Neurologic Emergencies must be managed efficiently and quickly, and several common presentations occur in the emergency setting. Common neurological emergencies include stroke, transient ischemic attacks (TIAs), altered level of consciousness, subarachnoid bleeding, seizures, and cauda equina syndrome. An approach to each emergency is briefly described below.
A Stroke is any vascular injury that reduces cerebral blood flow to a specific region of the brain. A TIA (transient ischemic attack) is a brief episode of neurologic dysfunction caused by a focal disturbance of brain or retinal ischemia, with clinical symptoms typically lasting less than 1 hour, and without evidence of infarction.
Circulation of the brain is provided through anterior and posterior circulation:
| Stroke location | Symptoms |
|---|---|
| ACA (anterior cerebral artery) | • Primarily frontal lobe function • Paralysis/hypesthesia of lower limb on contralateral side • Lower limb weakness > upper limb • Impaired judgement/insight |
| MCA (middle cerebral artery) | • Marked motor/sensory findings (upper limb > lower limb) on contralateral side • Ipsilateral hemianopsia • Agnosia common • Aphasia common if dominant hemisphere affected |
| Posterior Circulation Stroke (vertebrobasilar) | • Widest variety of symptoms, difficult to diagnose • Cranial nerves, cerebellum, neurosensory tract involvement • Vision and thought processing may be involved (occipital and parietal lobes) • May have “crossed deficits” - bilateral findings |
In acute ischemic stroke, hypertension should be managed and monitored. If using thrombolysis, one should treat to blood pressure < 185/110. If not a candidate for thromblysis, only treat if BP > 220/120, and aim for 10-20% reduction. Anti-hypertensives like nitrendipine, labetalol, nitroprusside can be used.
Altered level of consciousness can be caused by a wide variety of etiologies. Think about the context of the symptoms: the elderly are more susceptible to infectious etiologies, medication changes, stroke, occult trauma (e.g. - chronic SDH), young adults/adolescents are more susceptible to recreational drug use and trauma, and children are more susceptible to accidental toxic ingestions. Hypoactive delirium should be a diagnosis of exclusion and it is important to rule out any acute medical causes. Always check if the patient is protecting their airway (a VBG can be useful - if there is worsening hypercarbia, this requires an ICU consult!)
| Differential | |
|---|---|
| Metabolic/systemic derangements | Delirium, hypoxia, DKA, hypoglycemia, hypoperfusion, infection, toxic drug effects, post-ictal states, electrolyte disturbance, glucose disturbance |
| Structural lesions | Head trauma (SDH, EDH, SAH, concussion), stroke (thrombotic, embolic, hemorrhagic), tumour (mass effect, edema, bleeds), infection (meningitis, abscess, mass) |
The most common cause of Subarachnoid Hemorrhage (SAH) is trauma, and in non-traumatic cases, about 80% is due to aneurysms. SAH can present in one of three ways:
Seizures are sudden, uncontrolled electrical disturbances in the brain. The presentation can vary from uncontrolled jerking movement (tonic-clonic seizures) to something as subtle as a momentary loss of awareness (absence seizure).
If you witness a seizure, call for help, as the patient will likely have decreased LOC following the event. It is appropriate to call a code blue (“Medical Emergency”) if you need medications or more support. The first line treatment is with benzodiazepines either IV (preferred, or if not available then IM). Give lorazepam 2mg, or midazolam 2mg, or diazepam 5mg q2-5minutes PRN until seizures are controlled. If not already on antiepileptics, it is reasonable to load them with dilantin (20mg/kg) to prevent further seizures.
Cauda Equina Syndrome is a neurological syndrome caused by compression of the nerve roots of the cauda equina. The most common cause is due to massive midline disk herniation. There is a classic triad of: