Health

Pathophysiology (the problem)
ALS stems from progressive loss of UMNs, LMNs, or both. Its cardinal feature is muscle weakness. The cause of ALS is presently not known. It is hypothesized that the following may be responsible for it: genes, environment, infections, and the immune system.
Symptoms are reported by the patient while signs are noted by a doctor or clinician on physical examination. Some common symptoms and signs associated with ALS are listed below.

Cranial (Bulbar) Segment
A.    UMN Symptoms
1.    Involuntary biting and jaw clenching
2.    Slurred speech (dysarthria)
3.    Difficulty swallowing (dysphagia)
4.    Secretion mismanagement
a.    Drooling (siallorrhea)
b.    Excessive posterior pharyngeal (throat) secretions
c.    Aspiration of food, liquids, and secretions into the larynx (voice box) and respiratory tract
5.    Difficulty moving food about in the mouth
6.    Inappropriate laughing, crying, and/or yawning known as pseudobulbar affect (PBA) or inappropriate emotional expression disorder (IEED)
B.    LMN Symptoms
1.    Weakness of jaw muscles
2.    Slurred speech (dysarthria)
3.    Difficulty swallowing (dysphagia)
4.    Secretion mismanagement: drooling (siallorrhea) and or excessive posterior pharyngeal secretions
5.    Difficulty moving food about in the mouth (tongue weakness)
6.    Weakness of neck flexion (e.g. lifting head off of a pillow)

Cervical Segment
A.    UMN Symptoms
1.    Arm and hand weakness
2.    Poor coordination
3.    Arm stiffness (spasticity)
B.    LMN Symptoms
1.    Arm and hand weakness
2.    Neck weakness
3.    Muscle cramps
4.    Muscle atrophy
5.    Muscle fasciculations
C.    LMN Respiratory Symptoms
1.    Shortness of breath with activity (dyspnea)
2.    Shortness of breath when laying flat (orthopnea)
3.    Sleep disturbance
4.    Low speech volume
5.    Shorter sentences before next breath is required (lack of breath support for speech)
6.    Daytime headaches
7.    Confusion

Thoracic Segment
A.    UMN Symptoms
1.    Trunk and back (axial muscle) stiffness
2.    Poor balance
B.    LMN Symptoms
1.    Weakness of extensor (paraspinal) muscles that straighten the spine (difficulty maintaining erect posture when standing)
2.    Weakness of flexor (abdominal wall) muscles that bend the spine forward (poor bending at waist, difficulty performing sit-up and arising from laying down position, protuberant abdomen)
3.    Fasciculations
4.    Cramps

Lumbosacral Segment
A.    UMN Symptoms
1.    Leg weakness
2.    Incoordination
3.    Leg stiffness
4.    Spontaneous spasms
5.    Clonus (repetitive upward and downward tremor like reflex contractions at the ankle or sometimes knee joint)
6.    Gait difficulty, poor balance, tripping, falling
B.    LMN Symptoms
1.    Leg weakness
2.    Muscle cramps
3.    Muscle atrophy
4.    Muscle fasciculations

Cognitive Dysfunction
A.    Caused by progressive loss of frontal (non-motor) and temporal cortical neurons
B.    Up to 50% of ALS patients test differently from controls on formal tests of cognitive function known as neuropsychological testing
C.    Only 10% of ALS patients have severe enough frontotemporal cognitive dysfunction (personality change and or language dysfunction) to be considered to have frontotemporal dementia

Exclusionary Symptoms and Signs
A.    The following symptoms or signs are considered to exclude the diagnosis of classic ALS
1.    Sensation loss
2.    Tremor or other involuntary movements (exceptions include clonus, fasciculations, cramps, and spasms)
3.    Difficulty moving the eyes or weakness of the eyelids
4.    Bladder or bowel incontinence
B.    The term ALS-PLUS is often used when classic signs and symptoms of ALS are accompanied by one or more of these exclusionary features