chapter14
TRANSCRIPT
Neurological DisordersChapter 14
Learning Objectives
Discuss the mechanism of action of each of the major categories of neurological disorders.
Discuss the causes, symptoms, and treatment of brain tumors, seizure disorders, and cerebrovascular accidents.
Discuss developmental disorders resulting from toxic chemicals.
Discuss the causes, symptoms, and potential treatments for the brain degeneration caused by Alzheimer’s disease.
Neurological Disorders
Neurological disorders are disorders affecting the nervous system central or peripheral
Hundreds of identified disorders Tumors Seizure Disorder Cerebrovascular Accidents Disorders of Development Degenerative Disorders Disorders Caused by Infections Diseases
Tumors
Mass of cells whose growth is uncontrolled and has no function
Mechanisms of tumor damage Compression (benign and malignant) Infiltration (malignant)
Develop from cells which are able to divide Meningiomas Glioma neruoma
Types of Tumors
Malignant Cancerous Infiltrates
surrounding tissue
Benign “harmless” encapsulated
border
Seizure Disorders
Seizure period of sudden, excessive activity of
cerebral neurons Brain damage
hippocampal damage ▪ 50%
Excessive glutamate release
Causes of seizures
Scarring most common stroke, injury, brain abnormality, or
tumor Drugs
withdrawal ▪ alcohol or barbiturate
Infections that cause high fevers Genetic factors
Seizure First Aid
Stay calm Prevent injury Pay attention to the length of the seizure Make the person as comfortable as possible Keep onlookers away Do not hold the person down Do not put anything in the person's mouth Do not give the person water, pills, or food until
fully alert If the seizure continues for longer than five
minutes, call 911 Be sensitive and supportive, and ask others to do
the sameFrom: http://www.epilepsy.com/epilepsy/firstaid
Cerebrovascular Accidents (Stroke)
Hemorrhagic stroke Obstructive stroke
Disorders of Development
Genetic and environmental causes Toxic chemicals Mental retardation can result from
toxin exposure during fetal development
Toxins from viruses and drugs can impair fetal development
Fetal Alcohol Syndrome
Fetal alcohol syndrome
Critical Periods Neural tube complete by 28th day Neuronal porliferation (2-4 months) Migration (3-5 months) Gyri and sulci formation (5-9 months) Myelination (6 months – after birth)
Alcohol may interfere with neural adhesion protein
Degenerative Disorders
Disorders causing a progressive loss of structure or function in the nervous system Not attributed to normal aging
Alzheimer’s disease
Form of dementia Loss of cognitive abilities
Progressive memory loss resembling anterograde amnesia
Severe degeneration of the several brain regions hippocampus, entorhinal cortex,
neocortex, nucleus basalis, locus coeruleus, raphe nuclie
Alzheimer’s disease
Brain pathology
Neuritic plaques extracellular Beta-amyloid
protein
Neurofibrillary tangles intracellular tau proteins
Alzheimer’s disease
Causes of Alzheimer’s Disease
Heredity Some forms run in families Gene for apolipoprotein E (apoE)▪ E4 allele increases risk for late-onset
Sporadic Most cases
Protecting Against AD
Engaging in cognitively challenging tasks Positive correlation between years of
formal education and cognitive performance ▪ Even in individuals with plaques
In mice, training on a new task slowed the accumulation of beta amyloid
Maintain a generally healthy lifestyle