Neuro 2 Flashcards
1
Q
what is bulbar palsy?
A
bulbar palsy denotes diseases of the nuclei of CN IX-XII in the medulla
2
Q
what are the signs of bulbar palsy?
A
LMN lesion of the tongue and muscles of talking and swallowing: flaccid, fasciulating tongue (like a sac of worms); jaw jerk Is normal or absent, speech is quiet, hoarse or nasal
3
Q
what are the causes of bulbar palsy?
A
MND GBS polio MG brainstem tumours syringobulbia
4
Q
what is corticobulbar palsy ?
A
UMN lesion of muscles of swallowing and talking due to bilateral lesions above the min-pons eg corticobulbar tracts (MS, MND, stroke, central pontine myelinolysis)
it is commoner than bulbar palsy
5
Q
what are the signs of corticobulbar palsy?
A
slow tongue movements, with slow deliberate speech, increased jaw jerk, increased pharyngeal and palatal reflexes. pseudobulbar affect (weeping unprovoked by sorrow or mood-incongruent giggling - extremely laughing or crying)
6
Q
what is pseudobulbar affect seen in?
A
parkinsons brain tumour brain injury stroke dementia
7
Q
what is ataxia?
A
ataxia is the name given to a group of neurological disorder that affect balance, coordination and speech
8
Q
what is the cause of cerebellar syndrome?
A
Friedreich’s ataxia - AR, typical onset 10-15 years, gait ataxia and kyphoscoliosis are most common
Ataxic telangiectasia - AR, cerebellar ataxia, telangiectasia are common features
neoplasm - cerebellar haemangioma
stroke, alcohol, MS, hypothyroidism
drugs - phenytoin and lead posing
9
Q
how does cerebellar syndrome present?
A
DANISH
- D - dysdiadochokinesia, Dysmetria (past pointing, Drunk (may appear drunk)
- ataxia - limb and truncal
- nystagmus - intention tremor
- slurred staccato speech, scanning dysarthria
- hypotonia
10
Q
what is paraplegia?
A
paralysis of both legs - always cause by spinal caused by spinal cord lesion
11
Q
what is hemiplegia?
A
paralysis of one side of the body caused by a lesion in the brain
12
Q
what are the different tracts in the spinal cord?
A
corticospinal (motor, descending UMN, decussates at the medulla)
dorsal column (ascending sensory tract, proprioception, vibration and 2 point discrimination, decussates at the medulla)
spinothalamic (ascending sensory tract), pain and temp, decussates almost immediately in the spinal cord)
13
Q
what are UMN signs?
A
Upper motor neurone signs: signs are CONTRALATERAL to lesion
• Indicate that the lesion is above the anterior horn cell i.e. in the spinal
cord, brainstem and motor cortex
• Increased muscle tone - SPASTICITY:
- Velocity dependent and non-uniform i.e. the faster you move the
patients muscle, the greater the resistance, until it finally gives way
in a clasp-knife manner
• Weakness:
- Flexors are generally weaker than extensors in legs and reverse in
arms
• Increased reflexes, they are brisk - HYPERREFLEXIA
14
Q
what are lower motor neurone signs?
A
Lower motor neurone signs: signs are IPSILATERAL to lesion
• Indicate that the lesion is either in the anterior horn cell or distal to the
anterior horn cell i.e. in anterior horn cell, plexus or peripheral nerve
• Decreased muscle tone
• WASTING (atrophy) +/- FASCICULATIONS (spontaneous involuntary
twitching)
• Weakness that corresponds to those muscles supplied by the involved
cord segment, nerve root, part of plexus or peripheral nerve
• Reflexes are reduced or absent
15
Q
what is spondylolisthesis?
A
Slippage of one vertebra over the one below
Nerve root comes out ABOVE the disc, therefore root affected will be the
one BELOW the disc herniation e.g. L4/L5 herniation leads to L5 nerve
root compression
16
Q
what is myelopathy?
A
caused by spinal cord compression - UMN signs
spasticity, weakness, hyperreflexia
spinal cord disease
17
Q
what is radiculopathy?
A
caused by spinal root compression = LMN signs decreased muscle tone wasting weakness fasciculations pain down dermatome weakness in myotome no UMN signs
18
Q
what are some causes/risk factors for spinal cord compression?
A
vertebral body neoplasms (most common cause of acute compression usually secondary malignancy) spinal pathology (disc herniation, disc prolapse, spinal stenosis - can occur in the central canal producing myelopathy)
rarely may be caused by infection, haematoma (warfarin), primary spinal cord tumour (glioma, neurofibroma)
19
Q
what is the clinical presentation of spinal cord compression?
A
back pain - the earliest and most common symptom - may be worse on lying down and coughing
lower limb weakness
sensory changes: sensory loss and numbness
neurological signs depend on the level of the lesion. Lesions above L1 usually result in upper motor neuron signs in the legs and a sensory level. Lesions below L1 usually cause lower motor neuron signs in the legs and perianal numbness. Tendon reflexes tend to be increased below the level of the lesion and absent at the level of the lesion
in acute compression - often tone and reflexes take time to develop
20
Q
how do you diagnose spinal cord compression?
A
do not delay imaging at any cost - irreversible paraplegia may follow if the cord is not decompensated
MRI is the cold standard - it identifies the cause and sit of compression
screening bloods
CXR
21
Q
how do you treat spinal cord compression
A
immobilisation and decompressive/stabilisation surgery
high-dose oral dexamethasone
urgent oncological assessment for consideration of radiotherapy or surgery
22
Q
what is cauda equine syndrome?
A
it is a medical emergency
- the cauda equina is formed by the nerve roots distal to the level of termination of the spinal cord at L1/L2
cauda equina syndrome is damage at or caudal to L1
23
Q
what are the functions of the frontal lobe?
A
voluntary movement on opposite side of body
frontal lobe of dominant hemisphere controls speech (broca’s area) and writing.
intellectual functioning, thought processes, reasoning and memory.
24
Q
what is the function of the parietal lobe?
A
Receives and interprets sensations, including pain, touch, pressure, size and
shape and body-part awareness (proprioception)
25
what is the function of the temporal lobe?
Understanding the spoken word (Wernicke’s - understanding), sounds as well
as memory and emotion
26
what is the function of the occipital lobe?
Understanding visual images and meaning of written words
27
how many spinal nerves are there?
31 pairs
- Cervical - 8 nerves
- Thoracic - 12 nerves
- Lumbar - 5 nerves
- Sacral - 5 nerves
- Coccyx - 1 nerve
28
how should you treat a myasthenic crisis?
plasmapheresis and IV IG
29
what is spinal stenosis?
it is a condition typically resulting from degenerative changes in the lumbar spine
it leads to a narrowed spinal canal, lateral recesses and neural foramina
it is a common causes of spinal compression
30
what are the symptoms of spinal stenosis?
- back pain
- activity related back pain
- leg pain when walking
- stooped posture when walking
- leg numbness or paraesthesia
- absence of examination findings - (neurological deficits are common, diminished ankle/knee jerk reflex might be present)
31
what are some causes of spinal stenosis?
facet joint and ligamentous hypertrophy
intervertebral disc protrusion
spondylolisthesis
32
what investigations should you perform for spinal stenosis?
plain XR - degenerative changes or spondylolisthesis
MRI - compression of the neural elements and soft tissue
33
how would you treat spinal stenosis?
if there is significant acute neurological deficit - surgical decompression
if there isn't then give analgesics
34
what are the complications of spinal cord compression?
cauda equina
permanent neurological deficit
complication from immobility
progression of spondylolisthesis after surgery.
35
what are some common causes of a foot drop?
- L5 radiculopathy
- sciatic nerve lesion
- common peroneal nerve lesion
- superficial or deep peroneal nerve lesion
- other possible includes central nerve lesions (e.g. stroke) but other features are usually present
36
what is sciatica?
pain, numbness and a singling sensation that radiates from the lower back and travels down one of the legs to the foot and toes
S1 nerve root compression
37
how would cauda equine syndrome present?
```
flaccid, areflexic weakness
bilateral sciatica
saddle anaesthesia
bladder/bowel dysfunction
erectile dysfunction
variable leg weakness
```
38
what are some differential diagnosis for cauda equina syndrome?
conus medullaris syndrome
vertebral fracture
peripheral neuropathy
mechanical back pain
39
what investigations would you perform for cauda equina syndrome?
MRI to localise lesion
knee flexion - test L5-S1
ankle plantar flexion (downwards) - test S1-S2
straight leg raising L5, S1, too problem - people with acute disc can barely get one leg off bed
femoral stretch test - L4 root problem
40
how would you treat cauda equina syndrome?
refer to neurosurgeon ASAP to relieve pressure or risk of irreversible paralysis/sensory loss/incontinence
Microdiscectomy - removal of part of the disc - may tear dura!
• Epidural steroid injection - more effective for leg pain
• Surgical spine fixation - if vertebra slipped
• Spinal fusion - reduces pain from motion and nerve root inflammation
41
what is peripheral neuropathy?
damage to the peripheral nerves - can be divided into conditions which predominantly cause a motor loss or sensory loss
42
what are some peripheral neuropathies that cause predominantly motor loss?
Guillain-Barre syndrome - demyelinating neuropathy
Diphtheria - infective neuropathy
lead poisoning - toxic neuropathy
Charcot-Marie-Tooth (hereditary sensorimotor neuropathy) - degenerative neuropathy.
43
what peripheral neuropathies cause predominantly sensory loss?
- diabetes (metabolic/infarctive neuropathy)
alcoholism - toxic neuropathy - secondary to both direct toxic effects and reduced vitamin absorption - sensory symptoms typically present prior to motor symptoms.
vitamin b12 deficiency
leprosy
amyloidosis
44
how may a sensory neuropathy present?
numbness - pins and needles
affects extremities first e.g. glove and stocking distribution
there may be difficulty handling small objects such a buttons
signs of trauma e.g. finger burns or joint deformation may indicate sensory loss
diabetic and alcoholic neuropathies are typically painful
45
how may peripheral motor neuropathy present?
- often progressive - - may be rapid
- weak or clumsy hands
- difficulty in walking e.g. falls and stumbling
- difficulty breathing e.g. reduced vital capacity
- LMN lesion: wasting and weakness is most marked in the distal muscle of the hands and feet - foot or wrist drop, reflexes are reduced are absent
46
what is alcoholic neuropathy?
secondary to both direct toxic effects and reduced absorption of B vitamins
sensory symptoms typically present prior to motor symptoms
47
how can vitamin B12 deficiency affect the nervous system?
subacute combined degeneration of spinal cord
dorsal column usually affected first (joint, position, vibration) prior to distal paraesthesia
48
what is a mononeuropathy?
it is a process affecting a single nerve.
lesions of individual peripheral or cranial nerves
usually caused by trauma or entrapment
49
what is mononeuritis multiplex?
the term is used if 2 or more peripheral nerves are affected
50
what are some causes of mononeuritis multiplex?
```
Wegener's granulomatosis
aids
amyloid
RA
DM
sarcoidosis
polyarteritis nodose
leprosy
carcinoma
```
51
what is carpal tunnel syndrome?
it is the most common mononeuropathy
| it results from pressure and compression on the median nerve as it passes through the carpal tunnel in the wrist
52
what are some causes of carpal tunnel syndrome
usually idiopathic
can be associated with hypothyroidism, DM, pregnancy in the 3rd trimester, amyloidosis including dialysis patients, obesity, RA, acromegaly.
53
how does carpal tunnel syndrome present?
symptoms are intermittent and onset is gradual
aching pain in the hand and arm (especially at night) can wake the patient up
paraesthesia - tingling or pricking in the thumb, index, middle and 1/2 ring fingers plus palm (median nerve distribution)
may be sensory loss and weakness of abductor pollicis brevis and wasting of the thenar eminence
light tough and 2 point discrimination and sweating may be impaired
54
how can you diagnose carpal tunnel syndrome?
EMG
Phalen's test (patient can only maximally flex wrist for 1 minute
Tinel's test - tapping on the nerve at the wrist induces tingling but non-specific
55
how can you treat carpal tunnel syndrome?
wrist splint at night
local steroid injection (hydrocortisone)
decompression surgery
56
what is the medium nerve and what is its function?
```
C6-T1
the median nerve is the nerve of precision grip - muscles involved are easier to remember if you use LOAF
lumbricals
opponens pollicis
abductor pollicis brevis
flexor pollicis brevis
```
57
what can cause problems with the ulnar nerve? and what will problems with it cause?
ulnae nerve C7 -T1
vulnerable to elbow trauma - most often compression occurs at the epicondylar groove or at the point where the nerve passes between the 2 heads of the flexor carpi ulnaris
it leads to weakness/wasting of:
- medial wrist flexors
- interossei - cannot cross the fingers in the good luck sign
- medial 2 lumbricals - claw hand
- sensor loss over medial 1.5 fingers and ulnar side of hand
- weak little finger abduction
- flexion of the 4th and 5th DIP joint is weak
58
how do you treat an ulnar nerve compression?
rest and avoid pressure on the nerve
| night time soft elbow splinting may be required
59
what does the radial nerve and what happens when it is compressed/damaged?
the radial nerve opens the fist
it may be damaged by compression against the humerus
signs: test for wrist and finger drop with elbow flexed and arm pronates
- sensory loss is variable - the dorsal aspect of the root of the thumb (anatomical snuff box) is most reliably affected
```
muscles involved:
BEST
Brachioradialis
Extensors
Supinator
Triceps
```
60
what is the function of the phrenic nerve? and what can cause phrenic nerve mononeuropathy?
phrenic nerve - C3, 4, 5 keeps the diaphragm alive
*consider phrenic palsy if orthopnoea (shortness of breath whilst lying flat) with raised hemidiaphragm on CXR
causes:
- lung cancer
- myeloma, thymoma - tumour of the thymus
- cervical spondylosis/trauma
- MS
- thoracic surgery
- C3-5 zoster
- HIV
- muscular dystrophy
61
what can cause sciatic nerve neuropathy and what are the symptoms of it?
L4-S3
- damaged by pelvic tumours or fractures of pelvis or femur
- lesions affect the hamstrings and all muscles below the knee - resulting in foot drop
- there is also loss of sensation below the knee laterally
62
what can cause common peroneal nerve neuropathy and what are the symptoms of it?
lateral popliteal palsy
originates from the
sciatic nerve just above the knee
often damaged as it winds round the fibular head due to trauma or sitting cross-legged
signs: - foot drop, weak ankle dorsiflexion/eversion, sensory loss over dorsum (top) of foot
63
what can cause tibial nerve neuropathy and what are the symptoms of it?
originates from the sciatic nerve just above the knee
lesions lead to an inability to stand on tiptoe (plantarflexion), invert the foot or flex the toes
also sensory loss over the sole.
64
what is Pancoast tumour?
it is a bronchogenic carcinoma at the lung apex that may invade the lower roots of the brachial plexus producing progressive pain in the ipsilateral arm, distal wasting and weakness, sensory loss particularly in the C7, 8 and T1 dermatomes
there may be an associated Horner's syndrome as a result of involvement of pre-ganglionic sympathetic fibres
65
causes of polyneuropathy?
Infection (leprosy, Diptheria,, Lyme disease, HIV)
Inflammatory (GBS, chronic inflammatory demyelinating polyneuropathy, sarcoid, Sjogren's syndrome, vasculitis
neoplastic
metabolic (DM, uraemia, myxoedema, amyloid)
nutritional (VB12 deficiency)
Toxic - alcohol, lead, arsenic, gold, mercury, thallium, insecticides
drugs - isoniazid, metronidazole, nitrofurantoin, amiodarone
66
what is a subarachnoid haemorrhage?
spontaneous bleeding into the subarachnoid space - between the arachnoid layer and of the meninges and the pia mater
67
what is the most common cause of a subarachnoid haemorrhage?
ruptured berry aneurysm (rupture of the junction of the posterior communicating artery with the internal carotid or of the anterior communicating artery with the anterior cerebral artery
68
what are berry aneurysms associated with ?
polycystic kidney disease and coarctation of the aorta
69
what are some other causes of SAH?
- arteriovenous malformation
- sometimes no cause is found
- rare - bleeding disorder, mycotic aneurysms - endocarditis, acute bacterial meningitis, tumours
70
what are some RF for SAH?
```
HTN
known aneurysm
fam history
disease that pre-disposes to aneurysm - PCKD, Ehlers Danlos syndrome, coarctation of the aorta
smoking
bleeding disorder
post-menopausal decreased oestrogen
```
71
what is the clinical presentation of SAH?
- sudden onset severe occipital headache - thunderclap - like being kicked in the head, severe pain 12/10
- vomiting, collapse, seizure and coma often follow
- depressed level of consciousness
- coma/drowsiness may last for days
- neck stiffness
- kernig's sign
- Brudzinki's sign
- retinal and vitreous bleeds
- papilloedema - dilated optic disc
- vision loss or diplopia
- marked increase in BP as a reflex
- sentinel headache - may precede SAH due to a small warinign leak
72
what are the DD of SAH?
Migraine
meningitis
Intracerebral bleeds
cortical vein thrombosis
73
how would you diagnose SAH?
head CT - gold standard - detects >90% of SAH within the 1st 48 hours - you will see hyper dense areas in the basal cisterns, major fissures and sulci
```
FBC
Clotting profile
serum electrolytes
troponin I - often elevated
ECG
```
consider CT angiography if aneurysm confirmed to see extend
LP - if CT normal but SAH still suspected (xanthochromia - yellow CSF due to breakdown of blood products to produce bilirubin)
74
how should you manage a SAH?
IV fluids
calcium channel blocker to reduce vasospasm - IV or oral nimodipine
endovascular coiling
give stool softeners and antitussives (to stop cough - codeine phosphate) to reduce risk of rebleed
75
what is a subdural haemorrhage?
caused by the accumulation of blood in the subdural space - between the arachnoid and dura mater following rupture of a bridging vein between cortex and venous sinus
76
who is SDH common in?
most common where patient has a small brain e.g. alcoholics or dementia etc or babies that have suffered a trauma or elderly that have brain atrophy that makes the bridging veins more vulnerable
77
what are the different types of subdural haematoma?
- Acute subdural haematoma (<3 days old, diffusely hyperdense)
- Subacute subdural haematoma (3-21 days old, heterogeneously hyperdense/isodense)
- Chronic subdural haematoma (>21 days old, diffusely hypodense)
- Acute-on-chronic subdural haematoma (areas of hyperdensity within hypodense haematoma).
78
what is an acute subdural haematoma?
An acute subdural haematoma is a collection of fresh blood within the subdural space and is most commonly caused by high-impact trauma. Since it is associated with high-impact injuries, there is often other brain underlying brain injuries.
79
what is a chronic subdural haematoma?
A chronic subdural haematoma is a collection of blood within the subdural space that has been present for weeks to months.
80
what are the risk factors for a subdural haematoma?
- Traumatic head injury, cerebral atrophy/increasing age - makes bridging
veins more vulnerable
- Alcoholism (caused cerebral atrophy), anticoagulation and physical abuse of
infant
81
how might a SDH present?
- interval between injury and symptoms can be days to weeks or months
- fluctuating level of consciousness +/- insidious physical or intellectual slowing
- sleepiness
- headache
- personality changes
- unsteadiness
- signs of raised ICP - headache, vomiting, nausea, seizure and raised BP
- focal neurology (often occur a long time after injury)
- occasionally seizures
- stupor, coma
82
why does a SDH develop much more slowly in the elderly
in elderly due to decrease in brain weight and increase in subdural
space with increasing age, haematoma and symptoms will develop MUCH
SLOWER as brain effectively has more compliance to raised ICP
83
what are the DD for SDH?
```
stroke
dementia
CNS mass - tumour or abscess
SAH
EDH
```
84
how is a SDH diagnosed?
CT head - diffuse spreading crescent shaped collection of blood, as the clot ages and protein degradation occurs it becomes isodense - the same colour as brain tissue and eventually becomes hypodense, you will see shifting of the midline structures
can also consider and MRI or plain skull XR
85
how would you manage a SDH?
depends on size
small or incidental subdurals can be observed conservatively (obs, monitoring and follow up imaging, prophylactic anti-antiepileptics, correct coagulopathy)
if large - burr whole craniotomy - surgery
IV mannitol to reduce ICP
86
what is an extradural haemorrhage?
An extradural (or ‘epidural’) haematoma is a collection of blood that is between the skull and the dura. It is almost always caused by trauma and most typically by ‘low-impact’ trauma (e.g. a blow to the head or a fall). The collection is often in the temporal region since the thin skull at the pterion overlies the middle meningeal artery and is therefore vulnerable to injury.
87
what are the causes of EDH?
most commonly due to traumatic head injury resulting in fracture of the temporal or parietal bone causing laceration of the middle meningeal artery, typically after trauma of the temple
88
what is the clinical presentation of an EDH?
- brief post traumatic LOC or initial drowsiness
- lucid interval - period of time between traumatic brain injury and decrease in consciousness - whilst the haematoma is still small and there is some bleeding, can last several hours or even days, followed by altered consciousness
- severe headache, nausea and vomiting, confusion and seizures - due to rising ICP and hemiparesis (weakness of half the side of the body) with brisk reflexes
- rapid rise in ICP as the epidural space is full of blood resulting in brain compression
- ipsilateral pupil dilates, coma deepens, bilateral limb weakness develops and breathing becomes deep and irregular - signs of brainstem compression
- decreased GCS and coning (the brain herniates through the foramen magnum
- death due to respiratory arrest - of surgical intervention not done fast enough
- bradycardia and raised BP are late signs
89
what are the differentials of EDH?
```
epilepsy
carotid dissection
carbon monoxide poisoning
subdural haematoma
subarachnoid haemorrhage
meningitis
```
90
how do you diagnose and EDH?
CT - gold standard - will show a hyper dense haematoma that is biconvex/lense shaped/lemon shaped
Skull Xray - may be normal or show fracture line crossing the middle meningeal artery
91
how do you manage and EDH?
ABCDE emergency management - assess and stabilise the patient
give IV mannitol if there is increased ICP
refer to neurosurgery - clot evacuation +/- ligation of bleeding vessels
maintain airway via intubation and ventilation in unconscious patient
92
what is anterior cord syndrome?
damage to the anterior 2/3rds of the spinal cord usually as a result of decreased blood flow or occlusion to the anterior spinal artery
93
what are some causes of anterior cord syndrome?
trauma e.g. penetrating injury, burst fracture of vertebra
| occlusion of the anterior spinal artery
94
in anterior cord syndrome what tracts are affected?
corticospinal
| spinothalamic
95
how does anterior cord syndrome present?
bilateral motor paralysis
loss of pain and temperature sensations
autonomic dysfunction below the level of the lesion e.g. bladder, bowel and sexual dysfunction. dorsal columns are mainly preserved
96
how do you diagnose and treat anterior cord syndrome?
spinal MRI
| treat underlying cause
97
what is brown-sequard syndrome and how does it present ?
hemi-section of the spinal cord
- Ipsilateral loss of; proprioception, motor & fine touch
- Contralateral loss of; pain, temperature & crude touch
98
what is a myopathy?
disease of the muscle in which the muscle fibres do not function properly
they usually affect the muscle without involving the nervous system
99
how do myopathies present?
muscle weakness
fatigability
pain at rest indicated inflammatory myopathy
pain on exercise indicated ischaemia or metabolic myopathy
100
what are some causes of toxic myopathies ?
alcohol
steroid
ciclosporin
statins
to treat : stop the implicated drug
101
what is polymyositis and how does it present?
an inflammatory myopathy
insidious, symmetrical proximal muscle weakness due to muscle inflammation
auto-immune mediated striated muscle inflammation
can result is dysphagia, dysphonia or respiratory weakness
Extra-muscular signs - arthralgia (joint pain), Raunaud's, myocardial involvement
102
how do you diagnose polymyositis?
muscle enzymes - ALT, AST, CK all raised
EMG shows fibrillation potentials
muscle biopsy = diagnostic
103
how do you treat polymyositis?
oral prednisolone
| immunosuppressive e.g. azathioprine or cytotoxics
104
what is poliomyelitis?
what are the symptoms
and how do you treat it?
caused by polio - which was eradicated in the UK due to polio vaccine
it presents as a 2 day history of flu-like prodrome with fever then pre-paralytic stage
- pre-paralytic stage: fever, tachycardia, headache, vomiting, stiff neck and unilateral tremor (in 50% this progresses to paralytic stage)
- paralytic stage - myalgia, LMN signs +/- respiratory failure
Treatment = supportive
105
what is metabolic/acquired myopathy?
often part of systemic disease
| - thyroid disease, carcinoma, Cushing's disease, hypo and hypercalcaemia
106
what are muscular dystrophies ?
- Group of genetic diseases with progressive degeneration and weakness of
specific muscle groups
- Primary abnormality may be in the muscle membrane
- Secondary effects are marked variation in the size of individual muscle
fibres and deposition of fat and connective tissue
107
what is Duchenne's muscular atrophy?
• Most common - 3/1000 male live births
- X-linked RECESSIVE - thus ONLY AFFECTS MALES
• Duchenne gene produces dystrophin - in Duchenne’s the dystrophin
made is non-functional
108
how does Duchenne's muscular atrophy present?
- By 4yrs there is clumsy walking, then difficulty standing and
respiratory failure
- Pseudohypertrophy - due to fat & connective tissue deposition is
seen in calves - calves look muscular but just filled with fat &
connective tissue
109
how do you diagnose and treat Duchenne's muscular atrophy?
```
• Diagnosis:
- Creatine kinase (CK) is RAISED 40-FOLD
- Genetic testing
- Muscle biopsy - diagnostic
• Treatment:
- No cure - some survive beyond 20yrs
- Supportive - physiotherapy, occupational therapy
```
110
what is Becker's Muscular Dystrophy?
• Rarer - 0.3 per 1000 MALE births - X-linked RECESSIVE
• Duchenne gene mutation results in a PARTIALLY FUNCTIONAL
DYSTROPHIN
• Presents with similar but MILDER SYMPTOMS at a LATER AGE with a
BETTER PROGNOSIS than DUCHENNE’S
111
what are myotonic disorders?
cause tonic muscle spasm - myotonia
112
what is dystrophia myotonica?
```
• RARE - 1 in 20,000
AUTOSOMAL DOMINANT Cl- channelopathy
Onset at 25yrs
Clinical presentation:
- Distal-onset weakness - hand/foot drop
- Weak sternomastoids
- Myotonia
- Facial weakness and muscle wasting give long, haggard
appearance
- Cataracts, male frontal baldness, diabetes, testis/ovary atrophy,
reduced cognition
Treatment:
- Supportive aimed at managing symptoms
- Physiotherapy to maintain muscle strength
```
113
what things would suggest myopathy over neuropathy?
Gradual onset of SYMMETRICAL PROXIMAL WEAKNESS e.g. difficulty
combing hair and climbing stairs
Dystrophies usually affect SPECIFIC MUSCLE GROUPS i.e. specific
weakness on first presentation
Preserved tendon reflexes
114
what things would suggest neuropathy over myopathy?
paraesthesia
bladder problems
distal weakness
115
what does rapid onset of symptoms suggest?
neuropathy or a toxic or metabolic myopathy
116
what does exercise fatigability suggest ?
myasthenia gravis
117
what does spontaneous pain at rest and local tenderness suggest ?
inflammatory myopathy
