Consciousness and its disorders

Consciousness and its disorders The Department of Neurology General Faculty Hospital and First Medical Faculty of Charles University

Consciousness An individual is fully and appropriately aware of him/herself and of his/her environment, and is capable of acting according to his/her own will and of proper reacting to external and internal stimuli vigilance - wakefulness lucidity clearness of consciousness

Consciousness patophysiological substrate: Wakefulness - ARAS + diencephalon Lucidity - cerebral cortex

Altered consciousness In physiological conditions sleep Pathological Quantitative disruption of wakefulness Qualitative disruption of lucidity Short-term Long-term

Qualitative disorders of consciousness

Qualitative disorder of consciousness - delirium - disorder of lucidity with preserved wakefulness - altered state of consciousness with deficits in attention, memory and orientation Dysbalance of synthesis, release and inactivation of neurotransmitters that influence cognitive functions, behavior and mood

Qualitative disorder of consciousness - delirium occurs due to influence of stress situation in the background of brain pathology fully reversible Provoking factors: 1) extracerebral (e.g. intoxication by medication, alcohol, metabolic diseases, hypoxia) 2) cerebral (e.g. focal structural lesions of brain)

Qualitative disorder of consciousness - delirium epidemiology- 10-20% of all inpatients up to 80% of patients hospitalized in intensive care unit during the second day, with duration of 2.5-6 days 66-84% of cases of delirium not recognized Risk factors: high age (>65)- decompensation of borderline cerebral perfusion internal commorbidity psychiatric disorders polypharmacy alcohol, drug abuse social isolation

Qualitative disorder of consciousness - delirium Clinical manifestation: Person, place, time and activity disorientation Disruption of cognitive and mental functions - illusions, pseudohallucinations, hallucinations attention deficit delusional thinking confused incoherent verbal expression - confabulations Behavior disorder inadequate emotional reactions Altered responsiveness of autonomic system Subsequent amnesia

Qualitative disorder of Praha & EU: Investujeme do vaší budoucnosti consciousness - delirium Types according to psychomotor activity: 1) reduced - obtundation - apathy, abulia - elder patients danger of: aspiration, pneumonia, thromboembolism, decubitus ulcers 2) increased a) confusional states - confusion b) delirious states - confusion + perception disorder hallucinations without a real stimulus illusion - real stimulus but unrealistic processing c) confusional-delirious conditions - younger patients, agitation, auto-/hetero-aggresiveness

Qualitative disorder of consciousness - delirium Differential diagnosis: dementia depression sensory aphasia psychosis so-called acute amnestic conditions (confusional states caused by memory disturbance, especially recent)

Qualitative disorder of consciousness - delirium Therapy: 1) nonpharmacological Calm environment (room), re-orientation by medical staff and by family members Maintaining proper sleep-wake rhythm, stimulatory activites, early withdrawing invasive factors 2) pharmacological Revision of hazardous medication Medication of choice - atypical neuroleptic drugs - quick sedation by benzodiazepines CAVE! Excessive sedation immobility syndrome

Quantitative disorder of consciousness

Quantitative disorder of Praha & EU: Investujeme do vaší budoucnosti consciousness short-term Paroxysmal disorder Sudden onset, short duration and usually spontaneous recovery Usually severe disruption of vigilance types: 1) Syncope transient cerebral hypoperfusion 2) Epileptic seizure irritative lesion 3) Metabolic diseases e.g. resulting hypoglycemia

Quantitative disorder of Praha & EU: Investujeme do vaší budoucnosti consciousness long-term According to profundity of consciousness disturbance: Somnolence a patient is responsive when being spoken to Stupor - responsiveness to pain stimuli Coma no responsiveness to external stimuli (continuum) Caused by lesion: 1) structural 2) toxic-metabolic 3) irritative

Quantitative disorder of Praha & EU: Investujeme do vaší budoucnosti consciousness structural lesions Focal neurological symptoms Rostrocaudal deterioration Pathological findings on CT/MR scans of brain causes: stroke tumors inflammations trauma

Quantitative disorder of consciousness toxic-metabolic lesions Praha & EU: Investujeme do vaší budoucnosti Diffuse neurological symptomatology Rostrocaudal deterioration may be absent CT/MR of brain normal or diffuse changes causes: toxic, physical metabolic endocrine internal organs, vascular causes

Quantitative disorder of Praha & EU: Investujeme do vaší budoucnosti consciousness irritative lesions Centrencephalic epilepsy irritation of ARAS causes: structural toxic-metabolic idiopathic

Cerebral edema Excessive accumulation of water and sodium in the brain tissue Vasogenic: altered function of blood-brain barrier (tumors, abscess, contusion ) Toxic: dysfunction of ATP-dependent Na pump (hypoxic-ischemic, toxic lesions) Interstitial: diffusion of CSF into white matter (hydrocephalus)

Intracranial hypertension 18th 19th century Monroe Kellie hypothesis: 3 incompressible compartments Intracranial pressure: norm 7 15 mmhg (children 3 7 mmhg)

Intracranial hypertension Minimal compensatory mechanism (displacement of CFS) subsequently exponential increase in intracranial pressure Pressure-volume curve

Intracranial hypertension Perfusion pressure CPP = MAP ICP (we maintain 60 mmhg and more) Decrease in cerebral perfusion pressure e.g. when coughing

Intracranial hypertension Clinical symptoms: Headache, vomiting Vertiginous conditions Pain behind the eyes, visual disturbances Focal symptoms according to pathology localization Meningeal symptoms Increase in blood pressure and bradycardia (Cushing s reflex) Disturbed consciousness

Herniation Intracranial displacement of brain tissue in conditions with supra/infratentorial expansion directly life-threatening 1) Transtentorial descendent lateral 2) Transtentorial descendent central 3) Subfalcine 4) Fungus cerebri 5) Transtentorial ascendent 6) Occipital

Subfalcine herniation Cause: unilateral supratentorial lesion displacement of cingulate gyrus under the falx cerebri secondary ischemia in the territory of ant. cerebral artery Displacement of middle-line structures (pineal gland, septum pellucidum ) Progression of consciousness disturbance 3-5mm: somnolence 5-8mm: sopor more than 8mm: coma

Central and lateral transtentorial herniation Cause: bilateral or unilateral supratentorial lesion Central transtentorial herniation: axial displacement of diencephalon and mesencephalon into tentorial notch Lateral (uncal) herniation: displacement of uncus of hippocampal gyrus between cerebellar tentorium and brainstem Clinically ipsilateral mydriasis contralateral hemiparesis

Ascendent transtentorial herniation Cause: infratentorial expansion upward displacement into tentorial notch in all types of transtentorial lesions secondary development of brainstem hemorrhages ischemias in the territory of posterior cerebral artery

Ascendent transtentorial herniation

Occipital herniation Cause: infratentorial expansion displacement of cerebellar tonsils caudally through foramen magnum into spinal canal Clinically in slowly progressing lesion: symptoms from compression of oblongata i.e. nystagm with downward vertical direction opistotone, respiratory disorders danger of coma and of respiratory and circulatory arrest (cerebral death)

Examination of patient with disorder of consciousness 1. vital functions 2. medical history including objective anamnesis 3. somatic examination 4. neurological examination state of consciousness (GCS) brainstem functions (PBSS) respiratory type motor functions and muscle tone focal symptoms topology of lesion (brain damage levels) dynamics of findings 5. etiopathogenetic differential diagnostic analysis

ABC + GCS Airway free airways Breathing assessing and ensuring breathing Circulation assessing BP and HR elevation of upper 1/2 body (30 ) release of clothing elimination of dentures assessment of vital functions BP/HR, resp./min., S02 Insertion of PUC EKG TT cervical collar in traumas Insertion of PV catheter Blood and urine analysis examination according to condition Other somatic examination and shortened neurological examination Transport to CT event. MR further completing anamnesis and control somatic examination Biochemical analysis Na, K, Cl, osmol., urea, creatinine, glucose, TP, albumin, CRP, bili, ALT, ALP,AST,GMT, CK, CK-MB, Troponin, ft4, TSH, cortisol, ammonium Coagulation inc. D-dimers CBC lactate, Astrup A Glycemia from the finger Toxicology (blood, urine)

Examination of a patient base measures If immediate measurement of blood glucose not possible - i.v. bolus 25-50g G40% susp. Wernicke encephalopathy - glucose with thiamine susp. intoxication- administration of antagonists opiates - naloxon benzodiazepines - flumazenil

Neurological examination in altered consciousness Evaluation of conscious state brainstem reflexes ocular symptoms motor functions respiration

Neurological examination evaluation of conscious state

Neurological examination in altered consciousness Evaluation of conscious state brainstem reflexes ocular symptoms motor functions respiration

Neurological examination brainstem reflexes Pittsburgh brainstem score- PBSS Brain Stem Reflex Finding Points lash reflex present either side 2 absent both sides 1 corneal reflex present either side 2 absent both sides 1 doll's eye and/or ice water calorics present either side 2 absent both sides 1 right pupil reaction to light present 2 absent 1 left pupil reaction to light present 2 absent 1 gag and/or cough reflex present 2 absent 1 presence of all 15 points x absence of reflexes 6 points

Neurological examination brainstem reflexes ciliospinal frontoorbicular oculocephalic vertical pupillar corneal masseter oculocephalic horizontal oculovestibular thermic oculocardial gag (pharyngeal)

Neurological examination brainstem reflexes Oculovestibular reflexes

Neurological examination brainstem reflexes Oculovestibular reflexes:

Neurological examination in altered consciousness Evaluation of conscious state brainstem reflexes ocular symptoms motor functions respiration

Neurological examination - ocular symptoms Palpebral fissures and eyelid muscle tone: Open eyes - preserved vigilance x apalic syndrome Partially open eyes deep coma (muscle hypotonia) Tonic contraction and retraction of elevating muscles of eyelids - large pontine lesion asymmetry of width of palpebral fissures paresis of n.iii or Claude Bernard Horner syndrome - ptosis peripheral paresis of n.vii - lagophthalmos

Neurological examination - ocular symptoms Position of eyeballs: - conjugate eye deviation 1) horizontal supratentorial lesion destructive x irritative brainstem lesion destructive x irritative 2) vertical so-called skew deviation, persistent deviation of eyeballs downwards x upwards

Neurological examination - ocular symptoms Position of eyeballs: - nonconjugate eye deviation temporal lesion of n.iii x nasal lesion of n.vi 1) lesion of pontine centre for lateral gaze 2) lesion of medial longitudinal fasciculus 3) combination, so-called one and a half syndrome

Neurological examination - ocular symptoms Spontaneous movements of eyeballs: in horizontal direction wandering, ping-pong, restless eyes in vertical direction ocular dipping, ocular bobbing in all directions opsoclonus nystagmus

Neurological examination - ocular symptoms Pupil: we assess- width, symmetry, reaction to light norm - 2,5-4,5mm according to condition of autonomic NS (mild side asymmetry up to 1,5mm - physiological) unilateral lesion of sympathetic NS: miosis, preserved light reflex parasympathetic NS: mydriasis, light reflex is slowed down or extinct

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Neurological examination - ocular symptoms Pupil: corticosubcortical lesion pupils have normal size and appearance diencephalic lesions pupils are narrow (2mm), light reflex present Mesencephalic lesions anisocoria or wide pupils (4-6mm), light reflex absent pontine lesions pinpoint pupils (1mm), present light reflex

Neurological examination in altered consciousness Evaluation of conscious state brainstem reflexes ocular symptoms motor functions respiration

Neurological examination motor functions Motor functions: voluntary movements involuntary reflex movement (reaction to nociceptive stimuli) total akinesis

Neurological examination - abnormal posturing - mild diffuse corticosubcortical lesion paratonia more severe diffuse corticosubcortical lesion decorticate rigidity l. of mesencephalon and upper pons decerebrate rigidity l. of lower pons combined decerebrate rigidity l. of MO - generalized atonia

Neurological examination in altered consciousness Evaluation of conscious state brainstem reflexes ocular symptoms motor functions respiration

Neurological examination - respiration 1) diffuce corticosubcortical lesion posthyperventilation apnea 2) subcortical and diecephalic Cheyne-Stokes respiration 3) mesencephalopontine central neurogenic hyperventilation 4) lower pons apneustic breathing cluster breathing 5) medulla oblongata Biot s ataxic breathing, gasping 6) respiratory centre apnea

Neurological examination focal symptoms 1) lesions of cranial nerves 2) asymmetry of muscle tone and of spontaneous or reflexive movements 3) asymmetry of tendon reflexes 4) presence of spactic irritation phenomena 5) focal spasms, hyperkinesis meningeal symptoms don t have to be demonstrative

Neurological examination topology of lesion and dynamics of finding Level corticosubcortical diencephalic mesencephalic pontine bulbar Propagation of cerebral edema rostrocaudal deterioration x anterograde reparation

Neurological symptoms of lesions of individual brain levels in the context of Praha rostrocaudal & EU: Investujeme do vaší budoucnosti deterioration in focal supratentorial lesions

Corticosubcortical syndrome Praha & EU: Investujeme do vaší budoucnosti Diencephalic and brainstem reflexes: present Motor functions: aimed defensive movements, paratonia Eyes: base position, wandering movements, conjugate deviation Pupils: Isocoria with normal light reflex Respiration: normal

Diencephalic syndrome Diencephalic and brain stem reflexes present except from ciliospinal and frontoorbicular reflex Motor functions: untargeted defensive movements decorticate rigidity Eyes: base position, wandering movements Pupils: bilateral miosis (Horner), preserved light reflex Respiration: regular or periodic Cheyne-Stokes

Mesencephalo-pontine syndrome Praha & EU: Investujeme do vaší budoucnosti Diencephalic and brainstem reflexes: mesencephalic lesion: absent oculoceph. vertical and frontoorbicular rf. pontine lesion: present only oculocardial rf. Motor functions: decerebrate rigidity, event. combined decerabrate rigidity Eyes: normal or divergent position Pupils: isocoria or anisocoria without responsivenss or pontine miotic Respiration: regular or periodic Cheyne-Stokes or Biot respiration

Bulbar syndrome Diencephalic and brainstem reflexes: not present Motor functions: atonia, absence of postural reactivity Eyes: Base position Pupils: bilateral non-reactive mydriasis Respiration: ataxic gasping with apneic pauses or even apnea

Conclusion of neurological Praha & EU: Investujeme do vaší budoucnosti examination 1) vital functions 2) conscious state 3) brainstem functions 4) focal symptoms 5) dg. of topology + level of brain damage 6) etiology + diff. dg

Differential diagnosis of disorders of Praha & EU: Investujeme do vaší budoucnosti consciousness Special types of disorders consciousness: apalic syndrome akinetic mutism Differential diagnosis: locked in syndrome catatonia

Apalic syndrome Praha & EU: Investujeme do vaší budoucnosti (persistent vegetative state) Severe cortikosubcortical lesion with preserved brainstem functions (preceded by severe damage to the whole brain, reparation of more resistent phylogenetically older brainstem structures) irreversible if- longer than 12 months after trauma 3 months after anoxia Causes: anoxic-ischemic lesion diffuse axonal injury degenerative diseases metabolic diseases

Apalic syndrome Praha & EU: Investujeme do vaší budoucnosti (persistent vegetative state) Clinical picture: wakeful, not self-aware, not aware of own environment, open eyes primitive reflexes: chewing, yawning, grasping lesions of pyramidal pathways and extrapyramidal system (movements partially preserved but purposeful motor activity is absent) vegetative dysregulation preserved brainstem reflexes spontaneus respiration and circulation

Akinetic mutism Disruption of reticular- and limbic-cortical integration bithalamic paramedian lesion ev. bifrontal lesions in limbic cortex area transition into vegetative state Causes: e.g.: bilateral infarctions of ant. cerebral art. bilateral infarctions of basal ganglia or thalamus

Akinetic mutism Clinical presentation: total psychomotor inertia to all stimuli from external environment Impression of wakefulness, fixating and following gaze x no spontaneous speech or movement profound cognitive deficit hypersomnia urinary and fecal incontinence

Locked-in syndrome (Deefferentation syndrome) disruption of corticobulbar/spinal pathways mostly in ventrobasal pontine region preserved consciousness quadriplegia- akinesis, mutism palsy of cranial nerves Classical form: incl. horizontal gaze palsy Preserved blinking + vertical eyeball movements and convergence causes: -thrombosis of basilar art. -pontine tumors -pontine hemorrhage -myelinolysis of pons -trauma

Catatonia and other psychiatric conditions Vigilance fully preserved Abulia: severe apathy with loss of will, initiative and spontaneous movements Catatonia: mutism, motionless persisting in bizarre positions Psychogenic functional disorders of consciousness: -patient fights against external efforts to open his/her eyes -gaze is directed consciously away from an examiner Hysterical disorders of consciousness bizarre behavior in hysterical personalities

Cerebral death extinction of brain activity accompanied by arrest of brain circulation nonreactive coma areflexia above C1 apnea atonia hypothermia Atropine test

Cerebral death synonym for the death of an individual in both medical and legal terms authorizes a doctor to stop resucitation and to use suitable organs for transplantation (donor program presumed consent)

Cerebral death Diagnosis of cerebral death is made if: There is no doubt about cause of structural brain damage and its irreversibility Other possibilities have been excluded: intoxication effect of depressant and relaxation-promoting drugs effect of primary metabolic and endocrine disruption hypothermia

Cerebral death Panangiography Condition: mean BP above 60mmHg Evidence for brain circulation arrest, i.e. contrast media is visible the most distally in ACA A1, ACM M1 and proximate portion of AB exitus letalis oficially in time of contrast media instillation

Cerebral death brain perfusion scintigraphy i.v. RF-labeled lipophilic agent, accumulation in brain cells proportional to regional perfusion of brain absence of detection of RF confirms cerebral death transcranial doppler children

Cerebral death BAEPSSEP BAEP calvarial damage with loss or craniectomy cerebral death, absent II-V. EEG

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