• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/173

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

173 Cards in this Set

  • Front
  • Back
Does thalamic input contribute directly to EEG waves?
No. It is a deep strucutre, but thalamco-cortical influences allow it to influence the EEG indirectly
What is the primary role of thalamic relay neurons?
Relay sensory input to pyramidal cortical neurons in layer VI of the cortex
What channel is responsible for the slow Ca spike in Thalamic relay neurons?
T-type Ca channels
What is the name and frequency of the wave generated by slow Ca spikes?
delta wave, 3 Hz (occurs in slow wave sleep and absence epilepsy)
A mutation in T-type Ca channels, causing them to fire while you are awake, is characteristic of what pathology?
Absence epilepsy
Which nuclei in the brainstem and their neurotransmitters influence the thalamaco-cortical circuit, directly and indirectly?
RAS/acetylecholine, locus coeruleus/NE, raphe nuclei/serotonin - all 3 do direct and indirect influence in the sleep/wake spectrum
Define psychosis.
mental sign of brain malfunction
What is the difference between psychosis and delirium?
psychotics are oriented to place, person and time and they are alert
What are the 3 hallmark signs of psychosis?
auditory hallucinations, paranoid delusions, and formal thought disorder
What are the three causative factors in psychosis?
genetics (inhibitory neurons), neuronal lass in diencephalon and cortex, stress
What are the 3 different treatment modalities for psychosis?
pharm (decrease dopa), reduce stress, cognitive behavioral therapy
Explain the concept of restoration in relation to psychosis
Psychotic episodes can be efforts to expalin the loss of mental function and to alleviate triggers
What three diseases can cause psychosis?
Schizophrenia, Bipolar disorder, Parkinson's (L-dopa therapy)
The case of HM shows that the hippocampus was importnat for what type of memory?
declarative memory; the ability to recollect events or facts that have specific temporal and spatial component
What type of memory is controlled by the cerebellum, striatum, and frontal cortex?
procedural memory: the ability to learn new motor skills
Where are long term memories stored?
Neocortex
How long does working memeory last?
seconds to minutes (e.g., remembering if you put salt in the soup)
Where is working memory located?
in the frontal lobes with executive function
From where does the hippocampus receive input?
from the entorhinal cortex down a bundle of axons called the perforant path (aka, from the hyptothalamus)
What are the two types of neurons that play an important role in the hippocampus?
CA3 and CA1 groups of cells
Axons from cells in the dentate gyrus (mossy fibers) synapse on which hippocampal neurons?
CA3 neurons
From where do CA1 neurons receive axons?
From the Schaffer collateral axons originating in the CA3 neurons
What are the two characteristics in long term potentiation?
(1) only synpases that are being stimulated during tetanus undergo LTP and (2) LTP only takes place when the titanic burstis large enough to cause cell depolarization in the postsynaptic neuron
What is the molecular switch that detects the coincident stimulation of a synapse and depolarization of the postsynaptic cell?
the NMDA receptor
What is it about CAMKII (calcium/calmodulin protein kinase II) that allows the LTP to last long enough to produce memory?
the CAMKII phosphorylates itself causing prolonged activation of CAMKII...phosphorylation of AMPA receptors making them more receptive to glutamate
What part of the hippocampus is important for associative memory?
the LTPs in CA3 area
What two findings suggest the plasticity of adult memory?
(1) synapse formation and destruction (2)neurogenesis int he adult brain (olfactory bulb, currently debatable)
What protein causes synapse loss and neurodegeneration in Alzheimer's patients?
amyloid-B protein (Ab)
A failure to maintain the LTP in the hippocampus has been correlated to what patholophysiology in Alzheimer's?
presence of APP that elicit increases in Ab deposition
What type of receptors in the cortex are essential for aquisition of conditioned flavor aversion (CFA)?
Muscarinic receptors
What are the EEG differences between slow wave and REM sleep?
REM resembles being awake, but the arousal threshold is higher that SWS; SWS=high amplitude slow brainwaves
What is the relative Epworth score of pts with insomnia?
they have low Epworth scores compared to other pts with sleep disturbance problems
What is the treatment for Delayed Sleep Phase Syndrome in blind pts with disrupted retinohypothalamic tracts (RHT)?
Melatonin entrainment
What drugs are effective in treating conditioned insomnia?
None. Behavioral modification is the only treatment of conditioned insomnia
Match the following sleep disorder with the stage they arise from (awake, REM, SWS):
--Narcolepsy
--sleep terrors
--somnambulism
--cataplexy
--sleep paralysis
--hypnogogic hallucinations
--awake
--SWS
--SWS
--awake
--REM
--REM
What is the role of the SCN in control of the sleep/wake cycle?
receives light input from the retina via the RHT to the sleep/wake switch in hypothalamus, thus synchronizing the sleep/wake with circadian rhythyms and the 24 hour clock
For each of the following adverse reactions, state whether or not the drug is a GABA or non-GABA receptor drug:
rebound insomnia
antimuscarinic effects
abuse dependence
potentially fatal alcohol use
anterograde amnesia
GABA
non-GABA
GABA
GABA
GABA
What is the function of the extended amygdala?
the extended amygdala translate sensory input with motivational significance into survival value to inform and orchestrate response mechanisms
What the role of the ventral striatum in the reward pathway?
translates emotional state into movement
What is the role of the dorsal srtiatum in the reward pathway?
habit learning
What is the role of the hypothalamus in the reward pathway?
hormonally controlled responses
What is the role of the hippocampus in the reward pathway?
memory context needed to continue reinforcement
What is the role of the midbrain dopamine cells A8, A9, A10?
produce dopamine (=reward) and tells the amygdala that the current stimulus is good; site of action of addictive drugs
What is the role of the aygdala in the reward pathway?
takes in the sensory info and assigns value to the stimuli
What part of the amydala receives sensory input?
basolateral amygdala
What part of the amygdala sends out brainstem sympathetic activators to produce arousal?
central amygdala
What part of the hypothalamus increases parasympathetic activity?
anterior (the other one's the other one)
Which nuclei of the hypothalamus secrete hormones directly to the posterior pituitary? Which hormones?
The supraoptic n and paraventricular n: vasopressin and oxytocin
Through what intermediate structure does the hypothalamus influence somotic motor responses and ANS?
reticular formation in brainstem
Name 3 reciprocal pathways through which the hypothalamus coordinates behavior and emotional expression
(1) fornix (hippocampus), (2) stria terminalis (amygdala), (3) medial forebrain bundle (prefrontal cortex)
What regions of the hypothalamus lack a BBB?
OVLT, subfornical organ (SFO), median eminence, posterior pituitary
Where in the hypothalamus is osmolarity detected?
anterior hypothalamus (OVLT, SFO)
Lesion to the lateral nucleus leads to what eating behavior?
anorexia (the other one's the other one)
Where in the hypothalamus is temperature detected/regulated?
preoptic anterior hypothalamus (POAH)
What is the mechanism by which pyrogens increase body temperature?
pyrogens inhibit POAH thermoreceptors --> activates thermogenic behavior-->body temp rises to new set point --> pyrogen declines --> release of POAH inhibition->thermolytic behaviors
What is the molecule that acts directly on POAH receptors to induce fever?
PGE2s
Where is the point of entry for endogenous pyrogens in the production of fever?
OVLT (lacks a BBB)
Which region of the hypothalamus receives excitatory input from cutaneous cold receptors?
posterior hypothalamus, activates heat gain mechanisms (the other one's the other one)
The Sham Rage experiements demonstrate what about the hypothalamus?
The hypothalamus can initiate somatic and autonomic reactions to sensory input in the absence of cortical input, but the responses are not appropriate to the stimulus
What are the 3 central symptoms of ADHD?
(1)difficulty focusing on non-novel stimuli, (2)poor working memory, (3) impulsivity (acting before thinking)
What is the functional impact of ADHD?
poor educational outcomes
incarceration
substance abuse
comorbidity with other psych disorders
Name the ADHD model that corresponds to the psychiatric disorder:
-anxiety disorder
-conduct disorder
-major depression
-oppositional behavior
-substance abuse
(1)anxiety disorder - shared genetic risk (2)conduct disorder - brain abnormalities present with different symptoms at different ages (3)major depression-inappropriate focus (4)oppositional behavior: not due to ADHD but rather to living with someone living with your ADHD (5)substance abuse: self medicating for inadequate treatment
For how long must someone be treated for ADHD?
Life long; ADHD treatment is not curative
A 22 year-old medical studetn relates that she has recently begun to exeperience sudden bouts of dizziness and SOB that last about 20 minutes and then subside. Because of these attacks, she must sit near the door of the lecture hall so that she can leave in a hurry. This student has no hx of asthma. Other than increased pulse, physical findings are normal. What is the most effective immediate treatment for this pt when she develops these symptoms?
a benzodiazepine
A 22 year-old medical studetn relates that she has recently begun to exeperience sudden bouts of dizziness and SOB that last about 20 minutes and then subside. Because of these attacks, she must sit near the door of the lecture hall so that she can leave in a hurry. This student has no hx of asthma. Other than increased pulse, physical findings are normal. What is the most effective LONG TERM tx for this pt?
an antidepressant; specifically, and SSRI like Paxil
A 26-year-old 4th year medical student with no previous psychiatric hx reports that she has had a recurring though over the past year that she will kill a patient before she graduates. The student has never harmed a patient and has no intention of doing so. When he snaps his fingers repeatedly, he feels somewhat calmer. What disorder is this student most likely experiencing?
OCD; most effective treatment is an antidepressant, articularly an SSRI like Fluvoxamine
A 45-year old diabetic man is admitted to the hospital with a serious foot infection. During the last year, his wife divorced him and he declared personal bankruptcy. After this, he moved to a new apartment. On his first day in the apartment he was robbed at knife point in the elevator. Which of the events experienced by this man is most likely to result in PTSD?
The robbery, a life threatening event, is most likely to result in PTSD
A 23-year-old student reports that he becomes very "uptight" when he must use a public restroom but otherwise doesn't report episodes of anxiety. Because he becomes so uncomfortable abou using a public restroom he refuses when his classmates ask him to join them when they go out. Which pharmacological agent has FDA approval for the long-term treatment of this student's symptoms?
Effexor (venlafaxine) is FDA approved for long-term treatment of social phobia
What is the main side effect of anxiolytic drugs?
sedation (and lethal interaction with alcohol)
What is the target of BZDs in the CNS?
act virtualy exclusively on the GABA receptor
What subunit of GABA receptor is necessary for BDZ action?
gamma subunit; BDZs need GABA to have an effect
What is the MOA of BDZ agonists?
BDZ increase channel opening frequency = more inhibitory effects
What is the MOA of Barbs?
Barbs act to increase the duration of open time for the Cl- channel
What two characteristics of BDZ structure can increase the potency of the drug?
(1)having an e- withdrawing group and the R'2 position
(2)having high plasma binding
What is it about Triazolam and Alprazolam (anxiolytics) that decrease their t1/2?
They have fused Triazolo rings; don't go through the first two metabolic phases of transformation and therefore have a shorter half-life
Flumazenil, like anxiolytics, also binds to a GABA receptor, but what makes it different?
It binds to the GABA receptor but has no activity (fused imidazo ring) making it an antagonist
Which two BDZ are indiciated for the elderly and pts with impaired liver fnx since they are already hydroxylated and therefore do not go through stage two of BDZ metabolism in the liver?
oxazepam and larazepam
What feature of barbs make them good sedatives? anticonvulsants?
Barbs with short t1/2s are good sedatives; barbs with longer t1/2s are good anticonvulsants
For what other neurological issues are barbs used?
Barbs are used to treat ischemic and traumatic brain injury: decrease O2 consumption, decrease CA uptake into neurons, decrease IcP and edema
A 65-year-old man has been diagnosed with advanced prostate cancer. The pt has lost 20 punds and has decreased energy and difficulty sleeping because of pain. Over the past month he has been expressing fearfulness about dying and strong feelings of guilt about "bad things I've done in my life," which he believes have caused his illness. What is the sign or symptom most likely to indicate that this patient is having a major depressive episode rather than a normal reaction to a serious illness?
the feelings of guilt that he has caused his illness are more characteristic of depression than sadness of being very ill.
When compared with an American man, what are the chances that an American woman will develop major depressive disorder (MDD)over the course of her lifetime? Bipolar disorder?
higher, equal
A depressed 25-year-old female pt who is slow moving and shows flat affect is put on fuoxetine (Prozac). Within 2 weeks, she is showing greatly increased activity level, flight of ideas, and pressured speech. What has the medication done to this patient?
precipitated a manic episode (indicates the pt has bipolar disorder)
A 45-year-old man reports a variety of aches, pains, and extreme fatigue that have been present for the past 6 months. Physical examination is unremarkable, but the pt has lost 10 pounds without dieting since checkup last year. the pt reports that we wakes 2 hours before his alarm and has significant problems concentrating on work. The pt denies that he is sad or hopeless. After a 5-week trial of antidepressant medication, he pt's aches and pains are gone, he is sleeping all night, his energy level and concentration are normal and he has gained 5 pounds. Of what were the pt's symptoms before treatment a result?
Depression, albeit hidden or masked
A 45-year-old man reports a variety of aches, pains, and extreme fatigue that have been present for the past 6 months. Physical examination is unremarkable, but the pt has lost 10 pounds without dieting since checkup last year. the pt reports that we wakes 2 hours before his alarm and has significant problems concentrating on work. The pt denies that he is sad or hopeless. After a 5-week trial of antidepressant medication, he pt's aches and pains are gone, he is sleeping all night, his energy level and concentration are normal and he has gained 5 pounds. Analysis of neurotransmiter availability in the brain of this patient before treatment is most likely to reveal what?
Decreased serotonin reflected in decreased plasma levels of its major metabolite 5-HIAA
What is the difference in MOA between tricyclic and SSRI antidepressants?
Tricyclics block serotonin and NE; SSRIs only block serotonin
Which neurotransmitters are affected by MAOIs?
serotonin, dopamine and NE (monoamines)
Name 4 characteristics of ALL antidepressants.
(1)stimulate serotonin/NE/both
(2)delayed action
(3)induction of mania
(4)ECT is better than any drug
What combination of drugs causes serotonin syndrome?
SSRIs with MAOIs
What serious side effect is caused by tricyclics?
Anti-cholinergic (anti-SLUDGE):no pee, no see, no spit, no shit
Levels of what neurotransmitter are low in suicide victims?
serotonin
What major side-effect is common to all neuoleptics?
Parkinsonian syndrome
How would you characterize the MOA of neuroleptics?
competitive inhibition of DA receptors DRs1-5 and antagonizes the normal sensory gating functions
What is the primary target of atypical antipsychotics?
Serotonin 5HT-2 receptor
Enhanced appetite is a side effect of what drug class?
atypical antipsychotics
What is the minimum duration of symptoms necessary for schizophrenia diagnosis?
6 months
Is it possible for schizophrenia to be precipitated by substance abuse or other medical condition?
NO!
A 30 year-old woman who has no psychotic, residual, or mood symptoms tells you that sometimes she becomes frieghtened at night because her desk looks like a seated man lurking in the room. What category of symptomotology is this?
an illusion
A 53-year-old hospitalized schizophrenic patient tells her doctor that another patient was talking about her when he said, "A woman won $10,000 in the lottery today." This patient's statement demonstrates what symptom of schizophrenia?
an idea of reference - false belief of being referred to by others
A 58-year-old pt tells you that for the last 5 years his coworkers have been trying to get him fired from his job by telling lies about him to the boss. The patient is married and has lived int he same town for 35 years. Physical exam is normal. What is the most appropriate diagnosis for this patient?
Delusional disorder: nonbizarre delusions of paranoid type but normal social and occupational fnx
A 50-year-old man witha history of psychotic symptoms, severe depression, and periods of boundless energy and enthusiasm has held defferent jobs but none of them for more than 3 months. Physical exam is normal. The p is successfully treated for his mood symptoms but remains strange and distant. the most appropriate diagnosis for this patient is:
schizoaffective disorder - a combo of both mood disorder and schizophrenia
What is the lifetime prevalence of suicide in schizophrenia?
10%
What is the current belief regading the site of action of general inhaled anesthetics?
hydrophobic (lipophilic) regions of proteins
What is the general affect of volatile anesthetics?
potentiation of GABA receptor activity to depress neuronal excitability (IV anesth. as well)
At therapeuic doses, do general anesthetics block action potentials?
No. Only at doses above clinical range
List the brain regions effected by general anesthesia and the effects produced from altering those regions
(1)hypothalamic nuclei/sleep
(2)reticular formation/pain, consciousness, sleep
(3)hippocampus/amnesia
Why must volatile anesthetics be given at much higher doses than other drugs in order to be clinically effective?
because they do not have specific binding sites. Rather, molecules of particular size can fit into different binding pockets. So more drug is need to increase odds of a properly fitting drug.
What is the term for the progression from higher to lower function levels produced by general anesthetics?
descending depression
What are the 4 stages of anesthesia?
(1)analgesia
(2)excitement/delerium
(3)surgical anesthesia (can't get with N2O)
(4)medullary paralysis
The rate of uptake of anesthetic from blood to tissues is dependent on what 3 characteristics?
(1)solubility in the tissue
(2)tissue blood flow
(3)partial pressures in blood and tissues
What is the term for the time between initiation of administration of anesthetic and attainment of surgical anesthesia?
induction
What is the measure of potency in volatile anesthetics?
oil:water partition coefficient
What is the measure of solubility of volatile anesthetics?
blood:gas partition coefficient
What is the major route of removal for volatile anesthetics?
clearance by the lungs; the liver is not a major factor
What is the measure for brain anesthetic concentration in patients?
MAC (minimum alveolar concentration)
Wha tdo the dose-response curves for volatile anesthetics look like?
thay are STEEP; 50% of all pts fail to respond to noxious stimuli at 1.0 MAC, 99% are anesthetized at 1.3 MAC
Which form of epilepsy is more difficult to treat?
partial seizures are more difficult because they are so localized
What is the MOA of drugs for generalized tonic-clonic seizures?
use-dependent block of Na channels
What is the drug treatment for status epilepticus?
Diazepam (broad spectrum BDZ)
What is the MOA for drugs that treat absence seizures (oxazolidines and succinamides)?
block T type Ca channels and uncouple occilatory activation of thalamic cortical pathways
What is the major side effect of Felbamate (partial seizure drug)?
aplastic anemia
The majority of epilepsy dx have what etiology?
idiopathic, 50%
What is the difference between partial onset and generalized epilepsy?
Partial onset starts in one area of the cortex; generalized ocurs throughout the cortex as a whole
What is the difference between partial simple and partial complex seizures?
complex impairs consciousness (other one's the other one)
Absence seizures fall under which general category of epilepsy?
generalized
What is the difference between a partial complex and absence seizure?
absence seizures have a return to normalcy, no postictal period (experience of negative symptoms int he brain)
What percentage of epileptics respond to pharmaceuicals?
70%
What are the 2 main genetic causes of partial complex epilepsy?
ion channel mutations (Na channels) and chromosomal abnormalities (Angelman syndrome 15q11-q13)
What is the paroxysmal shift and what do the spikes represent?
feline in-vitro correlate to the interictal spike on EEG; first part of the hump is Ca-mediated followed by Na channels
What are the criteria for a dx of status epilepticus?
2 seizures within 5 minutes
Which type of seizure should you watch for in coma patients?
non-convulsive status epilepticus; EEG activity without motor activity
Are febrile seizures considered epilepsy?
no
What is the GCS score for an individual in coma?
GCS score of 8 or less
Between decorticate flexion and decerebrate extension, which has worse prognosis?
decerebrate extension is worse because it suggests a lesion at the brainstem
What are the criteria for the determination of death?
(1)irreversible cessation of circulatory and respiratory fnx
(2)irreversible cessation of all fnxs of the entire brain, including the brainstem, is dead
(3)determination of death must be made in accordance with accepted medical standards
What is the GCS score for n individual who is brain dead?
3
What cranial nerves are tested in the Cold Caloric Test?
III, IV, VI, VIII
What is the final protocal before disconnecting the ventilator?
Apnea Test Procedure
Can the traditional diagnostic test for brain death be performed on an infant (< 1yr)?
No. you must perform confirmatory tests
What is the most commonly performed confirmatory test?
4 vessel cerebral angiogram
What type of brain injury is more common in individuals with loss of consciousness?
cerebral contusion
What cortical cell layer contains pyramidal cells including the giant cells of Betz?
Layer V: internal pyramidal layer
Spatial attention is dominant in which hemisphere?
right hemisphere is dominant and receives input from both sides (L hemisphere only surveys the right hemispace)
What is the cortical function of the temporal lobe?
Lateral auditory processing
Semantics and grammar are dominant in which hemisphere?
left hemisphere
What is the "organizational effect"?
the ability of steroids to permanently alter the state of the body or brain during an early developmental critical period
What is the role or aromatase in sexual differentiation of the brain?
converts testosterone into estradiol, which is the crucial signal for male-type differentiation
What hormone is released by preoptic neurons in the hypothalamus?
LHRH therby stimulating the release of LH and FSH
How are LHRH neurons linked in the female hypthalamus and what is the effectt of this linkage?
linked by gap junctions causing a synchronous discharge burst of hormone
Why must a stroke be more massive in women than in men to produce the same degree of aphasia?
(1)language function is more distributed in the female brain
(2)language appears to be represented more bilaterally so language fnxns may be spared with a L-sided stroke
What is the default state for brain and sex differentiation?
female
What is the effect of steroids complexing with the GABA receptor?
increases the open time of the Cl- channel-->hyperpolarization-->increases efficacy of the receptor by making it more difficult for a neuron to fire an action potential.
What is the criteria for substance abuse?
One or more of the following in a 12 month period:
(1)failure to fulfil obligations
(2)use in physically hazardous situations
(3)substance related legal problems
(4)recurrent social/interpersonal problems
What is the criteria for substance dependence?
Three or more in a 12 month period:
(1)tolerance
(2)withdrawl
(3)large amounts and larger time than intended
(4)unsuccessful efforts to stop
(5)narrowing of repertoir
(6)continued use depsite awareness of problem
What is the primary MOA for stimulants (cocaine, amphetamines)?
MAOI (like antidpressants)
increasing DA, NE, 5HT
What unique receptor does caffine act on?
adenosine; enhances neurtransmitter release of NE, DA
All depressants have what common primary mechanism?
potentiate GABA
What is the primary MOA for hallucinigens (LSD, mescalin)?
agonize/antagonize specific serotonin receptors
What are the signs of acute toxicity for each of the following:
(1)cocaine
(2)extasy
(3)nicotine
(4)caffine
(5)alcohol
(6)opiods and other pain killers
(1)cardiac
(2)hyperthermia
(3)nausea
(4)anxiety/insomnia
(5)respiratory depression
(6)confusion
What are the withdrawl symptoms of the following drugs of abuse:
(1)cocaine/amphetamine
(2)nicotine/caffine
(3)CNS depressants
(4)Opiods/analgesics
(1)depression, sleep, apetite
(2)irritability, depression
(3)seizures (BDZ moderate), tremors, hallucinations
(4)anxiety, sleep distrubance, diarhhea, mydriasis, runny nose
(4)
What are the 4 treatment options ofr substance abuse?
(1)substitution
(2)partial agonists
(3)aversion therapy
(4)craving reduction
What the hell does anabuse do?
Anabuse blocks aldehyde dehydrogenase; build up of acetyl aldehyde = vomiting
Induction of what system leads to ethanol tolerance?
CYP450
When would you therapeutically give a high dose of ethanol?
Methanol or isopropanol poisoning; competitive inhibition
What are the three drug types used to treat alcoholism?
BZDs
alph2 agonists
beta antagonist
What is drug intoxication?
effects from the recent intake of the drug (reversible)
What is drug withdrawl?
effects from stopping the drug (reversible)
What is drug dependence?
When stopping results in withdrawl
What is drug tolerance?
When larger amounts are desired to acheive the desired effects (adaptation)
What are the criteria for fetal alcohol syndrome?
(1) growth retardation
(2)characteristic facial dysmorphology
(3)CNS involvement
what type of stimuli are drugs of abuse (reinforcing or punishing)?
Reinforcing (both positive and negative)
What are the three main treatment categories from drug abuse?
pharmacological punishment
social punishment
social reinforcement of nonuse
What percentage of people with antisocial personality disorder are also substance abusers?
75%
What are examples of substance related disroders?
Needle infections
Head injuries
Drug induced parkinson's