Chapter 6 Test (ADHD) Flashcards
Alpha activity
Defined as EEG activity between 8 and 12 Hz characteristic of a relaxed or meditative state
Attention-deficit/hyperactivity disorder
A disorder characterized by difficulties in attention to tasks, excessive motor activity, and impulsivity. Often diagnosed in early childhood but may persist in adulthood
Attentional gate
The inhibitory influence of the thalamic reticular nucleus to regulate sensory information along the thalamocortical pathway
Attention regulation
The process whereby cortical input to the thalamus filters and allows attention to specific sensory information.
Autistic psychopath
Used to describe what is now know as Asperger’s disorder
Who first used the term Autistic psychopath?
Hdans Asperger
Autistic spectrum disorder
These include autistic disorder, Asperger’s disorder, and Rett’s disorder
Beta activity
Desychronized EEG activity ranging between 13 and 30 Hz. typically of the normal arousal state
Corpus callosum
A band of approximately 200 million interconnecting myelinated axons that unite left and right cortical areas as well as interhemispheric regions
Cortical underconnectivity
Deficits in white matter that make up the cortical circuits that integrate inter and interhemispheric connections.
Dopamine deficit theory
Depressed dopamine activity in the caudate nucleus and frontal cortices may contribute to cortical hypoarousal in ADHD
Dopamine transporter (DAT)
Proteins on the presynaptic membrane that selectively transport extracellular dopamine back into the terminal button.
What is responsible for dopamine reuptake?
Dopamine transporter (DAT)
Early infantile autism
Used to describe what is now known as autism
Who was the first to use the term Early Infantile Autism and when
Leo Kramer in 1943
Hypoarousal
A decrease in cortical arousal characterized by an increase in slow wave alpha and theta activity observed with an electroencephalograph (EEG)
Infantile Schizophrenia
A term used under the original classification scheme proposed to characterize autism
Who proposed infantile Schizophrenia?
Eugen Bleuler
Locus coeruleus
A nucleus of noradrenergic cell bodies located in the pons near the fourth ventricle
Neuregulin
A protein that signals Schwann cells for axon myelination
Reticular activating system
A system of neurons originating in the reticular formation of brainstem projecting to the thalamus and cortex.
What is Reticular activating system involved in?
In attention and cortical arousal
Reuptake transporters
Proteins on the presynaptic membrane that transfer neurotransmitter substances in the synaptic gap back into the terminal button.
Sensory thalamus
Regions of the thalamus that receive sensory information and project it to the cortex via the thalamocortical pathway
Thalamic reticular nucleus
Outer cortex of the thalamus that regulates the sensory thalamus and activity along the thalamocortical pathway.
What does the thalamic reticular nucleus function as?
an attentional gate by allowing or inhibiting sensory input to the cortex
Theta activity
Cortical EEG activity in the range of 3.5 to 7.5 Hz often observed during the early stages of sleep
Tuberomammillary nucleus
A nucleus of histaminergic cell bodies located in the ventral surface of the hypothalamus.
What is the Tuberomammillary nucleus involved in?
Believed to be involved in cortical arousal
White matter
Large groups of fast-conducting myelinated axons that interconnect regions of the brain. Often compared to grey matter, which consists of unmyelinated neurons.
What does white matter consist of inside the brain?
Inside of the brain the white myelinating matter consists of a kind of glia cells called an oligodendrocyte.
What does white matter consist of outside the brain?
Outside of the brain, in the spinal cord, this myelinating glia is called a Schwann cell.
What is ADHD characterized by?
1) Pervasive inability to attend to tasks
2) Disruptive activity/ impulsivity
3) Excessive motor activity/impulsivity
What do children with ADHD struggle with?
1) attention
2) following instructions
3) completing tasks
What is the percent of children diagnosed with ADHD?
8%
What is the age children are normally diagnosed with ADHD?
4-17
How many children does attention disorders affect?
Over 4.5 million
Of those who are affected, how many are taking medication?
Over 2.5 million (a substantial proportion)
When are attention disorders typically first observed in children?
When they begin to develop independent locomotion
When does ADHD normally dissipate?
late adolescence or early adulthood.
In how many do symptoms of inattentiveness persist?
In as many as 50% into adulthood
What behavioral disorders does adult ADHD come with?
1) depression
2) anxiety
3) conduct disorder
4) drug abuse
5) antisocial behavior
What disorders may attention disorders co-occur with?
Autism and Asperger’s
How long must inattention or hyperactivity-impulsivity be present before diagnosis?
Six months
How many of the symptoms must be present and to what level?
Six of the symptoms and they must be disruptive and inappropriate for the child’s developmental level.
In ADHD, where is there a pattern of hyoarousal?
in the corical
In ADHD, where kind of activity is there a pattern of increase in?
Theta activity
How is a higher theta/beta activity ration among ADHD kids found?
In EEG
Where in particular is there consistent cortical hypoarousal?
frontal and cingulate cortices
What does FMRI studies find in the thalamic sensory activity?
A decrease in thalamic sensory activity
What does a decrease in thalamic sensory activity suggest?
Abnormalities in reticular activating system
What may contribute to cortical hypoarousal and an irregular EEG pattern?
A decrease in cholinergic input to the sensory thalamus and to the thalamic reticular nucleus.
What underlies attentional regulation?
Corticothalamic projections from the frontal cortex back to the TRN
What inhibits the stimuli that would normally arouse the cortex via the thalamacortical pathway?
thalamic reticular nucleus
What happens during normal wakefulness?
The cholinergic input to the TRN disinhibits the attentional gate allowing for cortical arousal?
What happens to the attention gate in ADHD?
It is closed and the cortex remains under aroused
Children with ADHD may express delayed or accelerated cortical maturation.
Delayed cortical maturation
T/F
There is a study showing similar developmental patterns between children with ADHD and those without but there is a significant different in cortical thickness in remaining cerebral areas.
True
Where are the deficits most pronounced in ADHD patiens?
Prefrontal regions of ADHD
What is presently unknown about ADHD
If delayed cortical maturation is a result of cortical hypoarousal or the cause of it.
What do stimulant drugs do to normalize cortical activity?
They increase beta activity and decreasing slower wave alpha and theta activity in frontal cortices
There is a —— expression of the dopamine transporter in ADHD patiens
increased
What have studies using radioactive ligands for dopamine receptors find?
increased DAT numbers in ADHD patientns
Where is there an increase number of DAT
Caudate nucleus
Where are the differences between those with ADHD and those without not found?
The putamen
What plays a key role in regulating dopamine activity throughout the brain by determining synaptic dopamine availability?
The dopamine transporter (DAT)
What does increase in DAT in the caudate nucleus and frontal cortices diminish?
dopamine availability and receptor activity in ADHD.
What is one of the most widely used assessment scales for measuring treatment outcomes for ADHD?
Connor’s Global Index (GCI) scale.
What is used to assess changes in ADHD specifically and based on the DSM-5?
A subscale of the Global Index (CGI-ADHD)
What is a more objective assessment for ADHD treatments?
fMRI or EEG
What were the results of the 1999 National Institute of Mental Health’s 14 month study of ADHD treatment options?
They found that…
1) treatments using stimulant meds were far superior to intensive behavioral treatment or community-based treatment alone
2) Children treated with meds (alone or with combination of therapy) showed greater academic performance and social skills than those in non-medicated comparison group
Drug abuse risk decreases or increases in stimulant-treated patients
Decreases
When were amphetamines used for treatment of ADHD?
1930s
What are Amphetamines used for ADHD
1) Dexadrine (dextro-amphetamine)
2) Adderall (dextro/levo-amphetamine)
3) Vyvanse (lisdexamfetamine)
What is the most recently approved amphetamine for ADHD?
Vyvanse (lisdexamfetamine)
What are the two stimulant drugs that are almost indistinguishable in effects from amphetamines
1) Ritalin (methylphenidate)
2) Focalin (dexmethylphenidate)
What methylphenidate is only available as a skin patch?
Daytrana
Methylphenidate and other amphetamine compounds account for how much off the prescription medication for ADHD?
90%
How do methamphetamines and amphetamines increase synaptic concentration of both norepinephrine and dopamine?
1) They block reuptake transporters for NE and increase NE released into synapse
2) Bind to vesicular transporter and cause DA release from storage into the cytoplasm of terminal button
3) Increase amount of DA released rom synaptic vesicles during neuronal signaling
How does Da contribute to cortical arousal in ADHD?
through the mesocortical pathway originating in the nucleus accumbens
How does NE activity contribute to cortical arousal?
By reticular activating system originating in the locus coeruleus
What are side effects of amphetamines?
1) Insomnia
2) nervousness
3) Irritability
4) weight loss
5) Dizziness
What side effects of amphetamines are related to the noradrenergic activity?
1) Hypertension
2) tachycardia
3) cardiac arrhythmias
What happens when one has an excessive or overdose of amphetamines?
psychotic states
seizures
cardiac failure
Is Ritalin (methylphenidate) associated with an increase in cancer or stunted growth?
No,
What is the most widely prescribed drug for ADHD?
Ritalin (methylphenidate)
Are Strattera (atomexetine) and Provigil (modafinil) stimulants or non-stimulants?
Non-stimulants
How does Strattera (atomexetine) and Provigil (modafinil) resemble amphetamines?
Both
1) block reuptake transporters for NE and DA
2) promote wakefulness and increase in activity
What does Provigil (modafinil) specifically do?
1) increases NE and DA activity in the brainstem and forebrain areas that regulate sleep and promote wakefulness
2) activates hypothalamic centers that regulate sleep-wake cycles by inducing orexin release
What is orexin?
An excitatory neuromodulator that regulates the activity of catecholamine brainstme nuclei involved in arousal.
What does modafinil (Provigil) promote?
alertness by increasing histamine release in the tuberomammilllary nucleus of they hypothalamus
What does histamine activity in the hypothalamus do?
1) regulates sleep
2) regulates wakefulness by activating hypothalamic nuclei involved in arousal
Increasing histamine = what
Decreasing histamine = what
Increasing contributes to wakefulness
Blockade causes drowsiness and sedation
What drug is approved for narcolepsy and excessive sleepiness associated with sleep apnea and shift-work sleep disruptions
modafinil (Provigil)
What drug is as effective as methylphenidate in reducing ADHD symptom and has fewer side effects
modafinil (Provigil)
What is drug is the catecholamine agonist that selectively blocks reuptake transporters for NE and may increase DA activity in frontal cortex indirectly
Strattera (atomoxetine)
what was Strattera (atomoxetine) originally developed for?
antidepressants
What is Strattera (atomoxetine)’s most notable side effects?
1) gastrointestinal discomfort
2) decreased apetite
3) Insomnia
4) agitation
5) increased heart rate
6) hypertension
How many children does the autistic disorder effect?
90 to 110 in every 10,000
What is the rate that autism occurs in men vs women?
four times more frequently in males than in females
When was Autism first named?
1943
By whom was autism first named?
Leo Kramer
Who often sees the first signs of autism
parents
What must be present for Autism?
1) deficits in social communication and social interaction as manifested by
2) Restricted repetitive patterns of behavior, activities, or interests
What is the most consistent pathological correlation for autism
Cortical underconnectivity and deficits in both functioning and volume of anterior cingulate cortex
What does the theory of cortical underconnectivity propose?
That autism is a result of deficits in white matter that makes up the cortical circuits that integrate interhemispheric connections
What was found in fMRI for autism?
1) less activity in left inferior frontal gyrus (Broca’s)
2) more activity in left posterior superior temporal gyrus (Wernicke’s)
Where was the delay during the comprehension tasks when compared to non autistic control subjects?
In the cortical activation
Does deficits in the development of myelination throughout the corpus callosum and the cortex underlie autistic disorder.
Yes
Where is there a reduction of corpus callosum size i autistics?
The anterior (genu) and posterior (splenium) regions
What does the protein neuregulin signal?
Schwann cells to myelinate
Is underconnectivity linked to a deficit in the protein neuregulin?
Yes
What is myelination critical for?
Normal signaling within the brain
What does myelination a major determinant of?
signal velocity
Is autism a consequence of abnormal synaptic activity or neuronal communication?
No
What is autism normally co-occuring with?
1) depression
2) anxiety
3) hyperactivity
4) seizures
5) sever behavioral agitaiton
How are co-occuring conditions of Autism managed?
With medications approved for other disorders (therefore they are off label)
