Session 9: Cortical Dysfunction Flashcards
What is Dementia?
- Progressive deterioration of higher cortical function.
- Dementia overall results in neuronal degeneration throughout the cortex which accounts for its wide variety of symptoms and clinical picture.
What is the presentation of dementia generally?
- Memory Deficit: struggle to learn new information, short term memory loss
- Behavioural: altered personality, disinhibition, labile emotions, wandering
- Physical: incontinence, reduced oral intake, difficulty swallowing
- Language disorder: anomic aphasia, difficulty understanding language
- Visuospatial disorder: unable to identify visual and spatial relationships between objects
- Apraxia: difficulty with motor planning resulting in inability to perform learned purposeful movements
What investigations are done for Dementia?
- Full history + MMSE (assess the degree of cognitive impairment and rate of progression of disease)
- Full neurological examination
- Blood Test
- CT/MRI head (rule out other causes such as tumour and check for features of dementia)
- Memory Clinic follow up
What are features of dementia on CT/MRI head?
- Dilatation
- Generalised Atrophy
- Hippocampal Atrophy
What does a CAM Score assess?
- Acute change or fluctuating mental status
- Altered consciousness – hypo (refusing food or drink) /hyperactive (rambling)
- Inattention
- Disorganised thinking
What CAM score describe delirium?
Combination of 1+2 and either 3 or 4 shows Delirium
What are the common non reversible causes of Dementia?
- Alzheimer’s Disease (commonest cause of dementia. Account for 60-80% of cases)
- Dementia with Lewy-Bodies
- Fronto-temporal Dementia
- Vascular Dementia
- Crutzfeldt-Jacob disease
What are the common reversible causes of Dementia?
- Depression
- Trauma
- Vitamin Deficiency
- Alcohol
- Thyroid Disorder
What is the macroscopic pathology of Alzheimer’s disease?
-Loss of cortical and subcortical white matter causing gyri atrophy with narrow gyri and wide sulci along with mark ventricular dilation reflecting loss of white matter
What is the microscopic pathology of Alzheimers disease?
Formation of
- Amyloid-beta plaques (proteolytic break down from amyloid precursor protein)
- Neurofibrillary tangles
Causes degeneration
What is the Clinical picture of Alzheimer’s disease?
- Starts with minor memory loss which may not be initially noticed or impact on their life
- Progression to development of problems with visuospatial awareness and apraxia making it difficult to carry out daily tasks such as getting dressed and cooking.
- In Alzheimer’s disease, there is a slowly linear decline over many years with no recovery, until the patient is incontinent, unable to recognize loved ones and loses a sense of self
What is the microcopid pathology of Dementia with Lewy bodies?
-Lewy Bodies in the cortex and Substantia nigra
What is the clinical picture of Dementia with Lewy bodies?
- Substantial fluctuating decline in cognition over time which may improve for a while and then drop back down.
- Parkinson’s symptoms (Bradykinesia, Tremor, Rigidity, Postural instability resulting in falls, Visual hallucination)
- Unresponsive to dopamine agonist treatment in the same way Parkinson’s disease would be
What is the pathology involved in Vascular Dementia?
- Arteriosclerosis of the blood vessels supplying the brain
- Diffuse small vessel disease vs infarcts (large vessel disease)
What is the clinical picture in Vascular Dementia?
- Abrupt, step wise decline in cognitive function related to vascular episode.
- Following insult, the patient will retain that current level of cognition until another episode occurs.
