However, patients are carefully selected for this type of procedure to ensure that they will likely benefit from this invasive procedure.Physical therapy often helps prevent joint immobility. Speech therapy may be useful for those with involvement of the facial muscles. Physiotherapy treatment focuses on reducing muscle tone, maintaining or improving range of motion, increasing strength and coordination, and improving functional mobility. In PLS, stretching is thought to improve flexibility and can also reduce muscle spasticity and cramps.Patients with PLS may find it beneficial to have an evaluation, as well as follow-up visits at multidisciplinary clinics, similar to those available for people with ALS. These multidisciplinary clinics may provide patients with the necessary treatment that they require by having an occupational therapist, physical therapist, speech language pathologist, dietician and nutritionist, all in one site. Prognosis
Patients can often live with PLS for many years and very often outlive their neurological disease and succumb to some unrelated condition. There is currently no effective cure, and the progression of symptoms varies. Some people may retain the ability to walk without assistance, but others eventually require wheelchairs, canes, or other assistive devices. References
External links

primary_lateral_sclerosis at NINDS
A lack of oxygen to the brain contributes to the formation of lesions usually near the three main cerebral arteries, located near the parietal lobe and occipital lobes of the brain. The cause of perinatal brain injuries includes: 

1. cerebral ischemia
2. cerebral hemorrhage
3. ascending intrauterine infections.Some risk factors for perinatal brain injuries include: low birth weight, preterm birth, poor perinatal cardiorespiratory fitness, and artificial ventilation. Cerebral ischemia
Cerebral ischemia occurs when the brain is not receiving adequate oxygen to continue normal functions. When this occurs, the body makes restoring oxygenated blood flow to life-sustaining organs a priority. The brain alters the diameter of major blood vessels to redistribute blood to key organs such as the brain, heart, and adrenal glands. If sympathetic nervous system activation does not produce any improvement, oxygen levels will continue to fall and disruptions to metabolism, other cellular processes, and overall functioning will ensue. Another serious result of inefficient blood flow is that cells do not receive adequate amounts of glucose. An immediate effect of low intracellular glucose is reduced ATP production in the cell. This effectively inactivates the Na-K pump, leading to the uptake of calcium ions by the cell. Continued influx of calcium serves to constitutively activate downstream effectors, including lipases, proteases, and endonucleases, whose actions eventually destroy the cell skeleton. Intracellular calcium concentrations are increased further due to the opening of glutamate-regulated ion channels.