Diagnosis of Neurological Disease

Neurological Interview

The neurologist may be an intimidating figure for some patients. To add to the stress of the neurological interview and examination, the patient may already have a preconceived notion that the disease causing the symptoms may be progressively disabling and possibly life threatening. Because of this background, the neurologist should present an empathetic demeanor and do everything possible to put the patient at ease. It is important for the physician to introduce himself or herself to the patient and exchange social pleasantries before leaping into the interview. A few opening questions can break the ice: “Who is your doctor, and who would you like me to write to?” “What type of work have you done most of your life?” “How old are you?” “Are you right or left handed?” For children, questions like “Where do you go to school?” or “What sports or other activities do you like?” After this, it is easier to ask, “How can I be of service?” “What brings you to see me?” or “What is bothering you the most?” Such questions establish the physician’s role in the relationship and encourage the patient to volunteer an initial history. At a follow-up visit, it often is helpful to start with more personalized questions: “How have you been?” “Have there been any changes in your condition since your last visit?”

Another technique is to begin by asking, “How can I help you?” This establishes that the doctor is there to provide a service and allows patients to express their expectations for the consultation. It is important for the physician to get a sense of the patient’s expectations from the visit. Usually the patient wants the doctor to find or confirm the diagnosis and cure the disease. Sometimes the patient comes hoping that something is not present (“Please tell me my headaches are not caused by a brain tumor!”). Sometimes the patient claims that other doctors “never told me anything” (which may sometimes be true, although in some cases the patient did not hear, did not understand, or did not like what was said).

Chief Complaint

The chief complaint (or the several main complaints) is the usual starting point of the diagnostic process. The complaints serve to focus attention on the questions to be addressed in taking the history and provide the first clue to the anatomy and etiology of the underlying disease. The chief complaint also provides insight into the patient’s level of understanding of his or her symptoms. For example, the patient may present with the triad of complaints of headache, clumsiness, and double vision. In this case, the neurologist would be concerned that the patient may have a tumor in the posterior fossa affecting the cerebellum and brainstem. The mode of onset is critically important in investigating the etiology. For example, in this case, a sudden onset usually would indicate a stroke in the vertebrobasilar arterial system. A course characterized by exacerbations and remissions may suggest multiple sclerosis, whereas a slowly progressive course points to a neoplasm. Paroxysmal episodes suggest the possibility of seizures, migraines, or some form of paroxysmal dyskinesia, ataxia, or periodic paralysis.

History of the Present Illness

As one continues interviewing the patient, localization, figuring out from where the problem originates, remains paramount. In addition, a critical aspect of the information obtained from this portion of the interview has to do with establishing the temporal-severity profile of each symptom reported by the patient. Such information allows the neurologist to categorize the patient’s problems based on the profile. For example, a patient who reports the gradual onset of headache and slowly progressive weakness of one side of the body over weeks to months could be describing the growth of a space-occupying lesion in a cerebral hemisphere. The same symptoms occurring rapidly, in minutes or seconds, with maximal severity from the onset, might be the result of a hemorrhage in a cerebral hemisphere. The symptoms and their severity may be equal at the time of the interview, but the temporal-severity profile leads to totally different hypotheses about the mechanism and etiology.

Often the patient will give a very clear history of the temporal development of the complaints and will specify the location and severity of the symptoms and the current level of disability. However, in other instances, the patient, particularly if elderly, will provide a tangential account and insist on telling what other doctors did or said, rather than relating specific signs and symptoms. Direct questioning often is needed to clarify the symptoms, but it is important not to “lead” the patient. Patients frequently are all too ready to give a positive response to an authority figure, even if it is incorrect. It is important to consider whether the patient is reliable. Reliability depends on the patient’s intelligence, memory, language function, and educational and social status and on the presence of secondary gain issues, such as a disability claim or pending lawsuit.

The clinician should suspect a somatoform or psychogenic disorder in any patient who claims to have symptoms that started suddenly, particularly after a traumatic event, manifested by clinical features that are incongruous with an organic disorder, or with involvement of multiple organ systems. The diagnosis of a psychogenic disorder is based not only on the exclusion of organic causes but also on positive criteria. Getting information from an observer other than the patient is important for characterizing many neurological conditions such as seizures and dementia. Taking a history from a child is complicated by shyness with strangers, a different sense of time, and a limited vocabulary. In children, the history is always the composite perceptions of the child and the parent.

Patients and physicians may use the same word to mean very different things. If the physician accepts a given word at face value without ensuring that the patient’s use of the word matches the physician’s, misinterpretation may lead to misdiagnosis. For instance, patients often describe a limb as being “numb” when it is actually paralyzed. Patients often use the term “dizziness” to refer to lightheadedness, confusion, or weakness, rather than vertigo as the physician would expect. Although a patient may describe vision as being “blurred,” further questioning may reveal diplopia. “Blackouts” may indicate loss of consciousness, loss of vision, or simply confusion. “Pounding” or “throbbing” headaches are not necessarily pulsating.

The neurologist must understand fully the nature, onset, duration, and progression of each sign or symptom and the temporal relationship of one finding to another. Are the symptoms getting better, staying the same, or getting worse? What relieves them, what has no effect, and what makes them worse? In infants and young children, the temporal sequence also includes the timing of developmental milestones.

An example may clarify how the history leads to diagnosis: A 28-year-old woman presents with a 10-year history of recurrent headaches associated with her menses. The unilateral quality of pain in some attacks and the association of flashing lights, nausea, and vomiting together point to a diagnosis of migraine. On the other hand, in the same patient, a progressively worsening headache on wakening, new-onset seizures, and a developing hemiparesis suggest an intracranial space-occupying lesion. Both the absence of expected features and the presence of unexpected features may assist in the diagnosis. A patient with numbness of the feet may have a peripheral neuropathy, but the presence of backache combined with loss of sphincter control suggests that a spinal cord or cauda equina lesion is more likely. Patients may arrive for a neurological consultation with a folder of results of previous laboratory tests and neuroimaging studies. They often dwell on these test results and their interpretation by other physicians. However, the opinions of other doctors should never be accepted without question, because they may have been wrong! The careful neurologist takes a new history and makes a new assessment of the problem. However, integration of objective data such as dates and test results into the patient’s subjective narrative is essential.

The history of how the patient or caregiver responded to the signs and symptoms may be important. A pattern of overreaction may be of help in evaluating the significance of the complaints. Nevertheless, a night visit to the emergency department for a new-onset headache should not be dismissed without investigation. Conversely, the child who was not brought to the hospital despite hours of seizures may be the victim of child abuse or at least of neglect.

Review of Patient-Specific Information

Information about the patient’s background often greatly helps the neurologist to make a diagnosis of the cause of the signs and symptoms. This information includes the history of medical and surgical illnesses; current medications and allergies; a review of symptoms in non-neurological systems of the body; the personal history in terms of occupation, social situation, and alcohol, tobacco, and illicit drug use; and the medical history of the parents, grandparents, siblings, and children, looking for evidence of familial diseases. The order in which these items are considered is not important, but consistency avoids the possibility that something will be forgotten.

In the outpatient office, the patient can be asked to complete a form with a series of questions on all these matters before starting the consultation with the physician. This expedites the interview, although more details often are needed. What chemicals is the patient exposed to at home and at work? Did the patient ever use alcohol, tobacco, or prescription or illegal drugs? Is there excessive stress at home, in school, or in the workplace, such as divorce, death of a loved one, or loss of employment? Are there hints of abuse or neglect of children or spouse? A careful sexual history is also important information. The doctor should question children and adolescents away from their parents if obtaining more accurate information about sexual activity and substance abuse seems indicated.