The distinction between the signs and symptoms of disease is as old as medicine itself. Signs are what the healthcare professional sees, hears, or feels when they examine you. Symptoms are what you experience. Patients with neurological conditions might experience headaches, blackouts, tremor (shaking), weakness, slowness or stiffness of movement, numbness or tingling sensations, burning or stabbing pains in the face or body, dizziness, problems with sleep, or issues with memory. Your description of your symptoms – your medical history – is especially important in a neurological consultation, as many of the commonest and most important neurological diagnoses (such as epilepsy, stroke, or migraine) are made almost exclusively on the basis of the history.
Headaches
Headaches are common. Nearly all of us experience mild tension-type headaches from time to time, though these rarely cause us any problems. By far the most common cause of recurrent debilitating headaches is migraine, which up to 30% of the population will experience at some point in their lives. Migraine headaches are often severe enough to stop us doing what we want to do, and are typically accompanied by other features such as nausea, or sensitivity to lights, noises, smells, or movement. About one-quarter of people with migraine experience an aura – typically flashing lights or blind spots in their vision, lasting up to 30 minutes – usually before the headache comes, but sometimes on its own without any other symptoms at all. Other primary headache disorders such as cluster headache have very particular and specific characteristics that allow diagnosis to be made and effective treatment instituted.
While we often worry that headaches are due to a serious underlying problem such as a tumour or an aneurysm, this is fortunately very rarely the case. However, sudden severe headaches that reach their peak within seconds, headaches associated with the other neurological symptoms discussed in this section, or headaches that do not go away, but get steadily worse over days or weeks, all warrant assessment, often including an MRI scan of the brain.
Further information about headaches can be found on the London Headache Centre website, or in Dr Weatherall’s book Living with Headaches.
Blackouts
Blackouts – a loss or near-loss of awareness or consciousness – are frightening, disconcerting experiences. By far the commonest reason for people to pass out is a simple faint, where the blood pressure drops to a point where the brain cannot function properly. Recovery from faints is usually rapid. People can sometimes be seen to twitch or shake as a consequence of a faint (see these classic videos of early 1990s German medical students being made to faint), and this can be difficult for non-medical personnel (and sometimes medical personnel!) to distinguish from a fit or seizure. A detailed history, including if possible an eye witness account of the event, can often distinguish a benign fainting episode from something more significant. Investigations in such cases might include a brain scan, an EEG (a recording of the electrical activity of the brain), 24 or 48 hour recordings of the heart rhythm, and an ultrasound scan of the heart.
Tremor (shaking)
We all shake. Put your arms out in front of you, and gravity will start to pull them down. Our body constantly has to actively compensate for this, but no-one’s body does this perfectly (apart from a lucky few who become Olympic shooting gold medalists). As we get older, these systems generally work a little less well, and if such shaking increases to a point that it starts to interfere with things (such as holding a cup of tea or coffee), then we may label it benign or essential tremor. This type of shaking often runs in families, and can sometimes start quite early in life when it does. Excessive shakiness in young people should be checked out, however.
The presence of a tremor in people as they get older often raises the question of Parkinson’s disease. Shaking in this condition is usually asymmetrical, and typically occurs when the limb is not being used. Other signs are usually required to firmly diagnose this condition, and there are other causes of tremor that can look a lot like Parkinson’s. In these cases, a detailed history and thorough examination will usually provide an answer, though in some cases investigations such as an MRI scan of the brain or a DAT scan may be helpful.
Weakness
When we want to move, our brain sends signals from the motor cortex on the surface of the top of the brain, down through lower centres in the brain, and into the spinal cord. At the relevant level of the spine, the signal is transferred to a nerve that exits though a nerve root, and then follows a course out through the body to the appropriate muscle, causing that muscle to contract. Weakness can therefore arise from problems at any point in this process. Clues from the history of the problem – whether it came on suddenly or gradually, whether there is associated pain or loss of sensation, and so on – are put together with the findings on examination to decide whether the problem lies in the central nervous system (brain and spinal cord), or the peripheral nervous system (muscles and nerves). Once the problem area has been localized, further investigations (scans, blood tests, and/or electrical tests of the nerves and muscles (NCS/EMG)) may help confirm the diagnosis, and give more information about the underlying cause.
Slowness or stiffness of movement
The nerve circuits (mentioned above in the section on Weakness) that control movement are complex. Specific systems ensure that muscle movements are smooth and co-ordinated. There are multiple ways in which these systems can go wrong, leading to slowness and stiffness of movements. Once again, the history and examination will provide pointers towards the underlying problem, or problems; the slowing down of movement caused by Parkinson’s disease and related conditions is usually apparent in this way, for example. Imaging of the brain and spine can be helpful in establishing, for example, whether there are any changes suggestive of inflammation or mini-strokes in the case of the former, or of wear and tear in the neck or lower back in the case of the former. Occasionally, movement problems of this nature are due more to problems with the joints than the nervous control of movement, in which case the opinion of a rheumatologist can be sought.
Numbness or tingling sensations
The pathways that take information from our extremities to our brain are the exact mirror image of those that take information the other way to initiate and control movement. In the same way, therefore, that problems anywhere in those pathways that descend from the brain to the body can cause weakness, problems anywhere in the pathways that ascend from the sensory nerve endings in the skin and internal organs back up to the brain can cause loss of sensation (numbness) or altered sensation (tingling). Examination will usually establish whether the problem is with a single nerve (such as in carpal tunnel syndrome, for example), the nerves more generally (peripheral neuropathy, most commonly seen in the UK in people with diabetes), the nerve roots, the spinal cord, or the brain. As with weakness, appropriate investigations depend on whether the problem is central or peripheral, but might include scans, NCS/EMG, and blood tests.
Burning or stabbing pains in the face or the body
Persistent burning or itching pain usually arises from problems with nerves, and is called neuropathic pain. It is often associated with loss of sensation related to the causes mentioned in the section above on Numbness or tingling sensations. Where nerves fire off by themselves, causing stabbing pains or electric shock-like symptoms, we call this neuralgia. The history of the problem, and the distribution of the pain, will usually lead to the diagnosis. Certain patterns are very characteristic, such as the excruciating stabbing pains in the cheek and/or jaw brought on by chewing, speaking, brushing one’s teeth, or even by exposure to the cold that is seen in trigeminal neuralgia. In most cases, treatment can be instituted immediately even if further investigations are required to ascertain the exact nature or cause of the pain.
Dizziness
Dizziness is word that means different things to different people. The first requirement therefore is to establish exactly what is meant by the term in each case, by taking a detailed history. For some people dizziness means a sense of the world moving or spinning around them, or them feeling as if they are moving or spinning when they know they are still – this is vertigo. It most often relates to problems with the inner ear; examination and, if required, hearing tests, and scans of the internal auditory meati (the area of the inner ear and related brain structures) will usually clarify the cause and guide treatment. For other people dizziness means light-headedness; this is often due to low blood pressure; simple bedside tests will often suggest this as a possibility, and relevant tests (often a head-up tilt table test) can be arranged. Sometimes dizziness can be related to other neurological conditions such as migraine, or even anxiety; again, a detailed history should make this clear.
Problems with sleep
Insomnia and other problems with sleep are very common. A basic sleep diary, which records the time of going to bed, of getting to sleep, of waking in the night, and eventually of getting up in the morning will often show a clear pattern. Further investigation is often not required, and treatment with sleep hygiene, sleep-specific cognitive behavioural therapy, and appropriate medications can be effective. Unusual experiences that occur on falling asleep, or whilst asleep (such as restlessness, muscle jerks, falling sensations, or periodic leg movements, for example) can also often be diagnosed and treated without recourse to further investigations. In more complex cases, an onward referral to a sleep clinic for actigraphy or formal polysomnography can be arranged.
Issues with memory
We all forget things. We all find ourselves half way through a sentence, struggling to remember what we meant to say, or have a brief block on the name of someone we have met before, or find ourselves in the next room wondering what we have come in to get. These brief episodes of forgetfulness are caused by transient interruptions to the processes of attention and concentration in our brains. These types of ‘memory’ problems are common in people with anxiety, or chronic pain. Simple bedside tests will usually establish that formal memory systems remain unimpaired. Where more significant memory problems are apparent, the same simple assessment tools will often provide a working diagnosis, guide initial investigations such as an MRI brain scan, and provide a baseline for requesting more detailed neuropsychological assessment if required.