Neurology

Question 1

Acoustic Neuroma

Vestibular schwannoma ()

Answer 1

account for approximately 5% of intracranial tumours and 90% of cerebellopontine angle tumours.

The classical history of vestibular schwannoma includes a combination of vertigo, hearing loss, tinnitus and an absent corneal reflex. Features can be predicted by the affected cranial nerves:

cranial nerve VIII: vertigo, unilateral sensorineural hearing loss, unilateral tinnitus

cranial nerve V: absent corneal reflex

cranial nerve VII: facial palsy

Bilateral vestibular schwannomas are seen in neurofibromatosis type 2.

Patients with a suspected vestibular schwannoma should be referred urgently to ENT. It should be noted though that the tumours are often slow growing, benign and often observed initially.

MRI of the cerebellopontine angle is the investigation of choice. Audiometry is also important as only 5% of patients will have a normal audiogram.

Management is with either surgery, radiotherapy or observation.

Loss of corneal reflex - think acoustic neuroma

Acoustic neuroma is an important differential diagnosis in patients with unilateral deafness or tinnitus

Important for meLess important

Acoustic neuroma is the correct answer and should always be considered in patients with unilateral sensorineural deafness or tinnitus. Patients may also develop facial palsy. Acoustic neuroma is a slow-growing neurofibroma and requires urgent referral to ENT for surgery.

Presbyacusis and otosclerosis are both causes of deafness but symptoms are bilateral. Additionally, otosclerosis causes a conductive, not a sensorineural deafness.

The normal ear examination and Rinne’s/Weber’s tests suggesting a sensorineural deafness exclude otitis media.

Meniere’s disease would normally present with attacks of vertigo, tinnitus, sensorineural deafness and fullness of the ear.

Question 2

Bell’s palsy

Answer 2

Bell’s palsy may be defined as an acute, unilateral, idiopathic, facial nerve paralysis. The aetiology is unknown although the role of the herpes simplex virus has been investigated previously. The peak incidence is 20-40 years and the condition is more common in pregnant women.

Features

lower motor neuron facial nerve palsy - forehead affected*

patients may also notice post-auricular pain (may precede paralysis), altered taste, dry eyes, hyperacusis

Management

in the past a variety of treatment options have been proposed including no treatment, prednisolone only and a combination of aciclovir and prednisolone

following a National Institute for Health randomised controlled trial it is now recommended that prednisolone 1mg/kg for 10 days should be prescribed for patients within 72 hours of onset of Bell’s palsy. Adding in aciclovir gives no additional benefit

eye care is important - prescription of artificial tears and eye lubricants should be considered

Prognosis

if untreated around 15% of patients have permanent moderate to severe weakness

*upper motor neuron lesion ‘spares’ upper face

Question 3

Brain lesions

Location

Answer 3

Parietal lobe lesions

sensory inattention

apraxias

astereognosis (tactile agnosia)

inferior homonymous quadrantanopia

Gerstmann’s syndrome (lesion of dominant parietal): alexia, acalculia, finger agnosia and right-left disorientation

Occipital lobe lesions

homonymous hemianopia (with macula sparing)

cortical blindness

visual agnosia

Temporal lobe lesion

Wernicke’s aphasia: this area ‘forms’ the speech before ‘sending it’ to Brocas area. Lesions result in word substituion, neologisms but speech remains fluent

superior homonymous quadrantanopia

auditory agnosia

prosopagnosia (difficulty recognising faces)

Frontal lobes lesions

expressive (Broca’s) aphasia: located on the posterior aspect of the frontal lobe, in the inferior frontal gyrus. Speech is non-fluent, laboured, and halting

disinhibition

perseveration

anosmia

inability to generate a list

Cerebellum lesions

midline lesions: gait and truncal ataxia

hemisphere lesions: intention tremor, past pointing, dysdiadokinesis, nystagmus

More specific areas

Area

Associated conditions

Medial thalamus and mammillary bodies of the hypothalamus

Wernicke and Korsakoff syndrome

Subthalamic nucleus of the basal ganglia

Hemiballism

Striatum (caudate nucleus) of the basal ganglia

Huntington chorea

Substantia nigra of the basal ganglia

Parkinson’s disease

Amygdala

Kluver-Bucy syndrome (hypersexuality, hyperorality, hyperphagia, visual agnosia

Question 4

Common peroneal nerve lesion

Answer 4

The sciatic nerve divides into the tibial and common peroneal nerves. Injury often occurs at the neck of the fibula

The most characteristic feature of a common peroneal nerve lesion is foot drop.

Other features include:

weakness of foot dorsiflexion

weakness of foot eversion

weakness of extensor hallucis longus

sensory loss over the dorsum of the foot and the lower lateral part of the leg

wasting of the anterior tibial and peroneal muscles

The common peroneal nerve supplies the muscles of the peroneal and anterior compartment of the leg and sensation to the dorsum of the foot.

It travels through the popliteal fossa, wrapping around the head of the fibula (where it is sometimes palpable).

Habitual leg crossing, prolonged bed rest, hyperflexion of the knee, pressure in obstetric stirrups and conditioning in ballet dancers are typical ‘textbook’ examples of scenarios where peroneal neuropathy can occur as a result of nerve compression against the head of the fibular. Transient trauma at this site (as in this scenario) can cause a temporary neurapraxia, whereas prolonged or more severe trauma can result in permanent foot drop.

Question 5

Brain abscess

Answer 5

Basics
- CNS abscesses may result from a number of causes including, extension of sepsis from middle ear or sinuses, trauma or surgery to the scalp, penetrating head injuries and embolic events from endocarditis

The presenting symptoms will depend upon the site of the abscess (those in critical areas e.g.motor cortex) will present earlier. Abscesses have a considerable mass effect in the brain and raised intra cranial pressure is common.

Although fever, headache and focal neurology are highly suggestive of a brain abscess the absence of one or more of these does not exclude the diagnosis, fever may be absent and even if present, is usually not the swinging pyrexia seen with abscesses at other sites.

Assessment of the patient includes imaging with CT scanning.

Treatment is usually surgical, a craniotomy is performed and the abscess cavity debrided. The abscess may reform because the head is closed following abscess drainage.

Question 6

Cranial Nerve Lesions

Answer 6

Functions

I (Olfactory)

Smell

II (Optic)

Sight

III (Oculomotor)

Eye movement (MR, IO, SR, IR)
Pupil constriction
Accomodation
Eyelid opening

IV (Trochlear)

Eye movement (SO)

V (Trigeminal)

Facial sensation
Mastication

VI (Abducens)

Eye movement (LR)

VII (Facial)

Facial movement
Taste (anterior 2/3rds of tongue)
Lacrimation
Salivation

VIII (Vestibulocochlear)

Hearing, balance

IX (Glossopharyngeal)

Taste (posterior 1/3rd of tongue)
Salivation
Swallowing
Mediates input from carotid body & sinus

X (Vagus)

Phonation
Swallowing
Innervates viscera

XI (Accessory)

Head and shoulder movement

XII (Hypoglossal)

Tongue movement

Question 7

Degenerative cervical myelopathy

Answer 7

Degenerative cervical myelopathy (DCM) has a number of risk factors, which include smoking due to its effects on the intervertebral discs, genetics and occupation - those exposing patients to high axial loading [1].

The presentation of DCM is very variable. Early symptoms are often subtle and can vary in severity day to day, making the disease difficult to detect initially. However as a progressive condition, worsening, deteriorating or new symptoms should be a warning sign.

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.

The most common symptoms at presentation of DCM are unknown, but in one series 50% of patients were initially incorrectly diagnosed and sometimes treated for carpal tunnel syndrome [2].

An MRI of the cervical spine is the gold standard test where cervical myelopathy is suspected. It may reveal disc degeneration and ligament hypertrophy, with accompanying cord signal change.

All patients with degenerative cervical myelopathy should be urgently referred for assessment by specialist spinal services (neurosurgery or orthopaedic spinal surgery). This is due to the importance of early treatment. The timing of surgery is important, as any existing spinal cord damage can be permanent. Early treatment (within 6 months of diagnosis) offers the best chance of a full recovery but at present, most patients are presenting too late. In one study, patients averaged over 5 appointments before diagnosis, representing >2 years.

Currently, decompressive surgery is the only effective treatment. It has been shown to prevent disease progression. Close observation is an option for mild stable disease, but anything progressive or more severe requires surgery to prevent further deterioration. Physiotherapy should only be initiated by specialist services, as manipulation can cause more spinal cord damage.

Question 8

Dementia Perception Syndromes

Answer 8

Capgras syndrome: the delusion that a friend or partner has been replaced by an identical-looking impostor.

Othello syndrome is the irrational belief that one’s partner is having an affair with no objective evidence.

De clerambault syndrome is the delusional idea that a person whom they consider to be of higher social and/or professional standing is in love with her.

Cotard syndrome is the delusional idea that one is dead.

Fregoli syndrome is the delusional idea that the various people that the patient meets are in fact the same person.

Question 9

Dermatomes

Answer 9

Nerve root

Landmark

C2

Posterior half of the skull (cap)

C3

High turtleneck shirt

C4

Low-collar shirt

C5

Ventral axial line of upper limb

C6

Thumb + index finger

C7

Middle finger + palm of hand

C8

Ring + little finger

T4

Nipples

T5

Inframammary fold

T6

Xiphoid process

T10

Umbilicus

L1

Inguinal ligament

L4

Knee caps

L5

Big toe, dorsum of foot (except lateral aspect)

S1

Lateral foot, small toe

S2, S3

Genitalia

Question 10

DVLA neurological disorders

Answer 10

The guidelines below relate to car/motorcycle use unless specifically stated. For obvious reasons, the rules relating to drivers of heavy goods vehicles tend to be much stricter

Epilepsy/seizures - all patient must not drive and must inform the DVLA

first unprovoked/isolated seizure: 6 months off if there are no relevant structural abnormalities on brain imaging and no definite epileptiform activity on EEG. If these conditions are not met then this is increased to 12 months

for patients with established epilepsy or those with multiple unprovoked seizures:

→ may qualify for a driving licence if they have been free from any seizure for 12 months

→ if there have been no seizures for 5 years (with medication if necessary) a ’til 70 licence is usually restored

withdrawawl of epilepsy medication: should not drive whilst anti-epilepsy medication is being withdrawn and for 6 months after the last dose
Syncope

simple faint: no restriction

single episode, explained and treated: 4 weeks off

single episode, unexplained: 6 months off

two or more episodes: 12 months off

Other conditions

stroke or TIA: 1 month off driving, may not need to inform DVLA if no residual neurological deficit

multiple TIAs over short period of times: 3 months off driving and inform DVLA

craniotomy e.g. For meningioma: 1 year off driving*

pituitary tumour: craniotomy: 6 months; trans-sphenoidal surgery ‘can drive when there is no debarring residual impairment likely to affect safe driving’

narcolepsy/cataplexy: cease driving on diagnosis, can restart once ‘satisfactory control of symptoms’

chronic neurological disorders e.g. multiple sclerosis, motor neuron disease: DVLA should be informed, complete PK1 form (application for driving licence holders state of health)

*if the tumour is a benign meningioma and there is no seizure history, licence can be reconsidered 6 months after surgery if remains seizure free

Question 11

Dystrophinopathies

Answer 11

Overview X-linked recessive

due to mutation in the gene encoding dystrophin, dystrophin gene on Xp21

dystrophin is part of a large membrane associated protein in muscle which connects the muscle membrane to actin, part of the muscle cytoskeleton

in Duchenne muscular dystrophy there is a frameshift mutation resulting in one or both of the binding sites are lost leading to a severe form

in Becker muscular dystrophy there is a non-frameshift insertion in the dystrophin gene resulting in both binding sites being preserved leading to a milder form

Duchenne muscular dystrophy

progressive proximal muscle weakness from 5 years

calf pseudohypertrophy

Gower’s sign: child uses arms to stand up from a squatted position

30% of patients have intellectual impairment

Becker muscular dystrophy

develops after the age of 10 years

intellectual impairment much less common

Overview

X-linked recessive

due to mutation in the gene encoding dystrophin, dystrophin gene on Xp21

dystrophin is part of a large membrane associated protein in muscle which connects the muscle membrane to actin, part of the muscle cytoskeleton

in Duchenne muscular dystrophy there is a frameshift mutation resulting in one or both of the binding sites are lost leading to a severe form

in Becker muscular dystrophy there is a non-frameshift insertion in the dystrophin gene resulting in both binding sites being preserved leading to a milder form

Duchenne muscular dystrophy

progressive proximal muscle weakness from 5 years

calf pseudohypertrophy

Gower’s sign: child uses arms to stand up from a squatted position

30% of patients have intellectual impairment

Becker muscular dystrophy

develops after the age of 10 years

intellectual impairment much less common

Question 12

Epilepsy classification

Answer 12

The basic classification of epilepsy has changed in recent years. The new basic seizure classification is based on 3 key features:

1. Where seizures begin in the brain
2. Level of awareness during a seizure (important as can affect safety during seizure)
3. Other features of seizures

Focal seizures

previously termed partial seizures

these start in a specific area, on one side of the brain

the level of awareness can vary in focal seizures. The terms focal aware (previously termed ‘simple partial’), focal impaired awareness (previously termed ‘complex partial’) and awareness unknown are used to further describe focal seizures

further to this, focal seizures can be classified as being motor (e.g. Jacksonian march), non-motor (e.g. déjà vu, jamais vu; ) or having other features such as aura

Generalised

these engage or involve networks on both sides of the brain at the onset

consciousness lost immediately. The level of awareness in the above classification is therefore not needed, as all patients lose consciousness

generalised seizures can be further subdivided into motor (e.g. tonic-clonic) and non-motor (e.g. absence)

specific types include:

→ tonic-clonic (grand mal)

→ tonic

→ clonic

→ typical absence (petit mal)

→ atonic

Unknown onset

this termed is reserved for when the origin of the seizure is unknown

Focal to bilateral seizure

starts on one side of the brain in a specific area before spreading to both lobes

previously termed secondary generalized seizures

Cataplexy

Cataplexy describes the sudden and transient loss of muscular tone caused by strong emotion (e.g. laughter, being frightened). Around two-thirds of patients with narcolepsy have cataplexy.

Features range from buckling knees to collapse.

Psychogenic non-epileptic seizures

Psychogenic nonepileptic seizures are sometimes referred to as pseudoseizures.
Factors favouring pseudoseizures

pelvic thrusting

family member with epilepsy

much more common in females

crying after seizure

don’t occur when alone

gradual onset

Factors favouring true epileptic seizures

tongue biting

raised serum prolactin*

Video telemetry is useful for differentiating

*why prolactin is raised following seizures is not fully understood. It is hypothesised that there is spread of electrical activity to the ventromedial hypothalamus, leading to release of a specific prolactin regulator into the hypophyseal portal system

Question 13

Epilepsy: treatment

Answer 13

Most neurologists now start antiepileptics following a second epileptic seizure. NICE guidelines suggest starting antiepileptics after the first seizure if any of the following are present:

the patient has a neurological deficit

brain imaging shows a structural abnormality

the EEG shows unequivocal epileptic activity

the patient or their family or carers consider the risk of having a further seizure unacceptable

Sodium valproate is considered the first line treatment for patients with generalised seizures with carbamazepine used for focal seizures.

Generalised tonic-clonic seizures

sodium valproate

second line: lamotrigine, carbamazepine

Absence seizures* (Petit mal)

sodium valproate or ethosuximide

sodium valproate particularly effective if co-existent tonic-clonic seizures in primary generalised epilepsy

Myoclonic seizures**

sodium valproate

second line: clonazepam, lamotrigine

Focal seizures

carbamazepine or lamotrigine

second line: levetiracetam, oxcarbazepine or sodium valproate

*carbamazepine may exacerbate absence seizures

**carbamazepine may exacerbate myoclonic seizures

Question 14

Seizures: acute management

Answer 14

Most seizures are self-limiting and stop spontaneously but prolonged seizures may be potentially life-threatening.

Basics

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:

Question 15

Essential tremor

Answer 15

Essential tremor (previously called benign essential tremor) is an autosomal dominant condition which usually affects both upper limbs

Features

postural tremor: worse if arms outstretched

improved by alcohol and rest

most common cause of titubation (head tremor)

Management

propranolol is first-line

primidone is sometimes used

Tremor

The table below lists the main characteristics of the most important causes of tremor

Conditions

Notes

Parkinsonism

Resting, ‘pill-rolling’ tremor
Bradykinesia
Rigidity
Flexed posture, short, shuffling steps
Micrographia
‘Mask-like’ face
Depression & dementia are common
May be history of anti-psychotic use

Essential tremor

Postural tremor: worse if arms outstretched
Improved by alcohol and rest
Titubation
Often strong family history

Anxiety

History of depression

Thyrotoxicosis

Usual thyroid signs e.g. Weight loss, tachycardia, feeling hot etc

Hepatic encephalopathy

History of chronic liver disease

Carbon dioxide retention

History of chronic obstructive pulmonary disease

Cerebellar disease

Intention tremor
Cerebellar signs e.g. Past-pointing, nystagmus etc

Other causes

drug withdrawal: alcohol, opiates

Tremor

The table below lists the main characteristics of the most important causes of tremor

Conditions

Notes

Parkinsonism

Resting, ‘pill-rolling’ tremor
Bradykinesia
Rigidity
Flexed posture, short, shuffling steps
Micrographia
‘Mask-like’ face
Depression & dementia are common
May be history of anti-psychotic use

Essential tremor

Postural tremor: worse if arms outstretched
Improved by alcohol and rest
Titubation
Often strong family history

Anxiety

History of depression

Thyrotoxicosis

Usual thyroid signs e.g. Weight loss, tachycardia, feeling hot etc

Hepatic encephalopathy

History of chronic liver disease

Carbon dioxide retention

History of chronic obstructive pulmonary disease

Cerebellar disease

Intention tremor
Cerebellar signs e.g. Past-pointing, nystagmus etc

Other causes

drug withdrawal: alcohol, opiates

Question 16

Facial nerve palsy

Answer 16

The facial nerve is the main nerve supplying the structures of the second embryonic branchial arch. It is predominantly an efferent nerve to the muscles of facial expression, digastric muscle and also to many glandular structures. It contains a few afferent fibres which originate in the cells of its genicular ganglion and are concerned with taste.

Supply - ‘face, ear, taste, tear’

face: muscles of facial expression
ear: nerve to stapedius
taste: supplies anterior two-thirds of tongue
tear: parasympathetic fibres to lacrimal glands, also salivary glands

Causes of bilateral facial nerve palsy

sarcoidosis

Guillain-Barre syndrome

Lyme disease

bilateral acoustic neuromas (as in neurofibromatosis type 2)

as Bell’s palsy is relatively common it accounts for up to 25% of cases f bilateral palsy, but this represents only 1% of total Bell’s palsy cases

Causes of unilateral facial nerve palsy - as above plus

Lower motor neuron

Bell’s palsy

Ramsay-Hunt syndrome (due to herpes zoster)

acoustic neuroma

parotid tumours

HIV

multiple sclerosis*

diabetes mellitus

Upper motor neuron

stroke

LMN vs. UMN

upper motor neuron lesion ‘spares’ upper face i.e. forehead

lower motor neuron lesion affects all facial muscles

*may also cause an UMN palsy

Path

Subarachnoid path

Origin: motor- pons, sensory- nervus intermedius

Pass through the petrous temporal bone into the internal auditory meatus with the vestibulocochlear nerve. Here they combine to become the facial nerve.

Facial canal path

The canal passes superior to the vestibule of the inner ear

At the medial aspect of the middle ear, it becomes wider and contains the geniculate ganglion.

• 3 branches:
  1. greater petrosal nerve
  2. nerve to stapedius
  3. chorda tympani

Stylomastoid foramen

Passes through the stylomastoid foramen (tympanic cavity anterior and mastoid antrum posteriorly)

Posterior auricular nerve and branch to posterior belly of digastric and stylohyoid muscle

Question 17

Glasgow Coma Scale: adults

Answer 17

Modality Options

Motor response

6. Obeys commands
7. Localises to pain
8. Withdraws from pain
9. Abnormal flexion to pain (decorticate posture)
10. Extending to pain
11. None

Verbal response

5. Orientated
6. Confused
7. Words
8. Sounds
9. None

Eye opening

4. Spontaneous
5. To speech
6. To pain
7. None

Question 18

Guillain-Barre Syndrome

Answer 18

Guillain-Barre syndrome describes an immune mediated demyelination of the peripheral nervous system often triggered by an infection (classically Campylobacter jejuni)

Pathogenesis

cross reaction of antibodies with gangliosides in the peripheral nervous system

correlation between anti-ganglioside antibody (e.g. anti-GM1) and clinical features has been demonstrated

anti-GM1 antibodies in 25% of patients

Miller Fisher syndrome

variant of Guillain-Barre syndrome

associated with ophthalmoplegia, areflexia and ataxia. The eye muscles are typically affected first

usually presents as a descending paralysis rather than ascending as seen in other forms of Guillain-Barre syndrome

anti-GQ1b antibodies are present in 90% of cases

Guillain-Barre syndrome is an immune-mediated demyelination of the peripheral nervous system which is often triggered by an infection. It presents with ascending motor neuropathy which is often rapidly advancing. Proximal muscles are more affected than distal muscles.

A transient ischaemic attack or stroke is usually of sudden onset and would typically cause unilateral symptoms which may include facial droop, arm weakness, slurred speech etc.

Raynaud’s disease typically affects the fingers and toes and causes numbness and pain, usually in response to cold weather or stress.

Question 19

Headache: red flags

Answer 19

Headache is one of the most common presenting complaints seen in clinical practice. The vast majority of these will be caused by common, benign conditions. There are however certain features in a history which should prompt further action. In the 2012 guidelines NICE suggest the following:

compromised immunity, caused, for example, by HIV or immunosuppressive drugs

age under 20 years and a history of malignancy

a history of malignancy known to metastasis to the brain

vomiting without other obvious cause

worsening headache with fever

sudden-onset headache reaching maximum intensity within 5 minutes - ‘thunderclap’

new-onset neurological deficit

new-onset cognitive dysfunction

change in personality

impaired level of consciousness

recent (typically within the past 3 months) head trauma

headache triggered by cough, valsalva (trying to breathe out with nose and mouth blocked), sneeze or exercise

orthostatic headache (headache that changes with posture)

symptoms suggestive of giant cell arteritis or acute narrow-angle glaucoma

a substantial change in the characteristics of their headache

A cluster headache results in intense pain around one eye which is often accompanied by lacrimation and redness of the eye. It usually lasts 15 mins - 2 hours. Treatments for this include triptans and oxygen.

The gentleman in this question has a tension-type headache which is not treated with oxygen. He should be asked more about how he could relieve some of his stressors and also consider using alternative analgesia. Migraines, post-coital headaches and temporal arteritis are not usually treated with oxygen.

Question 20

Cluster headache

Answer 20

Cluster headaches are known to be one of the most painful conditions that patients can have the misfortune to suffer. The name relates to the pattern of the headaches - they typically occur in clusters lasting several weeks, with the clusters themselves typically once a year.

Cluster headaches are more common in men (3:1) and smokers. Alcohol may trigger an attack and there also appears to be a relation to nocturnal sleep.

Features

pain typical occurs once or twice a day, each episode lasting 15 mins - 2 hours

clusters typically last 4-12 weeks

intense sharp, stabbing pain around one eye (recurrent attacks ‘always’ affect same side)

patient is restless and agitated during an attack

accompanied by redness, lacrimation, lid swelling

nasal stuffiness

miosis and ptosis in a minority

Management

acute: 100% oxygen (80% response rate within 15 minutes), subcutaneous triptan (75% response rate within 15 minutes)
prophylaxis: verapamil is the drug of choice. There is also some evidence to support a tapering dose of prednisolone

NICE recommend seeking specialist advice from a neurologist if a patient develops cluster headaches with respect to neuroimaging

Some neurologists use the term trigeminal autonomic cephalgia to group a number of conditions including cluster headache, paroxysmal hemicrania and short-lived unilateral neuralgiform headache with conjunctival injection and tearing (SUNCT). It is recommended such patients are referred for specialist assessment as specific treatment may be required, for example it is known paroxysmal hemicrania responds very well to indomethacin

Question 21

Huntington’s disease

Answer 21

Huntington’s disease is an inherited neurodegenerative condition. It is a progressive and incurable condition that typically results in death 20 years after the initial symptoms develop.

Genetics

autosomal dominant

trinucleotide repeat disorder: repeat expansion of CAG

as Huntington’s disease is a trinucleotide repeat disorder, the phenomenon of anticipation may be seen, where the disease is presents at an earlier age in successive generations

results in degeneration of cholinergic and GABAergic neurons in the striatum of the basal ganglia

defect in huntingtin gene on chromosome 4

Features typical develop after 35 years of age

chorea

personality changes (e.g. irritability, apathy, depression) and intellectual impairment

dystonia

saccadic eye movements

Question 22

Idiopathic intracranial hypertension

Answer 22

Idiopathic intracranial hypertension (also known as pseudotumour cerebri and formerly benign intracranial hypertension) is a condition classically seen in young, overweight females.

Risk factors

obesity

female sex

pregnancy

drugs*: oral contraceptive pill, steroids, tetracycline, vitamin A, lithium

Features

headache

blurred vision

papilloedema (usually present)

enlarged blind spot

sixth nerve palsy may be present

Management

weight loss

diuretics e.g. acetazolamide

topiramate is also used, and has the added benefit of causing weight loss in most patients

repeated lumbar puncture

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

*if intracranial hypertension is thought to occur secondary to a known causes (e.g. Medication) then it is of course not idiopathic

Question 23

Migraine management

Answer 23

It should be noted that as a general rule 5-HT receptor agonists are used in the acute treatment of migraine whilst 5-HT receptor antagonists are used in prophylaxis. NICE produced guidelines in 2012 on the management of headache, including migraines.

Acute treatment

first-line: offer combination therapy with an oral triptan and an NSAID, or an oral triptan and paracetamol

for young people aged 12-17 years consider a nasal triptan in preference to an oral triptan

if the above measures are not effective or not tolerated offer a non-oral preparation of metoclopramide* or prochlorperazine and consider adding a non-oral NSAID or triptan

Prophylaxis

prophylaxis should be given if patients are experiencing 2 or more attacks per month. Modern treatment is effective in about 60% of patients.

NICE advise either topiramate or propranolol ‘according to the person’s preference, comorbidities and risk of adverse events’. Propranolol should be used in preference to topiramate in women of child bearing age as it may be teratogenic and it can reduce the effectiveness of hormonal contraceptives

if these measures fail NICE recommend ‘a course of up to 10 sessions of acupuncture over 5-8 weeks’

NICE recommend: ‘Advise people with migraine that riboflavin (400 mg once a day) may be effective in reducing migraine frequency and intensity for some people’

for women with predictable menstrual migraine treatment NICE recommend either frovatriptan (2.5 mg twice a day) or zolmitriptan (2.5 mg twice or three times a day) as a type of ‘mini-prophylaxis’

pizotifen is no longer recommend. Adverse effects such as weight gain & drowsiness are common

*caution should be exercised with young patients as acute dystonic reactions may develop

Migraine

acute: triptan + NSAID or triptan + paracetamol
prophylaxis: topiramate or propranolol

Question 24

Migraine: diagnostic criteria

Answer 24

The International Headache Society has produced the following diagnostic criteria for migraine without aura:

Point

Criteria

A

At least 5 attacks fulfilling criteria B-D

B

Headache attacks lasting 4-72 hours* (untreated or unsuccessfully treated)

C

Headache has at least two of the following characteristics:

1. unilateral location*
2. pulsating quality (i.e., varying with the heartbeat)
3. moderate or severe pain intensity
4. aggravation by or causing avoidance of routine physical activity (e.g., walking or climbing stairs)

D

During headache at least one of the following:

1. nausea and/or vomiting*
2. photophobia and phonophobia

E

Not attributed to another disorder (history and examination do not suggest a secondary headache disorder or, if they do, it is ruled out by appropriate investigations or headache attacks do not occur for the first time in close temporal relation to the other disorder)

*In children, attacks may be shorter-lasting, headache is more commonly bilateral, and gastrointestinal disturbance is more prominent.

Migraine with aura (seen in around 25% of migraine patients) tends to be easier to diagnose with a typical aura being progressive in nature and may occur hours prior to the headache. Typical aura include a transient hemianopic disturbance or a spreading scintillating scotoma (‘jagged crescent’). Sensory symptoms may also occur

If we compare these guidelines to the NICE criteria the following points are noted:

NICE suggests migraines may be unilateral or bilateral

NICE also give more detail about typical auras:

Auras may occur with or without headache and:

are fully reversible

develop over at least 5 minutes

last 5-60 minutes

The following aura symptoms are atypical and may prompt further investigation/referral;

motor weakness

double vision

visual symptoms affecting only one eye

poor balance

decreased level of consciousness.

Question 25

Motor neuron disease

Answer 25

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, progressive muscular atrophy and bulbar palsy.

There are a number of clues which point towards a diagnosis of motor neuron disease:

fasciculations

the absence of sensory signs/symptoms*

the mixture of lower motor neuron and upper motor neuron signs

wasting of the small hand muscles/tibialis anterior is common

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

The diagnosis of motor neuron disease is clinical, but nerve conduction studies will show normal motor conduction and can help exclude a neuropathy. Electromyography shows a reduced number of action potentials with increased amplitude. MRI is usually performed to exclude the differential diagnosis of cervical cord compression and myelopathy

*vague sensory symptoms may occur early in the disease (e.g. limb pain) but ‘never’ sensory signs

Question 26

Multiple sclerosis

Answer 26

Patient’s with multiple sclerosis (MS) may present with non-specific features, for example around 75% of patients have significant lethargy.

Diagnosis can be made on the basis of two or more relapses and either objective clinical evidence of two or more lesions or objective clinical evidence of one lesion together with reasonable historical evidence of a previous relapse.

Visual

optic neuritis: common presenting feature

optic atrophy

Uhthoff’s phenomenon: worsening of vision following rise in body temperature

internuclear ophthalmoplegia

Sensory

pins/needles

numbness

trigeminal neuralgia

Lhermitte’s syndrome: paraesthesiae in limbs on neck flexion

Motor

spastic weakness: most commonly seen in the legs

Cerebellar

ataxia: more often seen during an acute relapse than as a presenting symptom

tremor

Others

urinary incontinence

sexual dysfunction

intellectual deterioration

Multiple sclerosis: management

Treatment in multiple sclerosis is focused at reducing the frequency and duration of relapses. There is no cure.

Acute relapse

High dose steroids (e.g. oral or IV methylprednisolone) may be given for 5 days to shorten the length of an acute relapse. It should be noted that steroids shorten the duration of a relapse and do not alter the degree of recovery (i.e. whether a patient returns to baseline function)

Disease modifying drugs

Beta-interferon has been shown to reduce the relapse rate by up to 30%. Certain criteria have to be met before it is used:

relapsing-remitting disease + 2 relapses in past 2 years + able to walk 100m unaided

secondary progressive disease + 2 relapses in past 2 years + able to walk 10m (aided or unaided)

reduces number of relapses and MRI changes, however doesn’t reduce overall disability

Other drugs used in the management of multiple sclerosis include:

glatiramer acetate: immunomodulating drug - acts as an ‘immune decoy’

natalizumab: a recombinant monoclonal antibody that antagonises Alpha-4 Beta-1-integrin found on the surface of leucocytes, thus inhibiting migration of leucocytes across the endothelium across the blood-brain barrier
fingolimod: sphingosine 1-phosphate receptor modulator, prevents lymphocytes from leaving lymph nodes. An oral formulation is available

Some specific problems

Fatigue

once other problems (e.g. anaemia, thyroid or depression) have been excluded NICE recommend a trial of amantadine

other options include mindfulness training and CBT

Spasticity

baclofen and gabapentin are first-line. Other options include diazepam, dantrolene and tizanidine

physiotherapy is important

cannabis and botox are undergoing evalulation

Bladder dysfunction

may take the form of urgency, incontinence, overflow etc

guidelines stress the importance of getting an ultrasound first to assess bladder emptying - anticholinergics may worsen symptoms in some patients

if significant residual volume → intermittent self-catheterisation

if no significant residual volume → anticholinergics may improve urinary frequency

Oscillopsia (visual fields apper to oscillate)

gabapentin is first-line

Question 27

Neuroleptic malignant syndrome

Answer 27

Neuroleptic malignant syndrome is a rare but dangerous condition seen in patients taking antipsychotic medication. It carries a mortality of up to 10% and can also occur with atypical antipsychotics. It may also occur with dopaminergic drugs (such as levodopa) for Parkinson’s disease, usually when the drug is suddenly stopped or the dose reduced.

The pathophysiology is unknown but one theory is that the dopamine blockade induced by antipsychotics triggers massive glutamate release and subsequent neurotoxicity and muscle damage.

It occurs within hours to days of starting an antipsychotic (antipsychotics are also known as neuroleptics, hence the name) and the typical features are:

pyrexia

muscle rigidity

autonomic lability: typical features include hypertension, tachycardia and tachypnoea

agitated delirium with confusion

A raised creatine kinase is present in most cases. Acute kidney injury (secondary to rhabdomyolysis) may develop in severe cases. A leukocytosis may also be seen

Management

stop antipsychotic

patients should be transferred to a medical ward if they are on a psychiatric ward and often they are nursed in intensive care units

IV fluids to prevent renal failure

dantrolene may be useful in selected cases

thought to work by decreasing excitation-contraction coupling in skeletal muscle by binding to the ryanodine receptor, and decreasing the release of calcium from the sarcoplasmic reticulum

bromocriptine, dopamine agonist, may also be used

Question 28

Neuropathic pain

Answer 28

Neuropathic pain may be defined as pain which arises following damage or disruption of the nervous system. It is often difficult to treat and responds poorly to standard analgesia.

Examples include:

diabetic neuropathy

post-herpetic neuralgia

trigeminal neuralgia

prolapsed intervertebral disc

NICE updated their guidance on the management of neuropathic pain in 2013:

first-line treatment*: amitriptyline, duloxetine, gabapentin or pregabalin

if the first-line drug treatment does not work try one of the other 3 drugs

tramadol may be used as ‘rescue therapy’ for exacerbations of neuropathic pain

topical capsaicin may be used for localised neuropathic pain (e.g. post-herpetic neuralgia)

pain management clinics may be useful in patients with resistant problems

*please note that for some specific conditions the guidance may vary. For example carbamazepine is used first-line for trigeminal neuralgia

Neuropathic pain

Neuropathic pain may be defined as pain which arises following damage or disruption of the nervous system. It is often difficult to treat and responds poorly to standard analgesia.

Examples include:

diabetic neuropathy

post-herpetic neuralgia

trigeminal neuralgia

prolapsed intervertebral disc

NICE updated their guidance on the management of neuropathic pain in 2013:

first-line treatment*: amitriptyline, duloxetine, gabapentin or pregabalin

if the first-line drug treatment does not work try one of the other 3 drugs

tramadol may be used as ‘rescue therapy’ for exacerbations of neuropathic pain

topical capsaicin may be used for localised neuropathic pain (e.g. post-herpetic neuralgia)

pain management clinics may be useful in patients with resistant problems

*please note that for some specific conditions the guidance may vary. For example carbamazepine is used first-line for trigeminal neuralgia

Question 29

Parkinson’s disease: management

Answer 29

Causes of Parkinsonism

Parkinson’s disease

drug-induced e.g. antipsychotics, metoclopramide*

progressive supranuclear palsy

multiple system atrophy

Wilson’s disease

post-encephalitis

dementia pugilistica (secondary to chronic head trauma e.g. boxing)

toxins: carbon monoxide, MPTP

*Domperidone does not cross the blood-brain barrier and therefore does not cause extra-pyramidal side-effects.

Levodopa should be offered for patients with newly diagnosed Parkinson’s who have motor symptoms affecting their quality of life

Essential tremor is an AD condition that is made worse when arms are outstretched, made better by alcohol and propranolol

Parkinsons disease should only be diagnosed, and management initiated, by a specialist with expertise in movement disorders. However, it is important for all doctors to be aware of the medications used in Parkinson’s given the prevalence of this condition. NICE published guidelines in 2017 regarding the management of Parkinson’s disease.

For first-line treatment:

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

Specific points regarding Parkinson’s medication

NICE reminds us of the risk of acute akinesia or neuroleptic malignant syndrome if medication is not taken/absorbed (for example due to gastroenteritis) and advise against giving patients a ‘drug holiday’ for the same reason.

Impulse control disorders have become a significant issue in recent years. These can occur with any dopaminergic therapy but are more common with:

dopamine agonist therapy

a history of previous impulsive behaviours

a history of alcohol consumption and/or smoking

If excessive daytime sleepiness develops then patients should not drive. Medication should be adjusted to control symptoms. Modafinil can be considered if alternative strategies fail.

If orthostatic hypotension develops then a medication review looking at potential causes should be done. If symptoms persist then midodrine (acts on peripheral alpha-adrenergic receptors to increase arterial resistance) can be considered.

Consider glycopyrronium bromide to manage drooling of saliva in people with Parkinson’s disease.

Further information regarding specific anti-Parkinson’s medication

Levodopa

usually combined with a decarboxylase inhibitor (e.g. carbidopa or benserazide) to prevent peripheral metabolism of levodopa to dopamine

reduced effectiveness with time (usually by 2 years)

unwanted effects: dyskinesia (involuntary writhing movements), ‘on-off’ effect, dry mouth, anorexia, palpitations, postural hypotension, psychosis, drowsiness

no use in neuroleptic induced parkinsonism

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

Dopamine receptor agonists

e.g. bromocriptine, ropinirole, cabergoline, apomorphine

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

MAO-B (Monoamine Oxidase-B) inhibitors

e.g. selegiline

inhibits the breakdown of dopamine secreted by the dopaminergic neurons

Amantadine

mechanism is not fully understood, probably increases dopamine release and inhibits its uptake at dopaminergic synapses

side-effects include ataxia, slurred speech, confusion, dizziness and livedo reticularis

COMT (Catechol-O-Methyl Transferase) inhibitors

e.g. entacapone, tolcapone

COMT is an enzyme involved in the breakdown of dopamine, and hence may be used as an adjunct to levodopa therapy

used in conjunction with levodopa in patients with established PD

Antimuscarinics

block cholinergic receptors

now used more to treat drug-induced parkinsonism rather than idiopathic Parkinson’s disease

help tremor and rigidity

e.g. procyclidine, benzotropine, trihexyphenidyl (benzhexol)

Question 30

Peripheral neuropathy

Answer 30

Peripheral neuropathy may be divided into conditions which predominately cause a motor or sensory loss

Predominately motor loss

Guillain-Barre syndrome

porphyria

lead poisoning

hereditary sensorimotor neuropathies (HSMN) - Charcot-Marie-Tooth

chronic inflammatory demyelinating polyneuropathy (CIDP)

diphtheria

Predominately sensory loss

diabetes

uraemia

leprosy

alcoholism

vitamin B12 deficiency

amyloidosis

Alcoholic neuropathy

secondary to both direct toxic effects and reduced absorption of B vitamins

sensory symptoms typically present prior to motor symptoms

Vitamin B12 deficiency

subacute combined degeneration of spinal cord

dorsal column usually affected first (joint position, vibration) prior to distal paraesthesia

Question 31

Epileptic Drugs

Sodium valproate

Answer 31

Sodium valproate is used in the management of epilepsy and is first-line therapy for generalised seizures. It works by increasing GABA activity.

Adverse effects

P450 inhibitor

gastrointestinal: nausea

increased appetite and weight gain

alopecia: regrowth may be curly

ataxia

tremor

hepatotoxicity

pancreatitis

thrombocytopaenia

teratogenic

hyponatraemia

hyperammonemic encephalopathy: L-carnitine may be used as treatment if this develops

Sodium valproate may cause weight gain

Phenytoin

Phenytoin is used in the management of seizures.
Mechanism of action

binds to sodium channels increasing their refractory period
Adverse effects

Phenytoin is associated with a large number of adverse effects. These may be divided into acute, chronic, idiosyncratic and teratogenic. Phenytoin is also an inducer of the P450 system.

Acute

initially: dizziness, diplopia, nystagmus, slurred speech, ataxia
later: confusion, seizures

Chronic

common: gingival hyperplasia (secondary to increased expression of platelet derived growth factor, PDGF), hirsutism, coarsening of facial features, drowsiness

megaloblastic anaemia (secondary to altered folate metabolism)

peripheral neuropathy

enhanced vitamin D metabolism causing osteomalacia

lymphadenopathy

dyskinesia
Idiosyncratic

fever

rashes, including severe reactions such as toxic epidermal necrolysis

hepatitis

Dupuytren’s contracture*

aplastic anaemia

drug-induced lupus

Teratogenic

associated with cleft palate and congenital heart disease

Monitoring
Phenytoin levels do not need to be monitored routinely but trough levels, immediately before dose should be checked if:

adjustment of phenytoin dose

suspected toxicity

detection of non-adherence to the prescribed medication
*although not listed in the BNF

Question 32

Radial nerve

Answer 32

Continuation of posterior cord of the brachial plexus (root values C5 to T1)

Path

In the axilla: lies posterior to the axillary artery on subscapularis, latissimus dorsi and teres major.

Enters the arm between the brachial artery and the long head of triceps (medial to humerus).

Spirals around the posterior surface of the humerus in the groove for the radial nerve.

At the distal third of the lateral border of the humerus it then pierces the intermuscular septum and descends in front of the lateral epicondyle.

At the lateral epicondyle it lies deeply between brachialis and brachioradialis where it then divides into a superficial and deep terminal branch.

Deep branch crosses the supinator to become the posterior interosseous nerve.

Regions innervated

Motor (main nerve)

Triceps

Anconeus

Brachioradialis

Extensor carpi radialis

Motor (posterior interosseous branch)

Supinator

Extensor carpi ulnaris

Extensor digitorum

Extensor indicis

Extensor digiti minimi

Extensor pollicis longus and brevis

Abductor pollicis longus

Sensory

The area of skin supplying the proximal phalanges on the dorsal aspect of the hand is supplied by the radial nerve (this does not apply to the little finger and part of the ring finger)

Muscular innervation and effect of denervation

Anatomical location

Muscle affected

Effect of paralysis

Shoulder

Long head of triceps

Minor effects on shoulder stability in abduction

Arm

Triceps

Loss of elbow extension

Forearm

Supinator
Brachioradialis
Extensor carpi radialis longus and brevis

Weakening of supination of prone hand and elbow flexion in mid prone position

Patterns of damage

wrist drop

sensory loss to small area between the dorsal aspect of the 1st and 2nd metacarpals

Axillary damage

as above

paralysis of triceps

Question 33

Sciatic nerve lesion

Answer 33

Basics

sciatic nerve is supplied by L4-5, S1-3

divides into tibial and common peroneal nerves

Supplies

hamstring muscles

adductor muscles

Features of sciatic nerve lesion

motor: paralysis of knee flexion and all movements below knee
sensory: loss below knee
reflexes: ankle + plantar lost, knee jerk intact

Causes

fracture neck of femur

posterior hip dislocation

trauma

The common reflexes are listed below:

Reflex

Root

Ankle

S1-S2

Knee

L3-L4

Biceps

C5-C6

Triceps

C7-C8

Question 34

Stroke: a very basic introduction

Answer 34

Strokes represent an important cause of morbidity and mortality. In the UK alone there are over 150,000 strokes per year, with over 1.2 million stroke survivors. Stroke is the fourth largest cause of death in the UK and kills twice as many women than breast cancer each year.

The prevention and treatment of strokes has undergone significant changes over the past decade. What was previously considered a devastating but untreatable condition is now viewed more as a ‘brain attack’, a condition which requires emergency assessment to see if patients may benefit from new treatments such as thrombolysis.

Pathological specimen showing the results of an ischaemic stroke to the occipito-parietal region of the cerebrum. Note there has been some secondary haemorrhage in the affected area.

What is a stroke?

A stroke (also known as cerebrovascular accident,CVA) represents a sudden interruption in the vascular supply of the brain. Remember that neural tissue is completely dependent on aerobic metabolism so any problem with oxygen supply can quickly lead to irreversible damage.

There are two main types of strokes:

ischaemic: these can be further subdivided between into episodes which last greater than 24 hours (termed an ischaemic stroke) and episodes where symptoms and signs last less than 24 hours (transient ischaemic attacks, TIAs, sometimes termed ‘mini-strokes’ by patients)

haemorrhagic

Symptoms and signs

Stroke is defined by the World Health Organization as a clinical syndrome consisting of ‘rapidly developing clinical signs of focal (at times global) disturbance of cerebral function, lasting more than 24 hours or leading to death with no apparent cause other than that of vascular origin’. In contrast, with a TIA the symptoms and signs resolve within 24 hours.

Features include:

motor weakness

speech problems (dysphasia)

swallowing problems

visual field defects (homonymous hemianopia)

balance problems

Cerebral hemisphere infarcts may have the following symptoms:

contralateral hemiplegia: initially flaccid then spastic

contralateral sensory loss

homonymous hemianopia

dysphasia

Brainstem infarction

may result in more severe symptoms including quadriplegia and lock-in-syndrome

Lacunar infarcts

small infarcts around the basal ganglia, internal capsule, thalamus and pons

this may result in pure motor, pure sensory, mixed motor and sensory signs or ataxia

An example of a lacunar infarct affecting the internal capsule.

One formal classification system that is sometimes used is the Oxford Stroke Classification (also known as the Bamford Classification), whichclassifies strokes based on the initial symptoms. A summary is as follows:

The following criteria should be assessed:

1. unilateral hemiparesis and/or hemisensory loss of the face, arm & leg
2. homonymous hemianopia
3. higher cognitive dysfunction e.g. dysphasia

Question 35

Ischaemic strokes

Answer 35

Urgent neuroimaging classifies the stroke as either ischaemic or haemorrhagic. If the stroke is ischaemic, and certain criteria are met, the patient should be offered thrombolysis. Example criteria include:

patients present with 4.5 hours of onset of stroke symptoms

the patient has not had a previous intracranial haemorrhage, uncontrolled hypertension, pregnant etc

Once haemorrhagic stroke has been excluded patients should be given aspirin 300mg as soon as possible and antiplatelet therapy should be continued.

Transient ischaemic attacks

Remember with TIAs the, by definition, symptoms last less than 24 hours although in the vast majority of cases the duration is much shorter, typically 1 hour or so. For this reason most patients symptoms will have resolved before they see a doctor.

The ABCD2 prognostic score has previously been used to risk stratify patients who present with a suspected TIA. However, data from studies have suggested it performs poorly and it is therefore no longer recommended by NICE Clinical Knowledge Summaries. Instead, NICE recommend:

Immediate antithrombotic therapy:

give aspirin 300 mg immediately, unless contraindicated e.g. the patient has a bleeding disorder or is taking an anticoagulant (needs immediate admission for imaging to exclude a haemorrhage)

If the patient has had more than 1 TIA (‘crescendo TIA’) or has a suspected cardioembolic source or severe carotid stenosis:

discuss the need for admission or observation urgently with a stroke specialist

If the patient has had a suspected TIA in the last 7 days:

arrange urgent assessment (within 24 hours) by a specialist stroke physician

If the patient has had a suspected TIA which occurred more than a week previously:

refer for specialist assessment as soon as possible within 7 days

Haemorrhagic strokes

If imaging confirms a haemorrhagic stroke neurosurgical consultation should be considered for advice on further management. The vast majority of patients however are not suitable for surgical intervention. Management is therefore supportive as per haemorrhagic stroke. Anticoagulants (e.g. warfarin) and antithrombotic medications (e.g. clopidogrel) should be stopped to minimise further bleeding. If a patient is anticoagulated this should be reversed as quickly as possible. Trials have shown improved outcomes in patients who have their blood pressure lowered acutely and this is now part of many protocols for haemorrhagic strokes.

A 69-year-old gentleman presents to the emergency department with sudden onset right-sided numbness, with no other symptoms. He has a background of poorly controlled hypertension and diabetes mellitus. A CT head was arranged which reported no haemorrhage or mass. He is diagnosed as having had a lacunar stroke.

Question 36

Transient ischaemic attack

Answer 36

The original definition of a transient ischaemic attack (TIA) was time-based: a sudden onset of a focal neurologic symptom and/or sign lasting less than 24 hours, brought on by a transient decrease in blood flow. However, this has now changed as it is recognised that even short periods of ischaemia can result in pathological changes to the brain. Therefore, a new ‘tissue-based’ definition is now used: a transient episode of neurologic dysfunction caused by focal brain, spinal cord, or retinal ischaemia, without acute infarction.

Patients often use the term ‘mini-stroke’ for TIAs.

Assessment and referral

The ABCD2 prognostic score has previously been used to risk stratify patients who present with a suspected TIA. However, data from studies have suggested it performs poorly and it is therefore no longer recommended by NICE Clinical Knowledge Summaries. Instead, NICE recommend:

Immediate antithrombotic therapy:

give aspirin 300 mg immediately, unless

1. the patient has a bleeding disorder or is taking an anticoagulant (needs immediate admission for imaging to exclude a haemorrhage)
2. the patient is already taking low-dose aspirin regularly: continue the current dose of aspirin until reviewed by a specialist
3. Aspirin is contraindicated: discuss management urgently with the specialist team

If the patient has had more than 1 TIA (‘crescendo TIA’) or has a suspected cardioembolic source or severe carotid stenosis:

discuss the need for admission or observation urgently with a stroke specialist

If the patient has had a suspected TIA in the last 7 days:

arrange urgent assessment (within 24 hours) by a specialist stroke physician

If the patient has had a suspected TIA which occurred more than a week previously:

refer for specialist assessment as soon as possible within 7 days

Advise the person not to drive until they have been seen by a specialist.

Further management

Antithrombotic therapy

clopidogrel is recommended first-line (as for patients who’ve had a stroke)

aspirin + dipyridamole should be given to patients who cannot tolerate clopidogrel

these recommendations follow the 2012 Royal College of Physicians National clinical guideline for stroke. Please see the link for more details (section 5.5)

these guidelines may change following the CHANCE study (NEJM 2013;369:11). This study looked at giving high-risk TIA patients aspirin + clopidogrel for the first 90 days compared to aspirin alone. 11.7% of aspirin only patients had a stroke over 90 days compared to 8.2% of dual antiplatelet patients

With regards to carotid artery endarterectomy:

recommend if patient has suffered stroke or TIA in the carotid territory and are not severely disabled

should only be considered if carotid stenosis > 70% according ECST* criteria or > 50% according to NASCET** criteria

*European Carotid Surgery Trialists’ Collaborative Group
**North American Symptomatic Carotid Endarterectomy Trial

Antiplatelets

TIA: clopidogrel

ischaemic stroke: clopidogrel

Importance: 80

Carotid artery endarterectomy is recommend if the patient has suffered a stroke or TIA in the carotid territory and is not severely disabled. It should only be considered if the carotid stenosis is greater than 70% or 50%, depending on the reporting criteria used - please see below.

NICE Clinical Knowledge Summaries state the following:

Antiplatelet therapy is initiated by secondary care on diagnosis of ischaemic stroke or TIA without paroxysmal or permanent atrial fibrillation for long-term vascular prevention:

The standard treatment is clopidogrel 75mg daily (licenced for use in ischaemic stroke, off-label use in TIA).

Modified-release dipyridamole 200 mg twice daily may be used if both clopidogrel and aspirin are contraindicated or cannot be tolerated.

Aspirin 75mg daily may be used if both clopidogrel and modified-release dipyridamole are contraindicated or cannot be tolerated.

Aspirin 75 mg daily with modified-release dipyridamole 200 mg twice daily may be used if clopidogrel cannot be tolerated.

The 2012 Royal College of Physicians National clinical guidelines for stroke now recommend using clopidogrel following a TIA. This brings it in line with current stroke guidance.

Question 37

Trigeminal neuralgia

Answer 37

Trigeminal neuralgia is a pain syndrome characterised by severe unilateral pain. The vast majority of cases are idiopathic but compression of the trigeminal roots by tumours or vascular problems may occur.

The International Headache Society defines trigeminal neuralgia as:

a unilateral disorder characterised by brief electric shock-like pains, abrupt in onset and termination, limited to one or more divisions of the trigeminal nerve

the pain is commonly evoked by light touch, including washing, shaving, smoking, talking, and brushing the teeth (trigger factors), and frequently occurs spontaneously

small areas in the nasolabial fold or chin may be particularly susceptible to the precipitation of pain (trigger areas)

the pains usually remit for variable periods

NICE Clinical Knowledge Summaries list the following as red flag symptoms and signs suggesting a serious underlying cause:

Sensory changes

Deafness or other ear problems

History of skin or oral lesions that could spread perineurally

Pain only in the ophthalmic division of the trigeminal nerve (eye socket, forehead, and nose), or bilaterally

Optic neuritis

A family history of multiple sclerosis

Age of onset before 40 years

Management

carbamazepine is first-line

failure to respond to treatment or atypical features (e.g. < 50 years old) should prompt referral to neurology

This woman has symptoms typical of trigeminal neuralgia. The first line treatment for this is carbamazepine, which should be started at 100 mg twice daily and slowly titrated up until pain is relieved.

Question 38

Tuberous sclerosis

Answer 38

Tuberous sclerosis (TS) is a genetic condition of autosomal dominant inheritance. Like neurofibromatosis, the majority of features seen in TS are neurocutaneous.

Cutaneous features

depigmented ‘ash-leaf’ spots which fluoresce under UV light

roughened patches of skin over lumbar spine (Shagreen patches)

adenoma sebaceum (angiofibromas): butterfly distribution over nose

fibromata beneath nails (subungual fibromata)

café-au-lait spots* may be seen

Neurological features

developmental delay

epilepsy (infantile spasms or partial)

intellectual impairment

Also

retinal hamartomas: dense white areas on retina (phakomata)

rhabdomyomas of the heart

gliomatous changes can occur in the brain lesions

polycystic kidneys, renal angiomyolipomata

lymphangioleiomyomatosis: multiple lung cysts

Question 39

Ulnar nerve

Answer 39

Overview

arises from medial cord of brachial plexus (C8, T1)

Motor to

medial two lumbricals

aDductor pollicis

interossei

hypothenar muscles: abductor digiti minimi, flexor digiti minimi

flexor carpi ulnaris

Sensory to

medial 1 1/2 fingers (palmar and dorsal aspects)

Path

the ulnar nerve travels through the posteromedial aspect of the upper arm to the flexor compartment of the forearm

it then enters the palm of the hand via the Guyon’s canal, superficial to the flexor retinaculum and lateral to the pisiform bone

Question 40

Visual field defects

Answer 40

The main points for the exam are:

left homonymous hemianopia means visual field defect to the left, i.e. Lesion of right optic tract

homonymous quadrantanopias: PITS (Parietal-Inferior, Temporal-Superior)

incongruous defects = optic tract lesion; congruous defects = optic radiation lesion or occipital cortex

A congruous defect simply means complete or symmetrical visual field loss and conversely an incongruous defect is incomplete or asymmetric. Please see the link for an excellent diagram.

Homonymous hemianopia

incongruous defects: lesion of optic tract

congruous defects: lesion of optic radiation or occipital cortex

macula sparing: lesion of occipital cortex

Homonymous quadrantanopias*

superior: lesion of temporal lobe
inferior: lesion of parietal lobe

mnemonic = PITS (Parietal-Inferior, Temporal-Superior)

Bitemporal hemianopia

lesion of optic chiasm

upper quadrant defect > lower quadrant defect = inferior chiasmal compression, commonly a pituitary tumour

lower quadrant defect > upper quadrant defect = superior chiasmal compression, commonly a craniopharyngioma

*this is very much the ‘exam answer’. Actual studies suggest that the majority of quadrantanopias are caused by occipital lobe lesions. Please see the link for more details.

Question 41

Wernicke’s encephalopathy

Answer 41

Wernicke’s encephalopathy is a neuropsychiatric disorder caused by thiamine deficiency which is most commonly seen in alcoholics. Rarer causes include: persistent vomiting, stomach cancer, dietary deficiency. A classic triad of ophthalmoplegia/nystagmus, ataxia and confusion may occur. In Wernicke’s encephalopathy petechial haemorrhages occur in a variety of structures in the brain including the mamillary bodies and ventricle walls

Features

nystagmus (the most common ocular sign)

ophthalmoplegia

ataxia

confusion, altered GCS

peripheral sensory neuropathy

Investigations

decreased red cell transketolase

MRI

Treatment is with urgent replacement of thiamine
Relationship with Korsakoff syndrome
If not treated Korsakoff’s syndrome may develop as well. 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.