ALS Flashcards
ALS- Definition
“a degenerative disease of the neuromuscular system involving both upper and lower motor neurons, resulting in weakness of the limbs, trunk, bulbar, and respiratory muscles”
ALS
- neuropathology
- signs/symptoms
neuropathology: lateral, corticospinal tracts, anterior horn cells, anterior roots and peripheral nerves, CN nuclei, corticobulbar trances
Signs and Sx: spasticity and weakness in bulbar and spinal system
Pseudo-Bulbar Palsy (PBP)
- neuropathology
- signs/symptoms
Neuropathology: bulbar nuclei
Signs and Sx: flaccid weakness of bulbar muscles (swallowing and speech)
Progressive Muscular Atrophy (PMA)
- neuropathology
- signs/symptoms
Neuropathology: Ventral horn cells of spinal cord (LMN)
Signs and Sx:weakness and wasting of extremities
Primary Lateral Sclerosis (PLS)
- neuropathology
- signs/symptoms
Neuropathology: motor cells of the cortex and corticospinal tracts (UMN)
Signs and Sx: spastic weakness of trunk and extremities
Spinal Muscular Atrophy (SMA)
- neuropathology
- signs/symptoms
Neuropathology: primary motor eurons in anterior horn of SC and brainstem motor nuclei
Signs and Sx: weakness and wasting of extremities and bulbar muscles
UMN Syndrome signs
Loss of dexterity loss of muscle strength spasticity hyperreflexia pathological reflex flexor spasms involuntary emotional expressive disorder (IEED)- inappropriate laughing and crying
LMN Syndrome signs
- loss of muscle strength
- muscle atrophy
- muscle hypotonia
- hyporeflexia
- fasciculations
- muscle cramps
Uncommon manifestations of ALS
- sensory impairments (if sensory impairment, not thinking ALS)
- ocular palsy (muscle of the eyes are typically spared)
- Bladder and bowel dysfunction
- Dementia
Fronto-Temporal Dementia (FTD)
occurs in 15% of ALS patients, involves cortical atrophy
symptoms:
- word finding difficulties
- behavioral changes
- executive dysfunction
- poor judgement
- memory is not usually impaired, screening exam with MMSE
Pathogenesis: 3 hypotheses
- oxidative stress and mitochondrial dysfunction causing inflammation
- excitotoxicity: increased levels of glutamate in CNS (kills neurons)
- Cell death and apoptosis (via MAP kinase activtation)
Diagnostic Testing: 3 factors
- Lower motor neuron involvement (EMG)
- Upper motor neuron involvement (MRI, MR Spec, TMS, clinical exam)
- Additional Tests to rule out everything else (lumbar puncture, muscle and nerve biopsies, blood tests)
Lower Motor Neurons Testing: Expected presentation/occurance on EMG
- Denervation
- decreased motor units
- fibrillations
Lower Motor Neurons Testing: Procedure of EMG
Needles are inserted into motor points.
Performed in the limb, tongue, paraspinals
Uncomfortable!
Upper Motor Neuron Testing: Clinical exam findings
- clinical exam extremely important in UMN diagnosis
- hyperreflexia/abnormal reflexes (babinski, hoffman)
Differential Diagnoses of ALS
- Degenerative arthritis
- motor neuropathy
- inflammatory muscle disease
- metabolic. infectious, endocrine and electrolyte imbalance
ALS: sex ratio, age of onset, racial predisposition
sex ratio: 1.2-1.6:1 (M:F)
age of onset: 60s
Racial: none
Prognosis: mean survival time, 5yr survival, 10yr survival
Mean survival time: 27-43months (2-4yrs)
5-year survival time: 9-40% (25% mean)
10-year survival time: 8-16%
*UMN lesions tend to live longer
AAN Practice parameters: guidelines for practice in treating ALS pt
- Breaking the news
- symptom management
- nutrition management
- respiratory management
- Palliative care
Only drug that is FDA approved as treatment in ALS
Riluzole- extends life by 3 months
Symptomatic Treatment: what symptoms get treated
- Muscle cramps
- Spasticity
- Sialorrhea Management (uncontrolled drooling/management of secretions)
- Depression
- Involuntary Expressive Disorder (IEED)