Neuro Flashcards
Which type of muscle fibre is rich in myoglobulin
Type I
What does myoglobulin do
supplies oxygen to your muscles
What are the main symptoms of myopathy
Proximal weakness
Hypotonia
Wasting (or fatty infiltration)
BUT reflexes are preserved
What would be raised on blood tests in myopathy
Creatine phosphokinase
What is a myopathic unit on a EMG?
Small, short-duration, spiky polyphasic units
What is the inheritance pattern of myotonic dystrophy type I
Autosomal dominant
What is the type of mutation in myotonic dystrophy type I
Expanded trinucleotide repeat (CTG)
Within the myotonic protein kinase gene on chromosome 19
Symptoms of myotonic dystrophy
Progressive muscle weakness, particularly in upper limbs
Myotonia
Many other symptoms (cataracts, frontal balding, dysarthria and dysphagia..)
Fatigue
Is myotonic dystrophy inheritance worse through females or males
Females, with anticipation.
What are the characteristics of metabolic myopathies
Exercise intolerance/pain/fatigue
Sometimes have periodic paralyses with high or low potassium
What is the inheritance pattern of periodic paralysis channelopathies
Autosomal dominant
What is the most common age range for inflammatory myopathies?
Middle age, classically:
Polymyositis and dermatomyositis (30/40 yr old woman)
Inclusion body myositis: over 50s male
What is the management for polymyositis and dermatomyositis
Corticosteroids +/- immunosuppression and removal of tumour if present
What is the treatment for inclusion body myositis
Supportive management (no treatment)
What is the definitive investigation for muscle disease
Muscle biopsy (determines fibre type, inflammation, dystrophic and histochemical changes)
What is the classical gait in Duchenne
Waddling gait
Where does pseudo-hypertrophy happen in Duchenne’s
Calves
What is a common cause of death in Becker’s muscular dystrophy
Cardiac arrhythmias
Characteristics of myopathies due to thyrotoxicosis
Shoulders mainly
Brisk reflexes
+/- fasciculations and atrophy
What drugs can cause myopathy
Steroids
Satins
Potassium-losing drugs
(also: chloroquine, amiodarone, doxorubicin, Zidovudine)
What type of virus is polio virus
Enterovirus
What percentage of patients with poliomyelitis have paralysis
0.1%
Symptoms of poliomyelitis
Abortive: self limiting GI and resp symptoms
Non-abortive: features of abortive with meningism. Complete recovery
Paralytic: abortive symptoms -> non-abortive -> myalgia and asymmetrical paralysis. Sometimes resp failure but usually lower limbs in children. Can cause bulbar involvement.
How is poliomyelitis distinguished from GBS
Polio doesn’t have sensory symptoms and has asymmetry