Chapter 19 (Neurocognitive Disorder) Dementia

Definition Dementia is an acquired, usually progressive generalized impairment of intellect, memory and personality with no alteration of consciousness. Epidemiology 1.Prevalence increases with age: 10% in patients over 65 yrs of age; 25% in patients over 85 yrs of age. 2.Prevalence is increased in people with down syndrome and head trauma 3.Alzheimers dementia comprises >50% of cases; vascular causes comprise approximately 15% of cases 4.Average duration of illness from onset of symptoms to death is 8-10%

Subtypes 1. With or without behavioural disturbance (e.g. wandering agitation) 2. Early onset: age of onset <65 yrs 3. Late onset: age of onset > 65 yrs Diagnostic criteria for Dementia according to DSM-IV A.The development of multiple cognitive deficits manifested by both 1. memory impairment ( impaired ability to learn new information or to recall previously learned information) 2. ≥1 of the following cognitive disturbances: # aphasia (language disturbance) # apraxia # agnosia # disturbance in executive functioning

B. The cognitive deficits in criteria A1 and A2 each cause significant impairment in social or occupational functioning and represent a significant decline from a previous level of functioning C. The course is characterized by gradual onset and continuing cognitive decline D. The cognitive deficits in criteria A1 and A2 are not due to any of the following: 1. other central nervous system conditions that cause progressive deficits in memory and cognition 2. systemic conditions that are known to cause dementia. 3. substance induced conditions. E. The deficits do not occur exclusively during the course of a delirium F. The disturbance is not better accounted for by another Axis I disorder.

How a patient presents in dementia 1.Loss of intellectual abilities disproportional to age 2.No disturbance of conciousness 3.Increased forgetfulness 4.Decreased concentration for tasks 5.Difficulty with decision 6.Problems with wordfinding 7.Impaired ability to learn new information 8.Irritability, emotional outbursts, labile mood 9.Neglect of lifelong routines 10.Decreased social and family interests 11.Decreased recreational and occupational interests 12.Deterioration in day today routines especially of learned skill 13.Disturbance in sleep, nutritional intake and caring for personal hygiene

Difference between Cortical Dementia and Subcortical Dementia CharacteristicsCortical DementiaSubcortical Dementia I. Important Causes Senile dementia, Presenile dementia (Alzheimer’s, Picks, Creutzfeldt disease) etc Progressive Supranuclear Palsy; Huntington’s Chorea, Parkinson’s disease, Wilson’s disease II. PersonalityNormal (unaware, lack of insight) Depressed or apathetic III. Motor System a. PostureNormalImpaired (Stopped or twisted) b. GaitNormalImpaired (ataxia) c. MovementNormalImpaired (Chorea, rigidity, tremors) d. ActivityNormalImpaired (Slow) e. SpeechNormalImpaired (Dysarthria, hypophonia)

IV. Mental State a. LanguageAphasiaNormal b. MemoryAmnesticForgetful c. Visuospatial Skills Impaired (Severe)Impaired (moderate) d. CognitionImpaired (severe, amnesia, agnosia, apraxia, acalculia) Impaired (slowed, forgetfulness, impaired, problem-solving strategy).

Investigations (rule out reversible causes) 1.Standard 2.As indicated: VDRL, HIV, SPECT, CT head in dementia 3.Indication for CT head: same as for delirium, plus: age <60, rapid onset, dementia of relatively short duration (<2 yrs), recent significant head trauma, unexplained neurological symptoms (new onset of severe headache?seizures)

Possible etiologies of dementia Degenerative dementia Alzheimers disease frontotemporal dementia perkinsons desease lewy body dementia idiopathic cerebral ferrocalcinosis progressive supranuclear palsy Miscellaneous huntingtons disease wilsons desease metachromatic leukodystrophy neuroacacthocytosis Psychiatri pseudodementia of depression cognitive decline in late life schizophrenia

Physiologic normal pressure hydrocephalus Metabolic Vitamin deficiencies (e.g. vitamin B12, folate) endocrinopathies (e.g. hypothyroidism) chronic metabolic disturbances (e.g. uremia) Tumor primary or metastatic ( meningioma or metastatic breast or lung cancer) Traumatic dementia pugilistica, posttraumatic dementia subdural hematoma Infection prion desease (e.g. creutzfeldt-jakob disease, bovine spongiform encephalities, gertsmann-straussler syndrome)

Acquired immune deficiency syndrome (AIDS) Syphilis Cardiac,vasculur, and anoxia infarction (single or multiple or strategic lacunar) binswangers disease ( subcortical arteriosclerotic encephalopathy) hemodynamic insuffiency (hypoperfusion or hypoxia) Demyelinating disease Multiple sclerosis Drugs and toxins alcohol heavy metals irradiation pseudodementia due to medications carbon monooxide

Cortical and subcortical dementia featuresCortical dementia Subcortical dementia 1. Site of lesion Cortex (frontal and tempo- parieto- occipital association areas, hippocampus Subcortical grey matter (thalamus, basal ganglia, and rostral brain stem) 2. examples Alzheimers, picks disease Huntingtons choria, parkinsons, progressive supranuclear palsy, wilsons disease (not severe) 3. severitysevereMild to moderate 4. Motor system Usually normal Dysarthria, flexed/extended posture, tremors, dystonia, chorea, ataxia, rigidity 5. Other features Simple delusions; depression uncommon severe aphaxia, amnesia, agnosia, apraxia,acalc ulia; slowed cognitive speed (bradyphrenia ) Complex delusions,; depression common; rarely mania 6. Memory deficit (short term) Recall helped very little by cues Recall partially helped by cues and recognition tasks

7. personalitynormalDepressed or apathetic Managemant 1.Treat underlying medical problems and prevent others 2.Provide orientation cues for patient 3.Provide education and support for patient and family (day progress, respite care, support groups, home care) 4.Consider long term care plan (nursing home) and power of attorney/living will 5.Inform ministry of transportation about patients inability to drive safely 6.Consider pharmacological therapy # cholinesterase inhibitors (e.g. donepezil) for mild to severe disease

# NMDA receptor antagonist (e.g. memantine) for moderate to severe disease # low dose neuroleptics (haloperidol, risperidone) and antidepressants if behavioural or emotional symptoms prominent – start low and go slow # reasses pharmacological therapy every 3 months