Paralytic Diseases

Paralytic diseases include different types of muscular and neural diseases that cause severe paralyses. This also includes spinal paralyses.

In all of these cases the muscles have lost the ability to perform movements. The brain, however, is still able to generate the according control impulses.

Course of the Disease

The individual disorders can have very different courses of disease. In place of other diseases that cause severe paralyses, the following disorders are described in more detail:

Muscular Dystrophy

Muscular dystrophy is the generic term for various myopathies that result in a degeneration of muscular tissue. There are approximately 30 different types of muscular dystrophies. In many cases their emergence is determined genetically, but in other cases it is not clarified conclusively yet. The most common types are Duchenne and Becker’s dystrophy.

Myatrophy is caused by an inherited lack of the muscular protein dystrophin, or by a defective composition of dystrophin and other proteins, the dystrophin-glycoprotein complex.

The disease takes a progressive course, meaning those affected become increasingly limited in their ability to move. Speech might also be impaired. Depending on the type of dystrophy, the disease progresses more slowly or more quickly. There is no treatment so far to stop muscle degeneration.

The different types of dystrophies occur with varying frequency. There is an average risk of occurrence of between 1:2000 and 1:5000. It generally appears during childhood or adolescence.

Amyotrophic Lateral Sclerosis (ALS)

French physician Jean-Martin Charcot, the first to describe this disease pattern in 1874, coined the term amyotrophic lateral sclerosis. Amyotrophic stands for a loss of muscular mass, and lateral sclerosis means an induration of the lateral spinal cord.

Muscular degeneration is caused by an impairment of the motor neurons – those nerve cells in charge of motion. Because of this, the connection between brain and muscles is lost and the control impulses concerning movement cannot be received anymore. The muscular system starts to regress.

Depending on the location where the motor neurons are affected first, the disease can initially appear in various forms. If the anterior horn cells in the spinal cord are affected first, the muscles in arms and legs, up to the muscles of respiration, are the first to recede. In case the disease initially affects motor neurons in the brain stem, initial problems concern the muscles for speaking, chewing, and swallowing. These symptoms of weakness are accompanied by muscle twitches and increasing signs of paralysis, often spreading within a short period of time. For the majority of affected persons the disease develops over a period of 3 to 5 years.

In the vast majority of cases the origin of the disease remains unclear. 5-10 % of the affected persons have a genetic predisposition causing a more frequent occurrence within a family. Latest scientific findings indicate a correlation with a dysfunctional repair and degradation protein.

ALS is a rare disease. On average 3 to 8 out of 100,000 people suffer from ALS, most of them between 50 and 70 years of age.

Spinal Paralysis

Spinal paralysis includes various symptoms caused by a disruption of the nerve pathways in the spinal cord. Beside the paralysis of the legs (paraplegia) and possibly the arms (tetraplegia), there are changes in the muscular contracting and stretching properties as well as in the circulatory system.

A spinal cord injury is most often caused by accidents in which the affected persons suffered from a spinal fracture. Supply disruptions of the spine, tumors or strokes, for instance, can be other causes of paralysis.

The degree of severity of the paralysis depends on the location where the nerve pathway in the spinal cord is disrupted. The higher up the so-called lesion of the spine, the more limited the affected person’s movements are.

About 30,000 people worldwide sustain a spinal cord injury each year. Life expectancy of persons with paraplegia or tetraplegia hardly differs from the average life expectancy; it is only significantly shorter in cases of a very high lesion, in which e.g. artificial ventilation becomes necessary.

Possible Therapies

According to the current medical state of knowledge it is not possible to cure any of the paralytic diseases described above. Only some cases of paraplegia can be cured successfully through surgical intervention.

Depending on the disease pattern, the affected persons can slow down the course of the disease, or relieve the symptoms with appropriate medication.

Additionally, affected persons receive intensive support from physical and occupational therapists as well as psychologists and speech therapists where appropriate.

The Approach

Based on the Brain Interchange technology, CorTec provides their customers with an implantable system that records and stimulates brain activity.

Movements trigger different patterns of brain signals. Paralyzed persons cannot perform these movements anymore but when they imagine a certain motion, in most cases their brain is still capable of producing the corresponding signals.

With the aid of CorTec’s Brain Interchange technology our customers can decode these signals and use them as control commands. This way, paralyzed persons can learn to control assistive devices such as computers, and eventually wheelchairs or ortheses. In cooperation with our partners we are currently developing a system for communication and environmental control based on neuronal control. We are planning to conduct initial studies with this system in the near future.

Literature for Further Reading

  • Heiko vom Bruch: Bewegungsbehinderungen. Ăśbersicht und funktionelle Grundlagen. Thieme Verlag. Stuttgart u.a. 1998
  • Helga Kesser: Starke Leben. Wie Muskelkranke ihren Alltag bewältigen. Sachbuchverlag rĂĽffer & rub. ZĂĽrich 2009
  • Volker Daut: Leben mit Duchenne-Muskeldystrophie. Eine qualitative Studie mit jungen Männern. Bad Heilbrunn 2005 (online)
  • Simone Spuler und Arpad von Moers: Muskelkrankheiten. Grundlagen, Diagnostik und Therapie. Schattauer. Stuttgart 2004
  • Denis Bron und Dieter Pongratz: Muskeldystrophie Duchenne in der Praxis. Verlag Hans Huber. Bern 2010
  • Amyotrophe Lateralsklerose (ALS). Eine Information fĂĽr Patienten und Angehörige. Hrsg. Deutsche Gesellschaft fĂĽr Muskelkranke e.V. und Schweizerische Muskelgesellschaft. 2012 (online)
  • DGM-Handbuch ALS. Mit der Krankheit leben lernen. HRSG. Deutsche Gesellschaft fĂĽr Muskelkranke e.V. Freiburg 2010 (online)
  • Bernhard Neundörfer: Praxis der amyotrophen Lateralsklerose. Uni-Med-Verlag. Bremen [u. a.] 2002
  • Math Buck, Dominiek Beckers und Cees Pont: Querschnittlähmung. Ein Ratgeber fĂĽr Betroffene und ihre Angehörigen. Springer. Berlin u.a. 1996
  • Leben mit Querschnittlähmung. FGQ-Info. Fördergemeinschaft der Querschnittgelähmten e.V. Jährlich
  • Volker Dietz: Querschnittlähmung. Physiopathologie, Klinik und Therapie von Blasenfunktion, Bewegung und Vegetativum. Kohlhammer. Stuttgart 2000