Abnormalities at different levels of the nervous system may be referred to by different terms. Encephalopathy: abnormality of the brain (can be refined by terms such as focal, diffuse, metabolic, or toxic).
BASIC PRINCIPLES
Different levels of diagnosis
Neurological thinking
Making a neurological diagnosis
5Neurological thinking
Common and important disorders
Investigation
Systemic
Vascular
Pathological processes in neurology
7Pathological processes in neurology
Extrinsic
Intrinsic
HISTORY AND EXAMINATION
Introduction
Basic background information
Presenting complaint
History taking
9History taking
Hypothesis testing
Common difficulties in taking a history
Neurological screening questions
Past medical history
Drug history
Family history
Social history
The examination is used, like the history, as a screening test and as an investigative tool (Fig. 1). These observations must then be integrated with the history to lead to a diagnosis or differential diagnosis.
General examination
However, this can mean that students tend to think more about the technique and less about the information they need to get from the exam. The examination is used to investigate the hypotheses generated by the history and to clarify and understand any abnormalities found during the screening examination.
Examination: introduction
For example, a sensory examination of the hand will need to be carefully performed in a patient with sensory symptoms affecting the hand; this would not be done in the same detail in a patient experiencing lapses of consciousness. These brief descriptions should be considered only as an outline to be built upon by bedside teaching.
11Examination: introduction
Organization of the examination
Mental state examination
Speech
Higher function
Speech and higher function
13Speech and higher function
An examination of the eyes and visual system may be helpful in patients without visual or ocular symptoms. This section will first describe the general eye examination, then the pupil examination, visual function, acuity, visual fields, and fundoscopy.
General examination of the eye
Examination of the pupils
Examination of acuity
Examination of visual fields
The eyes and visual system
15The eyes and visual system
This should not be the case with understanding how to use an ophthalmoscope, with a clear idea of what is normal and what are normal variants, the occurrence of common and important abnormalities and, of course, practice.
Setting up the ophthalmoscope
Fundoscopy
17Fundoscopy
Traditionally, the examination of the cranial nerves is reported according to their numerical order (Box 1). During the examination, however, it is easier to group them according to their function - for example to consider the 3rd, 4th and 6th together as eye movements.
Olfactory nerve (1st)
Eye movements (3rd, 4th, 6th)
Cranial nerves 1, 3–6
19Cranial nerves 1, 3–6
Face, motor and sensory Trigeminal nerve (5th)
Other cranial nerves
21Other cranial nerves
Hearing and vestibular function (8th)
Accessory nerve (11th)
Position and posture
Muscle inspection
Tone
Power testing
Limbs: motor
23Limbs: motor
Testing the strength of the supraspinatus: abductive arm. Testing the strength of the rhomboids: pushing the elbow backward. Long thoracic nerve.
25Limbs: motor
Examining reflexes
How to elicit tendon reflexes
Limbs: reflexes and sensation
27Limbs: reflexes and sensation
Sensory examination
Vibration sense
Joint position sense
Pinprick
Temperature
Light touch
Special situations
Limbs: reflexes and sensation
When examining gait and coordination, the results must be interpreted in the light of any motor or sensory findings in the other examination. Patients with significant weakness or sensory loss of the posterior column will have some loss of coordination.
Gait
Coordination
Abnormal movements and posture
Gait, coordination and abnormal movements
29Gait, coordination and abnormal movements
Gait, coordination and abnormal movements
NEUROLOGICAL INVESTIGATION
Computerized axial tomography
Magnetic resonance imaging
Neuroradiology
31Neuroradiology
Myelography
Angiography
Functional neuroimaging
The electroencephalogram
Neurophysiological investigations
33Neurophysiological investigations
Evoked potential studies
Nerve conduction studies
Electromyography
Nerve conduction studies and electromyography
35Nerve conduction studies and electromyography
Nerve conduction studies and electromyography
This section will describe some aspects of clinical neurogenetics and discuss the main patterns of inheritance and some of the clinical problems presented by the most common neurological conditions. In this section we will review the clinical approach to patients with genetic or suspected genetic disease and examine the ways in which newer genetic tests are used.
Clues to diagnosis
Disease definition and genetic testing
Selected inherited diseases Chromosomal abnormalities
Neurogenetics
37Neurogenetics
Ethical issues of the new genetics
Anatomy and physiology
Abnormalities of CSF constituents
Cerebrospinal fluid and lumbar puncture
39Cerebrospinal fluid and lumbar puncture
How to do a lumbar puncture
Problems with lumbar puncture Failed tap
Cerebrospinal fluid and lumbar puncture
NEUROLOGICAL PROBLEMS
History
Examination
Dangerous headaches
Subarachnoid haemorrhage
Headache
41Headache
Safe but unpleasant headaches
The aura is usually visual with flashes of light or more complicated zigzag enhancement spectra that shimmer and grow in size for 5 to 30 minutes. The attack can be triggered by dietary factors such as cheese, chocolate, coffee or red wine.
43Headache
Other head pains
Loss of consciousness is one of the most common occurrences in neurology, accounting for 18% of new neurology outpatients. Cardiovascular and nervous system examinations are particularly important - look for an irregular pulse, signs of heart failure, murmurs, extracranial bruising, blood pressure in the upright and supine positions, and any focal neurological signs.
Types of blackouts and ‘funny do’s’
Other patients can mean a range of other things, including dizzy feelings, memory loss or sometimes even episodes of weakness without impaired consciousness. Other key aspects of the history include a detailed description of the blackout - what the patient did, any precipitating factors and the time course of the blackout, including any prodromal symptoms, aura immediately before the blackout, characteristics of the blackout (ictus) itself and any postictal effects are all important in making the diagnosis.
Blackouts and ‘funny do’s’
Blackout is a term commonly used to mean episodes of blackout, but some patients use it to mean episodes of altered consciousness. To help you do this, the range of feelings most commonly included within the term is discussed below.
45Blackouts and ‘funny do’s’
Vertigo
Giddiness
47Giddiness
Excessive CSF production due to a CSF-producing choroid plexus tumor is a rare cause of communication. Failure of CSF reabsorption may occur due to thrombosis in the sagittal sinus, increased venous pressure that reduces the pressure gradient across the arachnoid villi, or because the function of the arachnoid villi is impaired by the contents of the CSF: excessive cell (chronic meningitis ). subarachnoid hemorrhage or very high protein content (some tumors and inflammatory conditions).
Raised intracranial pressure
When pressure builds up in one compartment, the brain can herniate through openings into neighboring compartments. The cerebellar tonsils and fourth ventricle may also be pushed down through the foramen magnum.
Intracranial pressure
49Intracranial pressure
Low intracranial pressure
Herniation
Treatment
Terminology
Aetiology and pathogenesis
Coma
Management of coma
Coma and alteration of consciousness
51Coma and alteration of consciousness
Prognosis in coma
This is an area with difficult terminology as most of the medical terms used are in everyday use. The manifestation of any state of confusion or delirium depends on the premorbid condition of the patient.
Clinical features
In this chapter, the term delirium will be used to avoid confusion (see what we mean). Confusion is a common, non-specific manifestation of the disease in the elderly and young children.
Differential diagnosis
Delirium is common and occurs in up to 20% of medical ward patients with estimates of up to 50% of elderly hospital patients over 65 years of age. A patient with a pre-existing higher functioning deficit will be more prone to florid delirium than someone with normal higher functioning.
Causes of delirium
Assessment
Confusion and delirium
53Confusion and delirium
Investigations
Management General measures
Most of these conditions develop slowly over many years, so the incidence and social burden of the condition is very high. The role of the clinician is to identify less common conditions that can be treated, to advise on prognosis and to identify the rare familial diseases for which counseling may be important.
The approach to a patient with suspected dementia
Dementia
55Dementia
Common visual symptoms are loss of vision, blurred vision, or loss of part of the visual field. Vision loss may affect one eye or one visual field, and patients may misinterpret this, for example mistaking a proper homonymous hemianopia for a vision defect in the right eye.
Monocular visual loss
It is important to define what they mean in order to decide which part of the picture.
Binocular visual loss
Disturbances of vision
57Disturbances of vision
Some investigations of visual disturbance
As with all neurology, the time course of development of weakness derived from history is paramount to understanding its etiology.
Type and distribution of weakness (Table 1)
Weakness
59Weakness
However, sensory symptoms and signs are 'softer' than many other neurological symptoms and may occur without an established underlying cause. Sensory symptoms and signs do not occur in diseases that exclusively affect muscles, the neuromuscular junction or anterior horn cell.
Numbness and sensory disturbance
They can also be very helpful in clarifying the diagnosis in patients with other symptoms and signs. Patients will often describe the sensory disturbance as "numbness" and this term alone can be used to mean:
61Numbness and sensory disturbance
Numbness and sensory disturbance
The onset of pain on walking may be neurogenic, usually arising from lumbar canal stenosis. In some patients, the ongoing worsening may be solely due to one-sided symptoms, for example dragging in one or the other leg.
Gait analysis
Not surprisingly, the ability to walk independently is a prominent factor across all scales of neurological disability. This section discusses the patterns of gait disturbances and some associated problems, particularly gait abnormality syndromes.
Walking difficulties and clumsiness
63Walking difficulties and clumsiness
Specific conditions
Clumsiness
Cerebellar syndromes
Walking difficulties and clumsiness
NEUROLOGICAL SYNDROMES AND DISEASES
Pathogenesis
65Stroke I
An ACA infarction produces a hemiparesis, of the leg more than the arm, with apathy and incontinence, and mixed aphasia if dominant or dyspraxia if non-dominant. Occlusion of the vertebral artery may leave no deficit or may produce one of the syndromes described below.
67Stroke II
Making the diagnosis of stroke on the basis of the history, either from the patient or a relative, and the Systemic metabolic disturbances, especially hypoxia and hyperglycemia, will affect the function of the ischemic brain and worsen stroke.
Treatment and prognosis Treatment
A diagnosis of stroke can be confirmed by CT or MRI imaging, which shows whether the stroke is hemorrhagic. A patient with hemorrhagic stroke usually has hypertension and often other risk factors for atheroma.
69Stroke III
A transient ischemic attack (TIA) is an acute loss of neurological function or monocular vision caused by ischemia with symptoms lasting less than 24 hours. The investigation and management of TIAs and minor strokes from which a good recovery has been made are the same because both offer a potential opportunity to prevent a more serious stroke.
Transient ischaemic attacks and prevention of strokes
71Transient ischaemic attacks and prevention of strokes
Primary prevention of stroke
Secondary prevention of stroke and transient ischaemic attacks
Transient ischaemic attacks and prevention of strokes
Pathology
73Subarachnoid haemorrhage
Special situations Unruptured aneurysms
Complications
Treatment and prognosis
The epilepsies are the most common serious neurological diseases; 5% of the population will experience an epileptic seizure at some point in their life. Seizures cause an unpredictable loss of control, making epilepsy one of the most stigmatizing and socially debilitating of all diseases, negatively affecting many aspects of life, such as increasing divorce rates and negatively affecting.
Diagnosis
Epilepsy is not a single disease, but is a symptom of congenital or acquired CNS disease in the same way that weakness is a symptom of a number of different disorders. Different types of epilepsy can be classified according to different characteristics, including seizure type, age of onset, prognosis and cause, and are better called epilepsy.
Classification of seizures and epilepsy syndromes
75Epilepsy I: diagnosis
Single seizures
Advice following one or more seizures
When to treat?
Principles of medical treatment
Choice of medication
Measurement of drug levels in blood
Adverse effects
Drug interactions
When to stop treatment
77Epilepsy II: treatment and management
Management of status epilepticus
Surgical treatment of epilepsy
Prognosis of established epilepsy
Epilepsy mortality
In Western countries, trauma is the most common cause of death in patients under 45 years of age. Neurologists can be involved in their care, especially in the recognition and treatment of the effects of head injury.
Pathology and pathogenesis Cerebral injury
Head injury
79Head injury
Prognosis
Other complications
Differential diagnoses
Investigation and management
The most common causes in young people are spinal cord trauma, which has a prevalence of 50 in 100,000, and multiple sclerosis affecting the spinal cord (60 in 100,000). The spinal cord ends at the lower border of L1; most diseases of the lumbar spine cause radiculopathy rather than spinal cord syndromes (p. 82).
Clinical presentation
Pathological processes Trauma
Spinal cord syndromes
81Spinal cord syndromes
Aetiology
Symptoms and signs
Radiculopathy
83Radiculopathy
This is an area of demyelination with loss of myelin and relative preservation of axons (Fig. 1). In more chronic lesions, the edema and inflammation have resolved and there is a demarcated area of gliotic scarring with atrophy and axonal loss.
Pathophysiology
The diagnosis of MS requires two separate episodes of central nervous system demyelination separated in space and time. Plaques can be found in all parts of the white matter of the brain and spinal cord.
Symptoms and signs Sensory
Multiple sclerosis I
85Multiple sclerosis I
Precipitating factors
Measuring disability
The diagnosis of MS depends on the identification of multiple episodes of demyelination separated in space and time. They are not diagnostic of MS and will be abnormal in the symptomatic eye if the optic nerve is compressed.
Multiple sclerosis II
The relapsing-remitting form of MS can be mimicked by other inflammatory diseases such as systemic lupus erythematosus, sarcoid, Behçet's disease and polyarteritis nodosa, and infectious diseases such as Lyme disease and syphilis. Abnormalities on MRI of the brain are found in over 90% of patients with clinically definite MS.
87Multiple sclerosis II
Other demyelinating diseases
Management and treatment Management
Essential tremor can produce a yes-yes head tremor or titubation and a trombone tremor of the tongue, features not seen in Parkinson's disease. Both of these syndromes tend to respond poorly to treatment and have a worse prognosis than idiopathic Parkinson's disease.
Pathology and pathogenesis
The gait patterns most commonly mistaken for Parkinson's disease are the 'marche à petit pas' of diffuse cerebrovascular disease and, less commonly, the apraxic gait of normal-pressure hydrocephalus (p. 63). There are a number of syndromes that share some characteristics with Parkinson's disease but have different pathologic findings.
Parkinson’s disease and other akinetic rigid syndromes I
In more severe diseases, there may be freezing - where the patient cannot begin to walk - a form of akinesia. Later in the disease there may be some altered higher functions, sometimes a slowing of thinking (bradyphrenia); a percentage, over a quarter, will go on to develop dementia.
89Parkinson’s disease and other akinetic rigid syndromes I
Parkinson’s disease and other akinetic rigid syndromes I
Various agents have been tried to provide a neuroprotective effect and slow the worsening of the disease, and a range of treatments such as transplantation may prove useful in the future.
Pharmacology
Parkinson’s disease and other akinetic rigid syndromes II
91Parkinson’s disease and other akinetic rigid syndromes II
Treatment of other akinetic rigid syndromes
Parkinson’s disease and other akinetic rigid syndromes II
Tremors Essential tremor
Focal dystonias
Generalized dystonias
Other movement disorders
93Other movement disorders
Intracranial tumors are the second most common tumor in childhood with an annual incidence of 2-3 per 100,000. Secondary intracranial tumors (or intracerebral metastases) occur in up to 20% of cancer patients at postmortem examination.
CNS neoplasia I: intracranial tumours
In adults, primary intracranial tumors represent only 3% of tumor-related deaths and have an annual incidence of 4-7 per 100,000. Primary intracranial tumors do not metastasize outside the CNS, and thus lack a central feature of malignancies elsewhere. in the body.
95CNS neoplasia I: intracranial tumours
Management of intracranial tumours
CNS neoplasia I
Pituitary tumours (common)
Cerebellopontine angle tumours (rare)
Pineal region tumours (rare)
CNS neoplasia II: special situations
97CNS neoplasia II: special situations
Other tumours
The central nervous system is protected by the blood-brain barrier and neurological infections are relatively rare in the Western world.
Meningitis Bacterial meningitis
Infections of the nervous system I
99Infections of the nervous system I
Slow infections
Cerebral abscess
Encephalitis
Infections of the nervous system I
Spinal infections
Peripheral nerve infections
Syphilis
Tropical neurology
Infections of the nervous system II
101Infections of the nervous system II
The immunocompromised host
HIV infections and AIDS
Infections of the nervous system II
If the neuron remains intact and the pathological process is reversed, there is room for regeneration. Peripheral neuropathies can be sensory or motor, although there is usually a combination with a predominance.
Diagnosis and differential diagnosis
There is distal sensory and motor dysfunction, affecting the legs more than the arms; Sensory changes in the hands are observed when sensory changes in the legs reach the knees. The speed of onset can be divided into acute, less than 4 weeks, subacute, which develops over 1-6 months, and chronic, which develops over 6 months.
Peripheral neuropathies I: clinical approach and investigations
Peripheral neuropathies are highly variable, both in their clinical manifestations and in their etiology (Table 1). This then produces isolated axonal degeneration in the axons distal to the infarct site.
103Peripheral neuropathies I: clinical approach and investigations
Peripheral neuropathies I
Demyelinating neuropathies Guillain–Barré syndrome
Axonal neuropathies Diabetic neuropathies
Peripheral neuropathies II: clinical syndromes
105Peripheral neuropathies II: clinical syndromes
Vasculitic neuropathies
Median nerve
Ulnar nerve
Common peripheral nerve lesions
107Common peripheral nerve lesions
Lateral cutaneous nerve of the thigh (meralgia paraesthetica)
Other mononeuropathies
Radial nerve
Common peroneal nerve
Common peripheral nerve lesions
A motor neuron or anterior horn cell lies in the anterior horn of the spinal cord.
Motor neurone disease
Disorders of the motor neurone
109Disorders of the motor neurone
Polio and post-polio syndrome
Inherited diseases of upper and lower motor neurones
It is important to diagnose MG as it is a dangerous and highly treatable disease.
Myasthenia gravis Pathophysiology
Disorders of the neuromuscular junction
111Disorders of the neuromuscular junction
Lambert–Eaton myasthenic syndrome (LEMS)
This also leads to developments in the classification of muscle diseases, for example channelopathies. Syndromes of episodic weakness or periodic paralysis due to disorders of the ion channels in the muscle.
Muscular dystrophies
This is an area in neurology where recent rapid developments in molecular genetics are providing new insights into the molecular basis of muscle disease. Inheritance patterns, age of onset, patterns of muscle involvement, and prognosis vary by species.
Metabolic myopathies
Myotonic syndromes
Muscle disease
113Muscle disease
Other syndromes of muscle stiffness
Acquired muscle disease
CNS structures that are particularly important in controlling the autonomic nervous system are in the hypothalamus and the brainstem. Preganglionic fibers arise from specific nuclei in the brainstem and base of the spinal cord and pass in discrete nerves to ganglia near the effector organs.
Causes of autonomic dysfunction
The autonomic nervous system
115The autonomic nervous system
Clinical manifestations of autonomic disturbance
Investigation of autonomic failure
There are many neurological patients with neurological symptoms and signs that are not due to underlying. The term somatization has been defined as 'the expression of distress in the idiom of bodily complaints'.
Non-epileptic attacks or pseudoseizures
There is much debate about the diagnoses, classification, and terminology used in this area of neurology. This is an umbrella term that includes diagnoses (such as hysteria) with the notion of an unconscious trigger for symptoms, and patients with anxiety or depression with unexplained somatic symptoms.
Functional disorders
In others, there is an elaboration of the neurologic abnormality so that the elicited symptoms exceed the distribution of the neurologic lesion or are out of proportion to the neurologic lesion. Psychological interventions, including cognitive therapy, which attempts to reattribute physical symptoms, have been helpful in some cases.
Clinical approach
The terms frequently used are inorganic, functional, psychogenic, or hysterical, although alternatives such as somatiform disorders or abnormal illness behavior and medically unexplained symptoms have recently been suggested.
117Functional disorders
Physiologically-induced sensations and physical symptoms of anxiety
Chronic fatigue syndrome
Fibromyalgia
Paralysis
Sensory loss
Visual loss
Background Normal sleep
Sleep disorders
Sleep and sleep disorders
119Sleep and sleep disorders
Sleep that happens at the wrong time
Psychiatric factors may be important in causing physical illnesses, especially those to which the individual is predisposed, e.g.
Psychiatric complications of neurological disease
Neurological diseases presenting with psychiatric manifestations
Neurology and psychiatry
121Neurology and psychiatry
Neurological and psychotropic medication
Neurology and psychiatry Neuropsychiatric complications
Severe physical disability affects 420,000 people aged 16 to 59 in the UK, which is 0.75% of the total population. Neurological rehabilitation aims to optimize the patient's level of functioning in his or her usual environment.
Impairment, disability and handicap
Neurological diseases can cause chronic neurological impairment, which represents a significant burden of morbidity in the community. Most of the burden of caring for disabled people is borne by their families, and the rehabilitation process includes training relatives and providing them with practical, emotional and psychological support.
Recovery in the nervous system Neurological recovery
Aims of rehabilitation
Rehabilitation
123Rehabilitation
Problem-orientated team approach
Neurological rehabilitation
CASE HISTORIES
Case histories
125Case histories
His physical examination is normal, but he remembers only one of the three objects after 1 minute and fails to draw intersecting pentagons. Her family describes an illness that started three months earlier with memory impairment and she has deteriorated rapidly.
127Case histories: answers
Carpal tunnel syndrome
Acute bacterial meningitis (p. 98)
Myasthenia gravis
Juvenile myoclonic epilepsy (p. 74)
Benign paroxysmal positional vertigo (BPPV) (p. 47)
Subdural haematoma (SDH) (pp. 67 and 78)
Cervical cord compression (p. 80–83)
Guillain–Barré syndrome (GBS) (p. 104)
Migraine and analgesic misuse headache (p. 43)
Syncope (p. 44)
Left carotid territory transient ischaemic attack (TIA)
Ulnar neuropathy
Multiple sclerosis (MS)
Motor neurone disease (amyotrophic lateral sclerosis,
Case histories: answers
- Subarachnoid haemorrhage (SAH) (pp. 72–73)
- Left hemisphere tumour (p. 94)
- Left vertebral artery dissection (pp. 64–69)
- Cardioembolic stroke
- Sporadic Creutzfeldt–
- Giant cell arteritis (GCA or temporal arteritis) (p. 40)
- Focal epilepsy
- Tuberculous meningitis (TBM) (pp. 97 and 38)
These are in the brainstem above the decussion of the descending pathways, which explains the right hemiparesis and sensory loss, and involvement of the ipsilateral cerebellar pathways explains the ipsilateral ataxia. Infarction of the facial and vestibulocochlear nerves and mild hydrocephalus on CT scan are due to inflammation of the basal meninges.
Index
133Index
Index134
135Index
Index136
