Guidance Offered for Managing Acute Non-Stroke Neurologic Emergencies
Tips to diagnose, distinguish, and manage acute nonstroke neurologic emergencies were offered by Megan Richie, MD, assistant clinical professor, Department of Neurology, University of California San Francisco.
Status epilepticus (SE) is defined as a continuous seizure >5 minutes or two or more seizures without return to baseline in between. The most emergent type of SE is convulsive.
The most common cause of SE is a patient with epilepsy who may be nonadherent to medications.
Another etiology is new brain injury; such patients may require treatment beyond their seizures to include treatment for the brain injury that caused the seizures, such as is the case with infectious encephalitis. Stroke and trauma can provoke SE, as can toxic/metabolic derangements. Less commonly recognized is posterior reversible encephalopathy syndrome.
The primary assessment of SE involves assessment of airway, breathing, circulation, and disability. Perform a limited medical and neurologic examination for signs of trauma, meningitis, focal deficits, and a brief laboratory workup that includes a finger stick glucose. Head imaging is indicated if the patient is not known to have a diagnosis of epilepsy. After stabilizing the patient, secondary assessment can include an EEG, lumbar puncture, and magnetic resonance imaging.
“As you’re doing your primary assessment, you’re also treating these patients. The first line is benzodiazepine therapy by whatever route is most convenient,” said Dr. Richie. “If that doesn’t work, you move forward with intravenous (IV) antiepileptic therapy.” If unsuccessful, the patient is then often intubated and treated with IV anesthetics. Address precipitating causes as they arise.
Dosing of treatments matters. “Both in the ambulance and the emergency department, patients in SE are routinely underdosed, often due to concerns that they are going to impair their airway,” she said. “Paradoxically, if you give them more benzodiazepine, they often need to be intubated less.”
Recommended dosing for IV/intramuscular (IM) benzodiazepines are lorazepam, 0.1 mg/kg IV; diazepam, 0.15 mg/kg IV; and midazolam, 10 mg IM. For IV antiepileptic therapy, dosing is fosphenytoin, 20 mg/kg; valproic acid, 40 mg/kg; and levetiracetam, 60 mg/kg.
If the patient is still seizing and continuous electroencephalography (EEG) is not available, keep in mind that if a patient can follow commands, are tracking and regarding, and are performing purposeful movements, the patient is probably not having ongoing generalized seizures. In such patients, consider weaning IV anesthetics and extubating. Evidence suggests that following an examination can be as valuable or more valuable than EEG “because the EEG is not 100% sensitive,” she said.
Other neurologic emergencies she addressed were acute spinal cord compression, emergent central nervous system (CNS) infections, and neuromuscular emergencies.
The potential etiology of cord compression can be neoplastic, traumatic, hemorrhagic, or infectious. Patients at risk of cord compression are those with known metastatic malignancy and high- or low-impact trauma.
Cord compression symptoms include back pain (most common symptom), weakness, sensory loss (1 to 5 levels below lesion), bowel and bladder dysfunction, and abnormal reflexes (areflexia or hyperreflexia). Clinical priorities are to protect the airway, stabilize cervical spine, and obtain imaging.
“The longer symptoms have been present, the less reversible they are,” Dr. Richie said. Preferred immediate imaging is magnetic resonance imaging (MRI) of the entire spine, with contrast for neoplasia or infection, and without contrast for trauma. If MRI is not immediately available, an alternative is computed tomography of the total spine. The key is to get the fastest image you can.
With confirmed cord compression, obtain immediate neurosurgical evaluation. Etiology-specific interventions are dexamethasone IV, which can reduce peritumoral edema, and radiation for neoplastic spinal cord compression; correction of coagulopathy for hemorrhagic; and antibiotics (vancomycin and ceftriaxone) for infectious, making sure to avoid lumbar puncture. The evidence is weak for steroids in the setting of traumatic spinal cord compression.
Emergent CNS infections can be bacterial meningitis, with a time course of hours to days, or herpes meningoencephalitis, the most common infectious encephalitis with a time course of days. Symptoms of bacterial meningitis are fever, meningismus, headache, and nausea. Symptoms of herpes meningoencephalitis are often referrable to temporal lobe dysfunction and can include abnormal behavior, memory dysfunction, language disturbance, and seizures with or without headache, fever, and rash.
With suspicion of herpes meningoencephalitis, do lumbar puncture first if nothing stands in your way. The cerebrospinal fluid (CSF) will be positive for herpes simplex virus by polymerase chain reaction. False negatives can occur if patients are <24 hours into the course, in which case a repeat lumbar puncture after a 72+-hour delay is indicated if suspicion for herpes meningoencephalitis remains high. Empiric acyclovir is recommended; DNA titers won’t begin to fall until after 10 days of acyclovir. “Treat first, then diagnose,” she said.
Among the acute neuromuscular emergencies, myasthenia gravis is localized to the neuromuscular junction and characterized by fluctuating diplopia, ptosis and proximal weakness, with preservation of reflexes, whereas Guillain Barré syndrome (GBS) is localized to peripheral nerves and symptoms of numbness, weakness, and back pain (may be prominent) are progressive, with loss of reflexes. Diagnosis of myasthenia gravis is made by the presence of ACH-R or MuSK antibodies. In GBS, the CSF may or may not show elevation of albumin, so trust the reflexes, she advised.
Treatment of myasthenia gravis and GBS is the same: plasma exchange (5 sessions over 7 to 10 days), making sure to take the patient off ACE inhibition, or IV immunoglobulin, 2 g/kg divided over 3 to 5 days. “Plasma exchange probably does work faster but may have more complications,” she said.
Disclosure
Nothing to disclose
Suggested reading
Status epilepticus
Brophy et al. Guidelines for the evaluation and management of status epilepticus. Neurocrit Care 2012;17:3‐23.
Glauser T, Shinnar S, Gloss D, et al. Evidence‐based guideline: treatment of convulsive status epilepticus in children and adults: report of the guideline committee of the American Epilepsy Society. Epilepsy Curr 2016;16:48‐61.
Kapur et al. Randomized trial of three anticonvulsant medications for status epilepticus. N Engl J Med 2019;381:2103‐2113.
Van Haerents S, Gerard EE. Epilepsy emergencies: status epilepticus, acute repetitive seizures, and autoimmune encephalitis. Continuum (Minneap Minn) 2019;25(2,Epilepsy):454‐476.
Cord compression
Boussios S, Cooke D, Hayward C, et al. Metastatic spinal cord compression: unraveling the diagnostic and therapeutic challenges. Anticancer Res 2018;38:4987‐4997.
Laufer et al. Predicting neurologic recovery after surgery in patients with deficits secondary to MESCC: systematic review. Spine (Phila Pa 1976) 2016;41(Suppl 20):S224‐230.
Acute CNS infections
Tunkel AR, Glaser CA, Bloch KC, et al; Infectious Diseases Society of America. The management of encephalitis: clinical practice guidelines by the Infectious Diseases Society of America. Clin Infect Dis 2008;47:303–327.
Tunkel AR, Hartman BJ, Kaplan SL, et al. Practice guidelines for the management of bacterial meningitis. Clin Infect Dis 2004;39:1267–1284.
Neuromuscular emergencies
Ciafaloni E. Myasthenia gravis and congenital myasthenic syndromes. Continuum (Minneap Minn) 2019;25:1767‐1784.
Gilhus NE. Myasthenia gravis. N Engl J Med. 2016;375:2570‐2581.
Hughes RAC, Wijdicks EFM, Barohn R, et al. Practice parameter: immunotherapy for Guillain‐Barré syndrome: report of the Quality Standards Subcommittee of the American Academy of Neurology. Neurology 2003;61:736‐40.
Sanders DB, Wolfe GI, Narayanaswami P. Developing treatment guidelines for myasthenia gravis. Ann N Y Acad Sci 2018;1412:95‐101.