neurologic disorders
Delirium
Diagnosis of Delirium
Mental status examination Standard diagnostic criteria to confirm delirium Thorough history Directed physical examination and selective testing to determine cause Delirium, particularly in older patients, is often overlooked by clinicians. Clinicians should consider delirium (and dementia) in any older patient who presents with impairment in memory or attention. Patients with any sign of cognitive impairment require a formal Examination of Mental Status . Attentionis assessed first. Simple tests include immediate repetition of the names of 3 objects, digit span (ability to repeat 7 digits forward and 5 backward), and naming the days of the week forward and backward. Inattention (patient does not register directions or other information) must be distinguished from poor short-term memory (patient registers information but rapidly forgets it). Further cognitive testing is futile for patients who cannot register information. After initial assessment, standard diagnostic criteria, such as theDiagnostic and Statistical Manual of Mental Disorders, 5th Edition(DSM-5) or Confusion Assessment Method (CAM), may be used. The following features are required for diagnosis of delirium using DSM-5 criteria: Disturbance in attention (eg, difficulty focusing or following what is said) and awareness (ie, reduced orientation to the environment) The disturbance develops over a short period of time (over hours to days) and tends to fluctuate during the day. Acute change in cognition (eg, deficits of memory, language, perception, thinking) In addition, there must be evidence from the history, physical examination, and/or laboratory testing suggesting that the disturbance is caused by a medical disorder, a substance (including drugs or toxins), or substance withdrawal. CAM uses the following criteria: An altered level of consciousness (eg, hyperalert, lethargic, stuporous, comatose) or disorganized thinking (eg, rambling, irrelevant conversation, illogical flow of ideas) History is obtained by interviewing family members, caregivers, and friends. It can determine whether the change in mental status is recent and is distinct from any baseline dementia (see table). The history helps distinguish a mental disorder from delirium. Mental disorders, unlike delirium, almost never cause inattention or fluctuating consciousness, and onset of mental disorders is nearly always subacute. Sundowning(behavioral deterioration during evening hours), which is common among institutionalized patients with dementia, may be difficult to differentiate; newly symptomatic deterioration should be presumed to be delirium until proved otherwise. History should also include use of alcohol and all recreational, over-the-counter, and prescription drugs, focusing particularly on drugs with anticholinergic and/or other central nervous system (CNS) effects and on new additions, discontinuations, or changes in dose, including overdosing. Nutritional supplements (eg, herbal products) should also be included. Examination, particularly in patients who are not fully cooperative, should focus on the following: Vital signs Hydration status Potential foci for infection Skin and head and neck Neurologic examination Findings can suggest a cause, as with the following: Fever, meningismus, or Kernig and Brudzinski signs suggest CNS infection. Tremor and myoclonus suggest uremia, liver failure, drug intoxication, medication toxicity, or certain electrolyte disorders (eg, hypocalcemia, hypomagnesemia). Ophthalmoplegia and ataxia suggest Wernicke Encephalopathy . Focal neurologic abnormalities (eg, cranial nerve palsies, motor or sensory deficits) or papilledema suggests a structural CNS disorder. Scalp or facial lacerations, bruising, swelling, and other signs of head trauma suggest Traumatic Brain Injury (TBI) . Testing usually includes CT or MRI Tests for suspected infections (eg, complete blood count [CBC], blood cultures, chest x-ray, urinalysis) Evaluation for hypoxia (pulse oximetry or arterial blood gases) Measurement of electrolytes, bloodureanitrogen (BUN), creatinine, plasma glucose, and blood levels of any medications suspected to be having toxic effects A urine drug screen If the diagnosis is unclear, further testing may include liver function tests; measurement of serum calcium andalbumin, thyroid-stimulating hormone (TSH), vitamin B12, erythrocyte sedimentation rate (ESR) and/or C-reactive protein (CRP), and antinuclear antibody (ANA); and a test for syphilis (eg, rapid plasma reagin [RPR] or Venereal Disease Research Laboratory [VDRL] test). If the diagnosis is still unclear, testing may include cerebrospinal fluid (CSF) analysis (particularly to rule out meningitis, encephalitis, or subarachnoid hemorrhage), measurement of serum ammonia, and testing to check for heavy metals. If nonconvulsive seizure activity, including status epilepticus, is suspected (suggested by subtle motor twitches, automatisms, and a fluctuating pattern of bewilderment and drowsiness), electroencephalography (EEG) monitoring should be done. 