Disorders of Consciousness

1
Disorders of Consciousness

• Refer to Chapter 1 of
• Clinical Neurology Textbook

2
Disorders of Consciousness

• Disorders of consciousness include
• Disorders in which the Level of consciousness is
  impaired e.g. acute confusional state, coma
• Disorders in which the level of consciousness is
  normal, but the Content is altered e.g. dementia
  or amnistic disorders

3
Disorders of Consciousness

• Level of consciousness
• Arousal or wakefulness
• Content of consciousness
• Cognitive function

4
Disorders of Consciousness

• Disorders Affecting the Level of Consciousness
• Characterized by impaired arousal or wakefulness
• Result from acute lesions of the
• Ascending Reticular Activating System
• Both Cerebral Hemispheres

5
Disorders of Consciousness

• Disorders Affecting the Level of Consciousness
• Examples
• Coma
• Most severe degree
• Pt cannot be aroused
• Acute Confusional State or Delirium
• Less severe degree
• Can present as an acute or subacute condition
• Pt is drowsy disoriented, but responds to
  stimuli

6
Disorders of Consciousness

• Disorders Affecting the Content of Consciousness
• Can be altered w/o affecting the Level of
  consciousness
• Examples
• Dementia
• Widespread deterioration of mental function
• Results from diffuse chronic pathological
  process

7
Diagnosis

• Evaluation is aimed at
• Characterizing the nature of the disorder ACS,
  Dementia
• Determining cause
• History
• HPI History of Present Illness
• PMH Past Medical History
• Cardiovascular Disorders level content
• Diabetes - content
• Head Trauma level content
• Alcoholism - content
• FH Family History
• SH Social History

8
Neurological Examination

• Mental Status Exam
• Helps to classify the disorder
• ACS, Dementia, Psychiatric Illness
• Performed in a standardized fashion
• Level of consciousness Attention
• Evaluated 1st
• Complex cortical fcn evaluated 2nd
• Language Speech, Mood Behavior, Content of
  Thought, Memory, Integrative Sensory Fcn,
  Integrative Motor Function
• Minimental Status Exam Table 1-5

9
Neurological Examination

• Mental Status Exam
• Level of Consciousness
• Described in terms of the pts apparent state of
  wakefulness response to stimuli and Documented
  w/ specific language
• Normal Awake alert with the eyes open at rest
• Impaired
• Mild sleepiness, but aroused w/ verbal stimuli
• Moderate Severe
• The level of the intensity of stimulation
  increases
• Duration of arousal decreases
• Less purposeful responses

10
Neurological Examination

• Mental Status Exam
• Attention
• The ability to focus on a particular sensory
  stimulus to the exclusion of others
• Concentration sustained attention
• Tested by
• Having the pt repeat a series of numbers normal
  5-7
• Having the pt indicate when a given letter
  appears in a random series normal no error
• ABACDAFHAEPAGPA

11
Neurological Examination

• Mental Status Exam
• Language Speech
• Essential elements of language speech
• Aphasia
• Compromised ability to communicate
• Acalculia
• Closely related to aphasia
• Dysarthria
• Articulation, mediated by lower CN, spares
  comprhension and written expression
• Wernickes Aphasia
• Comprehension

12
Neurological Examination

• Mental Status Exam
• Mood Behavior
• Mood how a pt feels most days
• Affect how a pt feel _at_ a given moment
• Dementia a condition of deteriorated mentality
  that is characterized by marked decline from the
  individual's former intellectual level
• Vs. Depression
• Delirium a mental disturbance characterized by
  confusion, disordered speech, and hallucinations
• The pt is agitated, noisy, easily provoked to
  anger

13
Neurological Examination

• Mental Status Exam
• Content of Thought
• What is the patient thinking about?
• Can help distinguish organic from psychiatric
  disease
• Are they
• Paranoid pyschosis
• Delusional false beliefs despite facts
• Phobic
• Experience Hallucinations perception w/o
  external cause
• Do they have difficulty w/ abstract thought?
• Judgment

14
Neurological Examination

• Mental Status Exam
• Memory
• Ability to register, store, retrieve
  information
• Functional Components
• Registration reception of info
• Storage info is learned or memorized
• Retrieval access of previously learned info

15
Neurological Examination

• Mental Status Exam
• Memory
• Amnesia can occur in any of the following
• Memory disorder isolated or global
• Acute Confusional State attention impaired
• Dementia attention normal, retrieval impaired
• Psychogenic affects subjective or emotional
  memories
• Organic affects objective facts
• Clinical Pearl
• Retrograde Amnesia
• Anterograde Amnesia

16
Neurological Examination

• Mental Status Exam
• Memory
• Evaluation Assessed by testing
• Immediate Recall
• Repeat random s or info not learned before
• Normal 7s forward, 5s backwards
• Registration
• Recent Memory
• Give 3-4 items to remember to repeat later
• Learning
• Remote Memory
• Recall of info pt should know
• Retrieval

17
Neurological Examination

• Mental Status Exam
• Integrative Sensory Function
• Cause lesions in the parietal lobe
• Description of the disorder misperception of or
  inattention to sensory stimuli, but primary
  sensory modalities remain intact
• Signs
• Astereognosis - touch
• Agraphesthesia written
• 2-Pt Discrimination
• Allesthesia misplaced localization
• Extinction
• Anosognosia inability to recognize
  contralateral limbs

18
Neurological Examination

• Mental Status Exam
• Integrative Sensory Function
• Signs
• Disorders of Spatial Thought
• Constructional Apraxia copy shapes, build w/
  blocks
• Rt/Lt Disorientation
• Neglect of External Space (contralateral side)

19
Neurological Examination

• Mental Status Exam
• Integrative Motor Function
• Apraxia the inability to perform previously
  learned tasks e.g. clapping motor sensory
  fcns remain intact
• Unilateral d/t contralateral premotor frontal
  cortex lesions
• Bilateral d/t bifrontal or diffuse cerebral
  lesions

20
Acute Confusional States

• Common Causes
• Drugs
• Endocrine Disturbances
• Nutritional Disorders
• Meningitis, Encephalitis, Sepsis
• Head Trauma

21
Acute Confusional States

• Common Causes
• Drugs Table 11-1
• Taken in greater doses than usual
• Taken in combination w/ other drugs
• Taken by pts w/ altered drug metabolism
• Taken by pts w/ preexisting cognitive impairment
• Laboratory Studies
• Blood UA Drug Screen

22
Acute Confusional States

• Common Causes
• Drugs
• Ethanol Intoxication
• Common findings
• Confusional state
• Nystagmus
• Dysarthria
• Limb gait ataxia
• Laboratory Studies Blood
• Intoxication 50-100mg/dl
• CNS Depression gt 100 mg/dl
• Fatal gt400 mg/dl

23
Acute Confusional States

• Common Causes
• Drugs
• Ethanol Withdrawal
• Three Withdrawal Syndromes
• Tremors Hallucinations self limiting occurring
  w/I 2 days after cessation
• Seizures occurs w/I 48 hrs after cessation, 90
  have 1-6, lasting 6 hrs
• Delirium if it occurs w/I 3-5 days, lasting up
  to 72 hrs, most serious can result in death

24
Acute Confusional States

• Common Causes
• Drugs
• Sedative Drug Intoxication
• Classic Signs
• Confusional state or coma
• Respiratory depression
• Hypotension, Hypothermia, Hyporeflexia
• Reactive pupils Nystagmus or absent ocular
  movements
• Ataxia
• Dysarthria
• Common Sedatives Benzodiazepine Barbituates
• Laboratory Studies Drug Screen

25
Acute Confusional States

• Common Causes
• Drugs
• Sedative Drug Withdrawal
• Symptoms identical to ethanol withdrawal
• Occurs when stopped abruptly
• Severity of symptoms
• Intermediate or short-acting agents are most
  likely cause
• Withdrawal Syndromes
• Similar to ethanol withdrawal

26
Acute Confusional States

• Common Causes
• Drugs
• Anticholinergics
• Classic Signs
• Agitation, Hallucinations, Fixed dilated pupils
• Blurred vision, Fever, Tachycardia
• Common Uses
• Gastrointestinal Disturbances, Parkinsons,
  Motion Sickness
• Insomnia, Asthma
• Common Anticholinergics Dramamine, Benztropine,
  Atrovent

27
Acute Confusional States

• Common Causes
• Endocrine Disturbances
• Hypothyroidism (Myxedema)
• Produces
• Confusional State
• Coma
• Dementia
• MC neurological finding delayed relaxation of
  DTR
• Labs

28
Acute Confusional States

• Common Causes
• Endocrine Disturbances
• Hyperthyroidism (Graves Disease)
• Thyrotoxic Crisis acute
• Activated Crisis young patients
• Apathetic Crisis older patients
• Neurological Examination
• Tremor Hyperreflexia
• Labs
• Thyroid Panel

29
Acute Confusional States

• Common Causes
• Endocrine Disturbances
• Hypoglycemia
• Prompt treatment essential d/t rapid progression
  from reversible to an irreversible state
• MC cause insulin overdose in diabetic pts
• Neurological s/s develop min to hrs
• Early tachycardia, sweating, pupillary dilation
• Late confusional state, agitation

30
Acute Confusional States

• Common Causes
• Endocrine Disturbances
• Hyperglycemia
• Diabetic Ketoacidosis
• Increase ketone bodies d/t abnormal carb
  metabolism
• Hyperosmolar Nonketotic State
• Table 1-12
• Clinical Findings
• Blurred vision, Dry Skin, 3 Ps, Hypotension
• Kussmaul Respiration, Mild Confusion-Coma

31
Acute Confusional States

• Common Causes
• Endocrine Disturbances
• Hyperadrenalism (Cushings Syndrome)
• MC exogenous glucocorticoids
• Excessive function of the adrenal gland
• Clinical Features
• Tuncal Obesity w/ thin extremities
• Facial Flushing
• Hypertension
• Purple Straie
• Depression, Anxiety, Memory Impairment

32
Acute Confusional States

• Common Causes
• Nutritional Disorders
• Wernickes Encephalopathy Korsakoffs Psychosis
  (AKA Wernikes Korsakoffs Syndrome, WKS)
• Wernickes Disease
• Confusion, Ataxia, Oculomotor Palsy
• Korsakoffs Psychosis
• Anterograde or Retrograde Amnesia, Dementia
• WKS d/t B1 deficiency
• Clinical Triad Ocular Abnormalities, Ataxia,
  Confusional State
• Polyneuropathy Occur in 80 of WKS

33
Acute Confusional States

• Common Causes
• Nutritional Disorders
• Vitamin B12 (Cobalamin) Deficiency
• MC cause pernicious anemia
• Clinical Features
• Neurological Degeneration
• Neurological Signs Symptoms 74 of pts, 25
  LMN, 12 UMN, 41 combined
• Non-Neurological Signs Symptoms

34
Acute Confusional States

• Common Causes
• Nutritional Disorders
• Vitamin B12 Deficiency
• Labs
• Macrocytic anemia (inc MCV)
• Leukopenia w/ hypersegmented neutrophils
  decreased luekocytes
• Thrombocytopenia w/ giant platelets decrease in
  platelets

35
Acute Confusional States

• Common Causes
• Meningitis, Encephalitis, Sepsis
• Bacterial Meningitis
• Leading cause
• Bacteria enter via mucous membranes of the
  nasopharynx, eventually seeding the subarachnoid
  space (invasion of the brain is rare)

36
Acute Confusional States

• Common Causes
• Meningitis, Encephalitis, Sepsis
• Bacterial Meningitis
• Clinical Features HA, fever, stiff neck, altered
  level of consciousness, 80 signs of meningeal
  irritation
• Neonate
• Children
• Adults
• Common Complications
• CN Palsies Sensorineural Hearing Loss

37
Acute Confusional States

• Common Causes
• Meningitis, Encephalitis, Sepsis
• Bacterial Meningitis
• Labs
• Elevated CSF pressure (90)
• CSF white cell count 1000-10,000/ml
• CSF protein 100-500 mg/dL
• CSF glucose lt 40 mg/dL
• Gram-stained smears of CSF identifies causative
  agent (70-80)

38
Acute Confusional States

• Common Causes
• Head Trauma
• Result in more deaths disability than any other
  neurologic cause before the age of 50
• Leading cause of death in men below age 35
• Mortality in severe head injuries approaches 50

39
Acute Confusional States

• Common Causes
• Head Trauma
• Mechanism of Injury
• Results from skull fracture and penetration
• Results from rapid brain acceleration and
  deceleration
• Acceleration/Deceleration causes injury to the
  brain at the point of impact, i.e. coup, and at
  the opposite pole, i.e. contrecoup
• Nerve tissue, blood vessels, and meninges are
  sheared, torn, ruptured

40
Acute Confusional States

• Common Causes
• Head Trauma
• Mechanism of Injury
• Neural disruption, intra- extracerebral
  ischemia /or hemorrhage, and cerebral edema
  result from the shearing, tearing, and rupture of
  before mentioned structures
• Hemorrhage or edema acts like an intracranial
  expansive lesion which can lead to focal
  neurologic deficits or can lead to fatal
  herniation of brain tissue through the tentorium
  or foramen magnum

41
Acute Confusional States

• Common Causes
• Head Trauma
• Mechanism of Injury
• Skull fractures can cause laceration of the
  meninges, which will lead to CSF leakage through
  the nose (rhinorrhea) or ear (otorhea). The
  fluid is colorless.

42
Acute Confusional States

• Common Causes
• Head Trauma
• Concussion
• A transient and rapidly reversible state of
  neuronal dysfunction associated with a loss of
  consciousness immediately following head injury

43
Acute Confusional States

• Common Causes
• Head Trauma
• Concussion
• Clinical Findings
• Loss of consciousness or confusion
• Structural lesions in the brain Neurological
  complications
• Unconscious Period
• Confusional State

44
Acute Confusional States

• Common Causes
• Head Trauma
• Post-Concussion Syndrome
• A syndrome that includes a variety of imprecise
  perceptual symptoms however, objective findings
  are lacking

45
Acute Confusional States

• Common Causes
• Head Trauma
• Post-Concussion Syndrome
• Clinical Findings
• Headache usually severe the day after the injury
  and can persist for weeks
• Cranial Nerve Signs Symptoms 50 dizziness,
  14 blurred vision
• Nonspecific Psychological Symptoms irritability,
  anxiety, depression, fatigue, impaired memory
  concentration

46
Acute Confusional States

• Common Causes
• Head Trauma
• Post-Concussion Syndrome
• Clinical Pearl
• Amount and role of organic brain damage is
  unclear
• Is unrelated to the potential for compensation
  from the injury

47
Dementia

• Acquired, generalized, and progressive disorder,
  which impairs cognitive function affecting the
  content of consciousness, but not the level of
  consciousness.

48
Dementia

• Diagnosis
• Need to characterize the disorder as either
• Level affect the level yes ACS
• Content affect the content global or
  circumscribed cognitive disorder
• Characterizing the disorder will determine the
  diagnostic approach taken

49
Dementia

• Diagnosis
• History
• Attempt to establish that the pts level of
  functioning has declined
• Time Course, Assoc s/s (HA, gait, incontinence)
• Family Hx, Concurrent medical illness
• Alcohol or drug use (Rx or non-Rx)
• Mental Status Exam
• Level vs Content
• Global vs Circumscribed

50
Dementia

• Alzheimers
• Disease vs Dementia
• The disease results in the dementia (87)
• Background
• Most common cause of dementia
• A cerebral disorder without extrapyramidal
  features
• Men Women in distribution
• Unknown cause

51
Dementia

• Alzheimers Disease
• Characteristics
• Cortical Atrophy
• Neuritic Plaques (AKA Senile Plaques)
• Extracellular deposition of protein in brain
  tissue
• Neurofibrillary Tangles
• Intracellular deposition of protein in brain
  tissue

52
Dementia

• Alzheimers Disease
• Diagnostic Categories
• Definite Alzheimers Disease
• Tissue confirmation
• Probable Alzheimers Disease
• Clinical picture of dementia, atypical features
  absent
• Possible Alzheimers Disease
• Clinical picture of dementia w/ atypical features
  present
• Clinical Pearl in the absence of tissue
  confirmation, clinical picture becomes most
  diagnostic feature

53
Dementia

• Alzheimers Disease
• Clinical Findings
• Early Signs
• Memory impairment earliest clinical sign
• Disorientation to time place
• Aphasia, Anomia. Acalculia
• Apraxias, Anosognosia, Depression
• Late Signs
• Psychiatric S/s Mutism, Incontinence, Dysphagia
  terminal
• Death
• Downs Syndrome
• If live past 40

54
Dementia

• Alzheimers Disease
• Studies
• Labs-no diagnostic value
• CT or MRI show cortical atrophy enlarged
  ventricals
• Cognitive testing is useful
• Differential Diagnosis
• Depression
• Memory Disorders
• Dementia w/ Lewy Bodies
• Multiinfarct Dementia
• Creutzfeldt-Jakob disease

55
Dementia

• Dementia w/ Lewy Bodies
• Background
• Second most common cause of dementia
• Cerebral disorder w/ extrapyramidal features
• Diagnostic Categories
• PD w/o Lewy bodies or AD changes
• PD w/ Lewy bodies w/o AD changes
• PD w/ Lewy bodies AD changes

56
Dementia

• Dementia w/ Lewy Bodies
• Clinical Findings
• No prominent early memory impairment i.e.
  recent memory
• Fluctuating cognitive ability
• Well-formed visual hallucinations
• Parkinsonian Signs (rigidity bradykinesia)

57
Dementia

• Vascular Dementia Syndrome
• Background
• 3rd most common cause of dementia
• Definition produced by cerebrovascular disease
• Encompasses Multiple Conditions
• Multi-Infarct, Hypoperfusion, Hemorrhagic Lesions
• Pathophysiology
• Lesion
• Multi-infarcts large, major cerebral arteries
• Lacunar State small, MC in brain nuclei, pons,
  internal capsule

58
Dementia

• Multiinfarct Dementia
• Clinical Findings
• Hx of HBP
• Stepwise progression of deficits
• Abrupt onset of dementia
• Focal neurologic symptoms

59
Dementia

• Multiinfarct Dementia
• Clinical Findings
• Neurological Exam
• Pseudobulbar palsy
• Dysarthria
• Dysphagia
• Pseudobulbar Affect
• Focal motor sensory deficits
• Ataxia
• Gait apraxia
• Hyperreflexia Babinskis

60
Dementia

• Multiinfarct Dementia
• Clinical Findings
• Studies
• The relationship between cortical vascular
  disease and dementia is poorly defined
• Absence of neuroradiologic signs of
  cerebrovascular disease strong evidence against
  vascular cause of dementia
• Presence of neuroradiologic signs of
  cerebrovascular disease no proven causal
  relationship

61
Dementia

• Creutzfeldt-Jakob Disease (CJD)
• History Overview
• Transmissible Spongiform Encephalopathy (TSE)
• AKA Prion Diseases
• PRION protein particle absent DNA
• CJD is one variable of TSE
• Pathophsyiology The infections agent (prion) is
  present in the brain, spinal cord, eyes, lungs,
  lymph nodes, kidneys, spleen, liver, CSF

62
Dementia

• Creutzfeldt-Jakob Disease
• Epidemiology
• Sporadic CJD 90 of cases
• Familial Variant are the other two types
• Annual Frequency 1/mil
• Distribution random
• De Novo Event ea case considered a new case

63
Dementia

• Creutzfeldt-Jakob Disease
• Clinical Findings (Table 1-27)
• Occurs in ages 16-82 peak 60-64
• Men Women in distribution
• Early Signs
• Mental deterioration, Physical Disabilities,
  Mixed 1/3 ea
• Course of the disease
• Memory loss Cerebellar or Visual-Oculomotor
  signs frequent _at_ onset
• Pyramidal Extrapyramidal signs variety of
  movement disorders
• Death w/I 6 months

64
Dementia

• Creutzfeldt-Jakob Disease
• Clinical Findings (Table 1-27)
• Dementia 100
• Memory Loss 100
• Cerebellar signs 71 (ataxia)
• Visual-Oculomotor 42
• Pyramidal signs 62 (corticospinal)
• Extrapyramidal signs 56 (rigidity,
  bradykinesia)
• Movement Disorders 78 (myoclonus esp)

65
Dementia

• Pseudodementia of Depression
• Depression can present similar to dementia
• Clinical Findings (Table 1-29)
• Abrupt onset
• Plateau of dysfunction
• Hx of depression
• Pt is aware of exaggerates deficits complains
  of memory loss
• Somatic complaints or hypochondriasis
• Depressed Affect
• Impairment not worse _at_ night