Diseases that involve nerve damage and muscle and ligament deterioration include motor neuron diseases (MNDs) and peripheral neuropathies. These diseases are generally progressive, that is, they usually worsen over time.
Motoneuron diseases are those that destroy motor neurons, the nerve cells that control muscles, according to the National Institute of Neurological Disorders and Stroke (NINDS). The nerve signals don't conduct properly and muscles begin wasting away. The muscle deterioration leads to shortening and stiffness of the tendons and ligaments.
MNDs can be inherited disorders or acquired, says NINDS. It is believed that environmental toxins and viruses may play a role in the development of MNDs.
Peripheral nerves are those that transmit information to and from the brain and spinal cord to the rest of the body. Peripheral neuropathies distort and interfere with these transmissions as nerve damage occurs. The nerve damage also results in deterioration of the muscles and ligaments, as well as chronic pain, numbness and loss of function.
There are many different causes of peripheral neuropathies, and more than 100 types have been identified.
MND: Amyotrophic Lateral Sclerosis (ALS)
Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's disease, is a fatal condition. Many doctors also refer to ALS as motor neuron disease. In ALS, the progressive nerve damage and muscle deterioration come to affect vital functions such as breathing, chewing and swallowing.
MNDs: Progressive Bulbar Palsy and Pseudobulbar Palsy
Progressive bulbar palsy, or progressive bulbar atrophy, refers to a condition affecting the bulbous part of the brainstem. The brainstem controls vital functions like breathing and swallowing, but this disease also affects the limbs.
Pseudobulbar palsy affects the ability to chew, speak and swallow. It also affects the facial muscles.
MNDs: Primary Lateral Sclerosis (PLS) and Progressive Muscular Atrophy
Primary lateral sclerosis (PLS) involves degeneration of the nerves that control voluntary movement. It usually first affects the legs and progresses to lack of control and deterioration of the muscles of the trunk, arms and then the brainstem.
Progressive muscular atrophy is an MND that causes muscle wasting in the hands and then the lower body.
MNDs: Spinal Muscular Atrophy (SMA) and Post-Polio Syndrome (PPS)
Spinal muscular atrophy refers to a cluster of conditions that involve nerve damage in the spinal cord and muscle wasting mostly in the legs and arms, but can affect those involved in breathing, swallowing and speaking. Werdnig-Hoffman disease, SMA type II, Kugelberg-Welander disease, Fazio-Londe disease, Kennedy disease, and congenital SMA with arthrogryposis are all forms of SMA.
Post-polio syndrome (PPS) affects polio survivors many years after their recovery. Illness, injury, ageing or weight gain are believed to trigger nerve damage, according to NINDS. This nerve damage leads to progressive muscle and ligament deterioration.
Peripheral Neuropathies Due to Injury and Illness
Physical injuries can often cause considerable nerve damage that result in muscle and ligament deterioration.
Systemic diseases are diseases that affect the entire body. These often result in nerve damage and muscle wasting. Alcoholism, blood and vascular conditions, cancers, chronic inflammation, diabetes, hormonal imbalances, kidney disorders, repetitive stress, toxins and vitamin deficiencies are all examples of these acquired peripheral neuropathies.
Peripheral Neuropathies Due to Infections or Autoimmune Conditions
Many bacteria and viruses can attack nerve tissues, says NINDS. Diptheria, Epstein-Barr, herpes simplex, herpes varicella-zoster, HIV and Lyme disease can all cause nerve damage and muscle and ligament deterioration.
Some bacteria and viruses trigger autoimmune conditions that result in nerve damage.
Gulillan-Barre syndrome and chronic inflammatory demyelinating polyneuropathy (CIDP) are examples of inflammatory conditions that damage nerves.
Inherited Peripheral Neuropathies
Some peripheral neuropathies are caused by genetic mutations or specific genes that are passed down. The most common are a group of inherited peripheral neuropathies known as Charcot-Marie-Tooth diseases.