Unit 16 Neuropsychological Syndromes PDF

Frontal lobe syndrome Temporal lobe syndrome Parietal lobe syndrome Occipital lobe syndrome Subcortical syndrome Disconnection syndrome Questions Personality changes due to brain lesions Frontal lobe dysfunctions with suitable diagrams Types of aphasia and...

Frontal lobe syndrome Temporal lobe syndrome Parietal lobe syndrome Occipital lobe syndrome Subcortical syndrome Disconnection syndrome Questions Personality changes due to brain lesions Frontal lobe dysfunctions with suitable diagrams Types of aphasia and their assessment Disconnection syndrome Temporal lobe anatomy and syndromes Parietal lobe syndromes  Frontal lobe Anatomy and syndromes Frontal lobe is the primary component of higher mental functions. It is separated from the parietal lobe by Central sulcus (posterior) and temporal lobe by sylvian fissures (inferior). Damage to the frontal lobe can lead to changes in cognition, movement, production of speech and personality. Testing for Frontal lobe function : Wisconsin Card Sorting Test abstract thinking and set shifting; L>R Trail Making visuo-motor track, conceptualization, set shift Stroop Color & Word Test attention, shift sets; L>R Tower of London Test planning Motor cortex: Responsible for voluntary movement. Directs muscles in various parts of the body. Contra-lateral. Primary motor cortex Control execution of movement Motor cortex dysfunction leads to disturbance in movement and verbal fluency. Premotor cortex Preparation for movement: Spatial guidance -Spontaneous movement can get affected Sensory guidance -Loss of pincer grasp. Use whole movements -Gegenhalten: involuntary resistance Supplementary motor Initiating movements -Verbal fluency: Loss of spontaneous speech, word area Procedural memory finding difficulties, long pauses. Bi-manual coordination (two sides) -Mutism Frontal eye lids Saccadic eye movements Deviation of movements Broca’s area Broadmann 44 Broca’s Aphasia Speech production Inability to speak fluently using grammar and finding appropriate words despite the presence of normal comprehension and intact vocal mechanisms. Aprosodia: Flat unmodulated speaking voice, right Frontal lobe involvement Prefrontal cortexExecutive function: Supervises other regions and functions such as perception, memory,emotion etc Impairment in attention, creativity, judgement, abstraction, concept formation, planning and organization and problem solving. Orbitofrontal cortex Base of frontal lobe Bilateral damage: Personality change but cognitive Personality, emotions, sexual abilities remain intact. Eg: Phineas gage. behavior and social behavior. Disinhibition, Impulsivity, Emotional lability, Hyperkinesis Unilateral damage: Pseudodepression: Left frontal damage Depressive symptoms present Dorsomedial PFC Motivation: Initiation of activity Akinesia Mutism Apathy Dorsolateral PFC Executive function Deficits in EF Working memory Inattention Attention Abulia  Frontal lobe syndromes Phineas Gage Excellent physical recovery Dramatic personality change: stubborn, lacked in consideration for others, had profane speech, failed to execute his plans Frontotemporal dementia Neurodegenerative disease that selectively attacks the frontal and anterior temporal regions The initial symptoms of FTLD often involve changes in personality, behavior, affective symptoms, and language function. Most patients with FTLD begin with language (left-sided cases) or emotional (right-sided cases) changes. The lack of insight seen in FTLD,leads patients to ignore or deny their deficits. The core features of FTLD as defined by the Neary criteria (Neary et al., 1998) are early decline in social and personal conduct, emotional blunting, and loss of insight. Behavior problems such as overeating, repetitive compulsive behaviors, apathy, and agitation and disinhibition Frontal lobe epilepsy Patients with frontal lobe seizures may present with a clear epileptic syndrome or with unusual behavioral or motor manifestations that are not immediately recognizable as seizures. May be associated with facial grimacing, vocalization, or speech arrest. Seizures frequently preceded by a somatosensory aura. Complex behavioral events characterized by motor agitation and gestural automatisms; viscerosensory symptoms and strong emotional feelings often described; motor activity and may involve pelvic thrusting, pedaling, or thrashing, often accompanied by vocalizations or laughter/crying; seizures often bizarre and may be diagnosed incorrectly as psychogenic Broca’s aphasia Sufferers of this form of aphasia exhibit the common problem of agrammatism. For them, speech is difficult to initiate, non-fluent, labored, and halting. Similarly, writing is difficult as well. Comprehension is generally preserved Psychiatric conditions Schizophrenia & frontal lobe:Some schizophrenic symptoms are found in frontal lobe disorder, in particular that involving dorsolateral prefrontal cortex. Symptoms included are those of affective changes, impaired motivation, poor insight. Depression & Frontal lobe: It has been found that the right frontal lobe demonstrated increased activity in response to negative moods whereas left frontal activity decreases. Not only reductions in left frontal activity, but injuries to the left frontal lobe have been consistently associated with depression, "psycho-motor" retardation, apathy, irritability, and blunted mental functioning. Agraphia Loss of ability to write without any sensory or motor dysfunctions  Temporal lobe Anatomy and syndromes Largest in man Approximately 17% of volume Bounded by sylvian fissure separating it from frontal lobe, it blends with parietal lobe and occipital lobe(Lateral temporo parietal line and occipito-temporo line) Covers a lot of important areas Superior Primary auditory L.Auditory cortex: Wernicke’s aphasia temporal lobe area (BA:41): Understanding words Heschl’s gyrus (written/spoken) BA:42 R.Auditory cortex: Melody, pitch Inability to recognize melodies, prosodies Recognition of speech Wernicke’s area L. temporal lobe Middle Hippocampus: Declarative memory, LTM Anterograde amnesia. Case of HM Temporal Lobe Each side of TL Perihinal, Parahippocampal: memory for entorhinal and routes parahippocampal cortices Uncus Olfactory functions Fornix Exact function not know Lesion cause memory loss Amygdala Emotions Lesions cause lack of fear and anger Fear memories Kluver Bucy syndrome: Hyperorality, Input: Hippocampus, Hypersexuality and Hypermetamorphosis Output:PFC Visual agnosia Inferior Fusiform gyrus Visual processing: Prosopagnosia: Face recognition temporal lobe Face perception difficulty Color formation Number recognition Disturbance in organization and categorization  Other temporal lobe syndromes Personality changes Over Religiosity Paranoia Egocentricity Aggression Increased or decreased sexual behaviour Dyslexia (angular gyrus is damaged) Temporal lobe damage principal Disturbance of auditory sensation and perception symptoms Disorders of visual perception Imapired organization and categorization of verbal material Disturbance of language comprehension Impaired LTM Changes in personality, affect and sexual behaviour  Occipital lobe Anatomy and syndromes Primary visual Recognition of words, face-All visual functions Hemianopia: Blindness in one cortex entire visual field Voluntarily focus vision Visual agnosia Visual hallucinations Prosopagnosia Left lesions: Visual agnosia Colour agnosia Alexia Right lesions: Visual hallucinations Visual orientation difficulties Balint’s syndrome: Inability to perceive the totality of a scene Optic ataxia: hand eye coordination Optic apraxia: Inability to scan voluntarily Visual perception difficulties: Macropsia Micropsia Pelopsia (closer) Teleopsia (Further distance) Agnosia: The inability to recognize objects or their pictorial representations or the inability to draw or copy them. One group of these functions involves color perception. Colour Agnosia The patient may be able to discriminate color accurately by simple matching but may be unable to link appropriate colors to objects or to sort colors into groups. Apperceptive Agnosia In the simplest case, patients are simply unable to recognize, copy, or match simple shapes. Simultagnosia Patients can perceive the basic shape of an object, but they are unable to perceive more than one object at a time. Thus, if two objects are presented together, only one is perceived. Prosopagnosia Patients with facial agnosia cannot recognize any previously known faces, including their own as seen in a mirror or photograph. Alexia An inability to read has often been seen as the complementary symptom to facial- recognition deficits. Visuospatial Agnosia Topographical disorientation—the inability to find one’s way around familiar environments such as one’s neighborhood. Right medial occipitotemporal region, including the fusiform and lingual gyri. Tests: Finger agnosia Spatial Agnosia (Drawing) Agnosia for objects (identification) Agnosia for pictures Colour identification Simultagnosia Prosopagnosia Ishihara’s colour blindness test Visual field charting  Parietal lobe Anatomy and syndromes Parietal has a somatosensory primary cortex. It also acts as an association cortex, receiving projections from other lobes and integrating funcitons such as visual,auditory and somatosensory. Bounded by central sulcus, sylvian fissure and parieto-occipital sulcus Anatomical orientation Post central gyrus Primary sensory cortex Superior parietal lobule Inferior parietal lobule Supramarginal gyrus Angular gyrus Lateralization Right parietal lobe Spatial attention and spatial Lesions: relationships Hemineglect Relation to our body parts and Constructional apraxia objects in space Dressing apraxia Topographic disorientation Left parietal lobe Calculation Lesions: Praxis Acalculia Visual language Apraxia Comprehending left and right Alexia Gerstmann syndrome  Syndromes in detail Features Site Tests Hemineglect Patients ignore Right inferior parietal Self care activities i) one half of their body or lobe/Temporo parietal for personal ii)the external space. junction neglect: Washing face In personal neglect patients ignore the contra-lateral side of their body.Personal neglect Clock drawing may lead to anosognosia: patient’s inability to recognise the presence of somatic dysfunction. Cancellation tasks Patients with neglect to external space may Line Bisection test ignore objects in one half of their space or a lateralized representational neglect Neglect is for the left hemifield since LH controls right hemifield Constructional Inability to copy three dimensional drawings or Right hemispheric Necker Cube Apraxia construct a visually represented image using lesions: Lack of accurate blocks. spatial relations and poor House drawing joining. Term apraxia was first used by Heymann block designs Steinthal in 1871 for a loss of motor skills. Left hemispheric lesions: Oversimplification of overlapping Praxis: Neurological process of planning what to figures and perseveration geometric shapes do and how to do it. suggesting planning deficits. Apraxia: Inability to perform skilled actions on verbal command Before testing for apraxia make sure inability to perform skilled purposeful movements is not caused by sensory loss or by more elemental motor disorders like motor weakness, rigidity or tremors. Dressing Patients find it difficult to orient themselves while Can be tested by Apraxia dressing asking a patient to wear a jacket that is Ideational or ideomotor apraxia have to be ruled turned inside out. out first.Automatic, spontaneous capacity for dressing is lost. Topographical Egocentric: Localising objects with respect to disorientation one’s bodies Heading disorientation: Difficult to tell how to go to some place Map drawing tasks Anterograde disorientation Landmark agnosia Parahippocampal gyrus Conceptual Fail to describe the function of a tool or point to Apraxia the tool when the function is described by the examiner. There can be i)Omission: Patient neglects an important step like putting paste on toothbrush. ii)Misuse: Patient uses a key as a hammer iii) Mislocation: Patient holding a pen upside down Ideational Patients have difficulty in sequencing the acts in apraxia the proper order. These patients can recognise a single object well and name them and describe its use correctly. Sequentially arranging a series of action pictures can also be difficult. Ideomotor Patient knows what to do but not how to do it apraxia Speech Apraxia Slow, dysprosodic and effortful speech. They may struggle with tongue, lips and jaw when they try to communicate. Bucco-facial Difficulty is doing non speech related movements apraxia like sucking, blowing Alexia Acquired deficit in the ability to interpret written language severe (not necessarily total) disturbance of both reading and writing preserved ability to copy written language, but in slavish and non-comprehended manner loss of ability to name letters, to comprehend spelled words, or to read out loud Aculcia i) Anarithmia:Patients have loss of numerical concepts, defects in using rules in calculation and deficits in understanding numerical signs. i)Alexic calculia: Produces an inability to read written numbers and numerical signs. ii)Spatial acalculiaInability to align numbers in columns preventing patients from performing written arithmetical operations Gerstman’s Finger agnosia: Inability to distinguish, name, or Extension of lesion syndrome recognize fingers not only in the patient’s own towards supra-marginal hand but also in the examiner's hand or in a gyrus causes this drawing. agraphia. Right-left disorientation: Right-left of one’s own body, and of others Agraphia: Apraxic agraphia rather than alexia with agraphia.  Anarithimia Disconnection Syndrome Damage to white matter axons of communication pathways leads to number to disorders/symptoms Norman Geschwind Interhemispheric Corpus callosum Left hand apraxia disconnection:Commissural Left hand agraphia fibres Pure alexia Intrahemispheric Arcuate fasciculus Conduction aphasia disconnection:Association fibres Ideomotor aphasia Prosopagnosia Visual object agnosia Projection Corticospinal tract Locked in syndrome Hemiparesis Aphasia Dementia TBI Stroke PD HD Epilepsy