Neuromuscular Disorders Flashcards
What is motor neuron disease?
Progressive degeneration of motor neurons, leading to muscle wasting and weakness
What is the average survival time for a patient with MND?
3 years
90% of MND involves lower motor neuron. True/False?
True
What is the most common phenotype of MND?
Amyotrophic lateral sclerosis (ALS)
What is the main difference between ALS and PLS?
ALS has both UMN and LMN features, PLS UMN only
ALS is associated with which type of dementia?
Frontotemporal dementia
List investigations for MND
Clinical diagnosis (onset: bulbar, chest etc.) Neurophysiology (EMG)
Outline management of MND
Assess needs and organise care
Speech therapy
Nutrition support
Ventilatory support
What is the classic sign of MND in the hands?
Split hand syndrome (preferential wasting of thenar group in the hand)
MND causes does not cause sensory problems. True or false?
True
Describe the basic pattern of symptoms in ALS
Both UMN and LMN features that starts in one limb and spread to other limbs and trunk
Progressive bulbar palsy involves which cranial nerves?
CN IX, X & XII
Progressive muscular atrophy has purely _____ motor neuron features
Lower
PLS has purely _____ motor neuron features
Upper
Botulism causes what symptoms?
Rapid onset weakness without sensory loss
What are the risk factors for botulism?
- IV drug use
- Food (clostridium botulinum is present in soil)
- Wounds
Botulism is a ___synaptic disorder?
Pre
Lambert Eaton Myasthenic Syndrome (LEMS) is a ___synaptic disorder?
Pre
Lambert Eaton Myasthenic Syndrome (LEMS) is strongly associated with which type of cancer?
Small cell lung cancer
Myasthenia gravis is a ___synaptic disorder?
Post
Myasthenia gravis is an autoimmune disease of which receptors?
Acetyl choline receptors
What is the most common presentation of myesthenia gravis?
Extraocular weakness, facial and bulbar weakness (eyes drooping by end of day, choke after big meal etc)
Facial weakness in myesthenia gravis is typically bilateral. True or false?
True
Ptosis in myesthenia gravis is worse at the beginning of the day. True or false.
False - typically bilateral and worse at end of the day/prolonged upgaze
Which antibodies indicate myesthenia gravis?
Anti-Ach Receptor Antibody (80-90% of patients
What tests can indicate myesthenia gravis?
- Fatigue tests (eg blink 20 times – MG patients will fatigue)
- Neck flexion – very few things have neck flexion weakness
- Ice test – ptosis improved after applying ice for 2 mins
What is the treatment for myesthenia gravis?
- Pyridostigmine (anticholinesterase)
- Steroids
_Steroid sparing agents – azathioprine / mycophenolate - Thymectomy
75% of myesthenia gravis patients have abnormalities in what organ?
Thymus
Polymyositis causes symmetrical distal muscle weakness. True or false?
False - it cases symmetrical, proximal muscle weakness
What are the cutaneous features of dermatomyositis
- V-shaped rash over chest
- Gottron’s papules (on hands)
- Heliotrope rash (on eyes)
- Shawl sign
What abnormalities are seen in blood tests in poly/dermatomyositis
Raised inflammatory markers and Ck
What antibodies are seen in polymyositis
Anti-Jo-1
What is the treatment of polymyositis
Steroids + immunosurpressive drugs (eg Methotrexate/azathioprine/ciclosporin)
How does inclusion body myositis differ from polymyositis?
It is progressive weakness and wasting of both distal and proximal muscles (often asymmetrical) whereas polymyositis is symmetrical, proximal muscle weakness
What is the muscle breakdown product that causes kidney damage in rhabdomyolysis?
Myoglobin
