Lectures Clinical Neuropsychology 2018-2019

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Lecture 1: Introduction to Clinical Neuropsychology

The brain and brain disordersIn clinical neuropsychology, we can differentiate between cognition and behaviour when it comes to neuropsychological disorders. Deficits in cognition are mainly cortically based. Disorders like these are amnesia, aphasia, agnosia, apraxia and deficits in executive functioning. Also problems with attention and focusing are cortically based. Deficits in behaviour are mainly subcortically based. Damage here can lead to symptoms like anxiety and depression, apathy, delusions and hallucinations and personality changes. The brain consists of four lobes: the parietal lobe (memory, language, sensation), the occipital lobe (visual information), the frontal lobe (motor functions) and the temporal lobe (auditory information). The cerebellum has the main function of coordination and the brainstem regulates life functions like breathing.Brain disorders occur in 20% of the people. About 600.000 people develop a disorder in the central nervous system, and about three million people deal with a psychological disorder sometime in their lives. It is important to figure out what the location of the lesion is. Consequences of damage in either white or grey matter can differ from one another. The size of the lesion can determine when the consequences are becoming visible. It is also important to know when someone gets their brain damaged. Below some different forms of brain disorders are given.Genetic disorders and developmental disordersMental retardation ADHDDyslexia Angelman Prader-Wilie Vascular disordersNeurotraumaNeuro-intoxicationsAlcoholMedicationDrugsPsychiatric disordersDepressionAnxietySchizophrenia Neurodegenerative disordersLewy Body diseaseParkinsonHuntingtonAlzheimerOtherHIVEpilepsyEncefalitisHydrocefalusLack of vitamin B12 When looking at brain scans it is important to note that when looking at the right side on the scan, you are looking at the left side of the brain and...

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Lecture 2: Neuroanatomy

The neuronThe neuron consists of dendrites, a soma (cell body) and an axon. Axons are long fibers connecting neurons to one another. An axon hillock is a place where an action potential should be at a certain threshold to cause some sort of signal. An action potential is a signal that travels along the axons, and it triggers an all-or-nothing response at the synapse. A synapse is a space between neurons. Action potentials lead to neurotransmitter release into the synaptic cleft. Both excitatory and inhibitory signals contribute to the summed signal at the axon hillock. Receptor cells in the postsynaptic membrane can adapt to under- or over-use of neurotransmitters. Some neurons can release more than one type of neurotransmitter, which depends on the type of stimulation (high or low). Neurotransmitters: typesThere are three main types of neurotransmitters. Small molecule neurotransmitters are neurotransmitters which act very quickly. Examples of these are acetylcholine, amines (dopamine, norepinephrine, adrenaline and serotonine), and amino acids (glutamate, GABA, glycine, histamine). Peptide transmitters are neurotransmitters which act very slowly. They consist of amino acid chains. Transmitter gases are neurotransmitters that very easily cross cell membranes and cause active metabolism. Examples of these are nitric oxide and carbon monoxide. The effect of neurotransmitters can be excitatory, inhibitory or both. Each type of neurotransmitter pairs with multiple receptor types in the postsynaptic membrane. Cortical cell layers Different types of neurons are often organised in layers, which have differences in thickness, depending on the location in the brain. Sensory neurons (input), interneurons (relay) and motor neurons (output) are grouped in these layers. The layers are different in different cortical areas, depending on the primary function of the location. Brodmann’s functional map is a map which divides the brain in different...

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Lecture 3: Neuroimaging

Measuring the brain Measuring the brain and its activity can be done in different ways. To create anatomical imagines and by that measuring the brain structure X-rays, MRI, D-MRI and MRS are commonly used techniques. CT and angiography are X-rays techniques. MRI is used to differentiate different tissue types. D-MRI is used to measure diffusion through white matter tracts and MRS is used to measure chemical compositions. The brain’s activation and with that the brain’s function can be measured both directly and indirectly. Direct techniques (neuronal firing) are EEG, MEG, ECoG and invasive line electrodes. Indirect techniques (blood circulation or oxygen levels) are fMRI, PET (3D) and fNIRS (2D). Techniques to stimulate the brain and measure perturbing brain functions are DBS, (r)TMS and TDCS. Brain structure: X-raysThe technique of X-rays was the first way of looking into the body without having to open it up. Bone structure can be see very clearly. Radiographs are the rays that are absorbed to a different extent by different tissue types and different doses of radiation. Soft tissue cannot be seen when using the X-rays technique. CT is an example of an X-rays technique. It has a moderate dose of radiation and by creating multiple projections the result will have a better resolution. A CT-scan is a radiograph from different angles. Soft tissue cannot be seen when using this X-rays technique. Angiography is an X-rays technique to image blood vessels by using contrast agents. Brain structure: MRIMRI is based on magnetic fields and does not use radiation. Contrast agents are sometimes useful, but not necessary. MRI also imagines soft tissue. Given contrasts by MRI are tissue characteristics, water diffusion and oxygen saturation. MRI consists of a nuclear magnetic resonance: spins of hydrogen atoms/protons are measured. It is used to apply pulses and see what the protons do. Proton density differs over tissue times and they behave...

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Lecture 4: Neuropsychological interventions

Rehabilitation by medical specialist care is done for those who are limited by illness, accident or congenital diseases. The patient receives multidisciplinary care headed by a rehabilitation physician. The main goals of rehabilitation are for the patient to receive optimal recovery, independence and to be able to participate in the community again. Brain injury can be divided in three main categories of causes. Those categories are acquired brain injury (trauma, tumor, infection/diseases, strokes), progressive disorders (Alzheimer’s, Parkinson, MS) and congenital disorders (from birth on) (Fetal Alcohol Syndrome, Down syndrome, ADHD). Traumatic brain injuryAbout 1.6 million people with traumatic brain injury are admitted to hospital every year in Europe. Causes can be falling (mostly children), a traffic accident, violence or sport injuries. The vast majority of those admitted have closed brain injury. The highest incidence is for children younger than 4 years old and men between 18 and 24 years old. Due to the force of the head and different densities of the brain secondary lesions may occur when acquiring brain injury. Disorders following acquired brain injury can be divided into three main categories. Cognitive disorders following acquired brain injury are deficits in attention and memory, neglect and visuo-spatial disorders. Emotional/psychosocial/behavioural consequences are personality changes, aggression, less impulse control and symptoms of depression or anxiety. Sensorimotor disorders are paralysis, loss of strength, central pain, spasticity, tinnitus and hemianopia. Psychosocial effects of acquired brain injury are affected basic functions, changes in views of the world, change in roles and difficulty carrying on as the patient did before acquiring brain injury. The injury is often invisible to others. Acquired brain injury doesn’t only affect the patient, but the family as well. Changes in roles may occur (someone else has...

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Lecture 5: Learning, memory and spatial behaviour

Check the slides on Blackboard for an overview of the models MemoryMemory is the ability to store information, to retain it and apply it later, both in recognition and reproduction. Semantic memory is the memory of facts, like words. Semantic memory is how our brain makes sense of the world and it can be compared to a living database. It helps us cope with new objects and new experiences. Semantic dementia, seen in the shown video, is the inability to distinguish one thing from another. It is caused by cell death in the left temporal lobe. Categories become more general. The patient is still able to identify ‘an animal’, but is having more trouble with identifying what specific animal it is. Semantic dementia results in problems with knowledge, not with language. Models about the short term memory are designed by Baddeley and Hitch and by Atkinson and Shiffrin. These models will be discussed later on. * Baddeley & Hitch model: short term memory The model designed by Baddeley & Hitch consists of several components. The central executive controls everything that happens in the short term memory. It is in control of the incoming information streams and it guides every incoming information stream to the correct location to be processed more accurately. The visuo-spatial store holds information active (repeating) until it must be memorized or forgotten. The visual spatial sketchpad deals with incoming visual information. It functions as a filter, to determine what information must be kept. Visual information is often dominant. The phonological store also holds information active until it is memorized of forgotten. Think of repeating one’s phone number until you can write it down and then forget it. The phonological loop deals with incoming auditory information. This also functions as a filter to determine what information to keep and what not. The episodic buffer is a buffer with limited capacity. If incoming information is...

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Lecture 6: Clinical Child Neuropsychology

Brain and behaviour are strongly correlated. Dysfunctions, structural and functional abnormalities have various causes and can result in problems in thinking, doing and feeling. Damage to a developing brain will have different consequences than damage to an adult brain. Neuropsychological assessment is done by history taking (interviewing parents and teachers), doing observations (How is the child behaving in class? Is the child easily distracted? How does the child behave in interactions with the teacher and with other children?), tests and questionnaires. Neuropsychological assessments in children are often long-term follow-up assessment. This is done because some weaknesses will be resolved within months or years or new deficits may develop due to the developing brain. There are different forms of treatment in clinical child neuropsychology. Psychoeducation is about educating the child, parents, teachers and others around about specific difficulties and how they display in daily life. Other forms of treatment are advising the child, parents and the school about how to deal with these difficulties, giving cognitive training, psychosocial counselling, enhancing coping strategies, (cognitive) behavioural therapy and supporting/counselling the family and the school. Normal brain developmentProliferation is the process of cell growth. It starts in the first month of pregnancy and it is a very rapid process, since up to 250.000 neurons are developed every minute. Migration is the process in which neurons are transported to their location via glia cells. This process ends at birth. Differentiation is the process of developing into specific neurons. This process ends just after birth. Synaptogenesis is the process of developing synapses after birth. Apoptosis is cell death. This is done because some neurons won’t be used or are not necessary (anymore). Myelination continues after birth. All parts of the brain will go through these stages, but...

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Lecture 7: Neuropsychiatry

Symptom validity testing Symptom validity testing is an aspect of neuropsychological testing where separate scales are used to establish the probability that a given test is affected by a tendency to fake bad, fake good or malingering. It happens quite frequently that patients are showing signs of doing so, not always knowing they are ‘faking’ their symptoms, nor knowing why they’re doing so. It is strongly advised to do more than one symptom validity test, to figure out whether the patient’s symptoms are real or not. La belle indifference means that a patient is indifferent to his or her symptoms. This is a sign of a psychological problem. A task example, shown by the lecturer, is to show two items, then show one of those items again and another, new item, and then ask the patient which item he or she has seen before. Whenever you see someone showing strange behaviour, the first thing you must ask yourself is if this person is in a (potential) delirious state. This is a psychotic state with changes in attention and consciousness, due to a(n) (underlying) somatic illness. You should state this first because it needs treatment. A delirious state can range from seconds to months after, for example, waking up from a coma. The difference between a delirious state and suffering from schizophrenia, is that when in a delirious state you are less ‘awake’ than when you’re schizophrenic. A delirious state is psychotic in nature but has a lower level of consciousness. During the lecture, some videos are shown and discussed. Video Wernicke-KorsakovA man in an acute phase of delirium is Korsakov is seen. He has gotten out of bed at 11 in the morning, which is strange for a man of his age. Apparently his night and day pattern has switched. He has forgotten about the name of his illness and whatever he is saying doesn’t add up, nor make sense (incoherence/associative thinking). He doesn’t finish his sentences and expresses single words only. He...

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Lecture 8: Neurotechnology

Electricity and brain stimulationElectricity is the basis of neural and muscular functioning. It’s how neurons communicate with one another and messages are being sent by electricity. These signals in the brain can be measured invasively (from inside the brain) or from the outside, like from the scalp. Neural signals can be influenced by excitation, inhibition and desynchronization. This can be done by machineries. An example is a pacemaker in the heart. This machinery is a widely accepted form of muscular stimulation. When it comes to the brain, people feel more uncomfortable with the thought of having such a machinery inside their brains. There are two main forms of brain stimulation. Invasive stimulation is done from inside the head. Examples of this form of brain stimulation are Deep Brain Stimulation (DBS), as used in Parkinson, and Cochlear Implants (CI). Non-invasive stimulation is done from outside the head, for example placing electrodes onto the scalp. Examples of this form of brain stimulation are Transcranial Direct Current Stimulation (tDCS) and Transcranial Magnetic Stimulation (TMS, rTMS). Functions of brain stimulation are restoring function (stimulating something until it works by itself again), replacing function (adding something to take the place of the specific organ), improving function and research. Deep Brain StimulationWith DBS, electrodes are deeply implanted and those can record activity, but deliver stimulation as well. It can be used in diseases like Parkinson, chronic pain, major depression, OCD, Tourette and perhaps epilepsy (more research is needed). The placement and calibration of the device depend on the clinical goal. It must be done very precisely and it is important to know what kind of stimulation is needed (e.g. OCD needs different stimulation than major depression). Everyone’s brain is different from one another, therefore many scans is research is needed to figure out what is where exactly and...