Brain Diseases 2 Flashcards
Schizophrenia
synptoms - + and -
associated with which other disorders/ problems?
+ = delusions, hallucinations,disordered thought/speech
- = flat affect, alogia, anhedonia(inability to feel pleasure), asociality(lack of motivation to be social), avolition
(often in association with depression, substance abuse and suicide)
life expectancy often reduced by 10-12yrs
SCZ
pathology
high levels of dopamine in the mesolimbic pathway
SCZ
incidence
0.6% of population, worldwide
can start at any age, but peak onset = early 20s
SCZ
causes
Genetics - 50% c rate with MZ twins
Environment - 50% c rate in MZ
Developmental - infection in utero, poor diet during pregnancy, asphyxia during birth
Social factors - urban environment, stressful relationships
Drug abuse - cannabis, amphetamine, cocaine - cause and effect?
Dopamine hypothesis - excessive D2R stimulation
reduced NMDAR function
SCZ
treatment
antipsychotics (typical and atypical)- more effective in treating positive symptoms
intense psychotherapy, social support
recovery and improvement in symptoms in»_space;50%
Depression
symptoms
lowered mood, anhedonia, avolition, altered appetite, hypo/hyperkinesia, guilt, lack of concentration, thoughts of death
3-7% risk of suicide
Depression
pathology
reduced hippocampal volume
vascular lesions
reduced BDNF
Depression
incidence
3% japan
18% USA ( average = 10% )
Women twice as likely as men
Massive cost to society
Depression
causes
genetic - 5HT transporter abnormalities
monoamine hypothesis - not all antidepressant drugs work on monoaminergic system) - depletion doesn’t consistently cause depression - drug effects refractory
Psychological - self/others/future
social - poverty/ stress/ abuse
Depression
treatment
light therapy, sleep deprivation psychotherapy tricyclic antidepressants SSRIs eg. Prozan and Paxil Exercise ECT
Stroke -define
characteristics?
a neurological deficit of cerebrovascular cause that persists beyond 24hrs or is interrupted by death within 24hrs
(distinguished from a transient ischaematic attack, which is a syndrome of stroke-like symptoms that resolve within 24hrs)
-brain relatively intolerant to ischaemia/lack of 02 and glucose
-Due to high energy demands and minimal energy reserves brain function ceases within 60-90 secs of ischaematic events
Irreversible damage if event >3hrs duration
-Neurological deficit related to the site and extent of damage
Types of strokes
1) Ischaematic - embolus= wandering clot, thrombus = ‘locally-formed’ clot, systemic hypoperfusion eg. heart attacks
2) Haermorrhaegic strokes: entry of blood into CNS via rupture of a blood vessel/ sinus or aneurysm
Physical arrangements of meninges
Closest to CNS to furthest:
Pia mater, arachnoid, Dura mater
- between pia and arachnoid = subarachnoid space
- lines connecting pia and arachnoid = trabeculae
- between arachnoid and dura = subdural space
Classification of haematomas affecting the brain:
epidural - traumatic damage to a meningeal artery or dural venous sinus (eg.blow to head)
subdural - caused by a rapid movement of head causing tearing of cerebral vein as it enters dural venous sinus
subarachnoid - damage to cerebral artery or vein and subsequent bleeding into subarachnoid space
intracerebral - caused by damage of a blood vessel within the brain
Stroke
incidence
10% deaths worldwide
2nd leading cause of death
95% occur >45yrs
Stroke
causes
- Ischaematic concade - ATP production reduced= ion pumps fail = increase glutamate = NMDA receptors activated = Ca++enters neuron = ROS/free radicals produced = cell death (inflammatory response may cause further damage
- Pressure
Stroke
risk factors
high BP high cholesterol Diet physical inactivity drug abuse
Stroke
treatments
a) preventative - anticogulants, diet, carotia angioplasty
b) acute ischaemic - thrombolysis, angioplasty, thromboectamy
c) acute haemorrhagic - surgery
d) chronic post stroke - control of hypertension, aspirin, physical and occupational therapy
Epilepsy define
2 types?
prevelance?
seizure = abnormal, transient highly synchronous brain activity (epilepsy = repeated seizures)
2 types:
1) partial/ focal
2) generalised
prevelance: 0.5-1%, 5% experience non febrile seizure
Examples of epilepsy:
-childhood absence epilepsy = 4-12yrs
absence seizures, 3Hz spike wave discharge, resolves during puberty, mutations in low threshold voltage-gated Ca++ channels
-Temporal lobe epilepsy = late childhood and adolescence
most common type in adults, epileptogenic focus in hippocampus or amygdala or parahippocampal gyrus, complex partial seizures, may develop into secondary generalised tonic-clonic/ grand mal seizures
Epilepsy causes
-2/3 = idiopathic nature, reflex seizures, genetic mutation in Na+ channels, tumours, drugs, disease, infection, disorders, trauma, pathological synaptic plasticity (producing an imbalance in excitation and inhibition in nervous system)
Epilepsy treatment
- acute = recovery position, reassurance, benzodiazepines
- chronic = pharmacological, surgical, electrical, avoidance of triggers
Alzheimers Disease
symptoms
short-term memory loss, progressive apathy, confusion, mood swings, LT memory loss, death within 7yrs of diagnosis
Alzheimers pathology
profound loss of neurons
plaques
neurofibrilloy tangles
Alzheimers incidence
1.5-2%, worldwide cost = 160 billion per yr
Alzheimers causes
age, 10% over 65, 50% >85 genetics (for early onset) trauma high bp/ hyperchlosteremia environment?
Alzheimers treatment
risk factors?
symptoms - acetylcholinesterase inhibitors, NMDA recpeptor antagonists
risk - MSAIDs and caffeine, intellectual stimulation needed, diet and exercise
