For the diagnosis of amyotrophic lateral sclerosis, the presence of clinical pathology of the 1st and 2nd motor neuron at one level is required; alternatively, for the 2nd motor neuron, electrophysiologic signs of damage at two levels are required.
The following symptoms and complaints may indicate amyotrophic lateral sclerosis (ALS):
Main symptoms
- Ataxia (gait disturbances)
- Atrophies (tissue atrophy) of the musculature (often starting in the hand muscles) → weakness of the arm and hand muscles
- Dysphagia (swallowing disorder)
- Fasciculations (involuntary movements of very small muscle groups) in paraspasticity of the legs (spastic paralysis of both legs) or spastic tetraparesis (paralysis of all four extremities)
- Fasciculations and atrophic paresis (paralysis) of the tongue.
- Increased masseter reflex (masseter reflex: physiological intrinsic reflex that causes adduction (bringing a body part closer to the body axis) in the temporomandibular joint after a blow from above to the mandible).
- Lockjaw (trismus; difficulty opening the mouth).
- Pathological (pathological) laughter or crying (about 50% of sufferers are affected).
- Weakness of the respiratory muscles (respiratory insufficiency) in the advanced stage → hypoxemia (lowered oxygen content in the blood) and hypercapnia (increased carbon dioxide content in the blood).
- Speech disorders (slowed and strained speech).
Caveat. Sensory disturbances or bladder disorders are not among the symptoms of ALS.
Secondary symptoms (esp. non-motor symptoms).
- Due to impaired respiratory function, insomnia (sleep disturbances), morning headaches, daytime fatigue, impaired concentration and restlessness may occur.
- Depression and anxiety
- Oculomotor impairments (including reduced speed in ocular sequential movements).
- Frontal abnormalities to frontotemporal dementia (FTD; a neurodegenerative disease usually occurring before the age of 60 years in the frontal or temporal lobe of the brain with the consequence of increasing personality decline) – an ALS-FTD complex is found in about 5-10% of all patients.
- Parkinson’s-like symptoms (rigor, bradykinesia, and Parkinson’s-like gait patterns).
- Sensory symptoms (hypesthesias, paresthesias, and neuropathic pain).
- Weight loss due to the difficulty of food intake.
- Lack of fluid intake → dehydration (fluid deficiency).
Other notes
- Results of a case-control study show that patients with amyotrophic lateral sclerosis often had a high-fat diet before the onset of the disease, but still had a lower body mass index (BMI) compared with a healthy control group. BMI was 25.7 compared with 26.0 in the control group.
