Diagnosis of reversible causes of coma.
Because coma has many causes, physicians must develop a structured, algorithmic approach to diagnose and treat reversible causes rapidly. The three main mechanisms of coma are structural brain lesions, diffuse neuronal dysfunction, and, rarely, psychiatric causes. The first priority is to stabilise the patient by treatment of life-threatening conditions, then to use the history, physical examination, and laboratory findings to identify structural causes and diagnose treatable disorders. Some patients have a clear diagnosis. In those who do not, the first decision is whether brain imaging is needed. Imaging should be done in post-traumatic coma or when structural brain lesions are probable or possible causes. Patients who do not undergo imaging should be reassessed regularly. If CT is non-diagnostic, a checklist should be used use to indicate whether advanced imaging is needed or evidence is present of a treatable poisoning or infection, seizures including non-convulsive status epilepticus, endocrinopathy, or thiamine deficiency.
Department of Emergency Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Rochester, MN, USA. Electronic address: jedlow@bidmc.harvard.edu.
Jonathan A
JA
Edlow
Department of Neurology, Mayo Clinic, Rochester, MN, USA.
Alejandro
A
Rabinstein
Department of Emergency Medicine, Mayo Clinic, Scottsdale, AZ, USA.
Stephen J
SJ
Traub
Department of Neurology, Mayo Clinic, Rochester, MN, USA.
Eelco F M
EF
Wijdicks
D000465:Algorithms; D001921:Brain / Q000000981:diagnostic imaging; D003128:Coma / Q000175:diagnosis* / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy; D006801:Humans; D008279:Magnetic Resonance Imaging; D008487:Medical History Taking; D008875:Middle Aged; D010808:Physical Examination; D011041:Poisoning / Q000150:complications; D011379:Prognosis; D014057:Tomography, X-Ray Computed