior
lesion of the inferior optic radiations in the temporal lobe (Meyer’s loop)
mnemonic = PITS (Parietal-Inferior, Temporal-Superior)
Right Superior QuadrantanopiaLesion Left Temporal Lobe - CVA
Homonymous quadrantanopias inferior
inferior: lesion of the superior optic radiations in the parietal lobe
mnemonic = PITS (Parietal-Inferior, Temporal-Superior)
Bitemporal hemianopia
lesion of optic chiasm
Bitemporal hemianopia
lesion of optic chiasm
upper quadrant defect > lower quadrant defect =
inferior chiasmal compression, commonly a pituitary tumour
Bitemporal hemianopia
lesion of optic chiasm
lower quadrant defect > upper quadrant defect =
superior chiasmal compression, commonly a craniopharyngioma
What is Wernicke’s encephalopathy ?
Wernicke’s encephalopathy is a neuropsychiatric disorder caused by thiamine deficiency which is most commonly seen in alcoholics.
What are the rarer causes of Wernicke’s encephalopathy?
Rarer causes include persistent vomiting, aոοrеxiа nervosa, stomach cancer, and dietary deficiency.
What is the classic triad seen in Wernicke’s encephalopathy?
A classic triad of ophthalmoplegia/nystagmus, ataxia and encephalopathy may occur.
Confusion, ataxia, nystagmus/ophthalmoplegia
What is the treatment of Wernicke’s encephalopathy?
Treatment is with urgent replacement of thiamine
give Pabrinex (IV B/C vitamins)
If Wernickes encephalopathy is not treated what may develop?
Korsakoff’s syndrome
What are the features of Korsakoff’s syndrome ?
This is termed Wernicke-Korsakoff syndrome and is characterised by the addition of antero- and retrograde amnesia and confabulation in addition to the above symptoms.
What are the features of Wernickes encephalopathy?
oculomotor dysfunction
nystagmus (the most common ocular sign)
ophthalmoplegia: lateral rectus palsy, conjugate gaze palsy
gait ataxia
encephalopathy: confusion, disorientation, indifference, and inattentiveness
peripheral sensory neuropathy
What are the investigations for wernickes encephalopathy?
decreased red cell transketolase
MRI
What is the acute management for seizures?
check the airway and apply oxygen if appropriate
place the patient in the recovery position
if the seizure is prolonged give benzodiazepines
BNF recommend dose for rectal diazepam, repeated once after 10-15 minutes if necessary
Neonate 1.25 - 2.5 mg
Child 1 month - 1 year 5 mg
Child 2 years - 11 years 5 - 10 mg
Child 12 years - 17 years 10 mg
Adult 10 - 20 mg (max. 30 mg)
Elderly 10 mg (max. 15 mg)
Midazolam oromucosal solution may also be used:
Neonate 300 mcg/kg (unlicensced)
Child 1 - 2 months 300 mcg/kg (max. 2.5mg, unlicensced)
Child 3 - 11 months 2.5 mg
Child 1 - 4 years 5 mg
Child 5 - 9 years 7.5 mg
Child 10 - 17 years 10 mg
Adult 10 mg (unlicensced)
Features of third nerve palsy?
eye is deviated ‘down and out’
ptosis
pupil may be dilated (sometimes called a ‘surgical’ third nerve palsy)
What are the causes of third nerve palsy?
Causes
diabetes mellitus
vasculitis e.g. temporal arteritis, SLE
false localizing sign* due to uncal herniation through tentorium if raised ICP
posterior communicating artery aneurysm
pupil dilated
often associated pain
cavernous sinus thrombosis
Weber’s syndrome: ipsilateral third nerve palsy with contralateral hemiplegia -caused by midbrain strokes
other possible causes: amyloid, multiple sclerosis
*this term is usually associated with sixth nerve palsies but it may be used for a variety of neurological presentations
Should Anti parkinson drugs be stopped on acute admission?
Levodopa and other antiparkinsons drugs are ‘critical’ medicines which should not be stopped on acute admissions and must be delivered on time
Acute withdrawal of levodopa can precipitate to..
neuroleptic malignant syndrome
Painful third nerve palsy =
posterior communicating artery aneurysm
What is the first line treatment for parkinsons?
if the motor symptoms are affecting the patient’s quality of life: levodopa
if the motor symptoms are not affecting the patient’s quality of life: dopamine agonist (non-ergot derived), levodopa or monoamine oxidase B (MAO-B) inhibitor
What is the mechanism of action of Levadopa and what is it taken with?
Levodopa by various routes crosses the blood brain barrier, is decarboxylated to form dopamine
nearly always combined with a decarboxylase inhibitor (e.g. carbidopa or benserazide)
this prevents the peripheral metabolism of levodopa to dopamine outside of the brain and hence can reduce side effects
What are the side effects of Levadopa?
common adverse effects:
dry mouth
anorexia
palpitations
postural hypotension
psychosis
some adverse effects are due to the difficulty in achieving a steady dose of levodopa
end-of-dose wearing off: symptoms often worsen towards the end of dosage interval. This results in a decline of motor activity
‘on-off’ phenomenon: large variations in motor performance, with normal function during the ‘on’ period, and weakness and restricted mobility during the ‘off’ period
dyskinesias at peak dose: dystonia, chorea and athetosis (involuntary writhing movements)
these effects may worsen over time with - clinicians therefore may limit doses until necessary
it is important not to acutely stop levodopa, for example, if a patient is admitted to hospital
if a patient with Parkinson’s disease cannot take levodopa orally, they can be given a dopamine agonist patch as rescue medication to prevent acute dystonia
What are the Dopamine receptor agonists?
Bromocriptine, cabergoline and pergolide (ergots) are orally active drugs that work on D1 and D2 receptors. They have limiting side effects – fibrotic reactions.
* Pramipexole and ropinirole are D2/3 selective receptor agonists that are better tolerated. Short half-life in plasma (6-8hrs) could be a problem
* Rotigotine newer agent delivered by a transdermal patch
* Apomorphine given by injection sometimes given to control the ‘off-effect’ of levodopa
What are the side effects of Dopamine receptor agonists?
ergot-derived dopamine receptor agonists (bromocriptine, cabergoline) have been associated with pulmonary, retroperitoneal and cardiac fibrosis. The Committee on Safety of Medicines advice that an echocardiogram, ESR, creatinine and chest x-ray should be obtained prior to treatment and patients should be closely monitored
patients should be warned about the potential for dopamine receptor agonists to cause impulse control disorders and excessive daytime somnolence
more likely than levodopa to cause hallucinations in older patients. Nasal congestion and postural hypotension are also seen in some patients
What are the MAO-B (Monoamine Oxidase-B) inhibitors and their mechanism of action?
e.g. selegiline, Rasagiline
inhibits the breakdown of dopamine secreted by the dopaminergic neurons
Combination with levodopa is more effective in relieving symptoms and prolonging life.
What is the mechanism of action of amantadine?
Antiviral drug discovered to be beneficial (1969) in PD.
* Increased dopamine release or direct action on dopamine receptors is
primarily responsible for its therapeutic effect.
* Less effective than levodopa or bromocriptine and action declines with time.
What are the side effects of amantadine?
side-effects include ataxia, slurred speech, confusion, dizziness and livedo reticularis
What are the features of Wernicke’s (receptive) aphasia?
Due to a lesion of the superior temporal gyrus. It is typically supplied by the inferior division of the left MCA
This area ‘forms’ the speech before ‘sending it’ to Broca’s area. Lesions result in sentences that make no sense, word substitution and neologisms but speech remains fluent - ‘word salad’
Comprehension is impaired
What are the features of Broca’s (expressive) aphasia?
Due to a lesion of the inferior frontal gyrus. It is typically supplied by the superior division of the left MCA
Speech is non-fluent, laboured, and halting. Repetition is impaired
Comprehension is normal
What are the features of Conduction aphasia?
Classically due to a stroke affecting the arcuate fasiculus - the connection between Wernicke’s and Broca’s area
Speech is fluent but repetition is poor. Aware of the errors they are making
Comprehension is normal
