Neuro Paces Flashcards
How to test upper limb myotomes and peripheral nerve
C5- shoulder abduction
C6- elbow flexion and wrist extension
C7- elbow extension
C8- thumb extension
T1- finger abduction
Median - flexion and pronation
Ulnar- flexion of ring and little finger DIP, intrinsic muscles of the hand
Radial- extension
How to differentiate ulnar nerve palsy from C8/T1 pathology
Abductor pollicis brevis would be weak in a C8-T1 lesion, it is supplied by the median nerve
Normal sensation in T1 if ulnar lesion
What are the signs of an ulnar nerve palsy?
- Relevant scar
- ‘Ulnar claw’ Extension at 4th and 5th metacarpal phalangeal joint and flexion at distal joint
- Wasting of small muscles of the hand
- Weak abduction of fingers
- Normal strength in abductor pollicis brevis
- Altered sensation in ulnar distribution
Types of diabetic neuropathy
- Distal symmetric polyneuropathy - progressive distal sensory loss in a glove and stocking distribution results in axonal loss in nerve conduction studies, motor involvement in severe cases
- Autonomic neuropathy- postural hypotension, gastroparesis, gustatory sweating, resting tachycardia
- Diabetic amyotrophy- microvasculitis presents with asymmetric pain then weakness in the proximal leg along with weight loss
Causes of peripheral neuropathy
Inherited
- Charcot Marie Tooth
Acquired
V
Infection
- HIV (distal sensory, painful)
- Lyme disease
T
Autoimmune / inflammatory:
- CIDP (relapsing course, not length dependent)
- Connective tissue disease (RA, sjogren, SLE, sarcoidosis)
- GBS
Metabolic:
- Diabetes (chronic, sensory predominant, length dependent)
- B12, B1, B6 deficiency
- Uraemia
- Hypothyroidism
- Lead
Idiopathic:
- Acute intermittent porphyria
Neoplastic:
- Paraprotrinaemic (myeloma or MGUS)
- Paraneoplastic (most commonly lung ca)
Drugs:
- isoniazid
- pyridoxine
- chemotherapy (vincristine)
DD
Investigating diabetic neuropathy
Bedside: urinalysis
Bloods: fasting glucose, HbA1c, B12 / folate,
S -
R -
Extras: nerve conduction studies:
- Sensory axonal loss with reduced or absent sensory nerve action potentials in a length- dependent manner with the legs being most affected
Management of diabetic neuropathy
MDT:
Diabetic foot team - PT, OT, orthotics, podiatrists, DSN, orthopaedics, endocrinologists,. microbiologist. Educate about necessity of foot care.
Prevention:
Optimise diabetes control
Medical management:
Postural hypotension - fludrocortisone
GI symptoms - prokinetics and antiemetics
Clinic signs of hereditary sensory motor neuropathy (Charcot Marie Tooth)
Wasting of distal lower limb muscles with preservation of the thigh muscle bulk
Pes cavus
Stocking distribution sensory loss
High steppage gait due to foot drop and stamping due to loss of proprioception
Wasting of hand muscles
Palpable lateral popliteal nerve
What causes hereditary sensory motor neuropathy
Most common types are I (demyelinating) and II (axonal) therefore nerve conduction studies are useful
Autosomal dominant inheritance (test for PMP22 mutations in HSMN I)
Tests for Hereditary Sensory motor neuropathy
Bedside
Bloods:
Secretions:
Radiology:
Extras: Nerve conduction studies, genetic testing
Management of HSMN
MDT: PT/OT, orthotics
Genetics: Genetic counselling
Causes of predominantly sensory peripheral neuropathy
V:
**Infection: **
* HIV
* Treponema infection (syphilis)
T:
Autoimmune / inflammatory:
* Acute - GBS
* Chronic - CIDP
**Metabolic: **
* DM
* Alcohol
* Uraemia
* Hypothyroid
* B12 and B1 deficiency
I:
Neoplastic / paraneoplastic processes
**Drugs: **
* Isoniazid
* Vincristin
* Phenytoin
D:
D:
Causes of predominantly motor peripheral neuropathy
V:
Infection:
* Diphtheria
* HIV
* Botulism (acute)
T:
Autoimmune / inflammatory:
* GBS (acute)
**Metabolic: **
Lead
**Idiopathic: **
* Acute intermittent porphyria
N:
D:
D:
D:
Congenital / genetic:
* HSMN (Charcot marie tooth)
Causes of mononeuritis multiplex
V:
Infection: HIV
T:
Autoimmune / inflammatory :
- Connective tissue (SLE, RA),
- Vasculitis
Metabolic: DM
I
Neoplastic: malignancy
D:
D:
D:
What causes a central scotoma?
Optic nerve disease eg. Optic neuritis
Affects ipsilateral side
What causes a bitemporal haemianopia?
Chiasmal lesion
Upper fields worse affected in pituitary tumours
Lower fields worse affected in craniopharynhiomas
What causes a homonomous superior quadrantanopia?
Temporal lobe lesion
What causes a homonymous inferior quadrantanopia?
Parietal lobe lesion
What causes a homonymous hemianopia?
Post chiasmal lesion, the more congruous the more posterior the lesion is
A posterior cerebral stroke can cause macular sparing due to dual blood supply
What is the Pathophysiology of MS?
BBB is more permeable to immune cellls. T cells enter the CNS. T cells attack the myelin sheath leading to inflammation.
How does MS present?
Sensory- Parasthesia, hypoaesthesia, pain, MS hugs
Optic neuritis- diminished visual acuity, decreased colour perception, periorbital pain preceding vision loss
Weakness- exercised induced weakness is characteristic, UMN signs
Spasticity
Bladder dysfunction
Constipation
Sexual dysfunction
Uthoff’s phenomenon- symptoms worse after hot bath
Lhermitte’s sign- lightening pains down the spine on neck flexion due to cervical cord plaques
Causes of Horner’s pupil
Ptosis / myosis / anhydrosis / enophthalmos (sunken eye)
1st order (brainstem)
* stroke (wallenbergs)
* MS
2nd order - spinal cord
* syrinx
3rd order [no anhydrosis]
* aneurysm
* Trauma
* Pancoast
Disease course of MS
Relapsing remitting
Secondary progressive
Primary progressive
Differentials for MS
Infection/ inflammation
Infection - HIV encephalitis / lyme disease
Inflammatory - neuromyelitis optica, ADEM (Acute disseminated encephalomyelitis) and CNS lupus/vasculitis
**Congential **
Mitochondial disease - MELAS
Acquired
V: recurrent TIA / stroke, CADASIL / fabry’s antiphospholipid syndrome
Infection: HIV enchephalitis / Lyme disease / syphilis / brucellosis / progressive multifocal leicoencephalopathy
T:
Autoimmune / inflammatory:
- Neuromyelitis optica
- Shortens
- ADEM (Acute disseminated encephalomyelitis)
- CNS lupus/vasculitis
Metabolic: B12 deficiency
Idiopathic: mitochondrial disease
NDDD
Diagnosis and investigation of MS
Need to prove dissemination of disease activity in time and space.
1. Clinical history
2. MRI
3. Unpaired oligoclonal bands in the CSF (not specific for MS, occur in 85% of cases)
Chronic management of MS
MDT: PT, OT, orthotics, social worker, neurologist, CNS, psychologist
Mild disease
- DMARDS - interferon B and glariramer reduce relapse rate but don’t affect prognosis
Severe disease (2 disabling replaces in 1yr)
- Biologics (-mabs)
- Stem cell transplantation
Manage complications of MS
Management of acute MS flare
Rule out psueudo relapse (ie. Worsening of existing symptoms by underlying stressor eg. Infection
Methyl pred
Management of MS complications
Spasticity - baclofen
Mood - anti- depressants
Pain - neuropathic analgesics
Bladder symptoms - antichoniergics/self catherisation
How is MS affected by pregnancy?
Reduced relapse rate in pregnancy
Increased risk of relapse in postpartum
What causes MS?
Both genetic (HLA-DR2 and interleukin 2&7 receptors) + environmental factors (EBV)
Clinical signs of cerebellar syndrome
Dysdiadochokinesis
Ataxia
Nystagmus
Intention tremor
Scanning dysarthria
Hypotonia/ hyporeflexia
How does the direction of nystagmus help determine side on the lesion?
The fast phase of the nystagmus is towards the side of the lesion and is maximal on looking towards the lesion
Causes of cerebellar syndrome
Vascular: Stroke (hemorrhagic or embolic or thromboembolic)
I:
Trauma: traumatic brain injury causing bleed
Autoimmune / inflammatory:
- MS
Metabolic:
- Alcohol related cerebellar degeneration
- Hypothyroidism
Idiopathic:
- Fredrich’s ataxia and ataxia telangiectasia
Neoplastic:
- SOL in posterior fossa
- Paraneoplastic
Drugs: phenytoin toxicity
D:
D:
Clinical signs pointing to different causes of cerebellar syndrome
Internuclear ophthalmoplegia, spasticity, younger female = MS
Optic atrophy = MS or Fredrichs ataxia
Clubbing/ cigarette fingers, radiotherapy burn = bronchial carcinoma
Liver disease = alcohol excess
Neuropathy = alcohol or fredrichs ataxia
Gingival hypertrophy = phenytoin
What happens in internuclear ophthalmoplegia?
The side of the brain affected is the same side as the eye that cannot adduct. Eg. A left sided lesion will result in the left eye not addicting when looking right and the right eye will have nystagmus.
Caused by a lesion affecting the medial longitudinal fasciculus (a heavily myelinated tract).
How can you differentiate sensory ataxia from cerebella ataxia
Sensory ataxia - impaired sensation particularly vibration and joint position, pseudoathetosis, able to finger nose test with eyes open but not with eyes closed
Cerebella ataxia - other cerebellar signs
How does ALS present?
UMN and LMN signs
Upper limb weakness> lower limb weakness
Fasciculations
Asymmetrical
Slurred speech
Dysphagia/dysarthria
How does progressive bulbar palsy present?
MND -poor prognosis
Affects lower cranial nerves (IX-XII)
- Facial muscle weakness
- Dysphagia
- Dysarthria
Emotional lability
How does progressive muscular atrophy present
Type of MND - best prognosis
LMN- Fasciculations, muscle weakness
Muscle atrophy - shoulders, arms and hands
How does primary lateral sclerosis present?
Type of MND- very rare - exclusively UMN
Spastic weakness of the limbs
Spastic dysarthria
Dysphagia
Aggressive course
How is a case of suspected MND investigated?
Bedside:
Bloods:
- Routine bloods
- Vitamin level
- CK assay
- Anti-GM1 antibodies (multifocal motor neuropathy / guillian barre)
Secretions:
Radiology:
- MRI (cervical myelopathy, cord compression, brainstem lesionsx)
Extras:
- EMG showing Fasciculations
- Nerve conduction studies
- Muscle biopsy
- Serum protein electrophoresis
What is Kennedy disease?
X linked spinobulbar muscular atrophy
Associated with a CAG trinucleotide repeat mutation
Lower motor neurone disease
Causes progressive weakness and wasting of the limb and bulbar muscles with an absence of spasticity and slight sensory neuropathy
Associated with gynaecomastia and reduced fertility
What are Fasciculations?
Axonal loss causing axons to recruit and innervate more myofibrils than usual resulting in large motor units
Commonly seen in syringomelia and MND
Causes of myelopathy
Congenital
Hereditary spastic paraplegia
Acquired
Vascular: Anterior spinal cord thrombosis
Infection: discitis / transverse myelitis
Trauma:
Autoimmune / inflammatory: MS
Metabolic: B12 deficiency / nitrous oxide use -> subacute combined degeneration of the cord (absent reflexes with upgoing plantars)
Idiopathic:
Neoplastic: Spinal cord compression
D:
D:
Degeneration: Syringomelia, spinal stenosis
Lower limb myotomes
Hip flexion - L2/3
Knee extension - L3/4
Foot dorsiflexion- L4/5
Knee flexion - L5/S1
Foot plantarflexion - S1/2
Causes of generalised wasting of hand muscles
Anterior horn cell
- MND
- syringomelia
- cervical cord compression
- polio
Brachial plexus
- cervical rib
- Pancoast’s tumour
- trauma
Peripheral nerve
- combined median and ulnar nerve lesion
- peripheral neuropathy
Muscle
- disuse atrophy
What are the key features of Kennedy disease?
Inherited (x-linked recessive - MEN AFFECTED) neuromuscular disorder
* Progressive weakening and wasting of the muscles and bulbar involvement.
* Associated with gynaecomastia and reduced fertility
How does poliomyelitis present?
Acute presentation of polio (polio = poliomyelitis)
GI prodrome.
Acute flaccid paralysis, typically unilateral.
LMN -> Reduced reflexes and atrophy of the affected limb
How to differentiate cause of myelopathy
Sensory level which might suggest where the lesion is
Scars or spinal deformity
Signs of MS
Bladder symptoms/catheter
Suggest testing anal tone
Clinical signs of myelopathy
Bilat UMN signs: hypertonia, ankle clonus, generalised weakness, hyperreflexia with up going plantars
Sensory level