Dementia

Diagnosis:

Neuropsychological/Psychometric testing
Or Clinical features
The underlying etiology is determined by a combination of clinical features, neuropsychological testing, imaging and laboratory testing
 

Clinical features:

This is an acquired persistent disorder where there is an impairment of the content of consciousness (intellectual function) with compromise in at least 2, e.g.:

  • Memory
  • Language i.e. aphasia
  • Visuospatial skills e.g. apraxia, agnosia, navigation
  • Executive function e.g. impaired abstraction, planning, judgment, reasoning etc.
  • +impairment in functional independence
  • Or pathology evidence of dementia

Severe dementia:

  • MMSE score below 15 (or <10)
  • or a clinical dementia rating CDR of 2 or higher

Differential Diagnosis:

  • Don’t misdiagnose dementia in a patient who is really depressed a.k.a. pseudodementia
  • Reversible causes are: thyroid dysfunction, B12 deficiency, intracranial mass, normal pressure hydrocephalus

Screening:

No single tests is satisfactory
MMSE, mini-mental state examination:

  • If 21-23, suggests mild dementia. +LR= 9
  • If <15 or <10, severe dementia
  • If 24-26, do further testing
  • If >26, suggests dementia is unlikely. –LR= 0.1
  • When monitoring, a change of 4 is considered significant.

Abbreviated mental test AMT:

  • If <6, suggests dementia

Investigations to consider:

Bloods:

  • FBC: macrocytic anemia, infection
  • ESR: chronic infection, vasculitis
  • Complete metabolic panel, Ca++ +phosphate +albumin: hypercalcemia
  • Glucose: a cause of delirium, diabetes as a risk factor
  • Cholesterol +triglycerides
  • TFT: hypothyroidism
  • B12 & Folate levels & blood smear: vitamin B12 deficiency
  • Liver enzymes: early hepatic encephalopathy
  • Syphilis serology: VDRL, FTA-abs
  • HIV serology: AIDS dementia complex
  • Vasculitis screen: ESR, CRP, ANA screen, ENA panel (anti- dsDNA, anti-Sm, anti-RNP, SSA, SSB, anti-Jo-1, antitopoisomerase ‘formerly anti Scl-70’, antinucleolar, anticentromere), ANCA (c-ANCA, p-ANCA), Complement C3, C4 and CH50
  • Ceruloplasmin, Copper: Wilson’s disease
  • HIV serology: AIDS dementia complex
  • PTH: Hyperparathyroidism
  • Short ACTH stimulation test: screening for Addison’s disease

ECG: evaluation of cardiac disease
CXR: paraneoplastic & metastatic
CT:

  • Normal pressure hydrocephalus
  • Chronic subdural hematoma
  • Neoplastic disease (orbitofrontal meningioma, Glioblastoma), multiinfarct dementia

Polysomnogram: obstructive sleep apnea
MRI:

  • Normal pressure hydrocephalus
  • Chronic subdural hematoma
  • Neoplastic disease (orbitofrontal meningioma), multiinfarct dementia, leukoareosis on MRI in Binswanger’s disease, hippocampal atrophy in alzheimer’s, lymphoma
  • CJD findings

EEG
MRI
Lumbar puncture:

  • TB meningitis, cryptococcal meningitis, vasculitis, protein 14-3-3 in CJD, lymphoma,

Thrombophilia screen
Neuropsychological/Psychometric testing: localises affected areas
Screening for Cushing’s disease
Serum toxicology
Urine toxicology
Urine heavy metals
EEG: CJD or nonconvulsive seizures
If is early onset & positive family Hx. genotype for APP PS1 & PS2 mutations
PET Scan
SPECT Scan
Apolipoprotein E
Brain and meningeal biopsy: CJD or vasculitis, various dementias

Monitor:

Regular review for cataract & glaucoma
Regular review for cognitive state
MMSE: a change of 4 is considered significant
Assess nutrition, hydration & skin care

Treatment:

General measures:

  • Influenza vaccination
  • Address hydration, nutrition, skin care, cataract & glaucoma, risk of falls
  • Avoid: Benzodiazepines as they worsen disinhibition & confusion
  • Social: very important
  • Education of family & carers
  • Reality orientation: reinforce name, date, place & time when speaking to the patient
  • Respite for carers
  • Day hospital attendance
  • Involve occupational therapy
  • Involving a community psychiatric nurse
  • See if they are eligible for benefits
  • Address type of accommodation
  • Recommend support from voluntary organisations

Specific Management for underlying cause

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