Subcortical Disorders Thomas G. Bowers, Ph.D.. Karen Quinland Case.
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Transcript of Subcortical Disorders Thomas G. Bowers, Ph.D.. Karen Quinland Case.
Pathology sample Pathology sample indicated prominent indicated prominent subcortical damagesubcortical damage
Especially in the Especially in the thalamusthalamus
However, there is also However, there is also evidence of evidence of considerable cortical considerable cortical damagedamage
835 grams835 grams
Karen QuinlandKaren Quinland
Anthony Bland CaseAnthony Bland Case
At age 18 suffered cerebral anoxia At age 18 suffered cerebral anoxia secondary to crushing injuries.secondary to crushing injuries.
Brain weighed 1007 grams (average Brain weighed 1007 grams (average ~1300 grams).~1300 grams).
Narrowed gyri, cerebral atrophyNarrowed gyri, cerebral atrophy
Cingulate Gyrus
Hippocampus
FornixMamimilary
Bodies
Hypothalamus
AnteriorThalamus
The Circuit of Papez: An Early Model of Neural Substrates of Emotion
White Matter in Cognition White Matter in Cognition
Three types of white matter fibersThree types of white matter fibers– 1. Association fibers1. Association fibers
Connect different regionsConnect different regions
– 2. Commissural fibers 2. Commissural fibers Connect corresponding hemispheresConnect corresponding hemispheres
– 3. Projection fibers3. Projection fibersUp-downUp-down
White Matter Changes in AgingWhite Matter Changes in Aging
LeukoaraisosisLeukoaraisosis– No mass effect, does not enhanceNo mass effect, does not enhance
Periventricular sourcesPeriventricular sources– Glio cell lossGlio cell loss– Small vessel infarctSmall vessel infarct– ArteriosclerosisArteriosclerosis– Infection/inflammationInfection/inflammation– DemyelinationDemyelination– VasculitidesVasculitides
MRI Characteristics MRI Characteristics
Patchy, diffuse hyperdensityPatchy, diffuse hyperdensity Pencil thin linesPencil thin lines
Cognitive CharacteristicsCognitive Characteristics
Attentional processesAttentional processes Working memory (not span)Working memory (not span) Encoding and retrievalEncoding and retrieval Spatial rotationSpatial rotation Discourse comprehensionDiscourse comprehension
Disease ProcessesDisease Processes
1. Infection and autoimmune 1. Infection and autoimmune disordersdisorders
2. Vasculitis2. Vasculitis 3. Multiple sclerosis (MS)3. Multiple sclerosis (MS) 4. HIV4. HIV 5. Neurotoxic 5. Neurotoxic 6. Gliomas6. Gliomas
Infection and AutoimmuneInfection and Autoimmune
Systemic lupusSystemic lupus– 1. cognitive impairment fluctuates1. cognitive impairment fluctuates– 2. Can appear manic2. Can appear manic– 3. Deficits in retrieval, delayed recall3. Deficits in retrieval, delayed recall– 4. Problems in cognitive speed and 4. Problems in cognitive speed and
flexibilityflexibility VasculitisVasculitis
– Inflammation of blood vessels Inflammation of blood vessels
Multiple Sclerosis (MS)Multiple Sclerosis (MS)
Variable lesions in white matter and Variable lesions in white matter and corpus callosumcorpus callosum
Many different clinical coursesMany different clinical courses Periventricular changesPeriventricular changes Very impaired on divided attention Very impaired on divided attention
taskstasks
Multiple Sclerosis (MS)Multiple Sclerosis (MS)
Problems in reading comprehension, Problems in reading comprehension, visual memory retrieval, verbal visual memory retrieval, verbal memory, motor slowingmemory, motor slowing
Executive dysfunction Executive dysfunction – Negative recency effect noted Negative recency effect noted – Possible loss of temporal codesPossible loss of temporal codes
Do well on STM tasksDo well on STM tasks
HIVHIV
Patchy white matter changesPatchy white matter changes Atrophy in later stagesAtrophy in later stages Prodromal stage (up to 2 years)Prodromal stage (up to 2 years)
– May be only mildly symptomaticMay be only mildly symptomatic Attention deficitsAttention deficits Memory deficitsMemory deficits Slowed processingSlowed processing Impaired conceptual processingImpaired conceptual processing Impaired self monitoringImpaired self monitoring
Neurotoxic InjuryNeurotoxic Injury
SolventsSolvents– Acute and late developing effectsAcute and late developing effects– Headaches, dizziness, mild depression, Headaches, dizziness, mild depression,
impaired behavioral controlimpaired behavioral control– Problems in attention, self-monitoringProblems in attention, self-monitoring
Chronic CO exposureChronic CO exposure
Ischemic Vascular DementiaIschemic Vascular Dementia
LeukencephalopathyLeukencephalopathy– 1. Arteriosclerosis1. Arteriosclerosis– 2. Spasm2. Spasm– 3. Transitant ischemia3. Transitant ischemia
Severity related to brain tissue lossSeverity related to brain tissue loss– 1. decreased processing efficiency1. decreased processing efficiency– 2. retrieval failures2. retrieval failures– 3. problems with semantic access3. problems with semantic access– 4. spatial rotation impairment4. spatial rotation impairment– 5. selective executive dysfunction5. selective executive dysfunction
Progressive gliosisProgressive gliosis
Also progressive subcortical gliosisAlso progressive subcortical gliosis Often may cause frontal problemsOften may cause frontal problems
Frontal Lobe DementiaFrontal Lobe Dementia
Changes in eating habitsChanges in eating habits Sleep disturbanceSleep disturbance Somatic complaintsSomatic complaints Mute, empty behaviorsMute, empty behaviors Not amnesic, but fail to use memoryNot amnesic, but fail to use memory
Diffuse Axonal InjuryDiffuse Axonal Injury
Acceleration/deceleration rotational Acceleration/deceleration rotational forcesforces
Yields shearingYields shearing Mechanical forces lead to neuronal Mechanical forces lead to neuronal
segmentation, small hemorrhages, segmentation, small hemorrhages, edemaedema
Diffuse Axonal InjuryDiffuse Axonal Injury
Povlishock workPovlishock work– Shearing due to axonal swelling, not Shearing due to axonal swelling, not
mechanical tearingmechanical tearing– Wallerian degeneration ensuesWallerian degeneration ensues– Evolves in 6-24 hoursEvolves in 6-24 hours– Affects more distal axonsAffects more distal axons– No disruption of myelin, of cellNo disruption of myelin, of cell– ““retraction ball” forms retraction ball” forms
Radiation Injury to BrainRadiation Injury to Brain
Acute effectsAcute effects– Edema, elevated ICPEdema, elevated ICP– Early delayed effects, inhibition f myelin Early delayed effects, inhibition f myelin
synthesis synthesis – Late delayed effects, damage to myelin, Late delayed effects, damage to myelin,
vascular damage, immune processesvascular damage, immune processes– Nausea, headache, drowsiness, anorexiaNausea, headache, drowsiness, anorexia– Verbal semantic LTM retrieval problemsVerbal semantic LTM retrieval problems– Memory/motor dysfunctionMemory/motor dysfunction
Radiation Injury to BrainRadiation Injury to Brain
Dementia can occur and lead to Dementia can occur and lead to deathdeath
More likely memory decline, gradual More likely memory decline, gradual recoveryrecovery
SummarySummary
White matter difficulty yields White matter difficulty yields problems in complex cognitive problems in complex cognitive processingprocessing– Problems in processing speedProblems in processing speed– Difficulties with high cognitive demandsDifficulties with high cognitive demands– Problems with complex stimulus Problems with complex stimulus
demands, as rotationsdemands, as rotations– Problems with attentional monitoringProblems with attentional monitoring– Impairment with multiple associations Impairment with multiple associations