02. Cognitive Impairment / Dementia

Resident Editor:  Carine Davila, MD

Faculty Editor: Carla Perissinotto, MD, MHS

            

BOTTOM LINE  

✔ Evaluate for depression and delirium, they can worsen or mimic dementia

✔ Screen for cognitive impairment  with the Mini-Cog. Follow up a (+) screen                     

Background/Epidemiology

  • Mild cognitive impairment (MCI): impairment that does not affect function in daily life. Increased risk of dementia. 
  • Dementia: decline in cognition from baseline severe enough to cause impairment in daily function
  • NIH estimates that 1 of every 7 adults >70 years old in the US has measurable cognitive impairment, 50% of adults > 85 years old 
  • Cognitive impairment is unrecognized in 27%–81% of affected patients in primary care
  •  Alzheimer disease is the most common form of dementia in the elderly, accounting for 60-80% of cases, and is the 6th leading cause of death

Signs and Symptoms

Disease

Characteristics

Alzheimer disease

Early: gradual memory loss (especially short-term memory or learning), and impaired language are hallmarks. Often unaware of deficits

Middle: apraxia, disorientation, and impaired judgment with IADL deficiencies. 

Late: aphasia, apraxia, agnosia, inattention, and left–right confusion, dependent in ADLs and IADLs. Psychiatric symptoms such as delusions and paranoia are common as illness progresses

Vascular Dementia

Loss of function may correlate with cerebrovascular events with “stepwise” deterioration. Suspect in any patient with vascular disease risk factors  Deficits are in various cognitive domains (e.g. not characteristically language and memory). 

Lewy Body Dementia

Parkinsonism hallmark; hallucinations and delusions early in the illness; gait difficulties and falls; fluctuating cognition; daytime drowsiness or long naps; disorganized speech.  Sometimes difficult to distinguish from delirium.

Frontotemporal Dementia

Onset often before age 60 years. Language difficulties common. Memory often preserved early on. Prominent personality changes, often with behavioral disturbances or socially inappropriate behavior (hyperphagia, impulsivity, aggression, loss of empathy, or prominent apathy).  Sometimes difficult to differentiate or misdiagnosed as primary psychiatric illness.

Parkinson’s Disease

Typically have motor symptoms before cognitive impairment develops. PD dementia characterized by executive dysfunction and visual–spatial impairment. 

Differential Diagnosis

  • Delirium: fluctuating level of alertness and attention, globally impaired cognition, abrupt onset, psychomotor retardation, hallucinations, delusions, and agitated behavior. Delirium due to underlying problem. Constipation and urinary retention common causes of delirium in the elderly. 
  • Consider in patients with recent acute illness or hospitalization. 
  • Major Depression: Complex relationship between depression and dementia. Cognitive impairment may result solely from major depression, depression may be a prodrome to dementia, ad depression also seen as symptom of dementia.
  • Medications: BZDs, barbiturates, anti-cholinergic meds, sedative-hypnotics of any type.
  • Subdural Hematoma: May or may not occur in setting of falls or head injury. Nonspecific headache. Level of consciousness may wax and wane. Neurologic deficits may be subtle.
  • Normal Pressure Hydrocephalus: Slow, broad-based gait, urinary incontinence, psychomotor slowing and apathy
  • Brain Tumor: Primary or metastatic. Possible seizures or other neuro deficits.
  • B12 Deficiency: Insidious onset. Decreased proprioception and vibratory sense, ataxia. 
  • Thyroid Disease: Both hypo- and hyperthyroidism can lead to cognitive impairment.
  • Other: chronic alcohol use, toxins, multiple sclerosis, CNS vasculitis, neurosarcoidosis, SLE, Wilson’s disease, chronic CNS infection, electrolyte abnormalities, neurosyphilis, HIV-associated dementia, Wernicke-Korsakoff syndrome. 

Evaluation

  • USPSTF states there is insufficient evidence to recommend for or against screening in asymptomatic patients; reasonable to screen if patient complains or if caregiver or clinician notes a decrease in cognitive function. AGS and Alz. Association advocate for screening because of underdiagnosis in primary care, and missed opportunities for secondary prevention, early intervention and advanced care planning.
  • Screen with the Mini-Cog: 3-item recall in 1 minute and clock drawing test. If positive (0 items recalled, or only 1-2 items recalled and an abnormal clock draw), move on to the MMSE or MOCA. Note: highly educated people may have only 2-3 points changes in MMSE. The MOCA is less sensitive to patient’s formal education. MOCA also validated in multilingual populations and will pick up MCI.
  • All patients: Chem10, CBC, TSH, B12 level, depression screen (Geriatric Depression Scale or PHQ-9).  Most also suggest RPR, HIV (r/o reversible causes)
  • Consider: Toxicology screen, folate, ESR, UA
  • CT or MRI brain in patients with cognitive difficulties < 3 years duration, early age of onset (<60 years), rapid progression, focal neurologic deficits, cerebrovascular disease risk factors, or atypical symptoms.
  • Neuropsychiatric testing indicated if diagnosis uncertain or complicated by psychiatric illness. May help with therapeutic options.
  • Routing CSF analysis or genetic testing is NOT recommended

Treatment

  • Safety: driving ability becomes impaired early in dementia. Once diagnosis of dementia, in CA must be reported to DMV, home safety assessment, medication administration, cooking or use of power tools, firearms, getting lost (consider safe return bracelet). High risk for elder abuse and scams as executive function diminishes.
  • Advanced Care planning: critical for both health care and finances before capacity diminishes. 
  • AchE and NMDA antagonists: trial and remember to d/c if no improvement (caring wisely campaign)
    • Acetyl-cholinesterase Inhibitors (tacrine, donepezil, galantamine, or rivastigmine) theoretically to delay cognitive decline and good evidence for neurobehavioral symptoms and apathy seen in dementia. Only modest benefits in stabilizing decline in patients with dementia. Side effects are common (GI, bradycardia and nodal blockade) but can usually be managed by starting low and increasing gradually and changing time of administration (with meals, at bedtime). Therapeutic trial should last 6 months if tolerated. Follow MOCA and caregiver’s global assessment while on treatment. No evidence of benefit in mild cognitive impairment.  EKG may be indicated at baseline if underlying conduction abnormalities.
    • NMDA-receptor antagonist: Memantine (Namenda) has been shown to improve function, cognition, and demand on caregivers in moderate-to-advanced Alzheimer disease.
  • Anti-depressants: Major depression is highly prevalent among patients with dementia. Consider low dose SSRI. If component of anxiety, start citalopram or venlafaxine in low doses, avoid meds with greater anticholinergic effects (paxil).  Also can be frist lien in neurobehavioral symptoms.
  • Anti-psychotics: Consider only if symptoms causing significant distress or danger to the patient or others; efficacy of risperidone and olanzapine is most studied (but quetiapine, aripiprazole often used), prescribe at the lowest possible dose. Note black-box warning for increased mortality and CV events. If prescribed, consider de-prescribing after either (1) 3 months of good response, to trial off, or (2) lack of response.  Also consent patient and family about black box warning and be aware of extrapyramidal side effects of typical antipsychotics.
  • Insomnia: Sleep hygiene first (sleep environment, decrease caffeine consumption, daytime sleeping, medication timing). If using meds, consider melatonin first and possibly trazodone 25-50 mg (though strong data for efficacy is lacking).
  • End of Life Care:  average life expectancy ~10 years, and thus must think about as terminal illness, with need to modify other chronic disease treatment plans with discussions on end of life care and ACP.
    • No evidence for PEG in dementia
    • Requires multidisciplinary team care to help families understand prognosis and progression

When to Refer

  • Consider referral to neurologist with memory disorder specialty or Geriatrics, in patients who exhibit the following features: early age of onset, rapid progression, early personality changes, early neurologic symptoms, or atypical symptoms. Also consider referral for difficult-to-manage psychiatric and behavioral disturbances.
  • Many patients with dementia may be best cared for in Geriatrics and/or home based care, when routine clinical settings to disruptive for patients with neuropsych symptoms and functional impairment.
  • Evaluations by a Memory Disorders Center may help the family understand and supports management by the primary clinician. 
  • Consider if your patient would benefit from consultation with an occupational therapist, physical therapist, social worker, and/or speech and language pathologist.

References

AAFP Practice Guidelines. Deprescribing Antipsychotics for Behavioral and Psychological Symptoms of Dementia and Insomnia. American Family Physician 2018; 98(6):394-395. 

Bennett S, Thomas A. Depression and dementia: Cause, consequence, or coincidence? Maturitas 2014; 79(2):184-190.

David M. Blass, Peter V. Rabins; Dementia. Annals of Internal Medicine. 2008; 148(7):ITC4-1. 

Doody RS, Stevens JC, Beck C, et al. Practice parameter: management of dementia (an evidence-based review). Neurology 2001; 56:1154-1166.

Falk N, Cole A, and Meredith TJ. Evaluation of Suspected Dementia. American Family Physician 2018; 97(6):398-405. 

Ferracioli-Oda E, Qawasmi A, Bloch MH. Meta-Analysis: Melatonin for the Treatment of Primary Sleep Disorders. PLoS ONE. 2013; 8(5):e63773. 

Knopman DS, DeKosky ST, Cummings JL, et al. Practice parameter: diagnosis of dementia (an evidence-based review).  Neurology 2001; 56:1143-1153.

Nasreddine ZS, Phillips NA, Bédirian V, et al. The Montreal Cognitive Assessment, MoCA: a brief screening tool for mild cognitive impairment. J Am Geriatr Soc 2005; 53:695.

Qaseem A, Snow V, Cross JT Jr, et al. Current Pharmacologic Treatment of Dementia: A Clinical Practice Guideline from the American Academy of Family Physicians and the American College of Physicians. Ann Intern Med. 2008; 148:370-8.

Screening for Cognitive Impairment in Older Adults, Topic Page. U.S. Preventive Services Task Force. http://www.uspreventiveservicestaskforce.org/uspstf/uspsdeme.htm. Accessed August 3, 2014.