Neurology Flashcards
Investigations for suspected GBS
Lumbar puncture (cytoalbuminologic dissociation- raised protein without raised WCC) and nerve conduction studies (decreased motor nerve conduction)
Also check (for any limb weakness)- FBC, UE, LFT, CRP, ESR, bone profile (calcium), phosphate, magnesium, B12, folate (haemanitics)
Myasthenia gravis
Autoimmune disorder, resulting in antibodies to acetylcholine receptors
Myasthenia gravis features
Muscle fatigability- muscles become weaker during periods of activity and improve after rest
Diplopia and ptosis (eg, at the end of the day after watching TV and reading)
Weakness of face, neck, limb girdle muscles
Dysphagia and slowness in chewing food
NO SENSORY PROBLEMS
NB- if concurrent thymoma, may see SVC syndrome (distended neck veins)
Myasthenia gravis associations
Thymoma
Autoimmune disorders eg. SLE
Thymic hyperplasia (most common)
Investigations for MG
All the blood tests you would do for limb weakness
Electromyography- diminished response to repetitive stimulation on EMG
Acetylcholine receptor auto antibodies (or anti muscle specific tyrosine kinase antibodies)
CT thorax to exclude thymoma
Creative kinase is normal
Long term management of MG
Pyridostigmine
Prednisolone
Immunosuppressants eg. Azathioprine
NB- thymectomy in hyperplasia but not thymoma
Management of acute MG crisis
Plasmapheresis
IV immunoglobulins
NB- resp failure can develop and kill these patients. Be prepared to step up management early
Drugs that can exacerbate pre existing MG
Beta blockers
Lithium
Phenytoin
Antibiotics eg. Gentamicin, macrolide, tetracyclines
Penicilliamine
Quinidine
Myelopathy
Disorders due to compression of the spinal cord
Myelitis
Neurological disorder due to inflammation of the spinal cord
Causes/risk factors for myelopathy
Trauma
Infection (abscess)
Neoplasm
Degenerative disease eg. Spinal stenosis, ankylosing spondylitis, disc prolapse
High axial loading job and smoking (disc prolapse risk factors)
Features of myelopathy
Limbs affects (upper or lower) depends on the site of the lesion eg. Cervical or thoracic region. Usually bilateral
Pain
UMN signs (increased tone, spasticity, hyperreflexia, up going plantar reflex, weakness)
Loss of motor function
Impaired sensation eg. Numbness, ataxia, loss of proprioception or vibration sense
Impaired bladder and bowel control (Impotence too)
Features of myelitis
Same as myelopathy
Lumbar region and myelopathy
No spinal cord in lumbar region, just nerve roots, so won’t get UMN lesions when a lumbar disc herniates (but can get LMN signs eg. Cauda equine, get autonomic (bladder and bowel), sensory (parathesia), and LMN signs (absent reflexes)
Radiculopathy
Neurological disease due to compression of nerve roots
Features of cauda equine syndrome
Back pain, radicular pain
Neurological deficits below the lesion eg. Sensory abnormalities first, then motor abnormalities
Bladder, bowel, sexual dysfunction
Saddle parasthesia
General features of myosotis (PM or DM)
Bilateral proximal muscle weakness (pelvis and shoulder girdle)
Functional difficulties eg. Dressing, climbing stairs
Dysphagia
Muscle tenderness
Cutaneous features of dermatomyositis
Gottrons papules (rough red papules over the extensor surfaces of the fingers)
Mechanics hands- thickening and hyperpigmentation
Heliotrope rash (upper eyelids)
Midfacial erythema (affects nasolabial folds unlike SLE)
Photosensitive rash
Inclusion body myosotis features
Progresses slowly over many years
Same symptoms as general myosotis but affects proximal and distal muscle groups
Investigations for suspected myosotis
Neurological examination and observations
FBC UE other electrolytes
CK- raised
Antibodies
Muscle biopsy
MRI- malignancy
Difference between PM, DM, and IBM
PM and DM are associated with younger people and malignancy, they can present quickly, affect the proximal muscles
IBM progresses slowly over many years and is associated with the elderly, affects the proximal and distal muscles
Antibodies for myosotis
PM- anti jo 1
DM- anti Mi 2 & ANA & anti synthase & anti jo 1
Management of myosotis
Refer to rheumatology
Supportive measures NSAIDS etc
Treat underlying malignancy
Steroids
Immunoglobulins
Biologics
Differentiate an acute peripheral neuropathy and an acute myelopathy (LMN vs UMN)
Tone and reflexes
Facial involvement