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case report

I. Causes of Late-Onset Psychotic Symptoms

1. Delirium
   1. MCC - use of prescription meds [upto 40%] or infection
2. Dementia
   1. presence of memory lapse alone - ARCD
   2. memory loss greater than that expected from normal aging in the absence of functional impairment - MCI
   3. Reversible causes
      • B12 defn
      • Thiamine defn
      • NPH - triad of gait disturbance, urinary incontinence, and cognitive impairment associated with ventriculomegaly
   4. DAT
      • 75% of cases
      • 1-2% of people above 60yrs, doubles every 5 yrs so that 50% people older than 85yrs
      • RFs - age, family h/o, head injury, downs syndrome
      • early stages - subtle loss of short-term memory, which progresses into word-finding and naming difficulties, often manifesting as vague speech and circumlocution
      • late stages - judgment becomes impaired, personality changes, and social withdrawal may occur
   5. VAD
      • 15-20% of cases
      • stepwise decline + focal neuro deficits
      • RFs - same as for vascular and embolic dz
   6. DLB
      • visual hallucinations, parkinsonism, and fluctuation in alertness or attention
      • sensitive to epse
   7. Less common types
      • FTD - presents insidiously with disinhibition, a decline in hygiene, and impulsivity that precede cognitive changes.
      • Secondary to PD, HD, PSP, CBD, Alcohol use
3. Psychiatric disorders
   • Late onset schizophrenia
   • Primary mood disorder like depression with psychosis or mania
   • if past h/o mood disorder then reemergence of symptoms later in life

II. Characteristics of dementia related psychotic symptoms

1. Delusions
   1. More than half DAT pts develop delusions
   2. most common delusions involve simple paranoid beliefs, most commonly of theft
   3. Other delusions include the beliefs that a person's house is not their home, a caregiver is an imposter (Capgras syndrome), a care-giver will abandon the patient, or a mate is unfaithful. These delusions may be “misidentifications” due to cognitive impairment rather than true psychotic symptoms
2. Hallucinations
   1. occurring in up to half of patients with dementia
   2. Visual hallucionations in 80% pts with DLB

III. Work up of late-onset psychosis

1. Step 1: Rule out delirium
   1. identification of potentially offending prescription medications, especially anticholinergic and sedative-hypnotic medications
   2. exclusion of an infectious etiology (most often urinary tract infection or pneumonia)
   3. exclusion of other metabolic causes
   4. Exacerbation of chronic illnesses, such as congestive heart failure, chronic obstructive pulmonary disease, renal insufficiency, and anemia, may also cause metabolic changes responsible for delirium.
2. Step 2: Either dementia or psych disorder
   1. careful history-taking with the use of collateral information from family members and others, as well as functional and cognitive assessments, can be helpful in establishing a working diagnosis and a treatment plan.