Coma Peilin Lu Neurology Department SRRSH
A 32 year-old woman is found on the floor at work, unconscious, but spontaneously breathing. In the ER, BP is 146/75, pulse 80, afebrile. Her left pupil is 5 mm and sluggishly reacts to light; the right pupil is 2 mm and briskly reacts to light. She does not grimace or move to painful stimuli, nor attempt to speak.
What is the problem? • What can I do to make diagnosis? • How to check and treat?
Definition • Coma • appears to be asleep • and incapable of being aroused by external stimuli or inner need • serious disturbance of consciousness.
Arousal disorders • Disturbance of consciousness • waking disorder (Arousal disorder), • Drowsiness, • Lethargy • Coma • Light coma • Moderate coma • Deep coma • conscious content disturbance
Drowsiness • Drowsiness is the lightest kind of disturbance of consciousness, • continuous pathological sleep state, • patients can be woke up by mild stimulation and correctly answer questions or make various responses, • but go back to sleep soon after stimulation stopping.
Lethargy • disturbance of conscious status whose awakening level is more severe than drowsiness， • may show a short awakening after strong or repetitive stimulation, • having no response or incorrect response to language, • falling into lethargy very soon once the stimulation is stopped.
Coma • a kind of severe disturbance of consciousness • appears to be asleep • incapable of being aroused by external stimuli or inner need • patients can not recognize themselves or the surrounding environment, • no eyes open movement and spontaneous language movement, • rare spontaneous limb movement • physiological reflex • normal, reduced or lost, • vital signs can be stable or unstable.
Brain death • over-coma. • irreversible brain damage • loss of whole brain function, • The termination of the cerebral circulation • The dysfunctional nervous system which can not maintain the stability of the body environment
Disturbance of conscious content • Confusion • mainly characterized by serious thought disorder, may be accompanied with disorientation, hallucinations, paranoia, anxiety, and so on.
Delirium state • Also known as acute mental disorder state, • Appears as poor performance of arousal level, disorientation, lax attention, and serious disorders of many aspects such as perception, intelligence, emotion, and so on.
Persistent vegetative state • A serious disturbance of consciousness • complete loss of perception, thought, emotion, memory, will and language activities, • No response to external stimulation and no limb spontaneous activities
Altered states of consciousness: • Stupor • severely impaired arousal with some responsiveness to vigorous stimuli
Spirit inhibiting status • Common in hysteria or after severe mental trauma, • Patients lose their response to external stimulation suddenly, • May accompanied with fast breathing or breath holding, • Their eyes are closed or blinking rapidly, • Pupil light reflex are more sensitive, • Limbs are straight, buckling, • Neurological examination has no positive sign.
Locked-in syndrome • the losing of all other movement functions except eyes open, eyes close and eyes vertical movements, but the conscious is not affected.
Anatomic basis of coma. • Consciousness is maintained • by the normal functioning of • brainstem reticular activating system above the mid pons • and its bilateral projections to the thalamus and cerebral hemispheres. • Coma results from lesions that affect • either the reticular activating system • or both hemispheres. • The content of consciousness resides in the cerebral hemispheres;
Causes of coma • 1· Supratentorial mass lesions • 2· Infratentorial mass lesions • 3· Metabolic
History • Severe traumatic brain injury, • Poison taking, • Medication, • Happened in active state, • The suddenly happen of coma after a meal
Environment factors • Common CO poisoning, • CO2 poisoning, • Chloride poisoning • Mostly caused by poor ventilation of living or working places of patients.
The changing process of symptoms • Coma after : • Fever • Severe headache • Precordial angina and profuse perspiration
Concomitant symptoms • Coma accompanied with: • Hyperspasmia • Vomiting • Hemiplegic paralysis • Incontinence of urine and feces • Right upper abdominal pain, • Eyelid edema • Asthma and cyanosis • Extremely thin
Past history • Injury happened in or longer than a week before coma, • Headaches, blurred vision and paroxysmal dementia, • Paroxysmal limbs convulsions, abnormal sensation or numbness
Past history • Hypertension • Liver disease • Diabetes mellitus, • Kidney disease,
Past history • Heart disease, • Lungs • Original infection • Original endocrine disease history • Tumor or cancer,
Personal history • Endemic areas living history • Toxic substances contacting history • Radioactive materials exposure history • Clues to the diagnosis of local and occupational diseases • Family history • Congenital or genetic disease.
Signs • Basic vital signs • General physical checkup • The neurologic examination
Basic vital signs • Breathing, • Body temperature, • Heart rate • Blood pressure.
Breathing • Respiratory rate • Normal : 14-20 times/min, • Bradypnea: <9 times/min • intracranial hypertension, • respiratory failure, • Slow and sighing like breath is mostly caused by morphine poisoning; • Tachypnea: >30 times/min, • acute infections
Breathing manner • Bilateral hemispheric or diencephalic damage: Cheyne-Stokes respirations (CSR) are a patter of periodic breathing in which phases of hyperpnea regularly alternate with apnea. • Of all the respiratory patterns listed, this has the least • specificity.
Hypothalamic-Midbrain damage • Central neurogenic hyperventilation is a sustained, rapid, and fairlydeep hyperpnea that often occurs in patients with dysfunction involving the rostral brainstem tegmentum.
Pons damage • Apneustic breathing • prolonged inspiratory cramp • (a pause at full inspiration). • uncommon but localizes accurately to a lesion in the mid- or caudal-pontine level.
Medullary damage • Ataxic breathing • (Biot’s respirations) • completely irregular and chaotic breathing pattern • deep and shallow breaths occur randomly. • The lesion involves the respiratory centers in the reticular formation of the medulla that control the normal to-and-fro pattern of breathing.
Respiratory depth • Shallow and regular breathing • low blood sugar; • Snoring breathing accompanied by one side of facioplegia • cerebral hemorrhage; • Inspiratory phase > expiratory phase (stridulous breathing) • intra tracheal foreign body and severe laryngitis; • Inspiratory phase < expiratory phase • chronic obstructive pulmonary disease; • Fast, deep and regular breathing • diabetic ketone poisoning, uremia, sepsis, and poisoning by methanol, paraldehyde, vinylethyl alcohol and salicylates, often leading to respiratory alkalosis.
Breath odor • uremia, • Diabetes • hydrocyanic acid poisoning • organophosphate poisoning • hepatic coma • excessive drinking • Ammonia smell breath - • Fruity breath - • Bitter almond smell breath - • The garlic smell breath - • Liver odor - • Alcoholic smell plus vomiting -
Fever • Infection • Absorption of necrosis, • Intracranial infection, • Brain hemorrhage. • Fever accompanied with neck soft • cerebral malaria; • Fever accompanied with neck rigidity • meningitis, • encephalitis • subarachnoid hemorrhage.
Hypothermia • shock, hypoglycemia, poisoning and endocrine dysfunction. • Negative urine sugar accompanied with watery stool • cholera, • Positive urine sugar • diabetic coma.
Heart rate • Accelerated heart rate • belladonna poisoning, • Fine and speed pulse • meningitis, • Slow and loud pulse • cerebral hemorrhage and alcoholism, • Slow and weak pulse • morphine poisoning..
Blood pressure • Low blood pressure is likely seen in myocardial infarction, pulmonary infarction, aneurysm rupture, post-traumatic entorrhagia and the late phase of severe intracranial hypertension, • High blood pressure is likely seen in hypertensive cerebral hemorrhage.
General inspection: • Dry and burning heat skin -thermoplegia; • Moist skin -hypoglycemia, morphine poisoning, myocardial infarction and heatstroke; • Pallor -hypoglycemia and uremia; • Flushing -cerebral hemorrhage, alcoholism and belladonna poisoning; • Jaundice -hepatic coma; • Bleeding spots -epidemic cerebrospinal meningitis; • Roseola-typhoid fever.
Cherry red lips • carbon monoxide poisoning, • Cyanosis • hypoxic diseases such as heart insufficiency and pulmonary insufficiency, • Herpes • lobar pneumonia, meningococcal meningitis and viral infection which is accompanied with vivax malaria.
Panda eye signs such as bilateral periorbital blue，nose bleeding or bloodstain, occipital or postmastoidecchymosis, basal skull fracture.
Chest, abdomen, spine and limbs inspection • Hemorrhagic shock • pneumohemothorax and abdominal internal haemorrhage, • Fat embolism • long bone fracture.
The neurologic examination • Mental Status Examination • language function • If no respond to verbal questioning, use painful stimulation (deep nailbed pressure, sternal rub, or a cotton swab inserted into the nasopharynx, etc)
Pupils • Pupillary size depend on the balance between • parasympathetic nervous system • (causing constriction via cranial nerve III) • the sympathetic nervous system • (causing dilation via the complicated sympathetic innervation of the pupil)