Altered Mental Status is one of the most frequently encountered admitting diagnosis in hospitals across the world, in large part due to the wide range of conditions affecting cognitive function. For the same reason, the descriptive and diagnostic value of “Altered Mental Status” in isolation is of little value to the hospital clinician as almost any medical condition can present with some degree of mental status change. In this chapter we will outline an approach to neurologic presentations associated with a change in mental status, and highlight the appropriate use of simple and well-established terminology. An emphasis will be further placed on always associating a diagnosis of “Altered Mental Status” with a better descriptive terminology to facilitate the appropriate therapeutic approach and improve patient outcomes.
CASE 22-1
A 75-year-old woman with a history of hypertension and hyperlipidemia presents acutely to the emergency department complaining of blurry vision and sleepiness. She had woken up around 7 a.m. on the day of admission feeling more drowsy than usual, and when walking to the bathroom, she noticed that she was unable to see clearly. Her husband called 911, and a stroke code was called for “Altered Mental Status.”
CASE 22-2
A 75-year-old gentleman with a history of hypertension, hyperlipidemia, and atrial fibrillation was in his usual state of health on a Sunday afternoon when he suddenly became drowsy, complaining of blurry vision. He was taken to the emergency department and a stroke code was called for “Altered Mental Status.”
One of these cases is a neurologic emergency, whereas the other is entirely benign. While the availability of specialty services may mitigate the hospital physician’s need to be able to distinguish one from the other, a major goal of this chapter is to review simple diagnostic tools to enable all physicians to make a more refined diagnosis related to changes in mental status, and thereby expedite and improve patient care.
The first step is to obtain a pertinent history. As elementary as this may seem, an incomplete history is one of the prime sources of most unnecessary testing and specialty consultations in the hospital setting. Despite its critical importance, a busy hospital practice with an emphasis on appropriate triage can make obtaining an accurate history challenging. But a pertinent medical history does not take long, and is absolutely essential to instituting the appropriate therapy. From a neurologic perspective, pertinent information includes:
A detailed description of current symptoms
Are the symptoms acute?
Have the symptoms occurred previously?
Are there any symptom triggers?
Are there other associated symptoms?
Are there significant medical problems that may contribute?
Have any new medications been started recently?
Does the patient take medications that can affect cognitive function?
Whether a patient’s change in mental status is from a neurologic cause can often be determined simply by a focused history. Changes in expressive or receptive language, ptosis, diplopia, facial asymmetry, trouble swallowing, or focal weakness would be examples of symptoms that, when coupled to a diagnosis of “altered mental status,” would be strongly suggestive of a neurologic etiology.
CASE 22-2 (continued)
More history was obtained from the cases presented above. In case #1, the patient said that images were blurry in all gaze directions. She did not endorse double vision, which is often described as blurry vision by patients. Her symptoms started acutely after getting out of bed and putting on her glasses, and have persisted since then. She endorsed feeling tired, but attributed this to a poor night’s sleep. She denied any problems in her general interaction with her husband or any difficulty with language. She denied other cranial nerve symptoms, such as vertigo, ataxia, facial weakness or swallowing problems. There were no arm or leg weakness or numbness, and her gait seemed to be normal. Her medical problems had been stable, and no new medication had recently been started. Importantly, the history was corroborated by her husband. Patients’ histories should always be corroborated by a second party whenever possible, even if this requires a 2-minute phone call.
The patient in case #2 had some trouble giving a history. He was able to convey that he felt very tired, and did not know why. He described blurry vision, and when asked in more detail endorsed horizontal double vision when looking left or right. He did not have difficulty swallowing, and had no weakness or numbness in the arms or legs. He thought his walking was ok. His wife corroborated this, and said that symptoms started abruptly, and that he has never had similar symptoms in the past. He was recently started on warfarin for newly diagnosed atrial fibrillation, and was getting regular blood draws for International Normalized Ratio (INR). Otherwise his medical conditions had been stable.
The medical and neurologic examinations allow you to localize the presenting problem or, at the very least, enable the addition of a useful symptom descriptive to the diagnosis of “Altered Mental Status.” Pertinent aspects of the examination include:
Vital signs
General medical examination
Neurologic examination
Level of alertness
Language
Cranial nerves
Motor examination
Sensory examination
Reflexes
Cerebellar function and gait
The neurologic screening examination, as outlined above, should not take more than 5 minutes, and provides invaluable descriptive information regarding the presenting symptoms, allowing the treating physician to more appropriately triage or, in the case of no specialty support, institute appropriate therapy.
How would we describe the level of alertness in the cases presented above?
Terms such as “sleepy” or “sedated” are often used on the wards, but a precise definition of levels of consciousness has long been used by neurologists and neurosurgeons. Based on Plum and Posner’s classic work,1 6 levels of consciousness can be defined, in order of severity:
Drowsiness
Clouding of consciousness
Delirium
Obtundation
Stupor
Coma
Drowsiness refers to a minimally reduced level of consciousness without an altered response to the environment. Such patients have no difficulty with orientation or tests such a serial-sevens (consecutive subtractions of 7, starting from 100) or spelling WORLD backwards. Clouding of consciousness refers to minimally reduced levels of alertness where patients do have minor difficulties with orientation of tests of alertness. Delirium is described in detail elsewhere in this book. Patients with delirium are often agitated, with disrupted sleep–wake cycles, and the frequent occurrence of hallucinations and delusions.2 Patients who are obtunded have a more reduced level of alertness compared to clouding, and display less interest in the environment with significant cognitive slowing. Patients who are obtunded often fall asleep during the interview and examination, with physical or auditory stimulation needed intermittently to keep the patients focused. Stuporous patients have a severe reduction in their level of alertness, and only awaken with “rigorous and sustained” stimulation. An example of this is a patient who can only answer some questions while the examiner performs a sternal rub, falling asleep immediately after the stimulation ends. Coma refers to a state of unresponsiveness, with eyes closed. Coma ranges from the complete absence of motor responses and reflexes, to varying responsiveness without awakening to rigorous stimulation.
How do we determine the level of alertness is an important step in the acute assessment of patients with “Altered Mental Status.”
This can be done quite easily by following a few simple steps:
Is the patient awake? Does he/she need stimulation to stay awake?
Is the patient oriented to self, place, date, and situation?
Can the patient spell WORLD backwards?
Can the patient repeat 5 numbers in a row (forward digit span)
Can the patient focus on the tasks at hand?
The patient who tends to fall asleep during your interview, but arouses to voice, and has no difficulty with 2–5 above, is considered drowsy. If the same patient has minor difficulties with 2–5 above, for example, not completely oriented to place and time, the patient is considered to have clouded consciousness. Ensure that this is different from the patient’s baseline as many individuals with an underlying cognitive deficit will have baseline difficulties with orientation and the tasks noted in 2–5 above. See examples of patients who are obtunded, stuporous, and in a coma above.
How do we assess basic features of language?
A language deficit may render the patient unable to answer many of your questions coherently, and while many patients who present with aphasia gets an admitting diagnosis of “Altered Mental Status,” there is typically no change in their level of alertness. Three major aspects of language must be determined as follows:
Does the patient follow commands? If the patient can answer your questions coherently, you have already addressed with question.
Is the patient able to express himself/herself appropriately? If he/she can provide a history, you have already answered this question.
Can the patient repeat a short sentence?
Patients who have difficulty with expressive language have a Broca’s, or nonfluent, aphasia. Patients who cannot understand commands, but speak fluently have a Wernicke’s, or fluent, aphasia. Repetition is used to distinguish lesions in Broca’s and Wernicke’s areas from those in higher cortical regions. Repetition is always abnormal when the former areas are involved, but is normal with cortical lesions inducing an aphasia, termed a transcortical aphasia.
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