Disorders of the Nervous System. Disorders of the Neurological System. General Endpoints of CNS Disease. General Endpoints of CNS Disease

Transcription

1 HD in Nursing-Pathophysiology Disorders of the Nervous System What are some disorders of the nervous system? Disorders of the Neurological System Dr. C.H. Lai The nervous system is vulnerable to various disorders. It can be damaged by: Injuries Infections Degeneration Structural defects Tumors General Endpoints of CNS Disease 1. Herniation part of the brain goes outside its casing. e.g. foramen magnum caused by blood collection; tumor; etc General Endpoints of CNS Disease 2. Cerebral edema swelling in the brain Many causes: a. Increased vascular permeability caused by widened endothelial gaps fluid enters increase pressure b. Altered cellular regulation astrocytes relax / malfunction c. Absorption of CSF

2 General Endpoints of CNS Disease 3. Hydrocephalus water on brain really its CSF increased in volume in the brain increase ventricle size Increase intracranial pressure and compress brain tissue General Endpoints of CNS Disease 3. Hydrocephalus water on brain Causes: over-production, blocked exit, resorption, tumor Neural Tube Defect Neural Tube Defect Embryologic development

3 Neural Tube Defect 1. Anencephaly no brain problem with the anterior pole during embryologic development Neural Tube Defect 2. Spina bifida hallmark neural tube defect a. Closing of the neural tube Neural Tube Defect 2. Spina bifida hallmark neural tube defect a. Closing of the neural tube Neural Tube Defect 3. Perinatal brain injury / cerebral palsy Causes brain damage occurring before or during the birth process Effects paralysis of the extremities as well as the speech muscle. With muscle and speech training and other therapeutic approaches, children with cerebral palsy can be helped.

4 Traumatic Vascular Injury Traumatic Vascular Injury 1. Epidural hematoma a. Blood between the skull and the dura (outside the dura) b. Middle meningeal artery temple often is the cause c. Causes cerebral edema possible herniation Traumatic Vascular Injury 2. Subdural hematoma a. Between dura and meninges b. Common in elderly c. Rupture cerebral VEINS from bump on head have high index of suspicion Traumatic Vascular Injury 3. Intraparenchymal bleeds bleeds in the brain ruptured aneurysm other ruptured BVs subarachnoid hematoma intercerebral hematoma

5 Ischemic Encephalopathy Brain dysfunction that happens from global damage from low O 2 states use this term only in global such as MI, respiratory failure, near drowning Disorders of the Brain Disorders of Synaptic Functions Diseases caused by an imbalance of neurotransmitters: Major Depression (Clinical Depression) Schizophrenia Myasthenia Gravis Parkinson's Disease Major Depression A mood or emotional disorder often caused by a deficiency of serotonin and or norepinephrine. Serotonin transmission from both the caudal raphe nuclei and rostal raphe nuclei is reduced in patients with depression compared with non-depressed controls.

6 Major Depression Schizophrenia Antidepressant drugs such as Effexor, Prozac, Sinequan and Zoloft make more of these neurotransmitters available to the brain. Schizophrenia is a thought disorder that may represent too much, or an over-sensitivity to the transmitter dopamine. Electrical Convulsive Shock Therapy (ECT) also makes more of these neurotransmitters available to the brain. Schizophrenia Schizophrenia is incurable Drug treatment often allows the disease to be controlled. e.g. Thorazine, Haldol and Clozaril make less dopamine available to the brain. NMJ Disorder: Myasthenia Gravis Occurs due to a deficiency of the transmitter Ach or its receptors at the neuromuscular junction Autoimmune disease Antibodies bind to the Ach receptors in the neuromuscular junctions and lead to their destruction

7 Myasthenia Gravis Without this transmitter nerves cannot make muscles contract and do work. Myasthenia gravis produces muscular weakness. Parkinson's Disease Occurs due to a lack of dopamine in specific parts of the brain which control movement. This results in a tremor (shaking) Parkinson's Disease Parkinson's is treated with the drug L-dopa which adds dopamine to the brain. Too much L-dopa can result in schizophrenic-like symptoms. Cerebrovascular accident (CVA); stroke Cerebral hemorrhage, blood clot Most common among people older than 40 years of age and those with arterial wall damage, diabetes, or high blood pressure

8 Cerebrovascular accident (CVA); stroke Cerebral hemorrhage, blood clot Cerebrovascular accident (CVA); stroke There are 3 easy SYMPTOMS to look for to tell if a person has just had a stroke: 1. A twisted face best seen when the person smiles. 2. Slurred speech. 3. Ask the person to stretch out their arms and close their eyes. One side will drift down in a stroke. If you find any one of these symptoms in a person that never had it before, the chance that they've had a stroke is 72% Cerebrovascular accident (CVA); stroke Paralysis, aphasia (expressive and / or receptive aphasia) Cerebrovascular accident (CVA); stroke Babinski s sign

9 Cerebrovascular accident (CVA); stroke Broca s area (adjacent to primary motor area ) is responsible for language production / speech. Cerebrovascular accident (CVA); stroke Wernike s area is responsible for comprehension of written and spoken language and formation of coherent speech Broca s aphasia: Will write. I know what I want to say but I just can t say it Wernike s aphasia: Will say Apples jump tiger toowoomba (produce meaningless strings of words) Epilepsy Epilepsy Not known in most cases Seizure activity; results in brain damage, uncontrollable movements of face, arm, or leg, and in loss of consciousness. A chronic disorder involving an abnormality of the electric activity of the brain with or without apparent changes in the nervous tissues.

10 Tumors Most brain tumors originate from the neuroglia (connective tissue of the brain) and are called gliomas. Depend on the type of tumor, its location, its destructiveness, and the degree to which it compresses the brain tissue. Encephalitis There are many causes of such disease, including viruses transmitted by insects or ticks. The invasion of brain tissue by lymphocytes is accompanied by swelling of the brain and diffuse nerve cell destruction. Typical symptoms include fever, vomiting, and coma. Tumors of the brain may develop in people of any age but are somewhat more common in young and middle-aged adults than in other groups. Alzheimer's disease An unexplained degeneration of the cerebral cortex and hippocampus. Degenerative Diseases Memory deficits, cognitive impairments and personality changes

11 Alzheimer's disease Alzheimer's disease The brain with more pronounced atrophy with Alzheimer's disease seen superiorly and laterally Clumps of abnormal nerve cells (senile plaques) surrounding abnormal protein deposits (amyloid) and clumps of material (neurofibrillary tangles) that disrupt the normal structure of nerve cells. These can be seen during an examination of the brain after the person has died. These brain changes may cause the memory loss and decline in other mental abilities that occur with Alzheimer's disease. It is not fully understood why these brain changes occur in some people. Ventricular dilation resulting from loss of cortex Alzheimer's disease Multi-infarct dementia The accumulation of brain damage due to chronic ischemia (lack of blood supply) after a series of small strokes Progressive loss of memory, judgment, and cognitive function. This computer graphic compares the brain of a patient with Alzheimer s disease, left, with a normal, healthy brain, right. A degenerative disease, Alzheimer s disease causes brain tissue to shrink and leads to a gradual, irreversible loss of memory and language ability.

12 Multi-infarct dementia Grossly, this composite view of the brain demonstrates multiple remote cystic infarcts in various locations. This process took several years. Parkinson's disease Arises from cell death in a part of the brain (substantia nigra) that produces the neurotransmitter dopamine. Normal PD patient Parkinson's disease Parkinson's disease Tremors, rigidity of limbs and joints, slow movement, and impaired balance Parkinson's Disease. Dementia is about six times more common in the elderly Parkinson patient than in the average older adult. It is most likely to occur in older patients who have had major depression. Unlike in Alzheimer's, language is not usually affected in Parkinson's related dementia. Visual hallucinations occur in about a third of people on long-term medications.

13 Multiple Sclerosis Disorders involving the Cranial Nerves Multiple Sclerosis Glaucoma Increase pressure of the eye fluid on the nerves, from the effect of poisons, and from some infections Destruction of optic nerve (II) fibers

14 Strabismus Lack of coordination of the eyeball muscles A deviation of the eye Bell s palsy Damage to the facial nerve (VII), usually on one side of the face Distortion of the face because of one-sided paralysis of the muscles of facial expression