Primary lateral sclerosis
is a type of motor neuron disease, where nerve cells that control voluntary muscle movement breakdown and die. In primary lateral sclerosis only the upper motor neurons in the brain are affected. Symptoms often begin with problems in the legs (e.g., weakness, stiffness, spasticity, and balance problems), but may also start with hand clumsiness and changes in speech. The symptoms worsen gradually over time, however people with this condition have a normal life expectancy. Progression of symptoms varies from person to person, some people retain the ability to walk without assistance, others eventually require assistive devices such as canes or wheelchairs. Diagnosis requires extensive testing to exclude other diseases. Treatment may include baclofen and tizanidine to reduce spasticity, quinine or phenytoin to reduce cramps, as well as physical and speech therapy as required. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.