Neurology Flashcards
What are the pathologies of peripheral neuropathy?
- Demyelination e.g. Guillain-Barre syndrome
- Axonal degeneration e.g. toxic neuropathies
- Wallerian degeneration e.g. direct trauma
- Compression e.g. carpal tunnel syndrome
- Infarction e.g. diabetes and vasculitis
- Infiltration / inflammation from infection (leprosy), malignancy, granulomatous disease (sarcoid) or amyloidosis
Causes of polyneuropathy / peripheral neuropathy?
- Neurological: GBS, Cauda Equina, CIDP
- Endocrine: DM, Hypothyroidism, Acromegally
- Infectious: HIV, HepC, Leprosy, Lyme
- AI: SLE, Sjogrens
- CRF
- Nutritional: Thiamine, B12,
- Drugs: amiodarone, metronidazole, cisplatin
- Genetic: CMT
- Alcohol
- Neoplastic
Peripheral neuropathy investigations
- Full blood count.
- Fasting glucose level and cholesterol panel.
- Thyroid stimulating hormone.
- Vitamin B12 levels.
- Serum and urine immuno-electrophoresis.
- Hepatitis B and C, HIV, Lyme, and syphilis serologies.
- ESR, antinuclear antibodies (including SS-A and SS-B), extractable nuclear antibodies.
- Nerve conduction studies and needle EMG.
- Possible sural nerve biopsy
Hemiplegia differential
Eldery: stroke, tumour, subdural haematoma, demyelination
Young: demyelination, stroke, tumour
Also, traumatic injury, hypoglycaemia, focal nerve palsy, post-ictal paralysis, cerebral absess
Hemiplegia investigations
- BP
- FBC (polycythemia, platelets, raised WCC)
- Coagulation
- U+Es (CRF)
- Glucose, cholesterol, ESR, CRP
- ECG (AF)
- Chest xray (lung cancer brain mets)
- CT/MRI head
- LP (oligoclonal bands)
Myotonic dystrohpy associated features
Multisystem disorder in which myopathy and myotonia are prominent features
- Cataracts
- Cardiac conduction abnormalites and cardiomyopathy
- Testicular atrophy
- Endocrine disturbance (DM)
- Cognitive dificulties
- Hypersomnolence
Proxial Myopathy Differential
- Inherited: muscular dystrophies
- Inflammatory: polymyositis, SLE, RA, sarcoid
- Drugs: steroids, statins
- Toxic: alcohol
- Endocrine: hypo/hyperthyroidism, addisons, cushings
- Infective: influenza, HIV lyme
- Hypokalaemia
Proximal myopathy investigations
- Review drugs
- Bloods: CK, U+Es, TFTs, LFTs, ESR, Ca, Mg
- ECG (hypokalemia, cardiomyopathy)
- Urinalysis (myoglobin)
- EMG
- Muscle biopsy
MND differential and tests
- Cervical spondylosis with myelopathy and radiculopathy
- MG
- Post-polio syndrome (LMN only)
- Multifocal motor neuropathy
Image spinal cord MRI, EMG diagnostic. Often clinical diangosis however.
MND phenotypes
Amyotrophic lateral sclerosis (UMN + LMN)
Bulbar presentation (limbs preserved early)
Progressive muscular atrophy (LMN signs)
Primary lateral sclerosis (UMN signs)
Cerebellar syndrome causes
- MS
- Stroke
- Tumour (acoustic neuroma, meningioma)
- Drugs (pheytoin)
- Alcohol (+wernicke-korsakoff)
- Paraneoplastic (lung, breast, ovary)
- Hypothyroidism
- Inherited (Friedreich’s ataxia)
Myasthenia Gravis differential
- Lambert-Eaton myasthenia syndrome (improves with exercise)
- Botulism (also hypotension, bradycardia, diarrohea, urinary retention)
- Primary myopathies (not fatigable weakness)
- Partial III nerve (unilateral ptosis)
- GBS
- Stroke, MND (dysarthria)
Myasthenia gravis investigations
- Serum antibodies (anti-AchR, anti-MuSK)
- Tensilon/edrophonium test
- EMG
- Serial pulmonary function tests
- CT thorax - thymoma (10-15%)
Myasthenia gravis treatment
- Myasthenic crisis: intubation and ventilation, plasma exchange or IVIG, supportive care, prednisolone
- Pyridostigmine, corticosteroids
- Thymectomy
- Supportive care = DVT prophylaxis, ulcer prophylaxis, nutrition, avoidance of infection
Cervical myelopathy Differential
- Transverse myelitis (isolated or MS)
- Compression (degenerative, neoplastic (1 or 2), infective)
- Trauma
- Spinal cord stroke
- B12 deficiency
- Syringomyelia
- Neoplasm of cord
- Hereditary spastic paraplegia
Cervical myelopathy investigations
- Bloods: FBC (macrocytosis), B12
- MRI cervical spine
- LP (transverse myelitis)
- Cervical xray / CT
Median nerve pasly causes
- Carpal tunnel syndrome
- Trauma (wrist)
- Surgical
- Mononeuritis multiplex
- Infection (leprosy)
- Inflammatory (CIDP)
Carpal tunnel syndrome causes
- Idiopathic (commonest)
- Anatomical
- Bone: #, acromegally
- Soft tissues: lipoma, ganglion
- Physiological
- Inflammatory: RA, gout
- Fluid balance: pregancy, menopause, hypothyroidism, obesity, amyloidosis, renal failure, contraceptive pill
- Neuropathic: DM, alcoholism
Ulnar nerve palsy differential
- C8/T1 nerve root lesions
- Brachial plexus lesions
- MND
- Poliomyelitis
- Syringomyelia
- Peripheral Neuropathy
- RA
Ulnar nerve palsy causes
- Anatomical: cubital tunnel syndrome at elbow
- Trauma: #’s, dislocations
- Degenerative arthritis: compresive proliferative synovitis and osteophytes
- Rare causes: compression from tight fascia, tumours, aneurysms etc
Radial nerve palsy differential
- C7 nerve root lesion
- MND
- Poliomyelitis
- Lesions of brachial plexus
- Mild stroke
Wasting of small muscles of hand differential
- C8/T1 nerve root lesions
- Brachial plexus lesions
- MND
- Poliomyelitis
- Syringomyelia
- Peripheral neuropathy
- Myotonic dystrophy
- RA
Polymyositis associations
- Autoimmune conditions
- Connective tiddue diseases
- Drugs (statins)
- Infections (HIV, acute viral illness)
- Idiopathic (rare)
Dermatomyositis with cancer (ovary, GI, breast)
Polymyositis differential
- Drug-induced mypathy (steroids)
- Toxic (alochol)
- Endocrine (hypo/hyperthyroidism, addisions, cushings)
- Hypokalaemia
- Inclusion body myositis
- Inherited (muscuar distrophies)
Polymyositis investigations
- Review drugs
- CK
- EMG
- Muscle biopsy
- ESR
- ANA
Parkinsons Disease Differential
- Essential tremor (usually symmetrical)
- Vascular PD (basal ganglia stroke, gait>upper limb)
- Drug-induced parkinsonism (symmetrical)
- Parkinson’s plus syndromes
- Progressive supranuclear palsy
- Multisystem atrophy
- Corticobasal degeneration
- Lewy body dementia
- Wilsons disease
Parkinson’s Disease investigations
- Clinical diagnosis, confirmed by dopaminergic agent trial
- MRI brain
- Flurodopa PET
- Serum ceruloplasmin and 24 urinary copper if young <40
- Neuropsychometric testing
Friedreich’s ataxia examination findings
- Inspection: distal muscle wasting, pes cavus, kyphoscoliosis, high-arched palate
- Reflexes: Reduced in lower (common) and upper limbs, extensor plantars
- Sensation: Loss of vibration and propriation in lower limbs
- Coordination: ataxia (past-pointing, dysdiado, tuncal)
- Ataxic gait and dysarthria, possibley nystagmus
Friedreich’s ataxia pathology and investigations
Autosomal recessive GAA repeat expansion
Associations: optic atrophy, sensorineural deafness, sphincter dysfunction, DM, impaired glucose
MRI brain and spinal cord shows atrophy of cerebellar vermis and spinal cord
Look for hypertrophic cardiomyopathy (ECG and echo)
No treatment
Charcot-Marie-Tooth Disease differential
- Diabetic neuropathy
- Chronic inflammatory demyelinating polyneuropathy
- Aquired peripheral neuropathy (toxins, hypothyroidism, vitamin deficiencies, renal failure etc.)
Charcot-Marie Tooth disease investigations
- Peripheral neuropathy tests
- Nerve conduction studies (axonal or demyelination)
- Genetic testing
Charcot-Marie Tooth disease treatment
- No cure
- Physiotherapy and exercise
- OT
- Bracing
- Orthopaedic surgery (correct deformities)
- Treat underlying DM (exacerbates disease)
Subacute combined degeneration of the cord examination
- Inspection: walking aids, normal muscle, vitiligo?
- Tone: normal
- Power: Normal or weakness
- Reflexes: brisk or reduced (absent ankles, brisk knees), extensor plantars
- Sensation: vibration and proprioception loss distally
- Coordination: sensory ataxia
- Ataxic gait, romberg’s positive
- Look for anaemia, glossitis, lemon yellow pallor, splenomegally
Subacute degeneration of the cord investigations and differential
- FBC
- B12, folate, VDRL, glucose
- Schilling’s test (pernicious anaemia)
- MR spine to rule out compression
Differential
- DM with cord compression
- Tabes dorsalis
- Hereditary syndromes
Brown-Sequard syndrome
Ipsilateral UMN lesion and loss of light touch (variable), vibration and proprioception
Contralateral loss of pain and temperature sensation
Brown Sequard Syndrome causes
- Penetrating trauma to spine
- Degenerative disease of spine
- Tumour of spinal cord
- Infection (meningitis, abcess, HSV, VZV, TB)
- Inflammation (myelitis)
- Vascular (ischamic or haemorragic)
Dissociated sensory loss differential
- Brown-Sequard syndrome
- Spinal cord stroke
- Syringomyelia
- Brainstem stroke
Cerebellopontine angle syndrome findings and causes
CN V, VII, VIII palsies and cerebellar signs
Isilateral facial sensory loss, loss of corneal reflex, LMN facial hemiparesis, sensorineural deafness, dysdiado, nystagmus, ataxia
Causes
- Schwannomas (acoustic commonest)
- Meningioma
- Mets
- Epidermoid cyst
Wallenberg’s Syndrome aka lateral medullary syndrome
Paraplegia Differential
- Transverse myelitis (isolated or MS)
- Compressive myelopathy (neoplastic, infective, degenerative, traumatic)
- Spinal cord stroke
- B12 deficiency
- Syringomyelia
- Neoplasm of spinal cord
- Inherited spastic paraplegia
Post poliomyelitis differential
- Radiculopathy
- Plexopathy
- MND
Causes of a third nerve palsy
- Microvascular causes: DM, HTN (usually pupil sparing)
- Intracranial aneurysms: posterior communicating artery
- Trauma
- Tumors
- Idiopathic
- (Compressive lesions pupil-involing)
Third nerve palsy differential
- Myasthenia gravis
- Thyroid eye disease
- Migraine
Causes of 6th nerve palsy
- Microvascular: DM, HTN
- MS
- Stroke
- Raised ICP
- Tumours
- Meningitis
- Aneurysm (basilar artery)
- Inflammatory process
Investigations for 3rd, 4th, 6th cranial nerve palsies
- FBC
- Inflammatory markers
- Syphilis serology
- Autoantibody screen
- BP and glucose
- CT or MRI/MRA if trauma, malignancy, meningitis
