ALS

Question 1

Amyotrophic Lateral Sclerosis (ALS) is also called…

Answer 1

Lou Gehrig’s Disease

Question 2

ALS LMN

Answer 2

Lesion sites:
-anterior horn cells (alpha & -gamma motor neurons (LMN signs)

Starts distal and works proximally –hands and feet are effected first and atrophies

Question 3

ALS UMN

Answer 3

Lesion sites:

• lateral corticospinal tract
• motor nuclei of brainstem
• motor area of frontal lobe (UMN signs)

-rarely any sensory involvement in ALS

Question 4

Primary pathologic defect…

Answer 4

• is in the motor neuron cell body (specific to anterior horn cell in the spinal cord)
• motor cells in the brainstem motor nuclei (cranial nerves)
• pyramidal cells in the primary motor cortex thus loss of the upper motor neurons in corticospinal tracts (Betz cells)

Question 5

Cause of the neuropathology associated with ALS

Answer 5

• unknown at this time
• Possible causes include: Mitochondria
• Currently, the most prevalent theory is that a SOD1 gene mutation causes the superoxide dismutase (SOD) enzyme to function improperly.

Question 6

SOD1 gene mutation

Answer 6

• causes the superoxide dismutase (SOD) enzyme to function improperly.
• SOD enzyme is a strong anti-oxidant that the mitochondria need to perform their respiratory function
• The respiratory and ATP function is compromised and the nerve cell begins to atrophy.

Question 7

Other possible causes are…

Answer 7

• Glutamate: elevated in the cerebrospinal fluid and blood in ALS patients up to concentrations that could be neurotoxic. Over-excitation of glutamate-sensitive cells in the nervous system may result in their premature degeneration and death.
• Exogenous toxins
• Viral disease
• Immunologic disturbances

Question 8

ALS Stats

Answer 8

• 0.1% of adult deaths in U.S.
• ALS is a disease of late middle life and is rarely seen prior to age 40.
• 90% of all cases begin between the ages of 40 and 70 years
• some predominance in men (estimated at 1.5-2.0 males to 1 females)

Question 9

Signs & Symptoms

Answer 9

• First sign is usually asymmetric, distal weakness (e.g. difficulty in manipulating objects with the fingers or dragging one leg during walking)
• When pt’s complain of weakness, they often have lost 80% of their alpha MN in the areas of weakness
• Progress to mm atrophy and severe mm weakness
• CN cell atropy
• Control of bladder, bowel, and autonomic function is largely unimpaired, however, some studies report sub-clinical involvement

Question 10

Early Signs

Answer 10

Severe muscle cramps and/or fasciculations at rest

Question 11

EMG

Answer 11

• Spontaneous fibrillations

- Fasciclations with giant unit spikes upon voluntary activity

Question 12

Progress to muscle atrophy and severe muscle weakness

Answer 12

• decrease # of muscle fibers

- type II fibers tend to atrophy earlier and more rapidly than type I fibers

Question 13

Cranial nerve cell atrophy leads to

Answer 13

• Dysarthria
• Dysphagia
• difficulty in chewing
• tongue weakness
• Fasciculations may be prominent
• Hypoglossal, facial, and trigeminal nuclei are most severely involved

Question 14

Motor and Sensory Signs

Answer 14

• Motor signs and symptoms only
• NOT sensory - sensory systems or the special senses are rarely involved (this is primarily a motor neuron cell body disease), however, pain and paresthesia are often reported

Question 15

LMN signs

Answer 15

• Progressive muscle atrophy
• Weakness (asymmetric weakness is often a presenting sign)
• Fasciculations (especially -evident in tongue, deltoid)
• Muscle cramps (painful)

Question 16

UMN Signs

Answer 16

• Spasticity
• Hyperreflexia
• Positive Babinski

Question 17

ALS Death and Life Expectancy

Answer 17

• Death in 2-5 years commonly from respiratory compromise
• Life expectancy of a patient with ALS can vary from less than 1 year to more than a decade with ventilator support
• Average survival rate is 4.1 years
• 20% survive more than 5 years
• Those who have ALS before age 50 generally live longer
• Those that have early CN involvement usually live less years post-Dx
• Stephen Hawkins is the exception

Question 18

Intervention

Answer 18

• General care revolves around the relief of discomfort and minimization of musculoskeletal, integumentary,& systemic effects
• Problems w/ swallowing, speech, postural control, and respiration are common so that equipment/therapy must be targeted to these needs (IPE – team approach)
• Therapy is directed at preventing contractures, skeletal deformity and/or respiratory complications, maintaining activity level, & recommending & issuing equipment as needed.
• pALS

Question 19

Intervention Part 2

Answer 19

• Muscle spasms – stretching, increased movement, quinine or baclofen
• Diet – anti-oxidants – vitamins E and C
• Encourage a balance between activity and rest.
• If more than 1/3 of the motor units are intact, exercise led to hypertrophy. If less than 1/3 of the motor units are intact, vigorous exercise damaged the muscles
• If the pt shows evidence of significant, persistent weakness following institution of an exercise program or persistent morning fatigue, the PT must redesign the HEP & monitor the pt’s activity level and response to HEP carefully