COMA is a topic covered in the Harrison's Manual of Medicine.

To view the entire topic, please or purchase a subscription.

Harrison’s Manual of Medicine 19th edition provides 600+ internal medicine topics in a rapid-access format. Download Harrison’s App to iPhone, iPad, and Android smartphone and tablet. Explore these free sample topics:

Harrison’s Manual of Medicine - App + Web

-- The first section of this topic is shown below --

Because coma demands immediate attention, the physician must employ an organized approach (Table 16-3). Almost all instances of coma can be traced to either widespread abnormalities of the bilateral cerebral hemispheres or to reduced activity of the reticular activating system in the brainstem.

  1. Diseases that cause no focal or lateralizing neurologic signs, usually with normal brainstem functions; CT scan and cellular content of the CSF are normal.
    1. Intoxications: alcohol, sedative drugs, opiates, etc.
    2. Metabolic disturbances: anoxia, hyponatremia, hypernatremia, hypercalcemia, diabetic acidosis, nonketotic hyperosmolar hyperglycemia, hypoglycemia, uremia, hepatic coma, hypercarbia, Addisonian crisis, hypo- and hyperthyroid states, profound nutritional deficiency
    3. Severe systemic infections: pneumonia, septicemia, typhoid fever, malaria, Waterhouse-Friderichsen syndrome
    4. Shock from any cause
    5. Postseizure states, status epilepticus, nonconvulsive status epilepticus
    6. Hypertensive encephalopathy, eclampsia
    7. Severe hyperthermia, hypothermia
    8. Concussion
    9. Acute hydrocephalus
  2. Diseases that cause meningeal irritation with or without fever, and with an excess of WBCs or RBCs in the CSF, usually without focal or lateralizing cerebral or brainstem signs; CT or MRI shows no mass lesion.
    1. Subarachnoid hemorrhage from ruptured aneurysm, arteriovenous malformation, trauma
    2. Acute bacterial meningitis
    3. Viral encephalitis
    4. Miscellaneous: fat embolism, cholesterol embolism, carcinomatous and lymphomatous meningitis, etc.
  3. Diseases that cause focal brainstem or lateralizing cerebral signs, with or without changes in the CSF; CT and MRI are abnormal
    1. Hemispheral hemorrhage (basal ganglionic, thalamic) or infarction (large middle cerebral artery territory) with secondary brainstem compression
    2. Brainstem infarction due to basilar artery thrombosis or embolism
    3. Brain abscess, subdural empyema
    4. Epidural and subdural hemorrhage, brain contusion
    5. Brain tumor with surrounding edema
    6. Cerebellar and pontine hemorrhage and infarction
    7. Widespread traumatic brain injury
    8. Metabolic coma (see above) with preexisting focal damage
    9. Miscellaneous: Cortical vein thrombosis, herpes simplex encephalitis, multiple cerebral emboli due to bacterial endocarditis, acute hemorrhagic leukoencephalitis, acute disseminated (postinfectious) encephalomyelitis, thrombotic thrombocytopenic purpura, cerebral vasculitis, neurologic paraneoplastic syndromes, gliomatosis cerebri, pituitary apoplexy, intravascular lymphoma, etc.

-- To view the remaining sections of this topic, please or purchase a subscription --