Cognitive disorders (Delirium, Dementia, Amnestic disorders)

Cognitive Disorders:

1. Delirium
2. Dementia
3. Amnestic disorders
4. Dissociative Disorders an interesting category, which is not organic, but DSM IV put it here:

Damaged functions we observe in cognitive functions are:

a.       Orientation

·         Person

·         Place

·         Time

b.      Consciousness

c.       Cognitive functions

Main cognitive disorders:

pDelirium

Symptoms:

nClouded consciousness

nconfusion

nDisoriented in time & space (partially retained allopsychic  and autopsychic orientation)

nAimless hyperactivity (or hypoactivity)

nAnxiety

nInsomnia (sundowner)

Causes

nWithdrawal of drug or substance

nacute medical condition

nPneumonia (children)

nErysipelas

nFever

nMalaria

nSepsis

nmeningitis

nSystemic infections

nDrugs (anticholinergics)

npostoperative

nMetabolic

nCardiovascular and other respiratory

Most vulnerable are children and elderly people

Prognosis

pusually good in terms of complete recovery, but mortality might be high :2% of even properly treatedcases

pCan progress to

nDementia

nKorsakoff’s sy

Somatic disorders frequently present as serous severe and acute psychiatric disorder (somatoform or acute exogenous psychosis) which can mask the underlying medical problem

Dementia

nGradual loss of memory and intellectual ability

nConsciousness not impaired till late stage

nIncreasing incidence with age

n20% above 80years old population demented

Alzheimer’s Disease:

nCriteris ais that no other cause of dementia is present

nPathology:

nEnlarged ventricles

nDiffuse atrophy

nFlattened gyri gaping sulci

nHistology:

nSenile/ amyloid plaques

nNeurofibrillary tangles

nNeuronal loss

nNeurochemistry

nDecrease of acetylcholine and norepinephrine

nReduced choline acetyltransferase

nLoss of cholinergic neurons

nOverstimulation of NMDA receptors by glutamate

nDecreased somatostatin, VIP, corticotropin

nAbnormal processing of amyloid precursor protein

nAbnormal membrane phospholipoid metabolism

nGenetics

·         Chromosome 21 is the genetic site of amyloid precursor protein

·         Early onset AD: chromosome chromosme1 & 14

·         Presence ApoE4 on chromosome 19 (women)

·         Close relative with AD

·         Female gender predisposing

nTherapy

·         Structured environment

·         Cholinesterase inhibitors

o   Donepezil (Aricept)

o   Rivastigmine (Exelon)

o   Galanthamine (Reminyl)

o   Tacrine (Cognex)

·         NMDA antagonist

o   Memantine (Amantadine)

o   Selegiline (Deprenyl) (DA agonist)

Vascular Dementia

n15-30% of all dementias

nMultiple small infarcts

nAtherosclerosis

nValvular heart disease

nArrhythmias

nSudden onset

nStepwise progression

nBetter preservation of the original personality

nMen are at higher risk

nAssociated focal neurological signs

nTreatment:

nTreat arrhythmia, hypertension and underlying medical conditions

Lewy Body Dementia

·         Progressive dementia

·         Fluctuation of mental abilities

·         Visual hallucinations

·         Parkinsonism

·         Positive psychotic symptoms

·         Unfavorable response for antipsychotic drugs

·         Pathology:

§  Lewy bodies in the brainstem & cortex

§  Neuritic plaques

§  Only few neurofibrillary tangles

Dementia due to HIV Infection

·         Dementia HIV complex

·         Direct infection of the brain

§  Cortical atrophy

§  Inflammation

§  Demyelination

·         Cerebral lymphoma

·         Opportunistic brain infections

·         Death within 6 month

Other Dementias

nBrain tumor

nMetastasis

nParkinson’s Disease (DD)

nHead trauma

nMultiple sclerosis

nPick’s disease

nHuntington’s Disease

Amnestic Disorders

·         Memory loss

·         Little or no cognitive impairment

·         Normal level of consciousness

·         Retrograd - congrad - anterograd amnesia

·         Confabulation

·         Korsakoff’s syndrome(living in the present minute only – and abridging the memory gaps with confabulations)

·         Thiamine deficiency in alcoholism

·         Head trauma

·         Cerebrovascular disease

·         Herpes simplex virus encephalitis

Dissociative disorders: Those are psychological conditions, which affects the memory functions or the perception of the self

·         Sudden but temporary loss of

o   Memory

o   Identity

·         Feelings of detachment (Oneiroid state)

·         From oneself

·         From the environment

·         Usually with normal level of consciousness

·         Not organic (rather psychologic)

·         Types:

·         Dissociative amnesia

·         Dissociative fugue

·         Dissociative identity disorder (multiple personality disorder)

·         Depersonalization disorder (or Derealization)

Differential diagnosis of the dissociative disorders

·         Organic psycho-syndromes

·         Substance abuse

·         Sequale of ECT

·         Anesthesia

·         Seizures

·         Head injury

·         Psychological

·         PTSD

·         Malingering

Etiology of Dissociative Disorders

·         Defense mechanisms

·         Dissociation

·         Denial

·         Repression in a response to a stressful event

·         In history child abuse (sexual)

Clinical curse:

·         Start in early adulthood

·         Episodic

·         Episodes may continue for years

Case Studies

v  A 72-year-old man is brought in by his wife to your clinic. The patient’s wife is concerned about his progressive confusion over the last year. She is particularly distressed that he repeatedly asks the same questions throughout the day. She also notes that her husband has become increasingly unsteady on his feet and needs to use a walker when they go out. She wonders if these symptoms may be related to the meningitis he suffered from 3 years ago.

1. For you to make a diagnosis of normal pressure hydrocephalus (NPH), further investigation in this case would have to reveal which of the following?

(A) elevated opening pressure upon lumbar puncture

(B) a history of incontinence

(C) oculomotor difficulties

(D) frontal release signs

(E) perseveration

2. Neuroimaging with noncontrast computed tomography (CT) in this case of NPH is most likely to reveal which of the following?

(A) dilated lateral ventricles

(B) normal ventricles

(C) frontal sulcal widening

(D) focal subcortical hypointensities

(E) cerebellar atrophy

1. (B) The classic triad of NPH is confusion, gait ataxia, and incontinence. Elevated opening pressure is not found in NPH (thus the “normal pressure” part of the diagnosis). Oculomotor difficulties are a part of the Wernicke-Korsakoff syndrome. Frontal release signs and perseveration are nonspecific findings common in demented patients.

2. (A) CT scan commonly reveals dilated ventricles thought to be the result of increased pressure waves impinging within the ventricular system. Normal ventricles would not be expected in NPH patients. Frontal sulcal widening is found in dementias that have underlying cerebral atrophy. Hypointensities found in subcortical areas are often indicative of lacunar strokes. Cerebellar atrophy is seen most often in congenital disorders and alcoholism.

v  . A 72-year-old woman presents to your clinic. On physical examination, she appears malnourished and dehydrated. The medical service initiates intravenous fluid replacement. On MSE, she is alert and oriented to person only. During the interview, the patient is easily distracted. She often forgets things shortly after she learns them. One hour later, her MSE has improved, reporting the correct day, time, and place. However, she cannot remember why she is there. When asked about the current president, she cannot remember his name butdescribes his appearance. She is able to perform serial sevens slowly but accurately without distraction. Based on the information in this case, the most appropriate diagnosis for this patient’s presenting symptoms is which of the following?

(A) amnestic disorder not otherwise

specified

(B) cognitive disorder not otherwise

specified

(C) delirium

(D) dementia not otherwise specified

(E) major depression                   

(C) This patient’s MSE is most consistent with delirium in that it is remarkable for relatively rapidly fluctuating memory, orientation, and attention. Also, her apparent dehydration and malnourishment provide evidence for an underlying medical cause of her mental status change. Amnestic disorder is not likely given this patient’s shifts in attention and memory fluctuations. Cognitive disorder, not otherwise specified, is reserved for cases exclusive of dementia and delirium such as cases of traumatic brain injury. Although this patient would seem a likely person to have dementia, her fluctuating mental status is indicative of a delirium. Dementias are diagnosed in the context of a relatively stable set of deficits on an MSE, and the underlying causes are rarely associated with acute medical insults. Importantly, however, the presence of dementia does predispose to delirium. Major depression can cause cognitive deficits on MSEs that are reversible with antidepressant treatment. These pseudodementias, like dementia, most often present as a more stable conditions during examination than is illustrated in this case.

v  The patient is an 80-year-old widowed woman admitted to the hospital under the medical service who is “confused.” Her primary medicine team has consulted a psychiatrist to help with the evaluation and management of her condition. On examination, she is somnolent at times, fluctuating with alert. She is not cooperative, hostile, and clearly hallucinating. Her insight and memory are poor. The primary team wishes to know if she is “delirious or demented.” Which of the following signs/symptoms in this patient is the most specific for delirium?

(A) Aggressivity

(B) Fluctuating consciousness

(C) Poor memory

(D) Psychosis

(E) Uncooperativeness

(B) The patient appears to be suffering from delirium. Although aggressiveness, memory deficits, psychotic symptoms, and uncooperativeness may be seen in either delirium or dementia, a fluctuation in the level of consciousness (i.e., from alertness to somnolence) is the hallmark for delirium.

v  A60-year-old man is brought to the emergency department by his family after they notice a decline in memory. On evaluation, the patient’s remote memory is intact as verified by the family, but his recent recall is severely impaired. The patient provides verbose but erroneous answers in response to questions testing recent recall.

1. This patient’s memory distortion is most likelywhich form of memory disorder?

(A) anterograde amnesia

(B) retrograde amnesia

(C) dissociative amnesia

(D) prosopagnosia

(E) astereognosis

2. Which of the following best describes the patient’s answers in response to recent memory testing?

(A) clang associations

(B) flight of ideas

(C) hypermnesia

(D) logorrhea

(E) confabulation

1. (A) This patient may be suffering from Wernicke-Korsakoff syndrome (frequently a complication of long-term alcoholism). Anterograde amnesia is the loss of immediate or short-term memory. Patients are unable to form new memories. Retrograde amnesia is the loss of remote or previously formed memories. Dissociative amnesia is the loss of memory without the loss of ability to form new memories. It is usually associated with emotional trauma and is not due to drugs or a medical condition. Prosopagnosia is the inability to remember faces despite being able to recognize that they are faces.

Astereognosis is the inability to recognize an object by touch despite the tactile sensations being intact.

2. (E) Confabulation is the fluent fabrication of fictitious responses in compensation of memory disturbance. Clang associations are the use of words based on sound and not with reference to the meaning. Flight of ideas is another form of speech in which one shifts rapidly from one idea to another but the relationship between the themes can sometimes be followed. Hypermnesia is the ability to recall detailed material that is not usually available to recall. Logorrhea is uncontrollable or excessive talking sometimes seen in manic episodes.