Spinal Muscular Atrophy

Spinal Muscular Atrophy is classify as an interneuron abnormality and loss of the anterior horn cells in the spinal column. SMA is categorized into three subtypes with the classification embedded on the motor milestone achieved. Spinal type I (Werdnig-Hoffman disease) child is to weak that they never learn to sit, type II child learn to sit but never learn to walk without assistive device, and type III (Kugelberg-Welander disease) child can walk independently (Tecklin, 2015).

DMD is caused by a mutation in the X-linked dystrophin gene, which results in a dysfunctional dystrophin protein. Dystrophin is a cytoskeletal protein that provides mechanical stability to muscle cells by connecting the muscle sarcolemma to the basal lamina of the extracellular matrix (ECM), and without it there, the muscle cells typically undergo a process of degeneration and regeneration. This process is limited by the survival of satellite cells present since satellite cells can only undergo mitosis a limited amount of times. Sarcolemma instability typically results in excess intracellular amounts of both sodium and calcium, which causes ATP depletion and mitochondrial uncoupling (Horn & Schleip, 2012). Satellite cells only have a limited number times they can undergo mitosis, and once a patient can no longer generate healthy muscle cells, the patient will typically experience cell death. This cell death and necrosis usually

This disease affects the nerve cells by enabling them to send electric impulses to the muscles which ultimately makes the muscle wither away and stop working. The nerves targeted are actually

Duchenne Muscular Dystrophy is one of the nine types of muscular dystrophy and the most known, it’s a genetic disorder distinguish by ongoing muscle degeneration and weakness. DMD is cause by a mutation on the X chromosome that stops the production of dystrophin, which is a normal protein in muscles.

In 1995 a French group of researchers discovered that SMA is autosomal recessive disorder due to loss of the survival motor neuron protein gene (SMN) (Lefebvre et al., 1995). Through experimentation the researchers discovered two copies of the SMN gene in chromosome five [chr 5q13.2]: telomeric and centromeric SMN copies. Experimentation proved that loss of the telomeric SMN (today known as SMN1) and not loss of its centromeric counterpart, SMN2, resulted in SMA.

In this article, the authors discussed the different types of Congenital Muscular Dystrophy: Fukuyama Congenital Muscular Dystrophy, Muscle Eye Brain disease, and Walker Warburg Syndrome. Congenital muscular dystrophies tend to be less common than other muscular dystrophies. Patients that are diagnosed with Congenital muscular dystrophy show symptoms before they are even born. Most rarely move in the womb, due to neonatal hypotonia. Neonatal hypotonia is known as “floppy baby syndrome”, in which patients do not have enough strength in their muscles to move voluntarily. Then once the patients are born, the symptoms only progress and muscles continue to deteriorate.

Primary lateral sclerosis is a rare disease that causes a gradual loss of the nerve cells (neurons) in the brain that control voluntary muscles. Voluntary muscles are the muscles you can control, such as the muscles in your arms, hands, legs, and face. In this disease, the muscles gradually become weak and stiff. Movement of the affected parts of the body becomes more difficult. The disease mainly affects the arms and legs.

Damage to the neuromuscular junctions is due to an autoimmune disease called myasthenia graves. The motor end plates, which are located on skeletal muscles, are affected because there is a decrease in the amount of Ach receptors located on the motor end plate, which is connected to the neuromuscular junction. The decrease is due to the unnecessary production of antibodies, which bind to the motor end plate. This prevents Ach from binding to the receptors to carry out a synapse between the skeletal muscle and a neuron, leading to a stop or weakening of muscle contraction. The decrease in the amounts of synapses cause the skeletal muscle to lose function, become weaker, and tire more easily.

Muscular dystrophy is a group of inherited diseases in which voluntary muscles or the muscles that control movement, gradually weaken. MD is caused by mutations in genes responsible for proper function and muscle structure. This disease in some forms, can also affect the heart and other organs. The mutations disable the cells from properly maintaining muscle. This advances to muscle weakness and progressive disability. These mutated genes are inherited from parents. MD can be passed on if one or both parents have genes that cause muscular dystrophy. The genetic mutation causing MD can develop as in infant, which is called spontaneous mutation. This occurs in very few cases however. Some clinical effects of MD are: progressive muscle weakness, difficulty using muscle groups, delayed motor skills, drooling, frequent falls, eyelid droops, difficulty climbing stairs, problems walking, vertebral deformities, tendon reflexes reduced, and respiratory problems.

What is Muscular Dystrophy, or MD for short. Muscular Dystrophy is a hereditary disease that effects the muscles which controls movement weaken overtime, and in some cases will affect the heart and other organs. Symptoms can show up in those as young as infants and can stay in those in the middle ages or older. There are nine major forms of MD including: Myotonic, Duchenne, Becker, Limb-girdle, Facioscapulohumeral, Congenital, Oculopharyngeal, Distal, Emery-Dreifuss. The form and severity vary by the age that MD occurs. Some types of MD will affect mostly males, while some people with MD will enjoy a slow progression with mild symptoms, but on the otherhand, others will experience swift and severe weakening, dying in their late teens and early 20’s. More than 50,000 Americans are affected by various types of MD.

Spinal muscle atrophy, also known as SMA, is a genetic disease that takes the physical strength of people. It affects the motor nerve cells in the spinal cord, leaving the people who are affected unable to walk, eat, and sometimes even breath on their own (Izenberg, 2016). Most of the nerve cells that control muscles are located in the spinal cord, this is why it is spinal. It is muscular because it affects the muscles. Atrophy is the medical term for getting smaller and that is what happens when they are not used (The Muscular Dystrophy Association, 2016). When an individual has SMA they are not using their muscles as much or at all. That is how Spinal Muscle Atrophy got its name.

The SMN1 gene is responsible for the creation of the SMN protein, and without this protein, the motor neurons of the spinal cord and brainstem die off and muscles weaken and waste (atrophy). Muscles used for swallowing, crawling, walking, sitting up and controlling head movement are mainly affected. If one copy of the defected gene and one regular copy of the gene are inherited, than the child will be a carrier of the disease and will not have any symptoms. There are four types of SMA, Type I, Type II, Type II, and Type IV. Each type has different symptoms, age of onset, and severity but, each type affects each person differently.

In each form of muscular dystrophy is caused by a genetic mutation particular to that type of the disease. Many of these actions are inherited but, some occur spontaneously

Be aware of neurological conditions that may present as orthopaedic conditions e.g. ataxia, reduced proprioception, dragging feet.

The French Neurologist Jean-Martin Charcot first discovered motor neurone disease MND in 1874. Motor function is controlled by the upper motor neurones in the brain that descend to the spinal cord, these neurones activate lower motor neurones. The lower motor neurones exit the spinal cord and directly activate muscles. With no nerves to activate them, muscles gradually weaken and waste. MND can affect a person’s ability to walk, speak, swallow and breathe. The muscles first affected tend to be those in the hands, feet and mouth, dependent on which type of the disease you are diagnosed with.