Poliovirus/Poliomyelitis

Classification

General Characteristics and Epidemiology

General characteristics of poliovirus

• Family: Picornaviridae Picornaviridae A family of small RNA viruses comprising some important pathogens of humans and animals. Transmission usually occurs mechanically. There are nine genera: aphthovirus; cardiovirus; enterovirus; erbovirus; hepatovirus; kobuvirus; parechovirus; rhinovirus; and teschovirus. Coxsackievirus
• Genus: Enterovirus Enterovirus A genus of the family picornaviridae whose members preferentially inhabit the intestinal tract of a variety of hosts. The genus contains many species. Newly described members of human enteroviruses are assigned continuous numbers with the species designated ‘human enterovirus’. Coxsackievirus
• Classified as a strain of Enterovirus Enterovirus A genus of the family picornaviridae whose members preferentially inhabit the intestinal tract of a variety of hosts. The genus contains many species. Newly described members of human enteroviruses are assigned continuous numbers with the species designated ‘human enterovirus’. Coxsackievirus C
• RNA RNA A polynucleotide consisting essentially of chains with a repeating backbone of phosphate and ribose units to which nitrogenous bases are attached. RNA is unique among biological macromolecules in that it can encode genetic information, serve as an abundant structural component of cells, and also possesses catalytic activity. RNA Types and Structure virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology:
  • Linear
  • Single-stranded
  • Positive-sense
  • Functions as mRNA mRNA RNA sequences that serve as templates for protein synthesis. Bacterial mRNAs are generally primary transcripts in that they do not require post-transcriptional processing. Eukaryotic mRNA is synthesized in the nucleus and must be exported to the cytoplasm for translation. Most eukaryotic mRNAs have a sequence of polyadenylic acid at the 3′ end, referred to as the poly(a) tail. The function of this tail is not known for certain, but it may play a role in the export of mature mRNA from the nucleus as well as in helping stabilize some mRNA molecules by retarding their degradation in the cytoplasm. RNA Types and Structure
• Diameter: 25–30 nm
• Icosahedral symmetry
• Lacks a lipid envelope Envelope Bilayer lipid membrane acquired by viral particles during viral morphogenesis. Although the lipids of the viral envelope are host derived, various virus-encoded integral membrane proteins, i.e. Viral envelope proteins are incorporated there. Virology
• Acid-stable

Clinically relevant species

Poliomyelitis is caused by 3 serotypes of poliovirus:

• Wild type 1 Type 1 Spinal Muscular Atrophy (most common)
• Wild types 2 and 3 (considered eradicated)

Epidemiology

• Poliovirus has been eradicated in most countries because of extensive vaccination Vaccination Vaccination is the administration of a substance to induce the immune system to develop protection against a disease. Unlike passive immunization, which involves the administration of pre-performed antibodies, active immunization constitutes the administration of a vaccine to stimulate the body to produce its own antibodies. Vaccination efforts.
• 150 cases were reported in 2019.
• Endemic countries include: 
  • Pakistan
  • Afghanistan

Pathogenesis

Reservoir Reservoir Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (disease vectors) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks. Humans may serve both as disease reservoirs and carriers. Escherichia coli

Humans are the only known reservoir Reservoir Animate or inanimate sources which normally harbor disease-causing organisms and thus serve as potential sources of disease outbreaks. Reservoirs are distinguished from vectors (disease vectors) and carriers, which are agents of disease transmission rather than continuing sources of potential disease outbreaks. Humans may serve both as disease reservoirs and carriers. Escherichia coli.

Transmission

This highly contagious virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology is transmitted via:

• Fecal–oral route
• Respiratory aerosols Aerosols Colloids with a gaseous dispersing phase and either liquid (fog) or solid (smoke) dispersed phase; used in fumigation or in inhalation therapy; may contain propellant agents. Coxiella/Q Fever

Pathophysiology

• Oral entry of the virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology → replication in the oropharyngeal and GI lymphatic tissues
• Asymptomatic viremia Viremia The presence of viruses in the blood. Erythema Infectiosum → reticuloendothelial system
• If the infection is not contained → secondary viremia Secondary viremia Mumps Virus/Mumps occurs → viral symptoms
• Virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology enters the CNS (unclear process)
• Viral replication occurs in neurons Neurons The basic cellular units of nervous tissue. Each neuron consists of a body, an axon, and dendrites. Their purpose is to receive, conduct, and transmit impulses in the nervous system. Nervous System: Histology of the spine Spine The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy (particularly the anterior horn Anterior horn One of three central columns of the spinal cord. It is composed of gray matter spinal laminae VIII and ix. Brown-Séquard Syndrome) and brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification stem → damage and necrosis Necrosis The death of cells in an organ or tissue due to disease, injury or failure of the blood supply. Ischemic Cell Damage → neurologic signs and symptoms

Clinical Presentation and Diagnosis

Abortive poliomyelitis

The majority of infected individuals are asymptomatic or develop a minor flu-like illness:

• Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
• Malaise Malaise Tick-borne Encephalitis Virus
• Headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess
• Pharyngitis Pharyngitis Pharyngitis is an inflammation of the back of the throat (pharynx). Pharyngitis is usually caused by an upper respiratory tract infection, which is viral in most cases. It typically results in a sore throat and fever. Other symptoms may include a runny nose, cough, headache, and hoarseness. Pharyngitis
• Nausea Nausea An unpleasant sensation in the stomach usually accompanied by the urge to vomit. Common causes are early pregnancy, sea and motion sickness, emotional stress, intense pain, food poisoning, and various enteroviruses. Antiemetics and vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia

Nonparalytic poliomyelitis

Approximately 4% of those infected will develop nonparalytic poliomyelitis. Presentation will be aseptic meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis after a prodrome Prodrome Symptoms that appear 24–48 hours prior to migraine onset. Migraine Headache similar to that of abortive poliomyelitis.

• Fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever
• Headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess
• Nuchal rigidity Nuchal Rigidity Meningitis

Paralytic poliomyelitis

A minority of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with nonparalytic poliomyelitis will progress to the paralytic form Paralytic form Rabies Virus of the disease, characterized by:

• Muscle spasms Spasms An involuntary contraction of a muscle or group of muscles. Spasms may involve skeletal muscle or smooth muscle. Ion Channel Myopathy
• Myalgias Myalgias Painful sensation in the muscles. Tick-borne Encephalitis Virus
• Profound, asymmetrical muscle weakness:
  • Legs most often affected
  • More severe in proximal muscles
• Diminished or absent reflexes
• Normal sensory Sensory Neurons which conduct nerve impulses to the central nervous system. Nervous System: Histology exam
• Urinary retention Urinary retention Inability to empty the urinary bladder with voiding (urination). Delirium
• Bulbar involvement:
  • Dysphagia Dysphagia Dysphagia is the subjective sensation of difficulty swallowing. Symptoms can range from a complete inability to swallow, to the sensation of solids or liquids becoming “stuck.” Dysphagia is classified as either oropharyngeal or esophageal, with esophageal dysphagia having 2 sub-types: functional and mechanical. Dysphagia
  • Dysphonia Dysphonia Difficulty and/or pain in phonation or speaking. Epiglottitis
  • Difficulty handling secretions
  • Respiratory compromise
  • Autonomic dysfunction Autonomic Dysfunction Anterior Cord Syndrome

Postpoliomyelitis syndrome

Postpoliomyelitis syndrome manifests as worsening symptoms in poliomyelitis survivors. It can occur decades after the initial infection.

• Fatigue Fatigue The state of weariness following a period of exertion, mental or physical, characterized by a decreased capacity for work and reduced efficiency to respond to stimuli. Fibromyalgia
• Progressive weakness and atrophy Atrophy Decrease in the size of a cell, tissue, organ, or multiple organs, associated with a variety of pathological conditions such as abnormal cellular changes, ischemia, malnutrition, or hormonal changes. Cellular Adaptation of affected muscles
• Fasciculations Fasciculations Involuntary contraction of the muscle fibers innervated by a motor unit. Fasciculations may be visualized as a muscle twitch or dimpling under the skin, but usually do not generate sufficient force to move a limb. They may represent a benign condition or occur as a manifestation of motor neuron disease or peripheral nervous system diseases. Polyneuropathy
• Pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
• Restless leg syndrome Restless Leg Syndrome Iron Deficiency Anemia
• Respiratory insufficiency

Diagnosis

Diagnosis is based on clinical presentation and supported by the diagnostic workup.

Lumbar puncture Lumbar Puncture Febrile Infant:

• Often done in the setting of aseptic meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis
• Findings:
  • Moderate pleocytosis Pleocytosis Tick-borne Encephalitis Virus
  • ↑ Protein
  • Normal glucose Glucose A primary source of energy for living organisms. It is naturally occurring and is found in fruits and other parts of plants in its free state. It is used therapeutically in fluid and nutrient replacement. Lactose Intolerance

Specific testing:

• Viral culture Viral culture West Nile Virus
  • Viral isolation in stool: gold standard
  • Can also be performed with throat Throat The pharynx is a component of the digestive system that lies posterior to the nasal cavity, oral cavity, and larynx. The pharynx can be divided into the oropharynx, nasopharynx, and laryngopharynx. Pharyngeal muscles play an integral role in vital processes such as breathing, swallowing, and speaking. Pharynx: Anatomy secretions/swabs
• PCR PCR Polymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules. Polymerase Chain Reaction (PCR)
• Serology Serology The study of serum, especially of antigen-antibody reactions in vitro. Yellow Fever Virus

Management and Prevention

Management

There is no effective antiviral Antiviral Antivirals for Hepatitis B therapy for poliomyelitis. Management is supportive.

• Close hemodynamic monitoring for patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with bulbar involvement
• Mechanical ventilation Ventilation The total volume of gas inspired or expired per unit of time, usually measured in liters per minute. Ventilation: Mechanics of Breathing for respiratory failure Respiratory failure Respiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure or airway Airway ABCDE Assessment protection
• Analgesics for pain Pain An unpleasant sensation induced by noxious stimuli which are detected by nerve endings of nociceptive neurons. Pain: Types and Pathways
• Splints to prevent deformities

Prognosis Prognosis A prediction of the probable outcome of a disease based on a individual’s condition and the usual course of the disease as seen in similar situations. Non-Hodgkin Lymphomas

Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with nonparalytic poliomyelitis make complete recoveries. For those with paralytic poliomyelitis:

• 2 out of 3 patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship will not regain full strength.
• 30%–40% will develop postpoliomyelitis syndrome.
• Mortality Mortality All deaths reported in a given population. Measures of Health Status: 
  • 4%–6%
  • 10%–20% in adults or bulbar disease

Prevention

There are 2 vaccines used:

• Salk (inactivated poliovirus vaccine Vaccine Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases. Vaccination):
  • Given parenterally
  • Forms only IgG IgG The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of igg, for example, igg1, igg2a, and igg2b. Hypersensitivity Pneumonitis antibodies Antibodies Immunoglobulins (Igs), also known as antibodies, are glycoprotein molecules produced by plasma cells that act in immune responses by recognizing and binding particular antigens. The various Ig classes are IgG (the most abundant), IgM, IgE, IgD, and IgA, which differ in their biologic features, structure, target specificity, and distribution. Immunoglobulins: Types and Functions, not IgA IgA Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory iga is the main immunoglobulin in secretions. Immunoglobulins: Types and Functions
• Sabin (oral poliovirus vaccine Vaccine Suspensions of killed or attenuated microorganisms (bacteria, viruses, fungi, protozoa), antigenic proteins, synthetic constructs, or other bio-molecular derivatives, administered for the prevention, amelioration, or treatment of infectious and other diseases. Vaccination):
  • Live attenuated
  • Creates IgG IgG The major immunoglobulin isotype class in normal human serum. There are several isotype subclasses of igg, for example, igg1, igg2a, and igg2b. Hypersensitivity Pneumonitis and IgA IgA Represents 15-20% of the human serum immunoglobulins, mostly as the 4-chain polymer in humans or dimer in other mammals. Secretory iga is the main immunoglobulin in secretions. Immunoglobulins: Types and Functions
  • Not used in the United States
  • Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship shed the virus Virus Viruses are infectious, obligate intracellular parasites composed of a nucleic acid core surrounded by a protein capsid. Viruses can be either naked (non-enveloped) or enveloped. The classification of viruses is complex and based on many factors, including type and structure of the nucleoid and capsid, the presence of an envelope, the replication cycle, and the host range. Virology → may be able to mutate and circulate

Comparison of Enteroviruses

Differential Diagnosis

• Guillain–Barré syndrome ( GBS GBS An acute inflammatory autoimmune neuritis caused by t cell- mediated cellular immune response directed towards peripheral myelin. Demyelination occurs in peripheral nerves and nerve roots. The process is often preceded by a viral or bacterial infection, surgery, immunization, lymphoma, or exposure to toxins. Common clinical manifestations include progressive weakness, loss of sensation, and loss of deep tendon reflexes. Weakness of respiratory muscles and autonomic dysfunction may occur. Polyneuropathy): acute, rapidly progressive, acquired inflammatory neuropathy Neuropathy Leprosy that can be triggered by infectious pathogens. Unlike poliomyelitis, the progressive muscle weakness in GBS GBS An acute inflammatory autoimmune neuritis caused by t cell- mediated cellular immune response directed towards peripheral myelin. Demyelination occurs in peripheral nerves and nerve roots. The process is often preceded by a viral or bacterial infection, surgery, immunization, lymphoma, or exposure to toxins. Common clinical manifestations include progressive weakness, loss of sensation, and loss of deep tendon reflexes. Weakness of respiratory muscles and autonomic dysfunction may occur. Polyneuropathy is symmetric, there is sensory Sensory Neurons which conduct nerve impulses to the central nervous system. Nervous System: Histology loss, and fever Fever Fever is defined as a measured body temperature of at least 38°C (100.4°F). Fever is caused by circulating endogenous and/or exogenous pyrogens that increase levels of prostaglandin E2 in the hypothalamus. Fever is commonly associated with chills, rigors, sweating, and flushing of the skin. Fever is rare. The diagnosis is clinical. A lumbar puncture Lumbar Puncture Febrile Infant will show a normal white cell count and elevated protein (albuminocytologic dissociation Dissociation Defense Mechanisms). Management requires intensive care support, IV immune globulin, and plasma exchange Plasma exchange Removal of plasma and replacement with various fluids, e.g., fresh frozen plasma, plasma protein fractions (ppf), albumin preparations, dextran solutions, saline. Used in treatment of autoimmune diseases, immune complex diseases, diseases of excess plasma factors, and other conditions. Thrombotic Thrombocytopenic Purpura.
• West Nile virus West Nile Virus West Nile virus is an enveloped, positive-sense, single-stranded RNA virus of the genus Flavivirus. Birds are the primary hosts and the disease is most often transmitted by Culex mosquitoes. Most people infected with West Nile virus are asymptomatic. Some patients develop West Nile fever (a self-limited, febrile illness) and a very small proportion of patients develop West Nile neuroinvasive disease. West Nile Virus infection: infection by a flavivirus Flavivirus A genus of flaviviridae containing several subgroups and many species. Most are arboviruses transmitted by mosquitoes or ticks. The type species is yellow fever virus. Tick-borne Encephalitis Virus. The majority of patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship with West Nile virus West Nile Virus West Nile virus is an enveloped, positive-sense, single-stranded RNA virus of the genus Flavivirus. Birds are the primary hosts and the disease is most often transmitted by Culex mosquitoes. Most people infected with West Nile virus are asymptomatic. Some patients develop West Nile fever (a self-limited, febrile illness) and a very small proportion of patients develop West Nile neuroinvasive disease. West Nile Virus will be asymptomatic or have headache Headache The symptom of pain in the cranial region. It may be an isolated benign occurrence or manifestation of a wide variety of headache disorders. Brain Abscess, myalgias Myalgias Painful sensation in the muscles. Tick-borne Encephalitis Virus and arthralgias, vomiting Vomiting The forcible expulsion of the contents of the stomach through the mouth. Hypokalemia, diarrhea Diarrhea Diarrhea is defined as ≥ 3 watery or loose stools in a 24-hour period. There are a multitude of etiologies, which can be classified based on the underlying mechanism of disease. The duration of symptoms (acute or chronic) and characteristics of the stools (e.g., watery, bloody, steatorrheic, mucoid) can help guide further diagnostic evaluation. Diarrhea, or a rash Rash Rocky Mountain Spotted Fever. A small proportion develop encephalitis Encephalitis Encephalitis is inflammation of the brain parenchyma caused by an infection, usually viral. Encephalitis may present with mild symptoms such as headache, fever, fatigue, and muscle and joint pain or with severe symptoms such as seizures, altered consciousness, and paralysis. Encephalitis, meningitis Meningitis Meningitis is inflammation of the meninges, the protective membranes of the brain, and spinal cord. The causes of meningitis are varied, with the most common being bacterial or viral infection. The classic presentation of meningitis is a triad of fever, altered mental status, and nuchal rigidity. Meningitis, or flaccid paralysis. The diagnosis can be made with serology Serology The study of serum, especially of antigen-antibody reactions in vitro. Yellow Fever Virus, PCR PCR Polymerase chain reaction (PCR) is a technique that amplifies DNA fragments exponentially for analysis. The process is highly specific, allowing for the targeting of specific genomic sequences, even with minuscule sample amounts. The PCR cycles multiple times through 3 phases: denaturation of the template DNA, annealing of a specific primer to the individual DNA strands, and synthesis/elongation of new DNA molecules. Polymerase Chain Reaction (PCR), and viral cultures. This will differentiate West Nile virus West Nile Virus West Nile virus is an enveloped, positive-sense, single-stranded RNA virus of the genus Flavivirus. Birds are the primary hosts and the disease is most often transmitted by Culex mosquitoes. Most people infected with West Nile virus are asymptomatic. Some patients develop West Nile fever (a self-limited, febrile illness) and a very small proportion of patients develop West Nile neuroinvasive disease. West Nile Virus from poliomyelitis. Management is supportive.
• Acute intermittent porphyria Acute intermittent porphyria An autosomal dominant porphyria that is due to a deficiency of hydroxymethylbilane synthase in the liver, the third enzyme in the 8-enzyme biosynthetic pathway of heme. Clinical features are recurrent and life-threatening neurologic disturbances, abdominal pain, and elevated level of aminolevulinic acid and porphobilinogen in the urine. Porphyrias: rare, autosomal dominant Autosomal dominant Autosomal inheritance, both dominant and recessive, refers to the transmission of genes from the 22 autosomal chromosomes. Autosomal dominant diseases are expressed when only 1 copy of the dominant allele is inherited. Autosomal Recessive and Autosomal Dominant Inheritance disease that results in a deficiency of hydroxymethylbilane Hydroxymethylbilane Heme Metabolism synthase. This deficiency leads to accumulation of heme precursors. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship may experience abdominal pain Abdominal Pain Acute Abdomen, psychiatric symptoms, and peripheral neuropathies Neuropathies Chédiak-Higashi Syndrome that can mimic GBS GBS An acute inflammatory autoimmune neuritis caused by t cell- mediated cellular immune response directed towards peripheral myelin. Demyelination occurs in peripheral nerves and nerve roots. The process is often preceded by a viral or bacterial infection, surgery, immunization, lymphoma, or exposure to toxins. Common clinical manifestations include progressive weakness, loss of sensation, and loss of deep tendon reflexes. Weakness of respiratory muscles and autonomic dysfunction may occur. Polyneuropathy. Progression to quadriplegia Quadriplegia Severe or complete loss of motor function in all four limbs which may result from brain diseases; spinal cord diseases; peripheral nervous system diseases; neuromuscular diseases; or rarely muscular diseases. The locked-in syndrome is characterized by quadriplegia in combination with cranial muscle paralysis. Consciousness is spared and the only retained voluntary motor activity may be limited eye movements. This condition is usually caused by a lesion in the upper brain stem which injures the descending corticospinal and corticobulbar tracts. Locked-in Syndrome and respiratory failure Respiratory failure Respiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure can occur. The diagnosis is based on elevated porphyrin precursors in the urine. Management includes IV heme, dextrose Dextrose Intravenous Fluids, and trigger Trigger The type of signal that initiates the inspiratory phase by the ventilator Invasive Mechanical Ventilation avoidance.
• Muscular dystrophy Muscular Dystrophy Becker Muscular Dystrophy: group of noninflammatory muscle disorders caused by a mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations in the DMD DMD Duchenne muscular dystrophy (DMD) is an X-linked recessive genetic disorder that is caused by a mutation in the dmd gene. The mutation leads to the production of abnormal dystrophin, resulting in muscle-fiber destruction and replacement with fatty or fibrous tissue. Duchenne Muscular Dystrophy gene Gene A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms. Basic Terms of Genetics. This mutation Mutation Genetic mutations are errors in DNA that can cause protein misfolding and dysfunction. There are various types of mutations, including chromosomal, point, frameshift, and expansion mutations. Types of Mutations leads to muscle fiber destruction and replacement with fatty or fibrous Fibrous Fibrocystic Change tissue. Patients Patients Individuals participating in the health care system for the purpose of receiving therapeutic, diagnostic, or preventive procedures. Clinician–Patient Relationship present with progressive proximal muscle weakness Proximal Muscle Weakness Lambert-Eaton Myasthenic Syndrome, which leads to the eventual loss of ambulation, as well as contractures Contractures Prolonged shortening of the muscle or other soft tissue around a joint, preventing movement of the joint. Wound Healing, scoliosis Scoliosis Scoliosis is a structural alteration of the vertebral column characterized by a lateral spinal curvature of greater than 10 degrees in the coronal plane. Scoliosis can be classified as idiopathic (in most cases) or secondary to underlying conditions. Scoliosis, cardiomyopathy Cardiomyopathy Cardiomyopathy refers to a group of myocardial diseases associated with structural changes of the heart muscles (myocardium) and impaired systolic and/or diastolic function in the absence of other heart disorders (coronary artery disease, hypertension, valvular disease, and congenital heart disease). Cardiomyopathy: Overview and Types, and respiratory failure Respiratory failure Respiratory failure is a syndrome that develops when the respiratory system is unable to maintain oxygenation and/or ventilation. Respiratory failure may be acute or chronic and is classified as hypoxemic, hypercapnic, or a combination of the two. Respiratory Failure. Unlike poliomyelitis, a marked elevation in CK may be observed. Genetic testing Genetic Testing Detection of a mutation; genotype; karyotype; or specific alleles associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing. Myotonic Dystrophies confirms the diagnosis. Management is supportive.   
• Multiple sclerosis Sclerosis A pathological process consisting of hardening or fibrosis of an anatomical structure, often a vessel or a nerve. Wilms Tumor ( MS MS Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease that leads to demyelination of the nerves in the CNS. Young women are more predominantly affected by this most common demyelinating condition. Multiple Sclerosis): chronic inflammatory autoimmune disease leading to demyelination Demyelination Multiple Sclerosis of the CNS. The clinical presentation of MS MS Multiple sclerosis (MS) is a chronic inflammatory autoimmune disease that leads to demyelination of the nerves in the CNS. Young women are more predominantly affected by this most common demyelinating condition. Multiple Sclerosis varies depending on the site of lesions, but it may include neurologic symptoms affecting vision Vision Ophthalmic Exam, motor Motor Neurons which send impulses peripherally to activate muscles or secretory cells. Nervous System: Histology functions, sensation, and autonomic function. Diagnosis is made with MRI of the brain Brain The part of central nervous system that is contained within the skull (cranium). Arising from the neural tube, the embryonic brain is comprised of three major parts including prosencephalon (the forebrain); mesencephalon (the midbrain); and rhombencephalon (the hindbrain). The developed brain consists of cerebrum; cerebellum; and other structures in the brain stem. Nervous System: Anatomy, Structure, and Classification and spine Spine The human spine, or vertebral column, is the most important anatomical and functional axis of the human body. It consists of 7 cervical vertebrae, 12 thoracic vertebrae, and 5 lumbar vertebrae and is limited cranially by the skull and caudally by the sacrum. Vertebral Column: Anatomy, as well as CSF examination. Management involves corticosteroids Corticosteroids Chorioretinitis for acute exacerbations and disease-modifying agents to slow progression of the disease.