Dementia

Background

DSM-IV Definition

• Major impairment in learning and memory plus impairment in handling complex tasks, impairment in reasoning ability, impaired spatial ability and orientation, or impaired language
• Symptoms significantly interfere with work, usual social activities, relationships
• Significant decline from previous level of functioning
• Disturbances are insidious and progressive
• Disturbances are not occurring exclusively during the course of delirium
• Disturbances are not accounted for by major psychiatric diagnosis
• Disturbances are not accounted for by systemic disease or another brain disease

Inappropriate Medications in Dementia

• Most common: Cholinesterase inhibitors, memantine hydrochloride, lipid lower agents, antiplatelet (except aspirin)
• Others: hormone antagonists, leukotriene inhibitors, cytotoxic chemotherapy, immunomodulators

Clinical Features

• Loss of mental capacity
• Slow and steady course
• Hallucinations, delusions, repetitive behaviors, and depression are all common
• May coexist with delirium
• Poor score on Mini-Mental Status Exam

Differential Diagnosis

Dementia Acronym

D = drug-induced

E = emotions (depression especially)

M = metabolic and endocrine issues

E = eyes and ears (sensory problems)

N = nutritional issues (B12 and Vit. D)

T = tumors

I = infections

A = alcohol

S = sleep disorders and rarely seizures

Dementia

• Degenerative
  • Alzheimer's disease
  • Huntington's disease
  • Parkinson's disease
• Vascular
  • Multiple infarcts
  • Hypoperfusion (MI, profound hypotension)
  • Subdural hematoma
  • SAH
• Infectious
  • Meningitis (sequelae of bacterial, fungal, or tubercular)
  • Neurosyphilis
  • Viral encephalitis (HSV, HIV), Creutzfeldt-Jakob disease
• Inflammatory
  • SLE
  • Demyelinating disease (e.g. multiple sclerosis)
• Neoplastic
  • Primary brain tumor / metastatic disease
  • Carcinomatous meningitis
  • Paraneoplastic syndromes
• Traumatic
  • Traumatic brain injury
  • Subdural hematoma
• Toxic
  • ETOH
  • Meds (anticholinergics, polypharmacy)
• Metabolic
  • B12 deficiency or folate deficiency
  • Thyroid Disease
  • Uremia
• Psychiatric
  • Depression (pseudodementia)
• Hydrocephalic
  • Normal pressure hydrocephalus (communicating hydrocephalus)
  • Noncommunicating hydrocephalus

Evaluation

Major workup consists of ruling out treatable causes of dementia / delirium

• Mini mental status exam
• Six item screen
• CBC
  • Megaloblastic anemia points to vitamin B12 deficiency
  • Normocytic anemia with an elevated RDW may indicated B12 deficiency as well if there are some RBCs with a small MCV and many with a large MCW.
• Chemistry 10
• LFTs
• Urinalysis
• ECG
• CXR
• ETOH
• Urine toxicology screen
• Head CT
• Consider
  • LFTs, TSH
  • B12, RPR, ESR, ANA, Folate, Thiamine, HIV
  • Neuropsych eval
  • Consider LP, urine heavy metals, EEG

Management

• Treat underlying cause (if possible)

See Also

• Altered Mental Status
• Dementia Work-Up