ch. 13 - subcortical dementias Flashcards
What are subcortical dementias?
Dementia syndromes where the primary pathology occurs in subcortical structures like white matter, axons, diencephalon, and basal ganglia.
What are some examples of subcortical dementias?
Parkinson’s disease, Huntington’s disease, Progressive Supranuclear Palsy (PSP), Creutzfeldt-Jakob disease
What makes Diffuse Lewy Body Disease (DLBD) unique?
It is a mixed dementia, having both cortical and subcortical features.
What subcortical structures are part of the basal ganglia?
- caudate nucleus
- putamen
- globus pallidus
- subthalamic nucleus
- substantia nigra
What is the primary cause of Parkinson’s disease?
Degeneration of dopamine-containing neurons in the substantia nigra pars compacta.
Name the four primary motor symptoms of Parkinson’s disease.
Gait instability, rigidity, tremor, and bradykinesia.
What percentage of substantia nigra cells must die before Parkinson’s symptoms appear?
75-80%
What are positive motor symptoms in Parkinson’s disease?
Resting tremor (pill-rolling), rigidity (cogwheeling), stooped posture, and impaired righting reflexes.
What are negative motor symptoms in Parkinson’s disease?
Bradykinesia, hypokinesia, gait disturbance (slow, festinating, freezing), masked facies, and slowed speech
What cognitive symptoms are seen in Parkinson’s disease?
- bradyphrenia (slow thinking)
- visuospatial deficits
- executive dysfuntion
- verbal fluency reduction
- memory impairment (poor recall, but better recognition)
What is the Hoeyn-Yahr Scale used for?
measuring the progression of Parkinson’s disease
What is the most effective medication for Parkinson’s disease?
L-dopa, a dopamine precursor.
What surgical treatments are used for Parkinson’s disease?
Pallidotomy, thalamotomy, and deep brain stimulation.
What genetic mutation causes Huntington’s disease?
A CAG repeat expansion in the IT15 gene on chromosome 4
What is the inheritance patten of Huntington’s disease?
Autosomal dominant - a child of an affected parent has a 50% chance of inheriting it
What are the three main symptom categories of Huntington’s disease?
- movement (chorea, bradykinesia, rigidity, dystonia)
- psychiatric (depression, psychosis, OCD)
- cognitive (slowing, memory impairment, executive dysfunction)
What makes PSP different from Parkinson’s disease?
PSP involves atrophy of multiple subcortical areas, severe executive dysfunction, and poor response to drug therapies.
What is a distinguishing eye movement symptom of PSP?
Downward gaze palsy.
What is a key postural symtpom of PSP?
backward falls (postural inability)
What are common cognitive symptoms of PSP?
- perseveration
- grasping reflex
- utilization behavior
- poor orientation
- slowed reasoning
- apathy
- inertia
What brain imaging sign is associated with PSP?
“penguin sign” (midbrain atrophy) on MRI
What type of disease is Creutzfeldt-Jakob disease?
A prion disease that causes rapid neurodegeneration.
What are hallmark motor symptoms of CJD?
Myoclonus (sudden jerks), extreme startle reflex, ataxia, and akinesia or akathisia.
What is the mean survival time after a CJD diagnosis?
4 months.
What variant of CJD is linked to mad cow disease?
variant CJD (vCJD)
What are the core symptoms of Dementia with Lewy Bodies (DLB)?
- dementia
- hallucinations
- fluctuating cognition
- Parkinsonism
What is a distinguishing cognitive feature of DLB?
Fluctuating cognition.
How does memory impairment in DLB compare to Alzheimer’s disease?
Mild or absent early on, unlike in Alzheimer’s where memory is severely impaired
What brain structures are affected by Lewy bodies?
- hippocampus
- amygdala
- cingulate
- neocortex
- brainstem
What is the main difference in memory impairment between cortical and subcortical dementias?
Cortical dementias affect recall and recognition; subcortical dementias mainly affect recall.
Which type of dementia is associated with aphasia?
cortical dementias
Which type of dementia is associated with slowed thinking and executive dysfunction?
Subcortical dementias.
