Cognitive Disorders

Question 1

What is AD?

Answer 1

-Neurodegenerative disorder- neuronal degeneration and loss
-Incidence age-related (exponential)- 0.5% per year in 65-70 age group, 8% per year above 85
-Progressive, typically over years (live 3-11 years after diagnosis)

Question 2

Describe AD pathophysiology and investigation

Answer 2

-MMSE
=Impaired recall
=Nominal dysphagia
=Disorientation

-Association with abnormally folded protein in CSF
=Abeta: senile plaques
=Tau: neurofibrillary tangles

-MRI: generalised atrophy with medial temporal lobe and parietal predominance
-Beginning in specific neuronal functional areas
=Typically beginning in Medial Temporal Lobes
=Typically Anterograde Episodic Memory Loss

Question 3

Causes and risk factors of AD

Answer 3

-Some cases Genetic (familial AD)
=Genetic factors involved in non-familial cases
-Age
-Vascular Risk Factors
-Low educational attainment

Question 4

Symptoms and signs of AD

Answer 4

-Begins with memory problems: loss of episodic memory including recent events, repeated questioning, difficulty learning new information
-Visuo-spatial, language problems develop (nominal dysphasia)
-Personality/ social function often relatively persevered in early stages
=Apathy
=Mood changes
=Difficulty with executive function

Question 5

What is Vascular dementia

Answer 5

-Explained by vascular causes in absence of other explanatory pathology, but AD can co-exist
-Second most common specific cause of dementia
-Prevalence increases with age: 0.4% in 60-64 age group, 4% per year above 85

Question 6

Pathophysiology and presentation of vascular dementia

Answer 6

-Multi-Infarct dementia: cortical infarcts associated with large vessel disease
=stepwise course with abrupt increases in severity of symptoms
-Strategic Infarcts: Subcortical ischaemic problems
[associated with small vessel disease]= gait and attention problems with change in personality
=insidious onset, gradual progression

-Focal neurological signs (hemiparesis or visual field defects)
-History of strokes
-Difficulty solving problems
-Apathy
-Disinhibition
-Seizures

Question 7

Cortical Lewy body disease as a clinical syndrome

Answer 7

-Dementia
=Fluctuating attention/cognitive impairment
=Memory not necessarily affected in early stages

-Visual hallucinations (recurrent)
-REM sleep behaviour disorder

-Increased sensitivity to drug-induced Parkinsonism
Parkinsonian features (bradykinesia, rest tremor, rigidity)

Question 8

Investigation and management of Cortical Lewy Body disease

Answer 8

-Clinical, SPECT: Widespread cortical Lewy Bodies

-Donepezil or rivastigmine are recommended first line.
-Galantamine is an option if donepezil and rivastigmine are not tolerated.
-Risperidone and haloperidol= antipsychotics
-Memantine
-Neuroleptics should be avoided

Question 9

What is FTLD and FTD?

Answer 9

-Clinically and neuropathologically a heterogenous group
-Linked by main involvement of frontal & temporal lobes
-Presenting with a fronto-temporal dementia syndrome

-FTLD: Fronto-Temporal Lobar Degeneration
=Essentially a pathological term

-FTD: Fronto-Temporal Dementia
=Essentially a clinical syndromic term (pattern of cognitive impairment), onset before 65
=Including association with MND
=Behavioural (loss of empathy, apathy, disordered social, sexual disinhibition) and language (progressive aphasia) variants

Question 10

Other cognitive disorders/ dementias

Answer 10

-Parkinson’s disease dementia
-Huntington’s Disease (frontal-type cognitive impairment with dysexecutive problem and motor disorder with choreiform movements)
-HIV-associated Dementia
-CJD (BSE contamination of diet)

Question 11

Management of AD

Answer 11

-Acetylcholinesterase inhibitors (donepezil, galantamine, rivastigmine)
-Memantine (NMDA receptor antagonist- 2nd line, moderate or severe)
-Antidepressants
-Antipsychotics

Question 12

Investigation of vascular dementia

Answer 12

CT or MRI= cerebrovascular lesion (infarcts), AF may be present

Question 13

Management of vascular dementia

Answer 13

AChE inhibitors or memantine are options if the person has suspected comorbid Alzheimer’s disease, Parkinson’s disease dementia, or dementia with Lewy bodies, antiplatelets, lifestyle modification

Question 14

Investigation and management of fronto-temporal dementia

Answer 14

-Formal cognitive testing (behaviour, executive functioning, poor emotional processing)
-MRI= focal atrophy in frontal and/or anterior temporal lobes (left-right asymmetry)

-Management: Not be offered AChE inhibitors or memantine, supportive care

Question 15

Presentation of normal pressure hydrocephalus

Answer 15

-Intermittent rises in CSF pressure, particularly at night.
-It is described in old age as being associated with a triad of gait apraxia (Parkinson’s disease), dementia, bradyphenia, and urinary incontinence.

Question 16

Investigation of normal pressure hydrocephalus

Answer 16

Hydrocephalus with ventriculomegaly in the absence of, or out of proportion to, sulcal enlargement (CT/MRI).