Motor Neuron's Disease Flashcards
Define Motor Neuron Disease:
This is a group of diseases characterised by rapid progressive motor neuron disorder of the voluntary muscle without any sensory symptoms.
What is the basic pathology behind MND?
Selective loss of neurons in the motor cortex, cranial nerve nuclei and anterior horn cells.
How can you distinguish between MND and myasthenia gravis?
MND NEVER affects the eyes
What would indicate a poorer prognosis in MND?
Bulbar onset
Older age
Decreased FVC
How is the gene associated with MND inherited?
Autosomal Dominant pattern
What form of MND accounts for 87% of all familial MNDs?
Amyotrophic lateral sclerosis frontotemporal dementia locus
What is the most common type of MND?
Amyotrophic lateral sclerosis (AML)
Is AML mainly UMN or LMN disease
Mix of both
Usually one is dominant
What diagnostic tool is used in the diagnosis of ALS?
El Escorial
Lower and Upper motor neuron signs in three regions is a definite diagnosis
What clinical sign is commonly seen in ALS?
Split hand sign
What is the average prognosis for ALS?
3-5 years
What medication can be given in MND to prolong life?
Antiglutamatergic drug –> riluzole
What % of patients with MND will suffer from frontotemporal dementia?
25%
What is a pathological hallmark of ALS?
Inclusion bodies
What is the classic onset of symptoms in ALS?
Focal onset in limbs then continuous spread
unilateral first
e.g. one leg then the trunk then the arm etc
List the symptoms of an UMN lesion?
NO muscle atrophy Spastic Gait Hyperreflexia Present Babinski Clonus Bradykinesia
List some of the clinical features of a lower motor neuron lesion
Absent reflexes
Fasciculations
Muscle atrophy
Muscle weakness
What form of MND presents with an Upper motor neuron lesion only?
Primary Lateral sclerosis
What is the pathology behind primary lateral sclerosis?
Loss of Betz cells in the motor cortex
What symptom is not seen in primary lateral sclerosis?
Cognitive decline
What form of MND affects only the cranial nerves?
Progressive bulbar palsy
What cranial nerves are affected in bulbar palsy?
CN IX - XII
Is progressive bulbar palsy going to elicit upper or lower motor neuron signs?
Lower
What medications can be given to MND patients as a management for drooling?
Amitriptyline
Propantheline
What form of ventilation can be given to patients who suffer from MND?
Bi-phasic, non invasive, ventilation
What form of MND only affects the anterior horn cells, leading to the symptoms being only LMN ?
Progressive muscular atrophy
In progressive muscular atrophy how do the symptoms present?
Distal muscle groups are affected before proximal muscle groups.
Flail arm and flail leg
(tends to be restricted to one limb)
Better prognosis than ALS
What is a common cause of death in patients with MND?
Respiratory failure due to aspiration pneumonia
