Neurocritical anamnesis: unveiling unknown territory

The performance of an adequate anamnesis is paramount to ensure precise diagnosis and effective treatment. This is a formidable task in critical illness and especially taxing when patients are confused, aphasic, or, worse, sedated, and intubated. Gathering all relevant information about the patient’s medical background, including past illnesses, surgeries, medications, and allergies, is essential (ideally, given by close family members), but these often must travel separately, arriving significantly after the patient. This information enables health-care providers to make informed decisions and provide the best possible care to their patients since it allows for a subjective vision of the nosological entity that affects the person and objectively with directed questions can be routed and understanding the natural history of the most frequent diseases of daily medical practice. It is crucial to consider fundamental factors such as sex, age, and gender. Since they make the person more or less at risk of presenting a specific pathology or make one diagnosis more probable than another. We can expect to miss important points; they accumulate quickly in the heat of the moment²,³.

In the intensive care setting, most of the time, the clinical condition of the patient makes it impossible to obtain as detailed anamnesis as desired, which is why family members are a fundamental part of this first step of the clinical history since they are the ones who will provide the most data on the onset of symptoms, whether these were sudden or gradual, associated with particular clinical situations (weight loss, behavioral or behavioral changes, fever, seizures, sensory or motor disturbances, and among others)⁴. When obtaining medical history, gathering comprehensive details regarding any prior medical conditions, the treatments received, and the approach taken to manage them is crucial. This information can provide valuable insights into a patient’s health status and guide healthcare professionals in making informed decisions regarding their care (Arterial hypertension, diabetes mellitus, hormonal disorders, etc.) With this knowledge, any clinical changes or emerging symptoms can be explained and addressed more effectively⁵.

Ensuring patient safety is an essential aspect of healthcare, and one of the critical measures to take is to check for any allergies the patient may have. This step is high-priority as it helps any adverse reactions or negative outcomes that may arise from exposure. It is crucial to confirm or rule out the consumption of substances of abuse, such as drugs or alcohol, since it is not uncommon for these to affect the mechanism of action of drugs frequently used in the ICU or, more regularly, for patients with drug dependence to require higher doses than usual or shorter intervals between doses. Another essential aspect of being considered is exposure to pollutants or substances with carcinogenic potential (wood smoke, tobacco, heavy metals, pesticides, etc.) since they can be fundamental in understanding lesions that are identified as imaging studies are evaluated⁵.

At the end of the anamnesis, a review by systems should be done to evaluate aspects that currently afflict the patient since, in some situations, the reason for the current consultation is not the same as at the beginning of the symptomatology or has been accompanied by other alterations that are important to highlight in the history. Aspects such as pain, weight loss, associated symptoms such as fever or cough, gastrointestinal problems, or changes in skin color can help the evaluating physician to identify aspects that give greater weight to define the diagnosis of a patient or that, on the contrary, suggest non-neurological clinical entities that may have repercussions in the nervous system⁶.

Neurocritical exploration: unmask neurological signs through physical examination

An adequate evaluation of the physical examination of the neurological and neurocritical patient is the cornerstone to understanding the current pathology on many occasions or why the association with other findings in different systems or organs. In the neurocritical patient, it is the tool that takes on greater weight for the physician since due to the patient’s acute and severe condition of the patients, it is not possible to make a structured and complete interview of the patient. It is for this reason that the reader (student, general practitioner, or resident) should gradually become familiar with the clinical manifestations of different nosological entities and create an algorithm of approach according to the objective findings that are obtained, thus in case of being front of a similar patient will be more familiar and therefore, the fear or distrust in their knowledge will be less and therefore be able to provide better care to their patients. It is not surprising that neurocritical patient is not to the liking of all health personnel since, in many cases, they are patients with behavioral and behavioral alterations that make them difficult to treat, either because they are aggressive or because they do not want to respond to questioning or collaborate in the physical evaluation, which makes the student initially avoid this type of patient⁷,⁸.

The physical examination has several parts that should ideally be evaluated, organized, and systematically. Still, it should be noted that it is not always possible to do it in the same order or the same number of maneuvers, which is why the examiner must create increasingly dynamic strategies in the evaluation and interpretation of clinical signs that help to guide the most likely diagnosis, which in many cases will be confirmed by both imaging and paraclinical studies (Fig. 2).

Figure 2 Example dynamic physical examination. Adaptaded from Sharshar et al., 2014. 

It is vital to identify findings that may suggest intra lesions on physical examination, such as retroauricular ecchymosis (Battle’s sign) or palpebral ecchymosis (raccoon eyes) that may occur in patients with skull base fractures. It is possible to identify tongue lesions in individuals who experience epileptic seizures¹.

To ensure a more objective neurological evaluation, it is important to recognize the initial stabilization of the patient. This begins with assessing the airway as the first step; it is essential to identify which patient requires securing the airway with invasive devices to avoid cerebral hypoxia, aspiration of secretions, and thus secondary pulmonary infectious processes⁶. Among the different aspects to evaluate which patient requires intubation are the Glasgow coma scale (GCS) (Table 1)⁹ and assess which patient’s state of consciousness is better to secure the airway and thus avoid more sequelae; as a general rule, all patients with GCS < 9 should have a secured airway. However, it is essential to rule out intoxications that can reduce the state of consciousness and thus decrease the GCS score to avoid intubation in patients who sometimes do not require it (especially in alcoholic intoxication and hypoglycemia). It is also vital to evaluate ventilatory aspects that inform the physician which patient may require assisted ventilation, such as the use of accessory muscles for breathing, foreign objects in the oral or nasal cavity that interfere with the adequate passage of air to the lungs, poor management of secretions or abundant bleeding that may cause bronchoaspiration and thus aspiration pneumonia. Fundamental for an objective assessment of the neurological examination is to maintain a mean arterial pressure between 65 mmHg and 70 mmHg to ensure adequate cerebral and spinal perfusion pressure. In some cases, revitalization with intravenous fluids or vasopressor drugs is necessary to provide these goals¹,⁶,⁹.

Once the patient is stable or as stable as possible, a directed neurological examination consistent with the patient’s clinical status should be performed since completing every aspect of the neurological evaluation is impossible. Ideally, a rapid evaluation of the patient’s mental component should be done from the moment the physician approaches the patient; they may notice changes in their behavior or behaviors that already provide information about possible pathologies or even affected encephalic areas. Initially, the patient’s consciousness should be evaluated, starting with alertness¹⁰. It is advisable to categorize the patient into one of the following categories:

The physician needs to detect changes in the state of alertness since several situations can simulate neurological deterioration and not necessarily be caused by central pathologies, such as hypoglycemia, alcoholic and non-alcoholic intoxication, hydroelectrolyte disorders (especially dysnatremia), exogenous or endogenous intoxications, alterations in renal function, and among others. For this reason, the physical examination will direct the subsequent medical conduct. However, it is not the objective of this review¹⁰,¹¹.

The degree of consciousness of a neurocritical patient can also be assessed objectively with the FOUR scale (Fig. 3)¹², which allows a more precise staging of the degree of response according to four essential parameters (ocular response, motor response, brain stem reflexes, and respiration). It is essential to evaluate the degree of sedation since most neurocritical patients are under the effects of drugs that cause the neurological examination may be modified or may not be able to develop all the activities of an adequate neurological examination; the Richmond agitation and sedation scale (Table 2)¹¹. The degree of consciousness of a neurocritical patient can also be assessed objectively with the FOUR scales, which allows a more precise staging of the degree of response according to the four essential parameters¹².

Figure 3 The FOUR scale. Adapted from Wijdicks et al., 2005¹². 

Frequently, there is some degree of disorientation in patients hospitalized in ICUs since, on many occasions, the lights are kept on day and night, and the circadian cycle is not adequately identified. There are also many internal and external monitoring systems with alarms and light bulbs that turn on and off 24 h a day, and some patients remain alone in the rooms, which increases the risk of disorientation and delirium⁷,⁸.

Language assessment is quite complex, and for the neurocritical patient, it is often necessary to be very specific to identify aphasia or dysphasia of a motor, sensorineural, or mixed type (Fig. 4). From the first moment, the physician introduces himself and greets the patient; he is performing the language evaluation since if the patient understands what is being discussed, obeys orders, and emits sounds, it is logical to think there are no significant alterations at this level. It is also important to evaluate the fluency of spoken language and speech coherence as they may be altered in patients with delirium, bipolar disorders (manic phase), and disorganized thinking. The speed of speech and the number of ideas that are expressed evaluate not only the language but also the speed of thought so that tachylalia and flight of opinions can give a picture of the degree of mental compromise in the patient¹,²,⁴.

Figure 4 Assessment types of aphasia. Adapted from Wijdicks, 2022³. 

Finally, it is essential to clarify that more areas are evaluated in the mental part but that, due to the clinical context of the patient, are not usually evaluated but that should be kept in mind in specific cases, and that may require more elaborate strategies carried out by psychologists or psychiatrists. A fundamental aspect that the reader should not forget is that before thinking or making diagnoses of mental illnesses, all possible organic causes that may lead to cognitive alterations should be ruled out since, many times, the reason is processes that can be medically corrected and thus resolve the clinical change. It is also important to rule out structural lesions before thinking about mental illnesses; that is why neuroimaging should be done to evaluate possible collections, masses, and cerebral edema before the psychiatrist’s evaluation¹³.

Neurocritical assessment of motor system: enhancing physical examination

An essential part of the physical examination of the neurocritical patient is the evaluation of strength in the four extremities, which requires the active collaboration of the patient to be more objective. Usually, the patient does not undergo a gait test in the critical care unit; however, at the time of admission and as long as the clinical condition allows it, special attention should be paid to the gait pattern since it may indicate to the physician alterations of both upper and lower motor neurons. It is vital to identify hemiparetic, tabetic, or ataxic gait, which in many cases may be secondary to contralateral cortical, posterior medullary, or cerebellar alterations, respectively¹⁴.

An easy scale to implement in the ICU is the Daniels scale, which allows us to give a more specific degree of paresis and thus be able to see the evolution of the same and thus define whether there is a neurological deterioration or, on the contrary, improvement at the motor level. For its proper completion, the patient’s collaboration is required, which is why it is not possible to evaluate critically ill patients in many cases. For patients with spinal cord trauma, it is essential to correctly complete the ASIA scale (Table 3)¹⁵ by evaluating all ten muscle groups it assesses. Remember that the higher the lesion, the greater the patient’s motor, sensory, or sphincter involvement¹⁴.

The evaluation of reflexes should become a daily activity of the physical examination and not only at the musculotendinous level but also myocutaneous, cremasterine, and bulbocavernosus reflexes, especially in patients in the context of spinal cord trauma since they will differentiate patients with complete spinal cord injury from incomplete and thus change the prognosis of improvement. It should be remembered that the evaluation of reflexes also guides the examiner about alterations of upper or lower motor neurons. When evaluating the plantar response, it should be described whether it is neutral, in flexion or extension (Babinski reflex), which is another vital sign that may indicate upper motor neuron pathologies¹⁶.

In patients with neuroinfection or subarachnoid hemorrhage, a certain degree of nuchal rigidity on cervical flexion is frequent, or pain may also be experienced starting in the nuchal region and extending to the head and interscapular region. In patients with suspected meningitis, it is critical to evaluate whether there is a pain in cervical flexion accompanied by flexion of the hips and knees (Brudzinski’s sign) or pain in flexion of the knees when performing hip flexion (Kernig’s sign)⁶,¹⁷.