A 10 - Emergency in Neurology Flashcards
what does neurological emergency associated with?
disorders of consciousness:
- respiratory
- circulatory failure
- epileptic activity
These three groups of symps interact with each other, i.e. any of them may lead to the other two or augment their effects within a short period of time.
in which situations Neurological emergencies arise in?
- A nervous system lesion causes central or peripheral respiratory failure
- A nervous system disease leads to life threatening complications (infections, thrombotic events)
- Nervous system dysfunction is caused by diseases and abnormal states originating outside the nervous system (metabolic disturbances, global cerebral ischemia, hypoxia, intoxication)
what can cause resp. failure in neurological emergency?
caused by damage to:
○ The CNS → Raised ICP
○ The PNS → Myasthenia, Guillan-Barré syndrome
○ Neural structures, including the muscles
what can be the complications of resp. failure?
Respiratory failure from any cause may also lead to secondary damage of parts of the CNS, which are sensitive to hypoxia (cortex, basal ganglia)
examples of circulatory failure due to neuronal causes?
- rare *
● Neurogenic pulmonary edema
● spinal shock
● CNS complications of circulatory failure however, are common and serious (e.g. in global cerebral
ischemia, complete destruction of the brain occurs in five minutes in normal ambient temp.)
● Global cerebral functional disturbance occurs in case of impairment of parenchymal organs (e.g.
renal or hepatic failure)
what are the 2 main groups of Disorders of consciousness?
Disorders of arousal (sleep-like state)
Disorder of awareness (inadequate thinking and behaviour)
what is arousal?
the ability to wake up from sleep when stimuli are applied
what is the Anatomical basis of arousal
intact functioning of the ascending reticular activating system (ARAS)
what is reduced arousla?
- mildest to severe forms *
○ Somnolence
○ Stupor
○ Coma
what is somnolence?
verbal stimuli enough to generate awakening reaction
what is stupor?
verbal stimuli hardly effective, may open eyes to painful stimuli
what is coma?
cannot be awakened and posture is usually abnormal (decorticate/decerebrate)
■ Coma I: Brainstem reflexes are preserved
■ Coma II: Brainstem reflex
Disorder of awareness?
inadequate thinking and behaviour
● The CNSs global function is impaired
● Signs of focal cognitive deficit (e.g. alexia, acalculia) are not part of this condition
● Arousal is normal, but the content of memory is disturbed, inaccessible or their use is
inappropriate
Clinical form in awareness disorder?
○ Persistent vegetative state (decorticate state/apallic syndrome)
what could be the causes of disorders of awareness?
Damage to the cerebral cortex:
○ Global cerebral ischemia caused by circulatory arrest, severe metabolic conditions like hypoglycemia, renal- and hepatic failure, postconvulsive state, Wernicke’s encephalopathy, final stages of cortical dementias
○ Extensive white matter damage (diffuse axonal injury after head trauma)
○ Bilateral damage to the thalamus