neurocognitive disorders Flashcards
learning & memory deficits in NCD
amnesia is a common feature of many NCDs – including inability to learn new info and failure to recall past events
- anterograde amnesia = memory loss for info acquired after the onset of amnesia
in degenerative disorders: memory deficits slowly develop from normal forgetfulness to a more full-blown inability to recall events
attentional & arousal deficits in NCD
lack of attention, being easily distracted & performing well-learnt activities more slowly than before
difficulty focusing on or keeping up w a convo + needing more time to make simple decisions
language deficits in NCD
- may appear to be rambling during convos + have difficulty conveying what they have to say in a coherent manner
- may have difficulty reading & understanding speech of others
are one of the most common features – collectively known as aphasias:
fluent, non-fluent, Broca’s & Wernicke’s
fluent vs non-fluent aphasia
fluent = the production of incoherent, jumbled speech
- speak in sentences that sound like normal speech, but some of the words are made-up words or have some sounds that are not correct
non-fluent = an inability to initiate speech - struggle to get words out, omit words, and speak in very short sentences.
Broca’s vs Wernicke’s aphasia
Broca’s = difficulties with speaking – word ordering, finding right word & articulation (associated w damage to left frontal lobe)
Wernicke’s = difficulties in comprehension of speech – recognizing spoken words & converting thoughts into words (associated w damage to regions behind frontal lobes)
Agnosia
the loss of the ability to recognize objects, persons, sounds, shapes or smells while the specific sense is not defective (no sig memory loss)
apraxia
the loss of the ability to execute or carry out learnt movements, despite having the desire & physical ability to do so
- in more complex cases: can emit a behavior when it is under routine conditions but not on command
executive function deficits in NCD
reflects the inability to effectively problem-solve, plan, initiate, organize, monitor & inhibit complex behaviors
- normally associated w the prefrontal cortex: damage to this area is frequently involved in these deficits
- can be tested by Wisconsin card sorting task
diagnosis of NCD
is difficult bcuz symptoms & deficits often closely resemble those of other psychopathologies
DSM-5 identifies 2 broader syndromes into which many NCDs fall: delirium & major/mild NCDs (dementias)
delirium NCD
a disturbance of consciousness that develops over a short period of time – reflected in a reduced ability to direct, focus, sustain & shift attention
- may not understand simple questions or shift attention from answering one question to another
- often occurs in context of other NCDs + accompanied by memory & learning deficits, disorientation & perceptual disturbances
- may be result of widespread disruption of brain metabolism & NT activity
- may also exhibit emotional disturbances
prevalence of delirium NCD
community prevalence = 1-2%
increases with age, rising to 14% over 85
major/mild NCDs (dementias)
conditions where there is evidence of a significant decline in performance across 1 or more cog domains
cog deficits in: complex attention, executive functioning, learning/memory, language, perceptual-motor, or social cognition
major vs mild levels of NCDs
mild = modest impairment that doesn’t interfere
major = substantial impairment that interferes w daily life
- language function may deteriorate: convo may become vague or empty + unable to name individual everyday objects
- may also be associated with apraxia & agnosia
- disturbances in exec functioning also common
NCD due to HIV infection
HIV enters the CNS early in the illness & neurological difficulties can develop in up to 60% of those infected
- impairments are usually minor but may induce multiple symptoms of motor & cog dysfunction
- impaired exec functioning, slowed processing speed, problems w attentional tasks & difficulty learning new info
- fewer than 5% meet the criteria for major NCD
associated with progressive cortical atrophy in grey & white matter
- but deficits often caused by body’s weakened immune system allowing other infections to attack the brain
NCD due to prion disease
variant Creutzfeldt-Jakob disease (vCJD) = a fatal infectious disease that attacks the CNS
- early signs: changes in mood, temperament & behavior + memory & concentration + confused thinking
- verbal fluency, numeracy ability, face recognition, memory & exec functioning
prion (infectious agent) = an abnormal, transmissible agent that is able to induce abnormal folding of normal cellular proteins in the brain
- rapid dementia in vCJD appear to result from prions/protein deposits encrusting or replacing neurons
vascular NCDs
damage to brain tissue can also occur as a result of a cardiovascular accident (CVA) = a stroke
- can be defined in 2 broad ways: an infarction or a hemorrhage
- symptoms of stroke: numbness, weakness or paralysis on one side of the body, slurred speech, blurred vision
- LT symptoms: aphasia, agnosia, apraxia & paralysis
- emotional disturbance – often depressed mood or emotional lability
what is an infarction
the injury caused when the blood flow to the brain is impeded in some way – results in damage to brain tissue fed by that blood flow
most common cause are an embolism or thrombosis
cerebral embolism
a blood clot that forms somewhere in the body before traveling through the blood vessels and lodging in the brain
– causes brain cells to become damaged bcuz of O2 starvation
cerebral thrombosis
an injury caused when a blood clot (thrombus) forms in an artery supplying blood to brain
– clot interrupts blood supply & brain cells are starved of O2
what is a hemorrhage
when a blood vessel in the brain ruptures and affects local brain tissue
- often the result of hypertension or high BP & often due to an aneurysm
aneurysm = a localized bulging in a blood vessel caused by disease or weakening of the vessel wall
degenerative disorders
NCDs that are characterized by a slow, general deterioration in cog, physical & emotional functioning as a result of progressive physical changes in the brain
- occurs gradually over a number of years + more frequent in old age
- prevalence: 7% over 65, 30% over 85
represent an active pathological organic deterioration of the brain
- many manifest with very similar cog impairments
alzheimer’s disease
most common form of dementia
involves progressive impairments in STM + symptoms of aphasia, apraxia & agnosia + impaired judgement, decision-making & orientation
- personality changes
known risk factors: age, sex (higher in women), genetics, family history of dementia, history of head injury & low educational status
causes of alzheimer’s
brain changes: are structural & involve develop of beta amyloid plaques & neurofibrillary tangles
- result is gradual shrinkage of healthy brain tissue + enlarged ventricles
Faulty production of ACH: alz affects structures involved in production of ACH
- ACH levels fall too low and memory & other brain functions are impaired
appears to be a significant inherited component: 50% of 1* relatives also develop the disorder
- several genes have been identified – APOE4 & GAB2
beta amyloid plaques & neurofibrillary tangle
beta amyloid plaques = abnormal cell development
neurofibrillary tangles = abnormal collections of twisted nerve cell threads
amnestic disorder
amnestic = amnesia – causes strikingly disturbed memory
- immediate recall + memory for remote past event are not usually affected but STM is typically impaired
- overall cog functioning is quite good & person may be able to execute a complex task
e.g. Korsakoff’s syndrome
Korsakoff’s syndrome
an amnestic disorder caused by deficiency in vitamin B1 (thiamine)
- problems associated can sometimes be reversed if it is detected early enough & B1 is given
- often found in chronic alcoholic or people who do not eat healthy
frontotemporal NCD
associated w a loss of neurons from the frontal & temporal regions – leads to progressive behavioral and personality changes and language impairment
- doesn’t usually affect memory – mainly impacts emotional processes (e.g. apathy & empathy)
- accounts for only 5% of all dementia
NCD due to parkinson’s disease
parkinson’s disease = a progressive neurological condition affecting movements such as walking, talking and writing, and causes psychological disturbance in 40 to 60% sufferers
main symptoms:
1. tremor, including jerky movements of the arms, hands and head that are also present during resting periods
2. slowness of movement (bradykinesia)
3. stiffness or rigidity of muscles
occurs as a result of damage in the basal ganglia, specifically the substantia nigra - responsible for producing dop: allows messages to be sent to parts of the brain that coordinate movement
more common in men + over 50
memory, learning, judgement, concentration + hallucinations & depression
NCD with lewy bodies
lewy bodies = abnormal protein deposits that disrupt the brain’s normal functioning
- are found in area of brain stem where they deplete dop = Parkinson’s symptoms
- can also diffuse throughout other areas of the brain
- may account for up to 30% of all dementia
varying cognition w obvious changes in attention & alertness + hallucinations + features of Parkinsonism prior to develop of cog decline
NCD due to Huntington’s disease
huntington’s = an inherited, degenerative disorder of the CNS, caused by a dominant gene
- principally a movement disorder + changes in temperament + decline in cog functioning
- prevalence: 8 in 100,000 people in the UK
cholinesterase inhibitors (alzheimer’s)
a group of drugs that prevent ACH breakdown in synapse by acetylcholinesterase + increases its uptake in the postsynaptic receptor
- produces moderate improvements in cog function in alz
- slows memory decline - best when treatment begins early in the disease
- alleviates behavioural symptoms, mood disturbances and delusions associated w alz
levodopa (parkinson’s)
a natural amino acid that is converted by the brain into dop - used in the treatment of Parkinson’s
- successful in controlling tremor and other motor symptoms
- little evidence that it alleviates any cognitive impairments
- side effects: hypertension, delusions, hallucinations
thrombolytic therapy
the use of drugs to break up or dissolve blood clots
- if it is administered within the first 3 hours of a stroke disability is significantly reduced
- success is dependent on the individual being able to identify early sings of stroke & seeking rapid treatment
- little evidence that this helps alleviate the cognitive deficits that come with stroke
antiretroviral drugs (NCD HIV)
chemicals that inhibit the replication of retroviruses, such as HIV
- reduce the severity of HIV dementia
- reduce the prevalence of diagnoses of NCDs
- act on different stages of the virus life-cycle
- produces a dramatic reduction in viral load + prevents further immune damage
deep brain stimulation (for parkinson’s)
uses a surgically implanted battery-operated device to deliver electrical stimulation the thalamus or the basal ganglia
- blocks the abnormal nerve signals that cause tremor and Parkinson’s symptoms
- results in improvements in physical abilities & quality of life
attention process training
a form of rehabilitation training for attention deficits that uses a number of different strategies to promote and encourage attentional abilities
- e.g. listening to an audio that contains target words that must be responded to by pressing a buzzer
provides gains in other everyday skills such as independent living and driving ability
time pressure management
an approach to dealing with attention deficits which aims to provide clients with some compensatory skills that will allow them to effectively manage their slowed information processing
computer-assisted training program aiding visual scanning
consists of a series of tasks where the patient practices various skills, e.g.:
- scanning full frontal environment
- coordination of scanning and physical movement
- detection of stimuli space
gestural training
a form of rehabilitation training for limb apraxia
- client is taught to recognise gestures and postures that are appropriate and in context
computer-based virtual reality environments
have been developed to enable individuals with brain injury to learn to improve basic daily living skills in a safe and controlled environment
constraint-induced movement therapy
used with aphasic patients - involves the mass practice of verbal responses
- patient may be required to communicate without gesturing or pointing to describe various objects of varying complexity
group communication treatment
used in the production and comprehension of speech
- focuses on increasing initiation of conversation and exchanging information using whatever communication means possible
goal management training
involves training in problem solving to help evaluate a current problem, followed by specification of the relevant goals + dividing the problem-solving process into subgoals or steps
self-instructional training
used in the intervention for executive functioning deficits where individuals learn a set of instructions for talking themselves through particular problems
