Disorders Associated With CNS

Disorders assoiciated with CNS • Injury of spinal cord above C3 causes paralysis of all respiratory muscles and death due to paralysis of diaphragm. • Quadriplegia: Injury of spinal cord at C4–C5 level paralyses all four limbs. • Erb’s paralysis: Injury to spinal nerves C5 and C6 causes loss of abduction of shoulder, loss of flexion of elbow, loss of supination and loss of extension of wrist. • Klumpke’s paralysis: Injury to spinal nerves C8 and T1 causes paralysis of intrinsic muscles of the hand causing claw hand. • Paraplegia: Injury of spinal cord between T2 and L1 paralyses both the lower limbs. • Ataxia: Inability to maintain the equilibrium of the body, while standing or while walking. This may occur as a result of interruption of afferent proprioceptive pathways, i.e. tracts in the posterior column and the spinocerebellar pathways (sensory ataxia). • Amyotrophic lateral sclerosis (ALS), also known as Lou Gehrig's Disease: It is a type of motor neuron disease. As motor neurons in the brain and spinal cord that control voluntary muscle movement degenerate and die, they stop sending messages to the muscles, which causes the muscles to weaken, start to twitch and waste away (atrophy). Eventually, the brain loses its ability to initiate and control voluntary movements. • Parkinsonism: Is degeneration of the substantia nigra, leading to much reduced of dopamine in patients. It is characterized by akinesia, rigidity, and tremors. • Lesions of the inferior colliculus produce defects in appreciation of tones, localization of sound, and reflex movements in response to sound. • Cerebral palsy: Is a clinical picture that occurs as a result of damage to the movement function area of the central nervous system before, after or during delivery. It is a group of disorders that affect a person's ability to move and maintain balance and posture. It can also be seen as a spastic type, which is characterized by the inability of the muscles in various parts of the body to relax, which progresses with excessive contractions at a rate of 80% in children. • Bell's palsy: Is a neurological disorder due to injure or stops working properly of facial nerve that causes paralysis or weakness of facial muscles on one side of the face. Symptoms appear suddenly over a 48- to 72-hour period and generally start to improve with or without treatment after a few weeks. They vary from person to person and can be mild to severe. Usually, you will 1 recover some or all facial function within a few weeks to six months. Sometimes the facial weakness may last longer or be permanent. • Bulbar palsy (or bulbar weakness): Paralysis due to a lesion in the medulla, which is refer to bilateral impairment of function of the lower cranial nerves IX, X, XI and XII, which occurs due to lower motor neuron lesion either at nuclear or fascicular level in the medulla. • Alzheimer’s disease: Is a brain disorder that slowly destroys memory and thinking skills and, eventually, the ability to carry out the simplest tasks. The disease is named after Dr. Alois Alzheimer. In 1906, Dr. Alzheimer noticed changes in the brain tissue included many abnormal clumps (amyloid plaques) and tangled bundles of fibers (neurofibrillary tangles). Another feature is the loss of connections between nerve cells in the brain. Neurons transmit messages between different parts of the brain, and from the brain to muscles and organs in the body. • Horner’s Syndrome: Interruption of sympathetic supply to the head and neck. This consists of the following: - Constriction of the pupil (miosis) - Drooping of the upper eyelids (ptosis) - Reduced prominence of the eyeball (enophthalmos) - Absence of sweating on the face and neck (anhidrosis) • Hydrocephalus: An abnormal increase in the quantity of CSF. Hydrocephalus may be caused by excessive production of CSF, by obstruction to its flow, or by impaired absorption through the arachnoid villi. Abnormal pressure of CSF leads to degeneration of brain tissue. It is classified as: - Obstructive or noncommunicating hydrocephalus, when there is obstruction to flow of CSF from the ventricular system to the subarachnoid space. Obstruction is most likely to occur where CSF has to pass through narrow passages, for example, the interventricular foramina, the aqueduct, and the apertures of the fourth ventricle. - Communicating hydrocephalus, when such obstruction is not present. Meningitis may also lead to hydrocephalus by affecting the arachnoid villi, thus, hampering the reabsorption of CSF. • Epilepsy: Is one of the most common serious chronic neurological conditions affecting people of all ages globally, with peaks in incidence rates in children and in adults over the age of 60. It is characterized by abnormal electrical activity in the brain, causing seizures or unusual behaviour, sensations and sometimes loss of awareness. Common causes include prenatal or 2 perinatal injuries, congenital abnormalities or brain malformations, head injuries, stroke, neurological infections such as meningitis, encephalitis and neurocysticercosis, and brain tumours. In about 70% of people with epilepsy, the cause is not known In the remaining 30%, the most common causesare: Head trauma Infection of brain Brain tumor and stroke Heredity. • Migraines: Are severe headaches that can cause severe throbbing pain or a pulsing sensation, a migraine is usually begin on one side of the head (often behind the eye) and spread to the whole head. Migraines can last from two hours to a few days. Migraines affect around one in ten people. They are three times more common in females and tend to affect young people who are otherwise healthy. Most people who get migraines will have a family member with the same problem. The cause of migraines is unclear. Studies suggest that a migraine is caused by swelling of the blood vessels in the scalp and tissues around the brain, causing more blood to pump through the brain. Changes in brain activity and chemicals also appear to play a part. It's often accompanied by nausea, vomiting, and extreme sensitivity to light and sound. • Myasthenia gravis: Is a chronic autoimmune, neuromuscular disease that causes weakness in the skeletal muscles (the muscles that connect to your bones and contract to allow body movement in the arms and legs, and allow for breathing). Myasthenia gravis is caused by an error in how nerve signals are transmitted to muscles. It occurs when communication between the nerve and muscle is interrupted at the neuromuscular junction. This occurs due to the antibodies (immune proteins produced by the body's immune system) block, alter, or destroy the receptors for acetylcholine at the neuromuscular junction. The following symptoms are commonly associated with myasthenia gravis: - Weakness of the eye muscles (ocular myasthenia) - Drooping of one or both eyelids (ptosis) - Blurred or double vision (diplopia) - Changes in facial expressions - Difficulty swallowing - Shortness of breath - Impaired speech (dysarthria) 3