Decreased level of consciousness Infection Meningitis Encephalitis Herpes

Decreased level of consciousness

Ø Infection Meningitis Encephalitis (Herpes simplex virus, arboviruses) Brain abscess or subdural empyema Human, immunodeficiency virus Tuberculosis meningitis Toxic , shock syndrome Postinfetious (acute disseminated encephalomyelitis)

Ø Trauma Abusive head trauma Hemorrhage (epidural, subarachnoid) Brain contusion Concussion Diffuse axonal injury

Ø Toxins (intoxication or Withdrawal) Ethanol Narcotics Barbiturates Antihistamines Iron Acetaminophen Aspirin(Reye syndrome) Illicit drugs Lead poisoning Thiamine deficiency(Wernice encephalopathy)

Ø Hypoxia-Ischemia Near-drowning Post –cardiopulmonary arrest(cardiac arrhytahmia, obstructive cardiomyopathy) Carbon monoxide intoxication Perinatal asphayxia Strangulation

Ø Epilepsy Subclinical(or nonconvulsive) status epilepticus Postictal states Ø Stroke Arterial ischemic stroke Cerebral sinovenous thrombosis Hemorrhage

Ø Increased Intracranial Pressure Brain tumor Cerebral edema Hydrocephalus Migraine Ø Systemic Disorders Gastrointestinal(intussusception) Vasculitis(systemic lupus erythematosus) Hepatic failure Hypertensive encephalopathy Reye syndrome Endocrine disorders (adrenal insuffiency, thyroid disorders Renal disorders(uremia) Demyelinating disorders (multiple sclerosis, ADEM)

Ø Metabolic Derangements Hypoglycemia Hyponatremia or rapid correction Hyperosmolality or rapid correction Hypercapnia Hyperammonemia Inborn errors of metabolism Diabetes mellitus- ketoacidosis or hypoglycemia -

ØDIAGNOSTIC APPROACH Routine laboratory testing Glucose Sodium, potassium, calcium, magnesium, chloride, bicarbonate, BUN, creatinine, AST, ALT, blood gases, ammonia Blood, urine analyses for toxic substances Blood, urine cultures if infection suspected Skeletal survay , ophthalmological examination if child abuse suspected

CSF Analyses including opening pressure , white and red blood cell counts, protein, glucose, and culture (± viral PCR testing) Neuroimagin Head CT Brain MRI, MRA, MRV Electrodiagnostic studies EEG Secondary laboratory testing (if cause remains unknow n) Lead level , pyruvate , lactate , serum amino acids , urine organic acids, acylcarnitine profile