Questions from Week 10: Blood supply References

1. Questions from Week 10: • Blood supply • References

2. Blood supply: Blue = Anterior Cerebral ArteryPink = Middle Cerebral ArteryYellow = Posterior Cerebral Artery

3. Blood supply: Blue = Anterior Cerebral ArteryPink = Middle Cerebral ArteryYellow = Posterior Cerebral Artery

4. References: • Cohen, R.A. (1993). The neuropsychology of attention. Plenum Press: New York. • Heilman, K.M.. & Valenstein, E. (2003) Clinical Neuropsychology. Third edition. Oxford University Press: New York. • Hodges, J.R. (2007) Cognitive Assessment for clinicians. Second edition. Oxford University Press: London. • Kohlb, B. & Whishaw, I.Q. (2009) Fundamentals of Human Neuropsychology. Sixth edition. Worth Publishers. USA. • Lezak,M.D., Howieson, D.B., & Loring, D.W. (2004). Neuropsychological Assessment. Fourth edition. Oxford University Press: New York. • Schoenberger, M.R., & Scott, J.G. (2011) The little black book of Neuropsychology: A syndrome-based approach. Springer: New York. • Strubb, R.L. & Black, F.W. (2000). The Mental Status Examination in Neurology. F.A. Davis Company. Philadelphia, USA

5. Attention and Arousal

6. Attention: “Everyone knows what attention is. It is the taking possession by the mind, in clear and vivid form, of one out of what seem several simultaneously possible objects or trains of thought. Focalization, concentration of consciousness are of its essence. It implies withdrawal from some things in order to deal effectively with others, and is a condition which has a real opposite in the confused, dazed, scatterbrained state which in French is called distraction, …” (William James (1890). The Principles of Psychology, Volume I, p. 403-404)

7. Attention is a multidimensional construct, incorporating interactive systems for sensory selective attention, arousal and sustained attention, and intentional control (Ponsford, 2008) • Attention constitutes a set of dynamic interactive processes that “direct themselves to appropriate aspects of external environmental effects and internal operations. Attention facilitates the selection of salient information and the allocation of cognitive processing appropriate to that information. Therefore, attention acts as a gate for information flow in the brain” (Cohen (1993, p. 3)

8. Arousal and alertness are prerequisites for attention • Overall cognitive productivity suffers in the face of attentional problems • Attentional capacity is a prerequisite skill for accurate assessment of neuropsychological functions • Memory • Executive function • Impaired attention and concentration are among the most common mental problems associated with brain damage • Reduced concentration • Distractibility • Inability to deal with more than one idea/task simultaneously • Inability to deal with high task demands

9. Clinical aspects of attention: • Arousal • Focused attention • Selective attention • Sustained attention or vigilance • Divided attention • Alternating attention **cf. domain specific attention – attention to space. Lesions: inferior parietal and prefrontal regions result in spatial neglect

10. Model: Two Systems 1. Reticular Formation system (a network of interconnecting and intertwined nerve cell bodies) in brainstem Contains ascending Reticular Activating System (RAS) Thalamus receives reticular activation and projects this arousal to cortex generalized attentional effect RAS also projects to prefrontal, limbic, parietal areas

11. 2. Cortical system of attentional regulation Prefrontal, limbic (amygdala and cingulate gyrus), temporal and parietal regions mediate attention Thalamus acts as a major relay station between ascending RAS and cortex with a reciprocal feedback loop from cortex to RAS Disruption in the ascending RAS results in disorders of arousal Disruption in the cortical areas results in specific components of attention (e.g. selective attention) being disrupted Bottom-up and top-down processing Prefrontal, Parietal and Temporal Thalamus Reticular Activating System Hodges (2007)

12. Arousal: The patient who is disoriented, agitated or presents with a disorder of consciousness • Arousal: the maintenance of an appropriate level of cerebral activity to successfully complete the task in which one is engaged. Arousal represents a general state of responsivity and alertness • Behaviour can be classified along a continuum of activity states • Coma and mania may represent extreme states of hypoarousal and hyperarousal • Arousal associated with attention • Attentional performance is impaired by extremes of activity states

13. Arousal: Neuroanatomic correlates: • Reticular activating system (RAS) in brain stem • Controls wakefulness and alerting mechanisms • Modulates attention through its arousal of the cerebral cortex • Brain stem lesions: • Sleep disturbances • Delirium • Disorders of consciousness • Drowsiness • Somnolence (tending to fall asleep, quiet with little activity) • Stupor (near-unconsciousness, acute lack of alertness) • Coma (deep unconsciousness)

14. Assessment of disorders of arousal • Delirium • Diagnosed mainly on manifest behaviour and history • Assessment of coma • Glasgow Coma Scale • Assessment of the confused/disoriented brain injury patient • Westmead Post-traumatic Amnesia Scale

15. DSM-IV criteria for delirium: • Criteria A: Disturbance of consciousness with reduced ability to focus, sustain or shift attention • Criteria B: Change in cognition (memory, orientation, language) or development of perceptual disturbance that is not better accounted for by pre-existing dementia • Criteria C: Development of disturbances over a short period of time (hours to days) and fluctuation during course of a day or over time • Criteria D: Evidence by history that these changes are associated with the patient’s general medical condition

16. Delirium: Attention and memory most striking and consistent abnormality: • patients are unable to generate and sustain attention and have problems with shifting attention • Distractible and lose track of conversations Tests: serial 7s, recitation of months of the year, days of the week in reverse order Disorientation in time – may fluctuate

17. Disturbance of memory – secondary to reduced attention • May be a dense amnesic period for the period of illness – or with fluctuations there may be islands of memory Tests: name and address Disturbance in Thinking – unable to formulate complex ideas or a logical train of thought, problems solving and planning drastically reduced • patients may present with delusions (false beliefs) at times with paranoid content

18. Disturbance in sleep-wake cycle – a disruption of normal sleep wake cycle is a consistent feature • Considered by some to be the pathogenesis of the syndrome • Insomnia and worsening confusion often at night • EEGs – show day time flucturations from wakefulness, light, rapid-eye movement and deep sleep • Night time loss of normal orderly progression of the stages of sleep

19. Disorders of perception: Attentional processes play a crucial role in the perception of sensory information any may relate to perceptual problems seen in delirium where vision and hearing most affected (distortion of shape and position, sounds, body image. Illusions (misperception of external stimuli) and Hallucinations (visual – simple shapes and patterns, objects, animals small people) Behaviour, emotion and mood: Hyperalert: restless, excitable and vigilant with voluble and pressured speech, shouting, laughing and crying present. Increased physical activity vivid hallucinations may be seen Hypoalert: quiet, motionless, speech sparse and slow, often incoherent Emotionally may vary from euphoria to depression.

20. Demographic and medical risk factors • Increased age • Previous cognitive compromise (stroke, dementia, trauma) • Chronic medical condition (diabetes, hypertension, cardio-pulmonary deficit) • Prolonged hospitalisation • Sensory disturbance, sleep-wake disturbance • Medical procedures with high blood volume loss/exchange (transplant) • Cardiac procedures with prolonged cardio-pulmonary bypass • Occupational exposure to toxins • Use of, or change in, dose of sedative, analgesic medications, or reaction to new medication (Schoenberg & Scott, 2011)

21. Medical conditions associated with delirium • Infection: Encephalitis, meningitis, sepsis • Withdrawal: Alcohol, sedatives, analgesics • Acute metabolic: Electrolytes, renal failure • Trauma: Post surgery, Post-traumatic amnesia • CNS: Haemorrhage, hydrocephalus, seizure, cerebral tumour • Hypoxia: Carbon monoxide poisoning, cardiac arrest • Deficiencies: Vitamen B12, thiamine • Endrocrinopathies: Hypo or hyperglycaemia, hypo or hyperthyroidism • Acute vascular: Hypertension, stroke • Drugs: Medication reaction/change/overdose • Heavy metal: Manganese, mercury (Schoenberg & Scott, 2011)

22. Assessment of Coma/Impaired consciousness Glasgow Coma Scale (GCS, Teasdale & Jennett, 1974) serial assessment of the presence, duration and depth of impaired consciousness and coma used to describe altered consciousness from mild confusional state to deep coma 3 aspects measured: verbal responses, motor responses and eye opening highly reliable when used by trained persons

23. GCS: Eye opening Spontaneous (opens eyes on own) 4 Speech (opens eyes to speech) 3 To Pain (pain stimulus is applied) 2 None (does not open eyes and not due to eye swelling) 1

24. GCS: Motor response Best Motor Response: Commands (follows simple commands) 6 Pain (pulls examiner’s hand away upon 5 pressure) Pain (pulls a body part away upon pressure) 4 Pain (arms contracted; abnormal flexion wrists/hands) 3 Pain (body becomes rigid in an extended 2 position upon pressure) Pain (“flaccid” motor response to pressure) 1

25. GCS: Verbal response Best Verbal response: Oriented: Carries on a conversation correctly and tells examiner who he is, where he is and why, and the month and year 5 Response seems confused and disoriented 4 Talks (random speech, incoherent) 3 Makes sounds that cannot be understand 2 Makes no noise 1

26. GCS GCS used to describe altered consciousness from mild confusional state to deep coma A coma score can be obtained (range 3-15; sum of highest score can be calculated) Coma has been defined when GCS ≤ 8 (e.g., 1 on eye opening, 2 on verbal response and 5 on motor response) A score of 3: deepest level of consciousness (no movements, sounds or eye opening)

27. GCS • Vulnerability of GCS to drugs and alcohol • Anaesthesia/surgery, opioids, sedation (intubation) • Day of injury alcohol may/may not lower GCS (Lange et al; 2010) • Effect of other injuries on GCS scores • Intubation/tracheostomy/facial/eye injuries may prevent accurate GCS assessment

28. Assessment of confusion/disorientation following brain injury • The period following coma/impaired consciousness during which the patient is confused and disorientated (Levin & Goldstein, 1989) • Post-traumatic amnesia (PTA) following traumatic brain injury (TBI) is characterised by intellectual and behavioural disturbances • Hallmark of PTA is amnesia where the patient is unable to record events in a continuous (Russell & Nathan, 1946) or connected manner • Duration of PTA defined as from the time of injury until return of continuous memory and includes the period of coma/impaired consciousness • Axonal injury related to disorders of consciousness following TBI • PTA is one of the best predictors of outcome following TBI (more accurate than GCS)

29. Retrograde Amnesia Retrograde amnesia (RA) is the inability to recall events prior to the injury • May involve seconds, minutes, hours and days • Patient able to recall more events as they recover from PTA (RA “shrinks”) • Duration correlated with severity of TBI • Frequently accompanies PTA

30. Post-traumatic Amnesia: WPTAS Westmead Post-traumatic Amnesia Scale (WPTAS; Marosszeky NEV, Ryan, L., Shores E.A., et al., (1997). The PTA Protocol: Guidelines for using the Westmead Post-Traumatic Amnesia (PTA) Scale. Sydney: Wild and Wooley.) www.psy.mq.edu.au/pta/ • administered daily • 7 orientation questions: (age, dob, month, time of day, day, year, place) • 5 memory questions: (examiner’s name and face, 3 picture cards) 3 rules of administration: • Know the correct answer for each item of the scale • Only change the 3 picture cards when the patient reaches a perfect score of 12/12 • Rehearse any incorrect items with patient at the end of testing

31. www.psy.mq.edu.au/pta/

32. Difficulties in assessing PTA Special patients: Chronic Amnesic patients Persevere with testing as long as possible May need to give patient 2-4 weeks break from testing Non-verbal patients yes/no – give 3 options for each question, present each of the 9 picture cards If unable to speak patient may be able to use writing or an alphabet board May be able to point or use arm movement to indicate choice from flash cards/white board Agitated patients May be a symptom of PTA Use other person to help settle while testing Reduce distractions, use praise and positive rewards CALD patients interpreter Borderline PTA scores Hovering on 11/12, 10/12 Refer to Clinical Neuropsychologist Assessment with the Westmead Selective Reminding Test

33. Post-traumatic Amnesia: Patient CD Patient: CD; Age: 39 years Date of Injury: 11/03/2005 Mechanism: MVA, Driver LOC: Unknown GCS at scene : 14/15 at 1624 hrs; 13/15 at 1640hrs; GCS on admission: 1825 hrs at 14/15; 13/15; 15/15 thereafter Day of Injury CT Brain: Normal Medication: At the scene: 1630hrs - Morphine 2.5 mgs; Fentanyl 200 mcgs, Ketamine 16.50mgs; On admission: PCA Morphine; Current medication: Oxycontin 20 mgs; Surgery: 11/03/2007 Day of assessment: 18.03.2005 Last memory: Driving home from work, and being around 1 to 2 minutes from home. Did not recall impact. First memory: Paramedics attempting to free her from the car, and experiencing pain in her legs. Reported islands of memories thereafter. PTA scores:

34. Patient CD: Westmead Selective Reminding Test, List A

35. Post-traumatic Amnesia: Patient AB Patient: AB Age: 23 years Date of Injury: 11/03/2007 Mechanism: Cyclist LOC: 5 minutes GCS at scene : 14/15 at 0422 hrs; confused and amnesic to events GCS on admission: 14/15 Day of Injury CT Brain Scan: Small haemorrhage in the grey/white junction left fronto-parietal lobe Medication: On admission - Morphine 2.5 mgs; Nil current medication Date of assessment: 16.03.2007 Last memory: 10/03/2007 2000hrs on way to party First memory: 12/03/2007, having lunch with his brother. Said he slept most of the next 4 days . Could not recall name of OT who saw him daily. PTA scores:

36. Patient AB: Westmead Selective Reminding Test, List A

37. Clinical aspects of attention: The patient who is inattentive and distractible • Focused attention • Selective attention • Sustained attention • Divided attention • Alternating attention

38. 2. Focused attention: The ability to respond to a specific situation/task/target by the direction of attention and effort to a particular target • Automatic and Conscious processing: the process where certain behaviours can be performed with little, if any focused attention (automatic), whereas other are highly sensitive to the allocation of attention (controlled, conscious or effortful). • Automatic processes direct behaviour that occurs without intention, involuntarily, without conscious awareness and without producing interference with ongoing activities • may be an innate property of the way in which sensory information is processed • can be produced by extended training (driving, typing) • relies on stimulus being presented in the environment • stopping at a red light • Automatic processes may rely on bottom-up processing (see previous model of Hodges, 2007) – individual not consciously aware of the process • e.g. amnesic patients can learn new tasks for which they have no conscious awareness

39. Conscious/controlled processing requiresfocused attention • directing controlled effort towards solutions • relies on information in memory and the task at hand • actively searching for a street • a chess player’s ability to come up with chess moves • Conscious processing may rely on top-down processing (Kolb & Whishaw, 2003) • Tests: All attention tests require focus particularly selective attention tests.

40. 3. Selective attention is the process where some informational elements are given priority over others • Highly related to focus • Differentiated to focused attention as the ability to respond ‘discretely to specific stimulus’ • Whereas focused attention refers to the capacity to ward off distractions to selective attention • Commonly referred to as concentration • Selective attention is directed by events in our environmental picture • A police car’s flashing lights in the distance – attention is likely to be pulled to the spatial location of the stimulus • Tests: Wisconsin Card Sorting Test - Number of categories, Stroop Neuropsychological Test, Ruff 2 and 7, Letter cancellation tasks, Test of Every day Attention (Map search, Telephone search)

41. youtube selective attention test

42. 4. Sustained attention or vigilance: The ability to attentionally persist with a task that may require continuous and repetitive activity over a relatively long period of time • Vulnerable to: • Fatigue • Conditions that support vigilance such as motivation • Most studies use vigilance paradigms i.e. where an infrequent occurrence of response is required (e.g. Continuous Performance Tests) • Neurological and psychiatric disturbances • Attention Deficit Hyperactivity Disorder • Schizophrenia • Depression • Anxiety (WAIS-IV - Digit Span Forward)

43. Tests: • Wisconsin Card Sorting Test – Failure to Maintain Set • Letter Cancellation Tasks • Connors Continuous Performance Tests • Ruff 2 and 7 • Test of Everyday Attention (lottery, elevator counting, elevator counting with reversal)

44. Letter Cancellation Tasks

45. 5. Divided Attention involves the ability to respond to more than one task at a time or to multiple elements or operations within a task, such as a complex task • In reality attention is always subject to division among a multitude of processes and potential stimuli • Divided attention is difficult because of interference created by competing stimuli • Capacity for divided attention is fairly limited • The greater the number of demanding informational sources the greater the marked decline of attentional performance • The quality of performance depends on how automatic the task is (i.e. how well integrated the task is into memory) • A typist may be able to talk or do other activities while they type if typing ability is very automatized

46. Tests: Trails Making Test - Trails B, WAIS-IV - Letter Number Sequencing, Symbol Digit Modalities Test, Test of Everyday Attention ( Telephone search while counting – dual task decrement) Trails B -Trail Making Test

47. 6. Alternating attention allows for shifts in focus and tasks • Specifically refers to the ability to rapidly shift attention • May be included with divided attention tasks • Tests: WAIS-IV-Digit Symbol/Coding, Symbol Search

48. Lesions causing attentional problems • Frequently impaired with frontal lobe lesions • Prefrontal cortex: responsible for voluntary initiation and sustaining attention, rapid alternation of attentional focus and shifting of attention • Dorsolateral frontal cortex: Initial of attentional focus • Orbitofrontal cortex: Sustaining of attentional focus • Thalamus: lesions may interfere with transmission of sensory input necessary for sustained or alternated attention • Limbic system (amygdala, cingulate gyrus and hippocampus): Saliency of increasing stimuli provides emotional tone facilitating attention and memory, involved with stimuli detection and appropriate alternation of attentional focus • A lesion affecting one part of the attentional system may affect more than one aspect of attention

49. Factors that impact on attention • Speed of information processing • Speed at which mental activity is performed • Delayed reaction time • Slowed verbal response • Slowed overall performance on timed tests in the absence of motor disability (e.g., WAIS-IV Block Design, Trails A of the Trail Making Test) • Interrelationship of speed of information processing and attention (divided) on tests (e.g. Symbol Digit Modalities Test) • Speed of motor responses • Associated with weakness, poor coordination • In testing may be seen in writing speed • Can be differentiated using Symbol Digit Modalities written and oral versions) • Tests: Grooved Pegboard, Purdue Pegboard