Cognitive Impairment in Adults - Neurodegenerative, Alcohol, HIV, Autoimmune, Malignancy, Epilepsy, Depression+Anxiety

Question 1

Possible causes of neurodegenerative conditions in younger patients

Answer 1

Depression, anxiety

Neoplastic, paraneoplastic

Iatrogenic (medication), general medical illness

TBI

HIV, CJD, infections

AI, inflammatory - MS, sarcoid, vasculitis

Sleep apnoea - tiredness, short term memory issues but can be managed with airway support

Epilepsy

Question 2

Approach to the clincal assessment

Answer 2

Patient + collateral
-AD - can respond in a socially competence way but have difficulties with short term memory

Timescale

Normal memory failure - cognitively overloaded, walking into a room and forgetting why you’re there

Any additional neurological symptoms?
Alcohol, drug use

Question 3

Neurodegenerative causes of cognitive impairment

• AD
• non amnestic forms
• FTL degeneration
• dementia with Lewy Bodies
• vascular dementia

Answer 3

AD - good social facade but poor memory recall
-can test this by cueing (helps in anxiety, not in AD)

Non amnestic AD - more common in younger patients but diagnosis often missed

• posterior cortical atrophy - visual-spatial judgement loss
• logopenic aphasia - language, communication affected first
• frontal variant - behaviour and executive function affected

FTL degeneration - group of conditions with misfolded protein aggregates
Behavioural variant - aggregates in frontal
-behaviour and executive function affected
-early loss of empathy, emotional reactivity
-perseverative, stereotyped, compulsive behaviour
-sweet foods, dietary change
-memory generally intact
Semantic variant - aggregates in temporal
-poor single word knowledge
-understanding and speech production unaffected
Progressive nonfluent aphasia -aggregates in temporal
-difficulty in speech production, agrammatism
-comprehension intact

DLB - fluctuating cognitive impairment

• PDlike but dominated by cognitive impairment
• RBD, visual hallucinations of animals, children

Vascular dementia - stepwise cognitive decline

• true diagnosis is tricky as age related vascular changes are normal
• overlap with AD

Question 4

Alcohol use and cognitive impairment

Answer 4

Gradual harm from long term use => alcohol neurotoxicity, hepatic encephalopathy, seizures

Malnutrition => thiamine deficiency

• WE - ataxia, nystagmus, acute encephalopathy
• KS - anterograde, retrograde memory impairment

Question 5

HIV

Answer 5

HAND - spectrum of disorders from asymptomatic neurocognitive impairment to HIV associated dementia

Prevalence has decreased due to HAART

HIV test for all cognitive impairment presentations

Question 6

Autoimmune, paraneoplastic neurological syndromes

Answer 6

MS, AB from past infection, AB to tumour
Often present with other symptoms

Can assess this with autoAB

Cognitive impairment responsive to immunosuppresion/tumour removal

Question 7

Epilepsy

Answer 7

Cognitive impairment common in chronic epilepsy
Seizure may present as cognitive impairment
AED side effects include dementia

Manage/optimize epilepsy treatment

Question 8

Systemic illness, medications

Answer 8

Side effects of polypharmacy particularly in older adults - cognitive impairment
=> medication optimisation

Depression, anxiety - treatable causes of cognitive impairment

Question 9

Investigations

• what you want to do
• others you may consider

Answer 9

FBC, U&E, LFT, CRP, TFT, B12, folate, HIV, treponemal serology - a variety of systemic causes can cause cognitive impairment

Other investigations are based on the history

• EEG - seizure
• overnight pulse oximetry - sleep apnoea

Structural brain MRI - scan may be normal in early disease

• AD - hippocampal atrophy, widened sulci, narrow gyri
• FTD - loss of temporal/frontal lobe
• prions - illumination of frontal lobe => v rapid progression of dementia

DATscan - PD
FDGPET - nervous function assessment to see where the problem is
Amyloid imaging - does not tell you how bad the problem is, just that the amyloid is present

CSF - assess for inflammatory, other causes of cognitive impairment

• MCS, protein, glucose, cytology
• oligoclonals, AB, biomarkers

Biopsy - rarely done but considered if declining rapidly, and clinical suspicion

Genetics - esp early onset
-AD - APP, PSN1,2

Question 10

Management

Answer 10

Manage any conditions that cause cognitive impairment

Non drug therapy - aims to maintain cognitive function

• cognitive stimulation
• keeping active, exercise
• optimise medical conditions, both physical and mental

Drug therapy
-depends on the type of cognitive impairment