Week 11/2 Degen Disord Et Al. Flashcards
Any tumor in the brain, benign or malignant, is harmful.
▪ Tumors are damaging to the brain because:
- the tumor occupies space and compresses the brain
tissue.
- the tumor invades the surrounding tissue as it grows
and destroys cells in its path.
A tumor is ?
▪ A benign tumor has ?
▪ If the tumors infiltrates the surrounding tissue, it is ? (i.e. cancerous).
A tumor is a uncontrollable growth of cells that serves no useful function.
▪ A benign tumor has a distinct border between the tumor cells and the surrounding tissue (i.e. it is encapsulated).
▪ If the tumors infiltrates the surrounding tissue, it is malignant (i.e. cancerous).
Malignant tumors give rise to a process of metastasis in which tumor cells travel through vascular system and grow elsewhere in the body.
tumor of the cells of the meninges is called a?
meningioma
It has displaced the right side of the brain.
The right ventricle is almost completely occluded.
Non malignant, benign in x.
Low other types names in text?
Glioma are the most ?
common and serious type of tumor. Grow from glial cells
Different specific types:
- Astrocytoma (astrocytes)
- Ependymoma (ependymal cells that line the ventricle)
- Medulloblastoma (cells in the roof of the fourth ventricle)
- Oligodendrocytoma (oligodendrocytes)
Extract and then try to destroy with radiation.
Seizure Disorders (Epilepsy)
▪ A seizure is period of sudden, excessive activity of cerebral neurons.
▪ If the cells constitute the motor system, the seizure will cause a wild, uncontrollable activity of the muscles called a convulsion.
Types of seizures?
▪ Partial seizures have a definite focus and remain localised.
▪ Diagnosis relies on EEG; epilepsy is associated with bursts of high amplitude EEG spikes which occur during an attack.
Types of partial seizures?
▪ Partial seizures have a definite focus and remain localised.
- Simple partial seizures involve changes to consciousness.
- Complex partial seizure lead to loss of consciousness.
What of seizure happens during rem sleep
Act out dreams or interact with ordinary ppl.
Can report experience.
Generalised Type Seizures: Grand Mal
Explain.
note has focus,
Generalised seizures are widespread involving most of the brain.
▪ A grand mal seizure is the most severe of all seizures. Preceding the seizure, the patient will experience:
changes in mood sudden jerks of muscular activity before waking
an aura; a peculiar sensation or psychological change
(e.g. a bad smell, hallucination, bright lights; euphoria).
What are the Grand Mal Seizure phases?
-Clonic Convulsion
▪ The grand mal seizure begins with the tonic phase:
- muscles contract forcefully
- arms outstretch rigidly
- patient makes an involuntary cry (patient is
unconscious)
- patient holds a rigid posture for 15 seconds
▪ In the clonic phase:
- muscles tremble
- muscles jerk convulsively (quickly at first)
- eyes roll
- face is contorted (tongue may be bitten)
- sweating and salivation
- after 30 seconds, muscles relax; breathing begins
again
- patient falls into an exhausted sleep
Generalised Seizures: Petit Mal
Aka?
EEG pattern?
▪ Children have spells of petit mal (absence) seizures:
- - - -
- -
vacant look
blink eyes repeatedly
unresponsive
can occur up to 100 times a day; they can be disruptive to normal day to day activities and often go undiagnosed
seizures frequently cease at adolescence
The EEG of a petit mal seizure shows a bilateral symmetrical pattern of a 3-per second electrical discharge.
Seizures have many causes including?
▪ The most common causes of seizures:
- scarring produced by stroke, injury or irritating effect of a
growing tumor.
- alcohol or barbiturate withdrawal (this can be fatal). Increase inhibit ation over firing
Seizures have serious consequences
▪ Almost half of the patients who have seizures will show evidence of damage to the hippocampus
▪ A single episode of status epilepticus (during which the patient experiences a series of seizures without regaining consciousness) causes excessive glutamate release during the seizure.
▪ Thus, NMDA receptors are involved in seizures.
Too much calcium, enters cell
Causes supsensitity, essp. Alcohol abuse, increase nmda.
Known as up regulation. Over acticity of glutamate
Seizures are related to NMDA receptor activity
▪ NMDA receptors control calcium channels.
▪ Alcohol blocks NMDA receptors.
▪ Long-term suppression of NMDA receptors (due to alcohol abuse) causes supersensitivity (up-regulation).
▪ When an alcoholic suddenly stops drinking, the suppressed NMDA receptors suddenly rebound.
▪ The increased activity of NMDA receptors cause seizures.
Cerebrovascular Disorders aka?
▪ Strokes are sudden-onset cerebrovascular disorders that cause brain damage.
▪ A hemorrhagic stroke is caused by bleeding within the brain. It occurs when a cerebral blood vessel ruptures due to high blood pressure.
▪ Ischemic strokes are caused by a disruption of the blood supply to an area of the brain. These are three main types
There are three main causes of ischemia:
- a blood clot (thrombus) that forms in the blood vessels (e.g air bubble, tumor, fat).
- an embolus, carried through the bloodstream, lodges itself preventing the flow of blood.
- an arteriosclerosis is caused by thickening of the arteria