Onset of<unk>  usually occurs spontaneously after age 50 and progresses gradually over a number of years, or even decades. The disorder usually begins in the legs, but it may start in the tongue or the hands. Symptoms may include difficulty with balance, weakness and stiffness in the legs, and clumsiness. Other common symptoms are spasticity (involuntary muscle contraction due to the stretching of muscle, which depends on the velocity of the stretch) in the hands, feet, or legs, foot dragging, and speech and swallowing problems due to involvement of the facial muscles. Breathing may also become compromised in the later stages of the disease, causing those patients who develop ventilatory failure to require noninvasive ventilatory support. Hyperreflexia is another key feature of<unk>  as seen in patients presenting with the Babinski's sign. Some people present with emotional lability and bladder urgency, and occasionally people with<unk>  experience mild cognitive changes detectable on neuropsychological testing, particularly on measures of executive function.<unk>  is not considered hereditary when onset is in adulthood; however, juvenile<unk>  (JPLS) has been linked to a mutation in the ALS2 gene which encodes the cell-signalling protein alsin. The issue of whether<unk>  exists as a different entity from ALS is not clear, as some patients initially diagnosed as having<unk>  ultimately develop lower motor neuron signs. When this happens it is classed as ALS. Spasticity<unk>  <unk>  usually presents with gradual-onset, progressive, lower-extremity stiffness and pain due to muscle spasticity. Onset is often asymmetrical. Although the muscles do not appear to atrophy as in ALS (at least initially), the disabling aspect of<unk>  is muscle spasticity and cramping, and intense pain when those muscles are stretched, resulting in joint immobility. A normal walking stride may become a tiny step shuffle with related instability and falling.
Primary lateral sclerosis
Juvenile primary lateral sclerosis
Amyotrophic lateral sclerosis
Surfer's myelopathy
Vascular myelopathy
CMV polyradiculomyelopathy
Tumefactive multiple sclerosis
Multiple sclerosis