Lecture 19 - Neurological Problems Flashcards
What is Anomia aphasia?
- Symptom of damage in frontal lobe —> struggle to find the right word to say.
Can you learn new words if you cannot repeat words?
It is extremely difficult because you can’t sound things out.
Normally, you say the word in your head even if you don’t say it out loud.
With an aphasia, there is recovery after a stroke and they have the ability to learn again
What influences recovery after a stroke?
- Age they got the stroke
- motivation tor recover
- Social support by the people around them
What is the main problem with strokes and recovery?
It usually happens in old age. People are already suffering the effects of age on their body, they are stressed about their life and independence and they are already losing their support network, sometimes because their friends or family die of old age. Therefore, they lack the motivation to recover when they have a stroke and they give up.
Name the concept:
- When we talk to ourselves, there are very slight movements of the muscles involved in speech that do not actually cause obvious movement.
Subvocal articulations
What are subvocal articulations?
Very slight movements of the muscles involved in speech that do not actually cause obvious movement.
Which area of the brain shows increased activation when people “say” words subvocally (in their head)?
Broca’s area
What is trouble with writing called?
Dysgraphia
Spelling a word can be accomplished by two manners. Which are they?
- Phonetically sounding out the word
- Visually imagining the word
What is phonological dysgraphia?
A condition where people cannot spell words by sounding them out.
- Common in Broca’s aphasia.
They can only write words by imagining how they look. They cannot write non-words like Val or blint.
What is orthographic dysgraphia?
A condition where people cannot spell words by visualizing them.
- Common in people with damage to the visual form area in the visual association cortex.
How common are stroke and what are they related to?
Incidence of strokes is about 750 000 a year.
It’s associated with age. It doubles each decade after 45 years and reaches 1/2% every year by age 75.
Name the process:
- Process in which linings of arteries develop a layer of plaque, deposits of cholesterol, fats, calcium and cellular waste products.
Atherosclerosis
What are the risk factors of atherosclerosis?
High blood pressure, cigarette smoking, diabetes and high blood levels of cholesterol.
Where do atherosclerosis plaques often form?
In the internal carotid artery, which supplied most of the blood flow to the cerebral hemisphere.
What are the two main kinds of strokes?
1) Ischemic stroke
- The occlusion of a blood vessel (87% of strokes)
2) Hemorrhagic stroke
- Rupture of a cerebral blood vessel
What is a thrombus?
A blood clot that forms within a blood vessel, which may block it and reduce blood flow to the affected area.
What is an embolus?
It’s a piece of matter (blood clot, bacterial debris) that dislodges from its site of origin and occludes and artery.
In the brain, an embolus can lead to a stroke.
What is the approach to minimize the amount of brain damage caused by strokes?
One approach is to administer drugs that dissolve blood clots in an attempt to reestablish circulation to an ischemic brain region.
(Time window of 3 to 4 hours after stroke has happened)
What are the main treatments after the stroke?
- Drugs that reduce swelling and inflammation
- Physical, speech and or occupational therapy
- Exercise and sensory stimulation
where do mutations have to occur for it to start to divide uncontrollably?
Within the cell
When can mutation occur?
- Any time a cell divides, or get radiation or gets damaged
Which cells in the body are the only ones to never divide?
Neurons
Where do we see cancer occur?
Where there is cell division
What does it take for a cell to become cancerous?
It has to suddenly decide it wants to divide and replicate itself uncontrollably.
They need to have mutation to protect themselves from the Immune system.
They will have a mutation that increases blood flow to the regions its in to promote the cell division
What is a tumour?
Mass of cells whose growth is uncontrolled and that serves no useful function.
What is a non-malignant tumour?
Non cancerous, benign tumour. It has a distinct border and cannot metastasize.
What is a malignant tumour?
Cancerous tumour. It lacks a direct border and may metastasize. Without a clear border, it is very difficult to cut out and surgeons will most likely forget a part behind which is why people still need to do chemotherapy after surgery to make sure all the malignant tumour is gone.
What is metastasis?
It’s the process by which cells break off of a tumour, travel through the vascular system and grow elsewhere in the body.
What is the major distinction between non-malignant tumours and malignant tumours?
Whether the tumour is encapsulated (whether there is a distinct border between the mass of the tumour cells and the surrounding tissue.
If there is such a border, it’s a non-malignant tumour.
How do tumours damage brain tissue?
1) compression
- The tumour takes up space and creates compression on the brain, that can directly destroy brain tissue or do so indirectly by blocking the flow of the cerebrospinal fluid and causing hydrocephalus.
2) infiltration
- will infiltrate the brain tissue
Name the type of brain tumours.
- cancer of a glial cell
- Very hard to treat
- When diagnosis —> 2 years left to live maybe
Gliomas
Name the type of brain tumours.
- Cancel of the cells of the meninges
- Are encapsulated and can be removed
Meningioma
Describe what are gliomas.
Glioma is a malignant brain tumour.
The tumour initiating cells originate from the neural stem cells that make glia.
They rapidly proliferate and are more resistant to chemotherapy and radiation than most tumour cells. The survival rate from malignant gliomas is very low.
Describe meningioma.
Non-malignant tumour
- Composed of cells that constitute the meninges
- Often right between the two cerebral hemispheres
- Will come on slowly and get worse and worse
What is encephalitis?
Inflammation of the brain caused by infection (bacterial or viral), toxic chemicals or allergic reaction
What are the first symptoms of encephalitis?
Headache, fever and nausea
What is meningitis?
Inflammation of meninges caused by viruses or bacteria.
- First symptoms are headache and stiff neck
What are the first symptoms of meningitis?
Headache
Stiff neck
What is Polio (acute anterior poliomyelitis)?
Viral disease that destroys motor neurons of the brain and spinal cord
1% of people who get it. A fraction of them will end up becoming entirely paralyzed.
Kind of irradiated cause of vaccines now
What is rabies?
Fatal viral disease that causes brain damage; transmitted through the bite of an infected animal.
Very rare in North America
Get vaccine after bite
What is herpes simplex virus?
Virus that normally causes cold sores near the lips and genitals. In rare cases, it instead enters the brain causing encephalitis and brain damage
What is closed-head injury?
It’s caused by a blow to the head with a blunt object.
- THe brain comes into violent impact with one side of the skull (coup)
- The brain then recoils and bounces off the opposite side of the skull (contrecoup)
What is open-head injury?
Penetrating brain injury causes damage to the brain .
- Can damage blood vessels
- Accumulation of the blood inside the brain can cause further damage by exerting pressure within the brain
What are the effects of traumatic brain injury in survivors?
Scarring forms within the brain, around the sites of injury, which increases the risk of developing seizures. The more you have traumatic brain injuries, the worse it gets.
- The likelihood of getting a neurodegenerative diseases is increased the more you have traumatic brain injury (Alzheimer’s for example)
What are the causes of seizure disorders?
- SCarring, which may relate to an injury, a stroke, the effect of a growing tumour or a developmental abnormality in the brain
- high fevers in young children
- Withdrawal from GABA agonists, such as alcohol and barbiturates (ex: alcoholics withdrawing from drinking)
The neural instability and increased risk of seizures can come about for genetic reasons, involving gene mutations that affect what?
- Amount or function of different ion channels in the brain
- Reciprocal wiring of excitatory and inhibitory neurons
- Rules that govern synaptic plasticity
What is seizure disorder?
Preferred term for epilepsy
- a seizure can cause a convulsion —> wild uncontrollable activity of the muscles
- Most seizures don’t have convulsion
What is a convulsion?
Violent sequence of uncontrollable muscular movements caused by seizure.
What is a partial seizure?
Seizure that begins at a focus and remains localized in a smart part of the brain.
What is the difference between a simple partial seizure and a complex partial seizure ?
SImple partial seizure
- seizure that does not produce loss of consciousness
Complex partial seizure
- seizure that produces loss of consciousness
What is a generalized seizure?
Seizure that involves most of the brain.
Includes tonic-clinic seizures, atomic seizures, and absence seizures
What is a grand Mal seizure?
Starts with an aura —> sensation that precedes a seizure
Tonic-clinic seizure —> a generalized, grand May seizure that typically starts with an aura followed with a tonic phase and then a clonic phase. Involves convulsion
Tonic phase —> first phase, in which all skeletal muscles are contracted
Clonic phase —> second phase, in which patient shows rhythmic jerking movements
What is an aura in a grand Mal seizure?
Sensation that precedes a seizure
What is a tonic-clonic seizure?
Generalized, grand mal seizure.
- Starts with an aura
- Followed by tonic phase and then clonic phase
- Involves convulsions
What is the Tonic phase in tonic-clonic seizures?
First phase —> all of the patient’s skeletal muscles are contracted
What is the clonic phase in the tonic-clonic seizure?
Second phase —> patient shows rhythmic jerking movements
Who are especially susceptible to seizure disorders?
Children
What do children’s have when it comes to seizure disorders?
- Very brief seizures that are referred to as spells of absence —> generalized complex seizures. Involves the whole brain
- No convulsions
- During absence seizures (petite mal seizures) —> stop what they are doing and stare off into the distance for a few seconds, often blinging eyes repeatedly
A tonic generalized seizure?
- Loss of muscle tone, temporary paralysis
- Generalized in the whole brain
how do we treat seizures?
Anticonvulsant drugs —> benzodiazepines
- Work by increasing effectiveness of inhibitory synapses
How do anticonvulsant drugs work?
increase effectiveness of inhibitory synapses
What can cause disorders of development?
-Exposure to certain toxins, viruses and drugs during pregnancy can impair fetal brain development and cause intellectual disability
- Insecticides, heavy metals like lead and mercury
- Famous viruses include the rubella virus (German measles) and the Zola virus
What is the most dangerous drug during pregnancy?
Alcohol
What is the fetal alcohol syndrome?
Serious condition associated with alcohol consumption during the 3rd or 4th week of pregancy.
- Associated with certain facial anomalies and severe intellectual disabilities
What are inherited metabolic disorders?
- Several inherited “errors of metabolism” that can cause brain damage or impair brain development.
What are errors of metabolism?
Genetic abnormalities in which recipe for a particular protein is in error. Enzyme not synthesized on account of mutations in both copies of the gene.
What is the Phenylketonuria (PKU)?
Inherited metabolic disorder
- Hereditary disorder caused by the absence of enzyme that converts the amino acid phenylalanine to tyrosine
- Accumulation of phenylalanine causes brain damage unless a special diet is implemented soon after birth.
What is Tay-Sachs disease?
Inherited metabolic disorder
- Heritable, fatal, metabolic storage disorder
- Lac of enzymes in lysosomes causes accumulation of waste produces and swelling of cells in brain
