Muscle atrophy and weight loss almost always are recognized by the time the patient seeks medical treatment. Fasciculations may be quite widespread and active. Surprisingly, the patient often ignores this symptom. Patients may have inappropriately active tendon reflexes and weak, wasted, twitching muscles. Muscle cramps are common.
Decubitus ulcers are rare.
The primary cause of death among patients electing to use ventilatory support is pulmonary infection. The specific cause is unknown. If a history of slow progression of lower motor neuron disease is lacking, consider disorders such as myasthenia gravis and Guillain-Barr syndrome. Often, neurologists need several weeks to exclude all other possible diagnoses in a patient presenting with upper and lower motor neuron signs. Electromyography shows fibrillation and fasciculations.