The Spastic Paraplegia Foundation is
dedicated to advancing research and ultimately developing
cures for two groups of closely related upper motor neuron
disorders called Primary Lateral Sclerosis (PLS) and
Hereditary Spastic Paraplegia (HSP).
These conditions share the common feature of degeneration
of long motor nerves called upper motor neurons. These
nerves begin in the motor cortex of the brain and extend
down the spinal cord. HSP and PLS can be referred to
as "primary upper motor neuron disorders"
because there is little, if any, lower motor neuron
involvement. See What's
In both disorders, this degeneration causes the
progressive loss of the use of the legs. In PLS, the
arms, speech and swallowing as well as the legs are
affected, usually over the period of a few years. In
rare forms of HSP, there are additional neurological
symptoms as well.
The disorder name "Hereditary Spastic Paraplegia"
describes the symptoms of the disease. HSP is Heredity
and it's symptoms are Spasticity
The disorder name "Primary Lateral Sclerosis"
describes the disease process, rather than the symptoms.
Degeneration occurs: Primarily
in the Lateral columns of
the spinal cord. Sclerosis
The primary degenerative process in both groups of
disorders occurs in the lateral columns, also called
the cortico-spinal tracts. The symptoms of
both conditions are increasing spasticity and weakness
of the affected muscles. Brain neurons appear to also
be affected in PLS, and, in some forms of HSP, as well.
The SPF is dedicated to conquering these two groups
of upper motor neuron disorders.