brain, spinal cord, and nerve disorders
Amyotrophic Lateral Sclerosis (ALS) and Other Motor Neuron Diseases (MNDs)
Diagnosis
A doctor's evaluation Tests such as magnetic resonance imaging, electromyography, and nerve conduction studies Blood and sometimes urine tests and a spinal tap Doctors suspect motor neuron disease in adults who have progressive muscle weakness without pain or loss of sensation. Doctors ask people the following: Which parts of the body are affected When symptoms started Which symptoms appeared first How the symptoms have changed over time This information gives them clues about the cause of symptoms. Causes can have many causes. Diagnostic tests, such as the following, are done to help narrow the possibilities: Electromyography , which involves recording electrical activity in the muscles, can help determine whether the problem is in nerves, neuromuscular junction, or muscles. Nerve conduction studies , which measure how fast nerves transmit impulses, may also be done. The speed of impulses is not affected until late in motor neuron disease, so if impulses are unexpectedly slow early in the disease, the cause of symptoms may be another disorder. Magnetic resonance imaging (MRI) of the brain and sometimes the spinal cord is done to check for abnormalities that may cause similar symptoms. Tests are done to check for other disorders that can cause weakness. To test for other disorders, doctors may do the following: Blood tests to check for infections and metabolic disorders Urine tests to check for heavy metals (such as lead or mercury) if people have been exposed to them A Spinal Tap (lumbar puncture) to check for signs of inflammation in the fluid that surrounds the brain and spinal cord (cerebrospinal fluid) Genetic tests to check for hereditary disorders such as Hereditary Neuropathies None Over time, motor neuron diseases tend to cause symptoms that are so characteristic that the diagnosis is obvious without any testing. 