Cognitive Disorders

YASER ALHUTHAIL, MDASSOCIATE PROFESSOR

PSYCHOSOMATIC MEDICINE

Disruption in one or more of the cognitive domains, and are also frequently complicated by behavioral symptoms.

Cognitive disorders exemplify the complex interface between neurology, medicine, and psychiatry

Delirium, dementia, and the amnestic disorders

DeliriumAcute onset of fluctuating cognitive impairment (global)and a disturbance of consciousness.

Delirium is a syndrome, not a disease, and it has many causes, all of which result in a similar pattern of signs and symptoms

A common disorder:

10 to 30 percent of medically ill inpatients

30 percent of patients in intensive care units and

40 to 50 percent of patients who are recovering from surgery for hip fractures

Underrecognized and undertreated !!

Classically, delirium has a sudden onset (hours or days)

A brief and fluctuating course

Rapid improvement when the causative factor is identified and eliminated

Abnormalities of mood, perception, and behavior are common psychiatric symptoms

Tremor, asterixis, nystagmus, incoordination, and urinary incontinence are common

Risk FactorsExtremes of age

Number of medications taken

Preexisting brain damage (e.g., dementia, cerebrovascular disease, tumor)

History of delirium

Alcohol dependence

Diabetes

Cancer

Sensory impairment

Malnutrition

Central nervous system disorder

Seizure (postictal, nonconvulsive status, status)MigraineHead trauma, brain tumor, subarachnoid hemorrhage, subdural, epidural hematoma, abscess, intracerebral hemorrhage, cerebellar hemorrhage, nonhemorrhagic stroke, transient ischemia

Metabolic disorder Electrolyte abnormalitiesDiabetes, hypoglycemia, hyperglycemia, or insulin resistance

Systemic illness Infection (e.g., sepsis, malaria, erysipelas, viral, plague, Lyme disease, syphilis, or abscess)TraumaChange in fluid status (dehydration or volume overload)Nutritional deficiencyBurnsUncontrolled pain

Medications Pain medications Antibiotics, antivirals, and antifungalsSteroidsAnesthesiaCardiac medicationsAntihypertensivesAntineoplastic agentsAnticholinergic agents

Cardiac Cardiac failure, arrhythmia, myocardial infarction, cardiac assist device, cardiac surgery

Pulmonary Chronic obstructive pulmonary disease, hypoxia, SIADH, acid base disturbance

Endocrine Adrenal crisis or adrenal failure, thyroid abnormality, parathyroid abnormality

Hematological Anemia, leukemia, blood dyscrasia, stem cell transplant

Renal Renal failure, uremia, SIADHHepatic Hepatitis, cirrhosis, hepatic failure

Neoplasm Neoplasm (primary brain, metastases, paraneoplastic syndrome)

Drugs of abuse

Intoxication and withdrawal

Toxins Intoxication and withdrawalHeavy metals and aluminum

Diagnostic Criteria for Delirium Due to General Medical Condition

A-Disturbance of consciousness (i.e., reduced clarity of awareness of the environment) with reduced ability to focus, sustain, or shift attention.

B-A change in cognition (such as memory deficit, disorientation, language disturbance) or the development of a perceptual disturbance that is not better accounted for by a preexisting, established, or evolving dementia.

C-The disturbance develops over a short period of time (usually hours to days) and tends to fluctuate during the course of the day.

D-There is evidence from the history, physical examination, or laboratory findings that the disturbance is caused by the direct physiological consequences of a general medical condition.

Diagnosis and Clinical FeaturesThe core features of delirium include:

Altered consciousness

Altered attention, which can include diminished ability to focus, sustain, or shift attention

Impairment in other cognitive functions, which can manifest as disorientation and decreased memory

Fluctuations in severity and other clinical manifestations during the course of the day, sometimes worse at night (sundowning)

Disorganization of thought processes

Perceptual disturbances

Psychomotor hyperactivity and hypoactivity

The major neurotransmitter hypothesized to be involved in delirium is acetylcholine

Anticholinergic activity

Laboratory Workup of the Patient with Delirium

Blood chemistries (including electrolytes, renal and hepatic indexes, and glucose)   Complete blood count with white cell differential   Thyroid function tests   Serologic tests for syphilis   Human immunodeficiency virus (HIV) antibody test   Urinalysis   Electrocardiogram   Electroencephalogram   Chest radiograph   Blood and urine drug screens

Differential Diagnosis

Dementia

Depression

Schizophrenia

Course and Prognosis

The symptoms of delirium usually persist as long as the causally relevant factors are present

Delirium is a poor prognostic sign

Treatment

The primary goal is to treat the underlying cause

The other important goal of treatment is to provide physical, sensory, and environmental support

Pharmacotherapy

haloperidol

risperidone, clozapine, olanzapine, quetiapine

DementiaGlobal impairment of cognitive functions occurring in clear

consciousness

Difficulty with memory, attention, thinking, and comprehension.

Other mental functions can often be affected, including mood, personality, judgment, and social behavior

Can be progressive or static !

Permanent or reversible (e.g., vitamin B12, folate, hypothyroidism)   

50 to 60 percent have the most common type of dementia, dementia of the Alzheimer's type

Vascular dementias account for 15 to 30 percent of all dementia cases

Possible Etiologies of Dementia Degenerative dementias

Alzheimer's disease Frontotemporal dementias (e.g., Pick's disease) Parkinson's disease Lewy body dementia Miscellaneous Huntington's disease Wilson's disease Psychiatric 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 (e.g., meningioma or metastatic breast or lung cancer)

Traumatic Dementia pugilistica, posttraumatic dementia Subdural hematomaInfection Prion diseases (e.g., Creutzfeldt-Jakob disease, bovine spongiform encephalitis, Gerstmann-Strأ¤ussler syndrome) Acquired immune deficiency syndrome (AIDS) SyphilisCardiac, vascular, and anoxia Infarction (single or multiple or strategic lacunar) Binswanger's disease (subcortical arteriosclerotic encephalopathy) Hemodynamic insufficiency (e.g., hypoperfusion or hypoxia)Demyelinating diseases Multiple sclerosisDrugs and toxins Alcohol, Heavy metals, Carbon monoxide

Dementia of the Alzheimer's Type

The most common type of dementia

Progressive dementia

The final diagnosis of Alzheimer's disease requires a neuropathological examination of the brain

Genetic factors

Acetylcholine and norepinephrine, both of which are hypothesized to be hypoactive in Alzheimer's disease

Vascular Dementia

The primary cause of vascular dementia, formerly referred to as multi-infarct dementia, is presumed to be multiple areas of cerebral vascular disease

Vascular dementia is more likely to show a decremental, stepwise deterioration than is Alzheimer's disease.

Diagnosis and Clinical Features

The diagnosis of dementia is based on the clinical examination

Memory impairment is typically an early and prominent feature

Early in the course of dementia, memory impairment is mild and usually most marked for recent events; As the course of dementia progresses, memory impairment becomes severe, and only the earliest learned information are intact

Orientation can be progressively affected

Personality change, intellectual impairment, forgetfulness, social withdrawal, anger and lability of emotions are common

Hallucinations………….20 to 30 percent

Delusions………………30 to 40 percent

Physical aggression and other forms of violence are common in demented patients who also have psychotic symptoms.

Depression and anxiety symptoms

Pathological laughter or crying

Diagnostic Criteria for Dementia of the Alzheimer's TypeA-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-one (or more) of the following cognitive disturbances: aphasia (language disturbance)

apraxia (impaired ability to carry out motor activities despite intact motor function)

agnosia (failure to recognize or identify objects despite intact sensory function)

disturbance in executive functioning (i.e., planning, organizing, sequencing, abstracting)

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 (e.g., cerebrovascular disease, Parkinson's disease, Huntington's disease, subdural hematoma, normal-pressure hydrocephalus, brain tumor)

2-systemic conditions that are known to cause dementia (e.g., hypothyroidism, vitamin B12 or folic acid deficiency, niacin deficiency, hypercalcemia, neurosyphilis, HIV infection)

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 (e.g., major

depressive disorder, schizophrenia

Diagnostic Criteria for Vascular Dementia A.The development of multiple cognitive deficits manifested by both

A. memory impairment (impaired ability to learn new information or to recall previously learned information)

B. one (or more) of the following cognitive disturbances: A. aphasia (language disturbance) B. apraxia (impaired ability to carry out motor activities despite intact motor

function) C. agnosia (failure to recognize or identify objects despite intact sensory

function) D. disturbance in executive functioning (i.e., planning, organizing, sequencing,

abstracting)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.Focal neurological signs and symptoms (e.g., exaggeration of deep tendon reflexes, extensor plantar response, pseudobulbar palsy, gait abnormalities, weakness of an extremity) or laboratory evidence indicative of cerebrovascular disease (e.g., multiple infarctions involving cortex and underlying white matter) that are judged to be etiologically related to the disturbance. D.The deficits do not occur exclusively during the course of a delirium.

Dementia Due to Other General Medical Conditions

HIV disease, head trauma, Parkinson's disease, Huntington's disease, Pick's disease, and Creutzfeldt-Jakob disease.

Substance-Induced Persisting Dementia

Alcohol-Induced Persisting Dementia

Physical Findings, and Laboratory Examination

A comprehensive laboratory workup must be performed when evaluating a patient with dementia

The purposes of the workup are to detect reversible causes of dementia

The evaluation should follow informed clinical suspicion

Differential Diagnosis

Delirium

Depression (pseudodementia )

Schizophrenia

Normal Aging

Feature Dementia DeliriumOnset Slow Rapid

Duration Months to years Hours to weeks

Attention Preserved Fluctuates

Memory Impaired remote memory Impaired recent and immediate memory

Speech Word-finding difficulty Incoherent (slow or rapid)Sleep cycle Fragmented sleep Frequent disruption (e.g.,

day–night reversal)

Thoughts Impoverished Disorganized

Awareness Unchanged Reduced

Alertness Usually normal Hypervigilant or reduced vigilance

TreatmentThe first step in the treatment of dementia is verification of

the diagnosis.

Preventive measures are important

Supportive and educational psychotherapy

Any areas of intact functioning should be maximized by helping patients identify activities in which successful functioning is possible

Caregivers

Pharmacotherapy

Benzodiazepines for insomnia and anxiety

Aantidepressants for depression

Antipsychotic drugs for delusions and hallucinations

Drugs with high anticholinergic activity should be avoided.

Cholinesterase inhibitors :

Donepezil (Aricept), rivastigmine (Exelon), galantamine (Remiryl), and tacrine