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Flashcards in Neurology Deck (62):
1

Femoral nerve anatomy

The femoral nerve (L2, 3, 4) is formed within psoas major and emerges from its lateral border to lie between psoas and iliacus in the iliac fossa.

It reaches the thigh beneath the inguinal ligament lying lateral to the femoral artery in the femoral triangle.

Its posterior division becomes the saphenous nerve as it enters the adductor canal.

The sciatic nerve divides into tibial and common peroneal nerves.

The lateral femoral cutaneous nerve supplies the skin over the lateral thigh.

2

Surface anatomy:
C4
T4/5
T8
T10
T12

The carotid artery bifurcates at C4.

The manubriosternsal joint (angle of Louis) lies at the level of the T4/5 intervertebral disk.

The caval opening in the diaphragm lies at T8.

The oesoghageal opening of the diaphragm lies at T10.

The aortic opening is at T12.

3

Foramen magnum

The foramen magnum transmits the

Medulla
Meninges
Vertebral arteries
Anterior and posterior spinal arteries
Spinal accessory nerves
Sympathetic plexus.

4

Brown-Sequard syndrome

Brown-Sequard syndrome is characterised by loss of ipsilateral motor function and contralateral loss of pain and temperature sensation.

It usually occurs following a penetrating injury.

It has the best prognosis of the incomplete spinal cord syndromes.

5

An elderly patient with a previous history of spinal canal stenosis sustains an extension injury of the cervical spine.

The upper limbs are more affected than the lower limbs and perianal sensation is preserved.

Type of injury?

Central cord syndrome usually occurs in patients over the age of 50 years as a result of extension injuries.

Upper limbs are more affected than lower limbs with both motor and sensory loss.

The prognosis is fair.

6

68-year-old man has recently had a carotid endarterectomy under deep cervical plexus block.

Picture shows small left pupil and ptosis

Cerebrovascular embolus
Horner's syndrome
Myocardial infarction
Recurrent laryngeal nerve palsy
Subarachnoid haemorrhage

Carotid endarterectomy may be performed under local anaesthesia using a deep cervical plexus block of C2, C3 and C4. Complications may occur related to anaesthesia or the surgery.

Cerebrovascular events such as embolisation or, less commonly, subarachnoid haemorrhage, may occur as well as post-operative myocardial infarction. Central nervous system (CNS) or systemic toxicity from the local anaesthetic may also occur. Local nerve effects such as recurrent laryngeal nerve (hoarse voice) and phrenic nerve block may occur due to the anaesthetic.

This man has a small left pupil and ptosis on the left which is consistent with Horner's syndrome. This could be due to the anaesthesia or the surgery itself.



7

BRACHIAL PLEXUS INJURIES:

A 38-year-old man presents with a small area of anaesthesia over the lateral aspect of upper arm following subcoracoid dislocation of the shoulder.

The axillary (circumflex) nerve is often damaged in anterior dislocation of the shoulder. There is consequent paralysis of the deltoid muscle, with a small area of anaesthesia at the lateral aspect of the upper arm.

8

BRACHIAL PLEXUS INJURIES:

A 54-year-old lady presents with a wrist drop and mild sensory loss over the lateral side of the back of the hand following a fall. She complains of pain over the mid-shaft of humerus

Radial nerve injury is commonly associated with the fracture of the mid shaft of the humerus, where the radial nerve lies in the spiral grove. Such injuries cause wrist drop (paralysis of the extensor muscles of the wrist, finger and thumb), and also paralysis of the brachioradialis and the supinator muscles. There is sensory loss over the dorsal aspect of the root of the thumb.

9

BRACHIAL PLEXUS INJURIES:

A 67-year-old lady presents to the Emergency department with a prominent (standing out) vertebral border and the inferior angle of the scapula. She recently underwent mastectomy for breast cancer.

Long thoracic nerve (nerve of Bell), comprising C5, 6, 7 nerve roots, supplies the serratus anterior muscle. This nerve may be injured following injuries to the brachial plexus or could be damaged during surgeries to the chest wall, breast or the axillary region. Paralysis of the serratus anterior muscle causes winging of the scapula

10

A 45-year-old male presents with discomfort in the fingers of his left hand. On examination the ring and little fingers of his left hand are flexed and unable to extend completely. He is able to make a fist with the hand. Palpation reveals thickened nodules on the medial half of the palm.

Duputyrens contracture

11

A 55-year-old female presents with a two month history of pins and needles in the fingers of the right hand, particularly at night. On examination, there is some loss of the sensation over the palmar aspect of the lateral three fingers.

Median nerve compression
Classical carpal tunnel syndrome is described with paraesthesiae, typically at night with the patient getting out of bed and shaking the hands. It is caused by entrapment within the carpal tunnel and is associated with:

pregnancy
obesity
manual work
acromegaly
hypothyroidism
rheumatoid arthritis.

12

A 37-year-old male, who has a 15 year history of type 1 diabetes, presents with a two day history of weakness of the left hand. On examination he is unable to extend his wrist or fingers of the left hand but there is no sensory loss. Right hand is normal.

Radial nerve palsy results in wrist drop with weakness of extension of the wrist and extension of the fingers. There may be associated loss of sensation over the back of the hand. It may be caused, as in this case, by mononeuritis multiplex associated with diabetes, but is usually caused by compression in the axilla (crutch or Saturday night palsy) or humeral shaft fracture.



13

A 20-year-old female presents with pain in her right hand particularly when writing. On examination she has a firm subcutaneous tender nodule on the dorsal aspect of the right wrist.

Ganglion
A ganglion is a protrusion of the synovial membrane of the wrist joint. Usually these are painless but can become painful with repetitive use. The condition may resolve but occasionally surgery is required.

14

A 40-year-old male complains of pain in the middle two fingers of his right hand whilst playing golf. On examination there is tenderness and swelling of the distal interphalangeal joints of the right ring and middle fingers.

Heberdens' node
Heberden's nodes are located on the distal interphalangeal joints and usually due to osteoarthritis/degenerative changes. Inflammation may occur giving rise to the pain.

Bouchard's nodes are located on the proximal interphalangeal joint.

15

A 45-year-old female presents with a month history of pain and tenderness over the right wrist particularly when gripping her tennis racquet. On examination there is pain on pinching the thumb and forefinger together and pain on palpation over the radial aspect of the wrist

DeQuervain's tenosynovitis implies inflammation of the tendons of two specific muscles on the thumb side of the hand - the abductor pollicis longus (APL) and the extensor pollicis brevis (EPB). The condition is 10 times more common in women, more often arises in the dominant hand, and usually occurs between the ages of 35 and 55. Rest and analgesics are the most appropriate treatment.



16

Visual field defects

Parietal lobe tumour

A Bitemporal hemianopia
B Central scotoma
C Cortical blindness
D Enlarged blind spot
E Homonymous hemianopia
F Inferior homonymous quadrantanopia
G Superior homonymous quadrantanopia
H Tunnel vision
I Uniocular blindness

Inferior homonymous quadrantanopia

A parietal lobe tumour is associated with disturbed sensation including localisation of touch and disturbed two point discrimination. The typical associated visual field defect is a lower homonymous quadrantanopia and it affects the upper fibres of the optic radiation. This is the classical lesion and tumours of the temporal lobe tend to produce superior homomomous quadrantanopia. However,very large tumours can produce homonymous hemianopia.

17

Visual field defects

Bilateral occipital infarction

A Bitemporal hemianopia
B Central scotoma
C Cortical blindness
D Enlarged blind spot
E Homonymous hemianopia
F Inferior homonymous quadrantanopia
G Superior homonymous quadrantanopia
H Tunnel vision
I Uniocular blindness

Cortical blindness

Bilateral occipital infarction results in cortical blindness where the brain is unable to process the light signals it receives from the retina and optic nerves.

18

Visual field defects

central retinal artery occlusion

A Bitemporal hemianopia
B Central scotoma
C Cortical blindness
D Enlarged blind spot
E Homonymous hemianopia
F Inferior homonymous quadrantanopia
G Superior homonymous quadrantanopia
H Tunnel vision
I Uniocular blindness

Uniocular blindness

A central retinal artery occlusion would typically result in sudden uniocular blindness. Causes of central retinal artery occlusion include emboli (carotid stenosis, AF) and giant cell arteritis.

19

A 12-year-old boy who is wheelchair bound with a meningomyelocele, has long term urinary incontinence which occurs both day and night. Urine culture is sterile.

A Antibiotics
B Bladder neck surgery
C Desmopressin
D Incontinence pants
E Intermittent self catherisation
F Star chart

The 12-year-old with meningomyelocele has an autonomic bladder and so would benefit from intermittent self catherisation.

20

A 6-year-old boy presents as his mother is concerned that he has began to wet the bed on a few occasions over the last month after being dry for the previous three months. Otherwise he is a healthy lad.

A Antibiotics
B Bladder neck surgery
C Desmopressin
D Incontinence pants
E Intermittent self catherisation
F Star chart

It is not unusual for children under the age of 6 to wet their beds now and again, even after having been toilet trained for a number of years. In fact, some children - boys especially - will continue to have the occasional wet bed even beyond their sixth year.

Although desmopressin is an appropriate treatment for nocturnal enuresis as this young child has, this child should respond to appropriate psychological training and the mother should be reassured. Using nappies for this lad would be negative re-inforcement for bed wetting and should be avoided. Using a star chart should be an encouragement

21

A 45-year-old man who is treated with gentamicin for abdominal infection presents with deafness. He has had peak and trough gentamicin concentrations measured which have been within the recommended therapeutic range. On examination, tuning fork tests and audiometry suggests a global decrease in hearing acuity.

A Acoustic neuroma
B Acute otitis media
C Barotrauma
D Ototoxicity
E Petrous temporal bone fracture
F Wax impaction

Deafness could result when there is impediment to conduction of sound waves from exterior to the brain or conductive - lesions could be in the auditory canal, middle ear or sensory neural - lesions of inner ear (cochlear) and acoustic nerve.

Clinical examination includes tuning fork tests which assess air conduction (AC) and bone conduction (BC) in the individual compared to that of the examiner (presuming his hearing is normal).

The common tests used are Rhinne's test and Weber's test.

Rhinne's test has two components - first where the AC of the examiner and the patient are compared. The second part helps differentiate conductive deafness and sensory neural deafness. In normal individuals, the AC > BC. But, in conductive deafness, BC > AC.

If a person is found to be deaf by Rhinne's 1 and has a normal AC BC relation, he has sensory neural deafness.

Weber's test compares BC on both sides and lateralises to the normal side.

Gentamicin is well recognised to be ototoxic and is particularly toxic to the cochlear. Although, ensuring adequate therapeutic concentrations may minimise this side effect ototoxicity may still occur even with concentrations maintained in the therapeutic range.

22

A 55-year-old man with poor physical hygiene presents with sudden onset severe left earache and deafness after taking a shower. He says he tried to clean his ears but it only worsened the pain. It is very difficult to get views of his eardrums.

A Acoustic neuroma
B Acute otitis media
C Barotrauma
D Ototoxicity
E Petrous temporal bone fracture
F Wax impaction

Hearing reduction after a shower is not uncommon with water in the auditory canal and may exacerbate hearing decline associated with wax. However, discomfort and hearing loss may be compounded by trying to displace the water through stuffing objects into the auditory canal.

23

Reflexes

Biceps

A L1
B L3, L4
C S1, S2
D C5, C6
E C7, C8
F C8, T1
G S3, S4

C5/6

The biceps jerk is elicited by supporting the patient's forearm on yours, this produces relaxation, as well as partially flexing the patient's arm. You can feel as well as see the normal response, which is contraction of the biceps muscle and flexion of the forearm.

24

Reflexes

Knee

A L1
B L3, L4
C S1, S2
D C5, C6
E C7, C8
F C8, T1
G S3, S4

L3/4

The knee jerk is elicited by letting the patient's leg dangle over the side of the bed (N.B. the legs should not be in contact). This flexes the knee and stretches the tendon. Strike the tendon directly just below the patella. Extension of the lower leg is the expected response. Placing the left hand on the thigh will confirm contraction of the quadriceps.

25

Reflexes

Ankle

A L1
B L3, L4
C S1, S2
D C5, C6
E C7, C8
F C8, T1
G S3, S4

S1/2

The ankle jerk is elicited by positioning the person with the knee flexed and the hip externally rotated (or alternatively asking the patient to kneel on a chair). Hold the foot in dorsiflexion, and strike the Achilles tendon directly. Feel the normal response as the foot plantar flexes against your hand.

26

Reflexes

Anal

A L1
B L3, L4
C S1, S2
D C5, C6
E C7, C8
F C8, T1
G S3, S4

The anal reflex is elicited by pricking the perianal skin with a needle. The normal response is an 'anal wink' and represents a visible contraction of the external anal sphincter.

27

Reflexes

Abdominal
A L1
B L3, L4
C S1, S2
D C5, C6
E C7, C8
F C8, T1
G S3, S4

The lower abdominal reflex is elicited by placing the patient in a supine position with the knees slightly bent. Use the handle end of the reflex hammer to stroke the skin, moving lateral to medial. The normal response is ipsilateral contraction of the rectus muscle with an observed deviation of the umbilicus towards the stroke. When the abdominal wall is very obese, pull the skin to the opposite side, and feel it contract towards the stimuli.

28

A patient presents with a history of low back pain and sciatica. The pain radiates to the little toe, the ankle reflex is absent and the patient has difficulty in everting the foot.

Which nerve root is likely to be trapped?

The root supply to the peroneal muscles (which control eversion of the foot and which also participate in the reflex arc of the ankle jerk reflex) is S1 via the tibial and superficial peroneal nerves.

The sensory dermatome of the S1 root gives innervation to the postero-lateral aspect of the leg and foot down to and including the little toe and sole of foot.



29

Pathology of Cranial nerves

A 61-year-old female presents with right sided ptosis. On examination her eyeball appears abducted and her pupil dilated.


A Cranial nerve II - Optic
B Cranial nerve III - Ocular motor
C Cranial nerve IV - Trochlear
D Cranial nerve V - Trigeminal
E Cranial nerve VI - Abducens
F Cranial nerve VII - Facial
G Cranial nerve IX - Glossopharyngeal
H Cranial nerve X - Vagus
I Cranial nerve XI- Accessory
J Cranial nerve XII - Hypoglossal

Cranial nerve III - Ocular motor

Cranial nerve III - ocular motor. Paralysis of the third cranial nerve affects the medial, superior, and inferior recti, and inferior oblique muscles.

30

Pathology of Cranial nerves

A 72-year-old male presents with unilateral wasting of his left sternomastoid and trapezius muscles.

A Cranial nerve II - Optic
B Cranial nerve III - Ocular motor
C Cranial nerve IV - Trochlear
D Cranial nerve V - Trigeminal
E Cranial nerve VI - Abducens
F Cranial nerve VII - Facial
G Cranial nerve IX - Glossopharyngeal
H Cranial nerve X - Vagus
I Cranial nerve XI- Accessory
J Cranial nerve XII - Hypoglossal

Cranial nerve XI - accessory nerve is the motor innervation to the sternomastoid and trapezius muscles.

31

Pathology of Cranial nerves

A 68-year-old female presents with unilateral pain confined to the right cheek area. On examination ruptured vesicles are identified in this area.

A Cranial nerve II - Optic
B Cranial nerve III - Ocular motor
C Cranial nerve IV - Trochlear
D Cranial nerve V - Trigeminal
E Cranial nerve VI - Abducens
F Cranial nerve VII - Facial
G Cranial nerve IX - Glossopharyngeal
H Cranial nerve X - Vagus
I Cranial nerve XI- Accessory
J Cranial nerve XII - Hypoglossal

Cranial nerve V - trigeminal nerve has sensory fibres which innervate the face. This nerve can be affected by shingles producing vesicles within its area of innervation.

32

Pathology of Cranial nerves

An 80-year-old male presents with paralysis of the right half of his face and loss of taste to the anterior 2/3 of his tongue.

A Cranial nerve II - Optic
B Cranial nerve III - Ocular motor
C Cranial nerve IV - Trochlear
D Cranial nerve V - Trigeminal
E Cranial nerve VI - Abducens
F Cranial nerve VII - Facial
G Cranial nerve IX - Glossopharyngeal
H Cranial nerve X - Vagus
I Cranial nerve XI- Accessory
J Cranial nerve XII - Hypoglossal

Cranial nerve VII

Cranial nerve VII - facial nerve innervates the muscles of facial expression and also has special sensory innervation to the anterior 2/3 of the tongue.

33

Pathology of Cranial nerves

A 62-year-old female presents with severe, sharp and episodic pain during swallowing.

A Cranial nerve II - Optic
B Cranial nerve III - Ocular motor
C Cranial nerve IV - Trochlear
D Cranial nerve V - Trigeminal
E Cranial nerve VI - Abducens
F Cranial nerve VII - Facial
G Cranial nerve IX - Glossopharyngeal
H Cranial nerve X - Vagus
I Cranial nerve XI- Accessory
J Cranial nerve XII - Hypoglossal

Cranial nerve IX - Glossopharyngeal


This story is typical of glossopharyngeal neuralgia, a similar condition to trigeminal neuralgia but affecting the IX nerve. The episodic lancinating pain may be produced by swallowing.

34

A 35-year-old man presents with paraesthesia in the central area of the dorsum of his foot and proximal toes except the fifth. He is also found to have some weakness of eversion of the foot.

Which of the following nerves is most likely to be involved?

(Please select 1 option)

The deep peroneal nerve
The common peroneal nerve
The superficial peroneal nerve
The sural nerve
The tibial nerve

The superficial peroneal nerve

The superficial peroneal nerve also supplies peroneus longus and brevis, tested by everting the foot against resistance.

The only sensory loss from damage to the deep peroneal nerve is in the first interdigital cleft.

The sural nerve supplies the dorsum of the lateral one and a half toes.



35

During a neurological examination of the lower limb you attempt to elicit the knee reflex. You place your hand under the knee, then strike the knee just below the patella whilst you watch the quadriceps muscle.

What nerve roots and nerve are involved in this reflex?

Femoral nerve L2, L3
Femoral nerve L3, L4
Sciatic nerve L2, L3
Sciatic nerve L3, L4
Sciatic nerve L4, L5

L3/4
The quadriceps muscle is innervated via the femoral nerve (L3, L4 nerve roots) and it is this that is involved in the knee reflex.

The femoral nerve is the largest branch of the lumbar plexus (L2-L4).

It forms in the abdomen within psoas major. It then descends and can be found at the midpoint of the inguinal ligament. It enters the femoral triangle lateral to the femoral artery and vein.

It supplies the anterior thigh muscles, sends articular branches to the hip and knee joints, and supplies an area of skin on the anterior thigh (and part of medial thigh not supplied by the obturator nerve: medial and intermediate nerves of the thigh).



36

A motorcyclist falls off his bike at speed, injuring his upper limb.

After the injury, his arm is held internally rotated with his forearm extended and pronated in the 'waiter's tip' position.

Where is the lesion?

Axillary nerve
Lower cord of the brachial plexus
Musculocutaneous nerve
Radial nerve
Upper cord of the brachial plexus

Upper cord of the brachial plexus

The injury described is also known as Erb-Duchenne paralysis and the affected area is the upper cord of the brachial plexus.

Mechanisms of injury which have been noted include childbirth and high speed motorcycle accidents.

The force is downward traction on the upper cord.

The affected muscles are

Biceps
Brachialis
Brachioradialis
Deltoid
Supraspinatus and
Infraspinatus.

37

A medicolegal claim is brought against a hospital because of injuries a child has sustained during birth.

She has been left with wasting of the muscles of her hand which causes her problems with holding on to objects. There is also loss of sensation over the inner forearm and fingers. Her hand is clawed.

Where is the lesion?

Lower brachial plexus
Median nerve
Musculocutaneous nerve
Radial nerve
Upper brachial plexus

Lower brachial plexus

The affected area is the lower brachial plexus (C[7], 8; T1), this is also known as Klumpke's palsy.

The mechanism of injury is most likely to be forced abduction of the arm. Delivery when a baby has shoulder dystocia may cause upward traction of the arm. This may damage the lower brachial plexus. Most such obstetric injuries recover by 6 months. Otherwise, some recovery may continue until the age of about 2.

Horner's syndrome can also occur if the T1 nerve root is affected.

Lesions affecting the upper brachial plexus would lead to Erb-Duchenne paralysis (waiter's tip position).



38

A 55-year-old woman has undergone right mastectomy with axillary node clearance.

Postoperatively she complains of numbness on the medial surface of the upper arm.

Which nerve has been damaged?

Axillary nerve
Intercostobrachial nerve
Long thoracic nerve
Medial pectoral nerve
Thoracodorsal nerve

Intercostobrachial nerve

The intercostobrachial nerve can be easily damaged during surgery in the axilla and it is important to warn the patient of this preoperatively.

The thoracodorsal nerve will also be encountered during surgery in the axilla, it supplies the latissimus dorsi muscle.

The long thoracic nerve is also visible in the axilla, if cut it will lead to winging of the scapula.



39

In an anatomy viva you identify the foramen magnum as the largest of the skull's foramina.

Which of the following structures passes through the foramen magnum?

The glossopharyngeal nerves
The hypoglossal nerves
The internal carotid arteries
The vagus nerves
The vertebral arteries

Vertebral arteries

The foramen magnum transmits the vertebral arteries, the lower part of the medulla and the spinal accessory nerves.

The hypoglossal nerve exits through the hypoglossal canal, and the internal carotid arteries pass through the carotid canal whilst the glossopharyngeal and vagus exit via the jugular foramen.



40

The anterior cranial fossa is formed by which bony structure?

The anterior cranial fossa is formed by which bony structure?

The greater wing of the sphenoid
The lesser wing of the sphenoid
The occipital bone
The sella turcica
The temporal bone

The lesser wing of the sphenoid

The anterior cranial fossa is formed by

The orbital plate of the frontal bone
The lesser wing of the sphenoid and
The cribiform plate of the ethmoid.

41

A 67-year-old lady attends the neurology clinic and is diagnosed with a trochlear nerve palsy.

Which of the following muscles will be affected?

The ciliary muscles
The inferior rectus muscle
The medial rectus muscle
The superior oblique muscle
The superior rectus muscle

The trochlear nerve enters the orbit through the superior orbital fissure to supply the superior oblique muscle.

The occulomotor nerve supplies the superior, inferior and medial recti (and inferior oblique) whilst the abducent nerve innervates the lateral rectus.

The ciliary muscles receive parasympathetic innervation via the occulomotor.



42

A 24-year-old man has sustained significant brain injury following an assault. He is showing signs of a raised intracranial pressure.

Which of the cranial nerves is usually the first to be affected by a raised intracranial pressure?

The abducent nerve
The facial nerve
The hypoglossal nerve
The vagus nerve
The vestibulocochlear nerve

The abducent nerve leaves the brain at the posterior border of the pons and has a long intracranial course to the cavernous sinus and orbit through the superior orbital fissure.

It supplies the lateral rectus muscle.



43

The contents of the cavernous sinus includes which of the following?

The basilar artery
The external carotid artery
The facial nerve
The optic nerve
The trochlear nerve

COATt

The cavernous sinus contains

The internal carotid artery
The occulomotor nerve
The trochlear nerve
The abducent nerve and
The three divisions of the trigeminal nerve.

44

Of the following which is the structure that projects inferiorly in the sagittal plane between the cerebral hemispheres?

The cavernous sinus
The diaphragma sellae
The falx cerebri Correct
The tentorium cerebelli
The tentorium cerebri




The falx cerebri is a large sheet of dura matter that partially separates the cerebral hemispheres.

45

Blood supply of the brain

Supplies medial and superior surfaces of brain

A Anterior cerebral artery
B Anterior communicating arteries
C Basilar artery
D Internal carotid
E Middle cerebral artery
F Posterior cerebral arteries
G Posterior cerebella artery
H Posterior communicating arteries
I Vertebral arteries

Anterior cerebral artery

The anterior and middle cerebral arteries leave the circle of Willis to supply the cerebral hemispheres.

An occlusion to the anterior cerebral artery causes weakness and paralysis of contralateral leg with milder symptoms in the arm.

46

Blood supply of the brain

Lateral surface of brain

A Anterior cerebral artery
B Anterior communicating arteries
C Basilar artery
D Internal carotid
E Middle cerebral artery
F Posterior cerebral arteries
G Posterior cerebella artery
H Posterior communicating arteries
I Vertebral arteries

Middle cerebral artery

Occlusion of posterior cerebral artery may cause a wide variety of signs.

47

A 63-year-old smoker presents with haemoptysis.
There is a right hilar mass on the chest x ray and the right hemidiaphragm is elevated.

Which nerve is involved?

External laryngeal nerve
Left vagus
Right phrenic
Right vagus
Sympathetic chain

Right phrenic

The right phrenic nerve passes over the front of the right hilum and is more frequently involved in malignant disease than the left, which passes more anteriorly.

The phrenic nerve is the only motor supply to the diaphragm. It also supplies sensation to the central part of the diaphragm.

Traumatic injury to the phrenic nerve and involvement in malignant processes can result in paralysis of the corresponding half of the diaphragm.

48

You are called urgently to the resuscitation area of the emergency department to see a 24-year-old male. He was attacked with an axe and has a wound on the back of the head, near to the vertex.

Which of the following is the sinus most likely to have been penetrated?

Cavernous sinus
Sigmoid sinus
Superior petrosal sinus
Superior sagittal sinus
Transverse sinus

Superior sagittal sinus

The superior sagittal sinus lies in the upper border of the falx cerebri.

It begins at the crista galli and terminates at the internal protuberance.

49

A child presents with a two day history of vomiting, headache and confusion. CT head shows swelling of the third ventricle and the lateral ventricles. The fourth ventricle appears normal.

Where is the obstruction likely to be?

Aqueduct of Sylvius
Foramina of Luschka and Magendie
Foramen of Monro
Fourth ventricle
Subarachnoid space surrounding the brainstem

Aqueduct of Sylvius


The CT findings suggest that there is an obstruction to CSF flow between the third and fourth ventricles. The cerebral aqueduct of Sylvius is the narrow channel connecting these ventricles.

Obstruction at this site results in hydrocephalus and may be caused by

Tumour
Cellular debris with intraventricular haemorrhage
Bacterial and fungal infections.

50

A 34-year-old male presents with weakness of the right hand. You note global wasting of the small hand muscles, there is also sensory loss over the medial border of the forearm and hand.

He says he was climbing a tree to rescue a kite and fell. Whilst falling he grabbed a branch and this pulled on his arm.

Injury to which of the following structures is the most likely explanation of this clinical presentation?

Cervical spine
Lower brachial plexus
Median nerve in the forearm
Radial nerve in the upper arm
Ulnar nerve at the elbow

Lower brachial plexus

This is a classic story of a lower brachial plexus injury; sudden upward movement of the abducted arm. This causes features of an ulnar nerve palsy which is supplied by the lower brachial plexus roots C8 and T1.(Klumpke's paralysis)

The median and radial nerves can be excluded because of the typical ulnar nerve findings.

The ulnar nerve can be damaged at the elbow from chronic pressure, leaning on the elbows, and direct trauma. However, this injury is a stretching injury of the arm.

A cervical spine injury would be expected to have other associated neurological signs.

51

A 62-year-old male presents with weakness of the right hand.
You note global wasting of the small hand muscles, there is also sensory loss over the medial border of the forearm around the elbow.

Which nerve root is damaged?

C5
C6
C7
C8
T1

T1

This patient has Klumpke's paralysis due to damage to the T1 nerve root.

This root eventually supplies the median and ulnar nerves.

The ulnar nerve supplies all of the intrinsic hand muscles except for those of the thenar eminence and the first and second lumbricals which are innervated by the median nerve.

52

A 56-year-old male with diabetes presents with a two day history of weakness of the left foot being aware of a feeling of dragging the toes along the floor when walking.

He has been diabetic for two years and on previous annual review no abnormalities were noted.
On examination he is unable to dorsiflex his left foot together with eversion of the foot. The right foot is unaffected. Plantar flexion and inversion are normal.
Which sensory abnormality would you expect to find in association with this motor defect?

No associated sensory loss
Sensory loss over the big toe
Sensory loss over the entire foot to the ankle.
Sensory loss over the lateral part of the leg and dorsum of the foot
Sensory loss over the plantar aspect of the foot

Sensory loss over the lateral part of the leg and dorsum of the foot

This male with diabetes appears to have developed a mononeuropathy with the features compatible with a common peroneal nerve neuropathy. This would result in a loss of sensation over the dorsum of the foot and lateral part of the leg with sparing of the fifth toe.

Although you could argue that a peripheral neuropathy might be expected in this diabetic, the question specifically asks what defect would you expect to find with this neuropathy.

Also previously normal findings would argue against a sudden peripheral neuropathy.

53

heterotopia

CT scan image

The diagnosis is heterotopia.

There is a large mass of grey matter, which has the same signal characteristics as cortical grey matter on all MRI sequences. Heterotopia results from arrest of neuronal migration along their passage to the cortex.

54

A 24-year-old female teacher collapsed in the classroom after complaining of a severe headache associated with nausea.
She had been well in the preceding few days. She had no past medical history and did not take any regular or illicit drugs. She did not smoke or drink.
On arrival in casualty department, her Glasgow coma scale was 12/15 (motor 6 vocal 3 eyes 3) and there was nuchal rigidity. Her blood pressure was 145/85 mmHg, pulse was 90 beats per minute and regular and temperature was 37.1°C. Heart sounds were normal and chest appeared clear. Cranial nerve examination revealed no abnormalities. Fundoscopy was normal. There were no obvious focal neurological signs on examining the peripheral nervous system, although both plantar responses were extensor.

Bloods normal. CRP 5 (0-5)

A CT scan of her brain was normal

Lumbar puncture:

Appearance Xanthochromia -
Opening pressure 15 cmH2O (6-18)
CSF White cell count 6 cells/mL (

Arrange a four vessel cerebral angiogram

The presentation of sudden onset of severe headache associated with nausea and/or vomiting is typical of a subarachnoid haemorrhage.

Computed tomography (CT) scan of the head should be performed in all suspected patients and has a sensitivity of 90-95%.

A lumbar puncture is performed in negative CT scan patients with specific identification of xanthochromia. If xanthochromia is detected, as in this patient, a four vessel cerebral angiogram should be arranged urgently.

Magnetic resonance (MR) angiography is less sensitive and there are no advantages to performing an MR scan brain if the CT scan is negative.

There is no evidence of infection in this patient and, therefore commencement of antibiotics is not required.

55

A 30-year-old male presents with a week history of right arm weakness. Originally the problem began with severe pain in the neck which radiated into the right shoulder, which was followed by weakness.

Examination revealed winging of the right scapula with weakness of right shoulder abduction and elbow extension. There was some sensory loss over the lateral aspect of the right shoulder and right triceps reflex was absent.
What is the most likely diagnosis?

C7 entrapment radiculopathy
Central C5/6 disc prolapse
Neuralgic amyotrophy
Suprascapular nerve entrapment
Traction of lateral cord of brachial plexus

Neuralgic amyotrophy

Neuralgic amyotrophy is a brachial plexopathy (usually upper brachial plexus) usually preceded by an infective picture.

It usually presents with severe pain for days to weeks followed by weakness and sensory loss over the corresponding territory of the brachial plexus (more commonly C5-7).

It is self-limiting condition but recovery may be slow (years).

56

A 75-year-old woman presents with a two month history of episodic loss of vision in her right eye. Her electrocardiogram was normal and carotid ultrasound reveal a 49% stenosis of the right internal carotid artery, as assessed by the NASCAT criteria.
What is the most appropriate treatment for this patient?

Aspirin
Carotid endarterectomy
Dipyridamole
Clopidogrel
Warfarin

Aspirin

NICE guidelines recommend that patients who have had a suspected TIA who are at high risk of a stroke (ABCD score of 4 or above) should have aspirin (300 mg OD) started immediately. They also need specialist assessment and investigation within 24 hours of onset of symptoms. Secondary prevention measures should be introduced as soon as the diagnosis is confirmed, with consideration of individual risk factors.

The ABCD scoring system uses:

Age ≥60 (1)
BP ≥140/90mmHg at initial evaluation (1)
Clinical features (unilateral weakness 2, isolated speech disturbance 1, other 0)
Duration of symptoms (≥60 minutes, 10-59 minutes, 70%) who has had a TIA. The peri-operative risk of disabling stroke or death is approximately 3%. Current UK guidelines recommend endarterectomy for symptomatic patients with greater than 70% stenosis, based on the North American Symptomatic Carotid Endarterectomy Trial which showed clear benefit. The endarterectomy should be performed as soon as the patient is fit for surgery, preferably within two weeks of a TIA.

The benefit is marginal for symptomatic patients with 50-69% stenosis, but may be greater in male patients. NICE recommends these patients are also considered for endarterectomy. There is significantly less benefit for asymptomatic patients, even those with greater than 60% stenosis. Patients with less than 50% stenosis should not be considered for carotid surgery.

Recurrent stenosis can occur in 1-20% of patients following endarterectomy, and re-operation is needed in 1-3% of cases. Ipsilateral strokes occur in 9% of patients following endarterectomy, and 26% of those treated with medical management alone (within 2 years).

All patients with suspected non-disabling stroke or TIA who are considered as candidates for carotid endarterectomy should have carotid imaging within 1 week. If the patient has had a disabling stroke there is no real benefit in them undergoing the procedure.

Modified-release dipyridamole is indicated in combination with aspirin only once a TIA has been confirmed by a specialist. Alone, it is recommended only if aspirin is contraindicated or not tolerated.

Clopidogrel is recommended in patients who have had an ischaemic stroke, rather than a TIA.

Warfarin is only indicated with cerebral venous sinus thrombosis, or if the patient has atrial fibrillation.

Please note that for this explanation we have used the North American Symptomatic Carotid Endarterecomy Trial (NASCET) criteria, as opposed to the European Carotid Surgery Trialists' Collaborative Group (ECST) criteria when discussing carotid endarterectomy. Patients should be considered for endarterctomy if they have symptomatic carotid stenosis of 70-99% as assessed according to the ECST criteria. Carotid imaging reports will state which criteria are being used.

57

A 60-year-old male is referred with episodes of severe vertigo which may last up to four hours and are associated with vomiting and pain in the right ear.
On examination during an attack he is noted to have right horizontal nystagmus together with mild right-sided sensorineural deafness.
Which one of the following is the most likely diagnosis?

Acoustic neuroma
Benign positional vertigo
Labyrinthitis
Ménière's disease
Vertebrobasilar ischaemic attacks

Ménière's disease

This is a typical history of Ménière's disease. The attacks are paroxysmal, last for hours and consist of:

Vertigo
Vomiting
Pressure within the ear
Deafness
After many attacks the patient may develop irreversible sensorineural deafness (of low frequency).

Prochlorperazine or cinnarizine usually helps vomiting, and restriction of salt and fluid may hasten resolution. Occasionally diuretics may be used but there is little evidence for efficacy.

58

An 18-year-old woman is noted to have persistent polyuria in excess of 4 litres per day whilst recovering from a head injury she sustained in a road traffic accident.
Investigations reveal:

Potassium 4.1 mmol/L (3.5-4.9)
Calcium 2.4 mmol/L (2.2-2.6)
Glucose 5.6 mmol/L (3.0-6.0)

Which one of the following is the most effective method of confirming the diagnosis?

Autoantibodies to vasopressin neurones
MRI of the hypothalamus and pituitary
Therapeutic trial of low dose DDAVP
Vasopressin concentration
Water deprivation test

Water deprivation test

The history and confirmed polyuria are suspicious of diabetes insipidus which is not uncommon after head injury. This can be confirmed with a water deprivation test where failure of urine concentration would be expected.

A MRI of the pituitary and hypothalamus may show no abnormality but would be undertaken after the diagnosis of DI is confirmed. Similarly anterior hormone assessment would also be undertaken after the diagnosis is confirmed.

A therapeutic trial of DDAVP is only appropriate if the diagnosis of DI is confirmed as primary polydipsia can also be a feature of trauma and in these circumstances DDAVP may precipitate hyponatraemia.

Autoantibodies to ADH neurones are irrelevant.

59

A 50-year-old man presented with paraesthesia in the ring and little fingers of his right hand.
On examination there was wasting of the hypothenar eminence of his right hand.
Which one of the following movements would you expect to be weak in this patient?

Abduction of the thumb
Adduction of the thumb
Extension of the little finger
Flexion of the index finger
Opposition of the thumb

Adduction of the thumb

The clinical features suggest an ulnar neuropathy. The ulnar nerve supplies the hypothenar muscles (opponens digiti minimi, abductor digiti minimi, flexor digiti minimi), the third and fourth lumbricals, dorsal and palmar interossei and adductor pollicis. It also provides sensory innervation to the fith digit and medial half of the fourth digit.

Abduction and opposition of the thumb and flexion of the index finger are via the median nerve.

Extension of the little finger is via the radial nerve.

60

A 75-year-old female presents with an acute stroke and is noted to have a partial left homonymous hemianopia, a mild left hemiparesis and left hemisensory inattention.
Where on the right is the most likely area of infarction?

Frontal lobe
Medial temporal lobe
Occipital lobe
Parietal lobe
Thalamus

Parietal lobe

A unilateral parietal lobe lesion, left or right, causes a contralateral hemihypesthesia, mild hemiparesis, parietal ataxia, homonymous hemianiopia or inferior quadrantanopia and unilateral impairment of optokinetic nystagmus.

A left (usually dominant) parietal lesion causes the above signs in addition to sensory aphasia, Gerstmann syndrome (dysgraphia, dyscalculia, finger agnosia, left-right disorientation), bilateral apraxia and tactile agnosia.

A right (usually non-dominant) parietal lesion also causes left extinction phenomenon, left visual neglect, neglect of the left side of the body, anosognosia, impaired spatial processing and dressing apraxia.

Biparietal lesions result in markedly impaired orientation and spatial processing and ataxia.

An occipital lobe lesion usually causes contralateral homonymous hemianopia or quadrantanopsia. It does not typically cause hemiparesis or inattention.

Frontal lesions do not usually cause visual defects.

Temporal lobe lesions classically cause an homonymous superior quadrantanopsia. Again, there is not usually hemiparesis or inattention.

61

A 40-year-old male presents to his GP with a two week history numbness and a burning sensation on the lateral aspect of the left upper thigh.
Examination reveals sensory loss over the anterolateral thigh.
Which one of the following nerves is most likely to be involved in this patient?

Femoral nerve
L2 nerve root IncorrectIncorrect answer selected
L3 nerve root
Lateral cutaneous nerve of the thigh
Obturator nerve

The pure sensory loss makes the diagnosis of meralgia paraesthetica and is a consequence of damage to the lateral cutaneous nerve of the thigh.

It is usually a consequence of entrapment at the lateral inguinal ligament or less likely, trauma, ischaemia or a retroperitoneal lesion.

Lateral cutaneous nerve of the thigh

The pure sensory loss makes the diagnosis of meralgia paraesthetica and is a consequence of damage to the lateral cutaneous nerve of the thigh.

It is usually a consequence of entrapment at the lateral inguinal ligament or less likely, trauma, ischaemia or a retroperitoneal lesion.

62

Which of the following statements is true of acute compartment syndrome?

Loss of distal pulse is an early sign
Only occurs following fractures
Passive stretch of affected muscles exacerbates pain
Rarely requires surgical intervention
The presence of pain is unhelpful in diagnosis

Loss of peripheral pulses is a late sign indicating that the pressure within the compartment has exceeded arterial blood pressure.

Compartment syndrome can occur in the absence of a fracture, for example, crush injuries.

Passive stretch of the muscles traversing the compartment increases pain.

Treatment involves decompression of the affected compartment(s) including the skin.

Pain is the earliest and most reliable symptom of the onset of compartment syndrome.