behavioral cortical dementia Flashcards
Recent or short-term memory
ability to recall information after several minutes of retention
remote or long term memory
ability to recall past events hours, weeks or even years afterward
Memory function depends on bilateral circuits involving what?
temporal lobe and thalamus specifically: 1. hippocampus 2. fornix 3. mamillary body 4. anterior thalamic nucleus
What is amnesia in Wernicke-Korsakoff syndrome caused by?
bilateral thalamic and mammillary body lesions
-thiamine deficiency
What causes amnesia in cardiac arrest survivors or herpes simplex encephalitis?
bilateral hippocampal lesions
cardiac arrest survivors=anoxia
Apraxia
the inability to conceptualize and perform a skilled, learned, motor act on command
unable to do action when commanded but able to do it at other times
What is gait apraxia and what lesion is involved?
inability to walk on command
-prefrontal lobe lesion
Constructional apraxia
Lesion?
patient cannot draw a house or copy a simple drawing
-parietal lobe
dressing apraxia
patient can not dress
-parietal
agnosia
impaired recognition of perceived stimuli caused by lesions of sensory association cortex
prefrontal or frontal lobe syndrome
- listless, apathetic, unconcerned, with poor hygiene and incontinence, poor judgment, executive functions impaired , lacks creativity
- motor preservation (aimless repetition of simple motor acts)
- gegenhalten or paratonia
- frontal lobe release signs
what is gegenhalten or paratonia
increased limb tone or resistance is felt as the examiner moves the patient’s limb more rapidly
What are frontal lobe release signs
previously normal findings in infancy
-suck, snout, root, plantar grasp
Syndrome of temporal lobes
- amnesia-bilateral hippocampal lesions
- cortical deafness-bilateral auditory cortex lesion
- kluver-bucy-limbic
- unilateral lesion of the superior posterior dominant temporal lobe–wernicke’s aphasia
Parietal lobe syndromes
- sensory cortex
a. astereognosis
b. agraphesthesia - lesions of the nondominant parietal lobe-impairment of spatial relationship between the body and its surroundings
a. anosognosia - dressing apraxia or constructional apraxia
- supramarginal or angular gyrus of the dominant parietal lobe
a. Gerstmann’s syndrome
anosognoisa
unaware of his or her hemiparesis
- denial of half of body or “hemispatial neglect”
- may neglect to groom left side of body
Gerstmann’s syndrome
- agraphia
- right-left disorientation
- dyscalculia
- finger agnosia
occipital lobe syndrome
- bilateral visual cortex to produce cortical blindness
- sometimes accompanied by a denial or unawareness of visual loss-Anton’s syndrome - bilateral temporo-occipital lesions
- visual agnosia (prosopagnosia ) - dominant temporo-occipital lobe
- color anomia
acute confusional state or delerium
fluctuating levels of attention and motor activity
- tremulous, asterixis, myoclonus, ataxia, dysarthria
- could be from viral encephalitis or post-ictal state
- kidney failure, metabolic abnormalities, or meds or drugs
- hours to days
dementia
diffuse impairment of cortical function which usually evolves less abruptly or over a longer period of months to years and impedes the daily function of patients
- memory loss
- changes in judgment and intellect
- aphasia, apraxia, agnosia
- personality changes
What could be causing dementia?
- alcohol or drugs, taking meds incorrectly, lack of vitamins
- vascular cause-stepwise, focal neurological deficits
- depression
- hereditary
- chronic, subdural hematomas, brain tumor, abscesses, multiple infarctions, hemorrhages, hydrocephalus
- chronic meningitis-fever
- HIV-in younger patients
- thyroid
- alzheimer’s
What is the evaluation for dementia?
standardized cognitive tests-MMSE
MRI
Alzheimer’s disease
most common type of dementia in the US
- gradual destruction of specific types of neurons by metabolic changes
- memory loss-medial temporal lobes and hippocampi
What is the pathologic hallmark of alzheimer’s
- accumulation of b-amyloid in the form of extracellular amyloid or senile cortical plaques
- coded on chromosome 21 - beta amyloid deposition leads to intraneuronal neurofibrillary tangles
- consisting microtubule-associated tau proteins - cell death especially cholinergic neurons
What are typical signs of vascular dementia? (from multiple bilateral cerebral ischemic infarcts)
focal, asymmetrical neurological deficits such as hemiparesis, hemisensory loss, hemianopia, or cerebellar signs
What does a PET scan utilizing Pittsburgh compound B, which selectively binds to B-amyloid show?
the typical alzheimer’s disease uptake in the prefrontal, temporal and sensory association cortex
-sparing the occipital and primary sensorimotor cortex
What can slow down AD?
central acetylcholinesterase inhibitors 1. donepezil 2. rivastigmine 3. galantamine later: 1. memantine-NMDA antagonist -opposes the excitotoxic effects of glutamate on the CNS
(die of aspiration pneumonia, pulmonary emboli and malnutrition)
