Session 3: Cognitive Problems

Definitions• Dementia: clinical state characterized by loss of function in multiple

cognitive domains; diagnostic features include : memory impairment and at least one of the following: aphasia, apraxia, agnosia, disturbances in executive functioning. Cognitive impairments must be severe enough to cause impairment in social and occupational functioning and there must be a decline from from a previously higher level of functioning.

• Acute confusional state: impairment of cognitive function that is not progressive, but is reversible. The impairment of consciousness varies, often being worse at night. It may be described as a transient organic brain syndrome characterized by concurrent disorders of attention, perception, thinking, memory, psychomotor behaviour and the sleep-waking cycle.

• Delirium: acute cognitive and behavioral change with attentional problems (analogous to above)

• Encephalopathy: diffuse brain dysfunction (includes acute confusional state and delirium)

• Amnestic syndrome: Partial or total loss of memory, usually resulting from shock, psychological disturbance, brain injury, or illness. (cf Bourne Identity)

• Mental retardation: a disability characterized by significant limitations both in intellectual functioning and in adaptive behavior as expressed in conceptual, social, and practical adaptive skills beginning before age 18.

• Schizophrenia: any of several psychotic disorders characterized by distortions of reality and disturbances of thought and language and withdrawal from social contact

Schizophrenia

Two (or more) of the following, each present for a significant portion of time during a 1-month period (or less if successfully treated):

– delusions – hallucinations – disorganized speech (e.g., frequent derailment or incoherence) – grossly disorganized or catatonic behavior – negative symptoms, i.e., affective flattening, alogia, or avolition.

Note: Only one symptom is required if delusions are bizarre or hallucinations consist of a voice keeping up a running commentary on the person's behavior or thoughts, or two or more voices conversing with each other.

Man found down

• BP: 116/68; 104 HR; 99.5 F; 14 RR

• Opens eyes to voice; grimaces to pain; unable to follow commands; blinks to threat bilaterally

• Normal oculocephalics; symm reactive pupils; facial symmetry

• Reduced tone with withdrawal of all extremities to pain

Laboratory Findings• Na 152, K 4.1, BUN 76,

Cr 2.1; Glc 116• AST/ALT: 23/47; INR 1.9• Urine tox neg; • serum alc 0• Head CT: bifrontal

hygromas without mass effect; old parietal encephalomalacia; basal ganglia calcification

• CXR: old granulomas• EEG: diffuse triphasic

waves

What is needed to work up confusion?

• Structural imaging:– Brain CT– Brain MRI

• Infection/hemorrhage/tumor evaluation:– Spinal tap

• Seizures/Brain death/psychogenic/other:– EEG

Herpes Encephalitis

Focal status epilepticusOther

Confusion in the Nursing Home

• Dementia with superimposed conditions• Infection: UTI, pneumonia• Medication errors/overdose• End-stage medical diseases: CHF, renal• Poorly managed diabetes• Stroke• Encephalitis/meningitis• Seizure/post-ictal state• Other

38 year old man

• Talking crazy/staggering around• No recent ETHO though has a history of chronic

liver disease, coagulopathy, hypertension, seizures, pancreatitis and head trauma

• Medications: ? Phenytoin and nadolol• Exam: disheveled; 96 F; 179/100 BP; HR 112;

disoriented to place, season and is confabulating with poor attention and recall; gaze-evoked nystagmus and incomplete right eye abduction on right gaze; absent reflexes and wide-based ataxic gait.

Issues

• Cognitive syndrome: encephalopathy

• Diagnosis

• Treatment

• Where is the pathology

Subtle bilateral abnormal hyperintense signal in the paraventricular region of the medial thalami seen on diffusion, flair and T2. Possible subtle abnormal signal of periaqueductal gray matter seen on flair and T2.

50 yo with mental status changes and abnormal eye movements.

• Findings Subtle bilateral abnormal hyperintense signal in the paraventricular region of the medial thalami seen on diffusion, flair and T2. Possible subtle abnormal signal of periaqueductal gray matter seen on flair and T2.

• Further history revealed alcohol abuse.

• Diagnosis Wernicke's encephalopathy

• Discussion MRI of the brain with contrast: MRI demonstrates acute lesions of Wernicke-Korsakoff syndrome in medial thalamic and periaqueductal regions. This can be a useful diagnostic procedure in patients presenting with suggestive history and stupor or coma, where ataxia and ophthalmoplegia are not detectable.

• Alcohol abuse is the most common etiology. Prompt Thiamine administration is essential and actually was given to the patient prior the this MRI. Wernicke encephalopathy is a medical emergency. Prompt recognition of the symptom complex and a high index of suspicion are crucial to ensure early treatment. Early treatment can rapidly reverse the ophthalmoplegia and improve ataxia/dysequilibrium and early mental confusion, as well as prevent development of the amnestic state. In advanced cases, where severe prolonged deficiency has led to permanent structural damage, permanent deficits most often are manifested as the amnestic state and severe ataxia.

• Reference: emedicine. • Contributor: Sanders

Acute Alcohol Intoxication

Alcohol Withdrawal

Withdrawal seizuresDelirium tremensAlcohol hallucinosisHeadache/hangover

Chronic Alcohol EffectsCerebellar degenerationVascular risks

ICHSDHThromboticEmbolic

SeizuresCognitiveSpinal cord: B12 defNeuropathyMuscular atrophy

Heavy drinkers compared with light or non drinkers are: twice as likely to die of heart disease twice as likely to die of cancer twelve times as likely to die of cirrhosis of the liver three times more likely to die in a car accident six times more likely to commit suicide

60 year old man

• Making mistakes; forgetful; unable to complete his report; no longer interested

• Irritable and defensive; lost his way home• Guarded/suspicious• Inattentive with digit span of 5; ¼ recall &

confabulates 2 others• Occasional paraphasias• Difficulty with 3 step command; problem

with 3 D cube drawing

Cognitive Syndrome

• Differential diagnoses• Work-up

– Blood: thyroid/B12/RBC folate +/- VDRL– Imaging?: CT/MRI

• Management– Behavioral– Pharmacological

• Acetylcholinesterase inhibitors• Glutamate modulators

• Prognosis

This 80-year-old man presented with a gradual decline in functioning. Examination revealed a marked aphasia and poor visual-spatial ability with an MMSE score of 18/30. These T1-weighted axial MR images reveal diffuse cortical atrophy with prominent sulci and enlarged lateral ventricles.

Cognitive Syndrome in the Young

• Differential diagnoses– Infection: HIV– Tumor– Drugs

• Tests

Vignette

• 75 year old with – Dementia– Hallucinations– Episodic alterations in consciousness– Bradykinesia

• Differential diagnoses

Click here to view movie

Dementia

Parkinsonism

Dementia

Dementia

DementiaParkinsonism

Parkinsonism

Initial Symptoms

AD

DLBD

PDD

Years Later

Vignette

56 year-old with 6 month history of rapidly

progressive dementia, myoclonus and

increased tone

SPORADIC CJDThere are three investigations which might provide support for a diagnosis

of sporadic CJD.  These are:The EEG The CSF 14-3-3 estimation The MR scan

Transverse FLAIR MRI showing bilateral anterior basal ganglia high signal

This is an EEG tracing showing the characteristic periodic complexes.

78 year old woman

• Confusion; started “talking crazy” and was stubborn

• Speaks with “meaningless words” and cannot answer yes/no questions accurately

• Can mime but cannot follow commands, name or repeat

• Unable to cooperate with most of exam

Questions

• What has happened to this woman?• The nature of her deficit• What mechanism?• Is she aware of her deficits? • In what settings is anosognosia seen?• Would she be able to read aloud, write or

comprehension related to reading?• Visual fields would show?• Discuss the Wernicke-Geschwind model of

language and the anatomical localization

A = AngularGyrus

SP = Superior Parietal Lobule

B =Broca’s Area

T=Pars Triangularis

H = Henschen’s Music Center

EC = Exner’s Writing Center

W = Wernicke’s Area

Definitions• Aphasia: loss of the ability to use or understand language due to a brain lesion• Mutism: the condition of being unable or unwilling to speak • Fluency: "Production and/or perception of verbal elements of communication

that adhere to the sequence, rhythm, and timing patterns approriate for the communicative context and expectations of the speaker and/or listener" (Cross, 1998).

• Paraphasia: A person with aphasia might use an incorrect word or unrecognizable word in place of the target word. This is a paraphasia. Paraphasias can be classified in 3 types. Phonemic or literal paraphasias are word errors that sound very close to the intended word (e.g., coke for coat). A verbal or semantic paraphasia occurs when a word that is related in meaning to the target word is substituted (e.g., plum for peach). The third type of paraphasia is a neologism - an invented word that is not recognizable as a word in the speaker's language.

• Dysarthria: impaired articulation due to impairment in peripheral nerves or in speech musculature

• Dysprosody: loss of or deficit in the comprehension or production of nonverbal aspects of language that convey attitudinal, emotional, and similar information to the listener.

• Apraxia: loss of the ability to produce purposeful, skilled movements as the result of brain damage

Aphasias

Fluency Comprehension Naming Repetition

Global - - - -

Broca - + - -

Wernicke + - - -

Conduction + - - -

Transcortical-M - + +/- +

Transcortical-S + - + +

Anomic + + - +

73 year old woman

• Sudden onset headache, dizziness with vomiting; unsteadiness of gait and poor coordination of the right arm

• What neurological conditions cause sudden, severe headache?

• What is the localizing value of dizziness, gait instability, and difficulty controlling the RUE?

Time Passes

• Patient is no long able to speak clearly; can open eyes and grunt

Then in ER:• BP 185/105; afebrile; no nuchal rigidity• Extensor posturing with stimulation• No response to voice and no spontaneous limb

movements• Pupils reactive• Eyes deviate to left with cold water in left ear without

nystagmus; no response when done to the right ear• 2 calls

– Test– Specialist

Questions

• What other parts of the exam is needed• Eye movements?• Caloric testing results in

– Normal awake patient– Comatose patient with intact brainstem– Brain-dead patient

• Characterize and localize patient’s limb movements

• What is the diagnosis• What phone calls were made• What is the prognosis

Definitions & Underlying Structures

• Coma

• Persistent vegetative state

• Locked-in syndrome

• Brain death

Arousal

• ARAS

Differentiate causes of Coma

• Diffuse processes– Findings– Causes

• Structural– Supratentorial– Infratentorial

Coma Exam

Findings Diencephalic Midbrain Pons Medulla

Pupils:

size/light response

Calorics

Corneals

Motor response

Respiration

Management

• How does increased intracranial pressure (ICP) cause coma?

• What are the treatments for increased ICP and how do they work?– Mannitol– Urea– Hyperventilation– Elevate head of bed– Steroids (for vasogenic only)

LEVELS OF CONSCIOUSNESS:

• Alert  normal awake and responsive state• Lethargic  easily aroused with mild stim.  Can maintain

arousal.• Somnolent  easily aroused by voice or touch; awakens

and follows commands; req stim to maintain arousal•  Obtunded/Stuporous  arousable only with repeated

and painful stim; verbal output is unintelligible or nil; some purposeful movement to noxious stim

• Comatose  no arousal despite vigorous stim, no purposeful movement- only posturing, brainstem reflexes often absent

PUPILS:   CN II afferent, CN III efferent.  Tests level of the midbrain as well as autonomic integrity.  

Some patterns:• Hypothalamus:    Horner’s (miosis, ptosis, and

anhydrosis)• Midbrain:              midpositoin, fixed • Peripheral III:        usually unilateral, more dilated, fixed• Pons:                      pin point pupils• Medulla (lat):        Horner’s- preserved response to light• Metabolic:             in general met derangements do not

affect pupils.  The major exceptions are sympathomimetics and anti-cholinergics which dilate, and opiates which cause pin point pupils.

Other Cranial Nerves

• CORNEALS:        V afferent, VII efferent.        -pons• OCULOCEPHALIC:  requires levels intact from III- VIII• GAG:      IX, X         -medulla

Check for asymmetric response as well as movement that localizes to pain, withdraws from pain, or represents posturing.

Posturing:   Decorticate:  extension LE, flexion at elbows/wrists                                                 Better prognosis than decerebrate                                                 Often without concomitant loss neuro-optho reflexes                                                 Usually lesion is above the midbrainDecerebrate:  extension LE, extension/pronation/adduction UE                                                  Often with neuro-ophtho changes                                                  Most commonly lesion at level of midbrain or di-

encephalon

Motor

Glasgow Coma Scale

             VERBAL              V5           oriented                                           V4           confused                                           V3           inappropriate words                                           V2           incomprehensible sounds                                           V1           nil

               EYE         E4           spontaneous opening                                E3            opens eyes to speech                                E2           opens eyes to noxious stim                                E1           nil

                MOTOR              M6          obeys motor requests                                           M5          localizes to noxious stim                                           M4          withdrawal from noxious stim                                           M3          abnormal flexion response (decorticate posturing)                                           M2          abnormal extension (decerebrate posturing)                                           M1          nil