The Neurologic History
When taking the neurologic history it is useful to have a systematic way of trying to establish the diagnosis. Firstly get the narrative, then focus the history (see below) and then do a neurology review of symptoms. By the end of the history you should have begun to formulate a differential diagnosis. The first step in establsihing the differential diagnosis will be localisation of the lesion. You should identify if it is likely peripheral versus central nervous system, if it is primarily a motor versus sensory problem or perhaps the issue is mobility and balance. With the localisation in mind it is time to start considering the underlying pathophysiology. It is only through a thorough history of the nature of onset and progression of the symptoms that you can begin to establish this. Then you put the two together and get your differential diagnosis. The differential diagnosis should only consist of about 3 possibilities. An extensive differential diagnosis is not practical and may waste time with unnecessaary tests.
It is important to interpret the patients description of their symptom appropriately. A patient may describe their limb as being numb but this may mean numbness, pins and needles and/or weakness. It is your job to determine what they mean. Similarly, patients will use the term dizziness to mean vertigo but also presyncope. Also, when describing the patients symptoms in the history it is better to use their terminology such as a problem with speech rather than dysarthria or dysphasia. Then when you are formulating your impression at the end of both the history and examination you can then make the interpretation as at this point it will be apparent if it is dysarthria, dysphasia or neither. Below is one example of how to systematically perform the neurologic history.
- Establish the narrative- what was the patient doing at symptom onset? what had they been doing that day? Was it a normal day? Had they slept ok the night before? Was it a particularly warm day? Is there a particular time of day that the symptoms are worst? Were they standing or sitting at onset of symptoms? If they were standing had they just stood up or were they standing for some time? Etc etc
- Establish what the symptoms are- is it numbness or tingling, is it weakness, if it is weakness what are the functional limitations? So if someone tells you their arm is weak then focus their history by asking in what tasks do they notice the weakness such as opening jars (suggesting distal or hand weakness) or is it more for heavy lifting (suggesting a more proximal weakness). Is it more like a stiffness than a weakness? Is there any fatigability assoicated with the weakness?
- Establish the nature of onset- was it sudden, acute (onset within a week), subacute (onset greater than one week but less than a few weeks) or insidious (onset over weeks- months). This is critical in neurology- weakness that came on suddenly is likely vascular in aetiology whereas onset over a week or so suggests an inflamamtory aetiology.
- Establish the pattern- getting worse over time, better over time, staying the same or fluctuating.
- Any exacerbating factors or relieving factors- For example lightheadedness on standing up that is relieved on sitting down suggests postural hypotension. Numbness in the hand that awakens someone from sleep and is relieved by moving or shaking the hand suggests something like carpal tunnel syndrome. Or for someone with a headache establishing if the person has an aversion to light or sound helps with a migraine diagnosis or a change in character between lying and standing helps establish if there may be a pressure component to the symptoms.
- Then at this point you will have begun to formulate a differential diagnosis and you can start checking for any background medical issues that may have been a predisposing factor. For example, if you think the diagnosis is a stroke or TIA you will proceed to ask of there is a history of hypertension, cholesterol, smoking history, previous cardiac history, exercise levels etc
- Then before concluding the neurology history ask about all the possible focal symptoms that have not been covered in the history of the presenting illness. And also ask if there were any other symptoms that the patient has not yet told you but that may be relevant.
- Any similar symptoms from the past should be included in the history of presenting illness. For example, if migraine is the issue then a brief summary of their overall migraine pattern preceding this latest episode should be included in the history of presenting illness. Also, any medications that may be relevant to the presenting illness should be included in the history of presenting illness. So for example, if you have a patient with a painful peripheral neuropathy the neuropathic pain killers they have tried, the dosages, the benefits or lack there-of and the side effects all need to be noted. Patients may not have the full details of this but it is useful to know even the names of medications that have been tried in the past.
- Then proceed with the rest of the history as normal- past medical history, medication history, family history and social history.
Before you even start your neurological examination you will have an idea of what to expect and what to look for.
You should have established which part of the nervous system is likely to be causing the problem. You will know it is primarily motor fibres, sensory fibres or autonomic fibres or a combination. You will have an idea if its peripheral nervous system versus central nervous system. For example if the patient is complaining of pain, numbness and tingling in both feet and maybe some issues with balance the most likely cause is a peripheral neuropathy (peripheral nervous system) or if stiffness and tremor are the main symptoms along with deterioration of mobility you will be thinking of a form of parkinsonism (basal ganglia and central nervous system). If there are multiple cranial nerve abnormalities then this may be peripheral (such as multifocal mononeuropathies) or central (brainstem) and the pattern will help you distinguish between them. Then knowledge of your “working diagnosis” will dictate the examination.
Things to note on observation that can be done whilst taking the history:
- Greeting, manner, orientation, attention, mental state, mood, personal hygiene.
- Cognitive conversational clues such as a patient turning to a relative to answer a simple question.
- Speech, language and facial appearance.
- Gait and stance.
- Involuntary movements.
- The patient's expectations of the consultation may also become apparent as you take the history- such as the expectation of having tests, needing medication, willingness to take medication etc.
The Neurologic History
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