Lecture 28- Disorders of the nervous system I Flashcards Preview

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Flashcards in Lecture 28- Disorders of the nervous system I Deck (39):

How many people are affected by mental and neurological disorders?

450 million


What are four categories of the WHO of the mental and neurological disorders?

1. Mental diseases 2. Neurological disorders 3. Learning and developmental disabilities 4. Substance abuse disorders


What is the classification of the disorders based on?

-antiquated notion that some disorders were organic (the subject of neurology= neurological disorder) and others just purely functional (the subject of psychiatry= mental)= a malfunction in the mental operations of the brain without an organic cause


What are learning and developmental disabilities?

-include functional limitations that manifest in infancy or childhood as a result of disorders of or injuries to the developing nervous system


What are the causes of the mental illnesses and neurological disorders? (8)

1.Genetic 2.Multifactorial 3.Nutritional 4. Infections 5.Toxic exposure 6.Perinatal complications 7.Injury 8.Poverty, economic disadvantage


What are the five types of genetically caused neurological disorders?

1. Chromosmal: Down syndrome, chromosomal rearrangements 2. Seg. autosomal syndromes: Prader-Willi, Angelmans syndromes 3. Sex-linked, single gene: Fragile X syndrome, Rett syndrome 4. Autosomal recessive: Phenylketonuria, Tay Sachs disease 5. Autosomal dominant: Neurocutaneous syndromes such as neurofibromatosis


What is the multifactorial cause of mental illness or neurological disorder?

Genetic and nutritional: Neural tube defects


What is the nutritional cause of neurological disorders?

-prenatal and childhood: maternal iodine deficiency, developmental iodine deficiency disorder


What are the two types of causes of infection neurological disorders?

1. Prenatal or perinatal: toxoplasmosis, rubella, cytomegalovirus, STD (eg. AIDS) 2.Postnatal or childhood: Encephalitis, meningitis, cerebral malaria, otitis media


What is the toxic cause of neurological disorder?

-prenatal: alcohol, lead, mercury, antimicrobials, other drugs (e.g. thalidomide)


What are the perinatal complication neurological disorders?

-brain injuries associated with premature birth, asphyxia: cerebral palsy, cognitive disabilities, seizure disorders


What are the injury induced neurological disorders?

-traumatic brain injuries, vehicle crashes, child abuse and neglect, warfare etc.: cognitive, motor, speech, vision, hearing, seizure and behavioural disabilities


What is the neurological disorder caused by poverty or economic disadvantage?

-mild mental retardation


What are mental disorders?

-diseases that affect cognition, emotion, and behavioural control and substantially interfere with the ability of children to learn and ability of adults to function in their families, at work, and in the broader society -tend to begin early in life and often run in a chronic recurrent course


Do mental disorders have complex aetiologies?

-yes, involve interactions among multiple genetic and non-genetic risk factors


When is gender related to risk of mental disorders?

-males have higher rates of attention deficit hyperactivity disorder, autism, and substance use disorders -females have higher rates of major depressive disorder, most anxiety disorders and eating disorders


What are the four most significant mental disorders?

1. Schizophrenia 2. Bipolar affective disorder 3. Major depressive disorder 4. Panic disorder


What does the development of pharmacological therapies for mental disorders suggests?

-the development of pharmacological therapies that treated the symptoms of schizophrenia, depression, anxiety disorders and others suggests possible underlying pathophysiology


What are the six classifications of anxiety disorders?

-these are all abnormal experiences of anxiety 1. Generalised anxiety disorder 2. Panic attack 3. Panic disorder 4. Phobias 5. Obsessive compulsive disorder 6. Post-traumatic stress disorder


What does benzodiazepine do?

-gets rid of anxiety

-GABA gates a Cl- channel, if you make it more or less sensitive to GABA then you change the excitation/ inhibition in the system

-simple drug changes sth so complicated

-can modulate a very complex tthing like anxiety by just one drug

-ethanol can do a similar thing! why we lose inhibition when drunk!

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How is schizophrenia treated?

-with D2 antagonists -D2= dopamine


What are the 4 most significant neurological diseases?

1. Alzheimer's disease and other dementias 2. Epilepsy 3. Parkinson's disease 4. Stroke


What is dementia?

-deterioration of intellectual function and other cognitive skills that is of sufficient severity to interfere with social or occupational functioning


What is the most common form of dementia and what is it characterised by?

-Alzheimer's -first described by Alois Alzheimer in 1907 -characterised by deposition of amyloid protein and the disruption of the neuronal cytoskeleton


What does Alzheimer's do to the neuronal cytoskeleton?


-the cells start dying

-neurofilaments give the cell the phenotype of neurons

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What happens with the amyloid protein in Alzheimer's?

-extracellular plaques caused by a build up of an abnormal configuration of a protein amyloid

-this causes neurons to produce abnormal intracellular aggregations of tau protein

- in brains producing amyloid, an intracellular tau forms aggregates (neurofibulary tangles) = this may be cause of neuronal death

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What are neurofibulary tangles?

-aggregates of tau protein in brains producing amyloid -possible cause of death of neurons


What does tau protein do normally?

-tau protein is normally present in neurons where it stabilises microtubules


Where are most of the amyloid plaques and neurofibulary tangles in an Alzheimer brain?

-tends to be localised so some function not as bad

-medial temporal lobe= role in memory formation

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What is epilepsy characterised by?

-common brain disorder -characterised by two or more unprovoked seizures -more of a symptom than a disease


How prevalent is epilepsy?

-around 7 to 10% of the population may experience a seizure during their lifetime, epilepsy is the condition of recurrence of seizures -this affects about 1% of the population -50-70 million worldwide


What is epilepsy? (in terms of what is happening in the brain at the time?

-epilepsy is abnormal coherent behaviour of the brain

-increasingly synchronasied state of the brain and not compatible with normal brain activity

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What are epileptic seizures?

-seizures are discrete events caused by transient, hyper-synchronous, abnormal neuronal activity -seizures can occur in close temporal association with acute stroke, sepsis or alcohol withdrawal -however the vast majority of seizures have no immediate identifiable cause


What are the three categories of epilepsy?

1: Idiopathic epilepsy (such as childhood-onset absence epilepsy), which is thought to have a genetic basis (10%) 2: Secondary or symptomatic epilepsy, which is caused by a known central nervous system injury or disorder such as infection, stroke, or traumatic injury 3: Cryptogenic epilepsy, for which there is no clear evidence of an etiological factor (60%)


Have the genetic mutations underlying the familial (inherited) epilepsies been uncovered?

-yes -genes associated with synaptic transmission is involved in epilepsy -genes encoding proteins directly associated with neuronal excitability such as ion channels, neurotransmitter receptors -even a little change can have an impact


What can initiate spreading synchronous firing?

-an imbalance of excitation and inhibition, beginning at a site of brain damage or as a result of a mutation in an ion channel gene can initiate the coherent firing --the change is very nuanced


Who was one of the first people to suffer from Multiple Sclerosis?

-Jacqueline du Pré, british cellist -she started experiencing loss of sensation on her fingers and other parts of her body -irreversible


What are the risk factors associated with multiple sclerosis?

-young -female -middle class


What is MS (multiple sclerosis)?

-chronic autoimmune disease characterised by destruction of myelin in the CNS -MS can cause a variety of symptoms, including changes in sensation, visual problems, muscle weakness, depression, difficulties with coordination and speech, sever fatigue, cognitive impairment problems with balance, overheating and pain