Anterior Horn Cell Disorders - ALS Flashcards
ALS is what
Amyotrophic Lateral Sclerosis
Meaning of ALS - variant
Can refer to several adult onset conditions characterized by progressive degeneration of motor neurons (variants)
Meaning of ALS - Typical ALS
A specific form of motor neuron disease, involving both upper and lower motor neuron signs
ALS - Define
Motor neuron disease
Adult onset, progressive, motor neuron system degeneration disease (both UMN and LMN)
Amyotrophic means what
No muscle nourishment
Muscle atrophy, weakness, fasciculations
LMN signs
Lateral Sclerosis means what
Degeneration and scarring (due to gliosis) of CST in spinal cord UMN signs (inc DTR, spasticity)
S/S ALS - UMN
Spasticity
Hyperreflexia
Pathological reflexes
S/S ALS - LMN
MM weakness MM atrophy Fasciculations Hyporeflexia Hypotonicity MM cramps
S/S - Bulbar signs
Dysarthria
Dysphagia
Sialorrhea (salivation)
Pseudobulbar palsy
S/S Respiratory
Nocturnal resp. difficulty
Exertional dyspnea
Accessory mm use
Parodoxical breathing
Other s/s
Fatigue Weight loss Cochexia Tendon shortening Joint contractures
2 types ALS - Ways to get it
Familial ALS
Spontaneous/Sporadic ALS
Familial ALS
Less than 10% of all ALS cases
Spontaneous/Sporadic ALS
90% of all cases
Etiology is unknown
Prognosis
Non curable, is fatal
Median survival is 3 yrs (20% will survive up to 10 yrs)
Better prognosis with what
early age
onset of limb weakness initially (as opposed to bulbar initially)
ALS - cause of death is commonly
respiratory failure
Main area of research for the cause
Glutamate toxicity
Glutamate is primary excitatory NT used by the motor system - it is normally broken down by a protein but people with ALS are deficient in that protein so there is a build up or clogging at the synaptic cleft
Excess amount of glutamate is toxic
Other possible causes
SOD1 dysfunction
Microglial mediated neurotoxicity
Mitochondrial dysfunction
SOD1 as a cause
Acts as an anti-oxidant in the cell and eliminates free radicals - not working properly in someone with ALS though so leads to oxidative damage and kills neurons
Microglial mediated neurotoxicity as a cause
Microglia - main form of active immune defense in the CNS (surrounds the neuroglia) - with ALS there is a proliferation of microglia (too many of them) - and leads to enhanced inflammatory response which can lead to MN degeneration
Mitochondrial dysfunction as a cause
Mitochondria regulating cell death - there is altered mitochondrial enzyme function though which can lead to oxidative damage and increased apoptosis
Diagnostic parameters
Both UMN and LMN signs are present Absence of pain or sensory changes Intact bowel and bladder Extraocular mm spared Diagnostic imaging to rule other things out
Diagnositc parameters - why is there an absence of pain and sensory changes
Spinocerebellar and sensory systems are spared
Diagnostic Parameters - What else besides diagnostic imaging is done
EMG Muscle biopsies NCV Clinical presentation Clinical lab
Treatment - medications for ALS
Riluzole - gluamate antagonist
The only drug approved for tx fo ALS
Effective in inc life 2-3 months
Treatment - medicatiosn for people with ALS - for symptoms
Control salivation Antispasticity Mucolytics Anti-anxiety Anti-depressants Injectable B12
In the initial stages of the disease, most will present with
focal weakness, typically in the distal leg, hand, or bulbar mm
Often see foot drop, inability to use hand with ADL, difficulty with speech/swallowing
Clinical presentation - Cog
Executive function, memory loss in 50% of cases
About 15% have frontotemporal dementia
Tx - nutrition
Ketogenic diet/supplementation
SLP/nutritionist
PEG tube
Tx - communication
Speech language pathologist (SLP)
Tx - respiratory intervention
Need to manage secretions with coughing techniques
When VC decreases to 50% of predicted, may need to assist more with positive airway pressure
Eventually need to decide on ventilatory support with tracheostomy of hospice
Goals of PT
Optimize remaining function early on
Maintain functional mobility
Maximize QOL
Stage 1 description
Independent in mobility and ADL, weakness in a specific group of mm (often is a distal limb)
What to do in stage 1
Energy conservation Home modification Continue normal activities AROM/Stertching Strengthening of unaffected Aerobic exercise at submax
Stage 2 description
Moderate weakness in groups of muscles
Usually distally
Stage 2 - what to do
Adaptive equipment AROM/stretching Strengthening of unaffected Aerobic as able AAROM/PROM via caregivers to prevent contractures and pain
Strengthening in stages 1 and 2
Exercise in several brief periods throughout the day - 2 to 3 sessions, 15 to 45 minutes total
Lighter weights and less reps
Stage 3 descrition
Mild-Moderate limitation of function, severe foot drop, marked hand weakness, neck flexion due to neck extensor weakness, STS deficits
Stage 3 what to do
AFOs/splints/soft collar W/c for longer distances Lift devices for chairs PROM/AAROM Deep breathing, chest expansion/stretching
Stage 4 description
Severe weakness in LEs
Stage 4 what to do
WC - eval for power WC AAROM/PROM Isometric contraction Deep breathing Skin inspection/pressure relieving strategies
Stage 5 description
Moderate to sever deterioration or mobility and endurance
Stage 5 what to do
Power wc
Lift for transfers at home
Frequent position changes
Pain - gentle AAROM/PROM, thermal modalities, splinting
Head neutral position - might need to progress to rigid collar
Stage 6 description
End stage, dependent
Stage 6 what to do
Reposition
Pain management
Progressive respiratory distress - chest PT
The role of exercise
Strengthening and aerobic exercises are effective
Cochrane review
Stretching
No literature support but we know it can help with weakness that will lead to imbalance, it can help prevent mm shortening and contractures
RCTs with exercise - strengthening
2 groups - 1 strengthening and stretching and the other was just stretching
Group with strengthening had improved function on outcome measure and improved QOL
Exercised 3/wk for 6 months
Studies with aerobic exercise - mouse models
Mouse models show moderate intensity can increase survival, but high intensity worsens it
Studies with aerobic exercise - RCT that had one group do aerobic program of choice and the other do their normal ADL
At 3 months, aerobic group had improved function and less spasticity
At 6 months, there was less of a difference between groups
