Disorders of the Anterior Horn Cells (ALS) Flashcards
A motor neuron disease in which degeneration of CN IX and XII occurs:
Progressive Bulbar Palsy
A group of 4 inhereted and sporadic motor neuron diseases of UMN’s, LMS’s or both:
- ALS
- Primary Lateral Sclerosis (degeneration of UMN)
- Progressive bulbar palsy (degeneration of CN IX and XII)
- Progressive muscular atrophy (loss of LMN)
ALS clinical manifestations:
- 80% with UMN signs
- Normal cognition (35% with cognitive impairments, FTD)
- LMN S & S: weakness, hyporeflexia, hypotonicity, fasciculations (especially of tongue), atrophy
- UMN S & S: spasticity, pathological reflexes, hyperreflexia, muscle weakness
- Bulbar S & S: dysphagia, Dysarthria, sialorrhea, Pseudobulbar affect: uncontrollable crying ot laughing
- Respiratory: Exertional dyspnea, Nocturnal respiratory difficulty, Orthopnea, Hypoventilation, Secretion retention, Ineffective coug.
- Cognitive: mild to severe FTD, difficulty with verbal fluency, language comprehension, memory, abstract reasoning, intellectual function.
- Rare impairments: sensory, bowel and bladder dysfunction, ocular palsy
ALS Diagnosis:
No gold standart for ALS Dx:
- Based on pattern of S & S along with ruling out everyhting else.
- Absence of sensory involvement* (Recent research shows some sensory involvements occurs)
- Progression of S & S is essential for confirmed Dx of ALS
- 70% have increase Creatine Phosphate Kinase
- Genteic testing for pt with family Hx of ALS
- EMG: signs of active denertvation
- NVC: usually normal
- MRI: to exclude other causes; MS, DDD
ALS Etiology:
- Unknown cause
- 90% -95% sporadic
- 5% - 10% familial
ALS Pathology:
Affects UMN’s and LMN’s:
- Massive loss of Anterior Horn Cells of spinal cord (LMN) – Results in muscle atrophy & weakness (amyotrophy)
- Loss of Betz cells in motor cortex (UMN) leads to demyelination & gliosis of corticospinal & corticobulbar tracts (lateral sclerosis) – Results in UMN symptoms
True or false:
EMG/NCV diagnostic test for ALS shows that ALS is not consistent with peripheral neuropathy neither with polyradiculopathy, but with other type of nerve disorder.
True
True or false:
Environmental toxins such as lead, aluminum, agricultural chemicals, selenium in drinking water, and exposure to electrical shocks are associated with causes of ALS.
True
Hyper-reflexia and spasticity are _ _ _ signs
UMN
In ALS, loss of Betz cells leads to what?
demyelination & gliosis of corticospinal & corticobulbar tracts (lateral sclerosis).
– Results in UMN symptoms
Gliosis: A process leading to scars in the central nervous system that involves the production of a dense fibrous network of neuroglia (supporting cells) in areas of damage
In ALS, massive loss of Anterior Horn Cells of spinal cord results in what?
- LMN signs:
- Results in muscle atrophy & weakness (amyotrophy)
In ALS, what is protein aggregates?
Abnormal clumps of protein in motor neurons found in persons with ALS
Autoimmune-Induced Calcium Influx theory of ALS:
Calcium channel antibodies have been isolated which may lead to prolonged influx of calcium into neurons, resulting in cell death
Name of disease in which degeneration of UMN’s occurs and belongs to a group of disorders known as motor neuron diseases:
Primary Lateral Sclerosis
Name of disease in which loss of LMN’s occurs and belogns to a group of motor neuron diseases:
Progressive Muscular Attrophy
In ALS, what can an Oxidative injury cause?
Accumulation of free radicals leads to cell death by oxidizing cell membranes, proteins or genetic material
Primary role of imaging in ALS is to
- exclude other causes:
- MS & Cervical degenerative disc disease
The most common genetic casue of ALS is a mutation in which gene?
gene C9ORF72
Also linked to Frontotemporal dementia (FTD)
Theories of what causes ALS:
- Glutamate excitotoxicity
- Oxydative injury: cell death by free radicals
- Protein aggregates: in motor neurons
- Axonal strangulation: nutrients can not reach the cell body
- Autoimmune-Induced Calcium influx: resulting in cell death
- Viral infections
- Deficiency of Nerve Growth Factor
- Apoptosis: preprogramed cell death
- Trauma
- Environmental factors: Lead, Aluminum, Agricultural chemicals, Selenium in drinking water, Exposure to electrical shocks.
This disease is a progressive degeneration of motor neurons in spinal cord (Massive loss of Anterior Horn Cells), brainstem & motor cortex (loss of Betz cells) and affects UMN’s & LMN’s:
AMYOTROPHIC LATERAL SCLEROSIS (ALS)
Weakness and atrophy are _ _ _ signs
LMN
What ALS theory states that when neurofilaments of axons become tangled, nutrients cannot reach cell bodies resulting in cell death
Axonal Strangulation
What are the later clinical manifestation of ALS?
Weakness spreads:
- Distal to proximal, then bulbar symptoms
- Flex. weaker that ext.
- Asymmetrical weakness
- Dysphagia
- Dysarthria
- Respiratory dysfunction
What are the typical MRI findings in ALS that have been described in literature?
High signal intensity of corticospinal tract, extending from corona radiata through posterior limb of internal capsule, ventral brain-stem and into spinal cord
What does the World Federation of Neurology consider a Clinically Definite diagnosis of ALS?
- Concomitant UMN & LMN signs in 3 spinal regions (cervical, thoracic, lumbar) OR
- UMN & LMN signs in bulbar region and at least 2 spinal regions
What is essential to confirm Dx of ALS?
- Progression of S & S during the entire lifespan.
- Pattern of S & S along with inclusionary & exclusionary diagnostic tests suchs as MRI
What is spared in ALS?
- Bowel and bladder function is normal
- Oculomotor nuclei is spared
- Sensory
What is the gold standart lab test for the diagnosis of ALS?
- No single lab test can confirm Dx of ALS
- 70% of patients have increased CPK
- Genetic testing for patients with family Hx of ALS
CPK: Creatine Phosphate Kinase
What is the primary role of MRI imaging in ALS?
-
to exclude other causes:
- MS
- Cervical degenerative disc disease
What are the earlier clinical manifestation of ALS?
Muscle weakness:
- Focal, asymmetrical
- Hands, feet, arms legs and/or muscles of speech, swallowing or breathing
- In 60% of patients
- By the time weakness is noticeable, most pt have lost 80% of motor neurons.
Which is the most common form of motor neuron disease?
Amyotrophic Lateral Sclerosis (ALS)
World Federation of Neurology suggested which diagnostic criteria for patients with ALS in clinical practice, clinical trials and research?
looks at UMN/LMN findings in 4 regions of body
Secondary & Composite impairments in ALS:
- Fatigue/ deconditioning
- Weight loss
- Cachexia (or wasting syndrome is loss of weight, muscle atrophy, fatigue, weakness, and significant loss of appetite in someone who is not actively trying to lose weight)
- ROM
- Tendon shortening,
- Joint contracture or subluxation
- Pain
- Balance/postural control
- Gait disturbances
ALS - Disease course:
- Onset of LE weakness more common than UE
- Onset with bulbar symptoms less common.
- Unremitting spread of weakness: total paralysis of spinally innervated muscles and muscles innervated by CNs.
- More rapid loss of strength in UE than LE
- Death 3-5 years after Dx due to respiratory failure
Prognosis of ALS:
- More rapid progression to death if onset with bulbar S & S vs limb onset
- Median survival 4.08 years after onset:
- 50% die within 18 months of DX
- 9% to 40% survive 5 years
- 8% to 16% survive 10 years (usually on ventilator)
- 5% survive > 20 years (not true ALS)
Factors related to a better prognosis in ALS:
- Age <35-40 better 5 yr survival rate
- Less severe at time of Dx
- No dyspnea at onset
- Psychological well being
True or false:
Small number of patients with ALS exhibit halting of progression of disease or remittance of symptoms.
True, casue is unknown
True or false:
Small number of patients with ALS exhibit halting of progression of disease or remittance of symptoms
true
What is the only drug aproved by the FDA to treat ALS?
Riluzole (Rilutek), prolongs survival of patients with ALS by slowing progression of disease
Which ALS drug treat pseudobulbar affects symptoms?
Nuedexta
Pharmacological treatments of ALS under research:
– Gabapentin
– Tocopheral (vitamin E)
– Insulin-like growth factors (rhIGF-1)
– Mexiletin
– GM604
Stem cell treatments of ALS:
- Brainstorm study: use patient’s own stem cells from bone marrow
- Fetal-derived neural cells introduced into patient’s spinal cord
Rehabilitation considerations of ALS:
- Rate of disease progression
- Stages of disease
- Extent and areas of involvement
- Need to re-examine at regular intervals
- Pt, family, caregiver education
- Psychological support
- Referrals
Goals of rehabilitation in ALS:
- Difficult due to progression
- Maintain maximal idependence and QOL as long as possible
therapeutic preventions during ALS:
-
Prevention of disuse atrophy:
- Prevent further disuse beyond level caused by disease process itself
-
Prevention of overuse injury
- “Do no harm”
- Research: vigorous exercise damaged muscles with less than 1/3 of motor units functional
- Amount of strengthening proportional to # of intact motor units
- Avoid heavy eccentric exercise
True or false:
Studies show that weakened, denervated muscle may not be able to tolerate amount of exercise needed for training effect to occur in normal muscle and that strength training of muscles with less than 10% of normal strength is ineffective.
True
Respiratory Management of ALS:
- Respiratory therapy:
- Pulmonary PT: chest PT, breathing exercises, energy conservation
-
Non-invasive ventilation:
- Extends survival by several months
- Improves QOL
- Progress to ventilation via tracheostomy OR
- Palliative care