Textbook of Clinical Neurology

Voorwerk

1. A brief history of neurology

Abstract

It took some time for our awareness of the nervous system to evolve: it was only after the Middle Ages that the current concepts accepted in regular Western medicine were developed. Important foundations for neurological theory were laid down in the 19th century. These were corroborated using scientific techniques in the 20th and 21st centuries, and many of these methods have become normal features of clinical practice. The substantial expansion of knowledge and understanding has given rise to more and more specialist fields of neurology.

J. B. M. Kuks, J. W. Snoek

2. The neurological consultation

Abstract

A diagnosis and treatment plan is drawn up following history-taking and clinical examination at the bedside or in the consulting room. These elements of every consultation are vital to good practice and save a good deal of time, money, problems and uncertainty, provided they are carried out properly. Each element of history-taking, clinical examination and diagnostic testing has a particular diagnostic value, changing the prior probability into a posterior probability. If the prior probability is low it will often be decided not to carry out any further tests unless diagnosing the condition has major consequences for the patient.

J. B. M. Kuks, J. W. Snoek

3. An overview over nervous system and muscles. Technical investigations in neurology

Abstract

The nervous system can be divided into two parts, the central and the peripheral nervous system. The central nervous system is a hierarchical structure, with higher centres modulating lower ones. The peripheral nervous system originates in the motor anterior horn of the spinal cord and terminates in the dorsal ganglion, near the spinal cord. At rest, nerves and muscles are in electrical equilibrium. When they are stimulated, action potentials develop: these follow particular paths and produce an effect remotely through nerve-to-nerve and nerve-to-muscle communication, which is mediated chemically by transmitters. In pathological situations nerves or muscles fail to respond when stimulated. Electromyography provides a lot of information by measuring nerve conduction velocity or abnormal muscle action. An EEG measures brain activity. The indications for EEG are epilepsy, sleep and coma. To enable readers to understand the opportunities afforded by supplementary tests in the case of neurological disorders this chapter gives a brief recapitulation of neuroanatomy and neurophysiology. A broad outline of anatomy is given in sect. 3.1, and 3.2 gives information on imaging. Sections 3.3, 3.4 and 3.5 recapitulate the physiology of nerves, muscles and motor units respectively, which is required for the explanation of electromyography in sect. 3.6. The measurement of signals in and from the central nervous system is explained in sect. 3.7, and 3.8 discusses other laboratory techniques.

J. B. M. Kuks, J. W. Snoek

4. Strength and sensation

Abstract

Skeletal musculature is affected by the peripheral motor neuron in the anterior horn of the spinal cord. This motor neuron acts within a reflex arc steered by sensory information from the peripheral parts of the body. The spinal reflex is modulated by higher parts of the central nervous system in order to damp the motor reaction. In the case of failing central regulation, reflexes become exaggerated and spasticity occurs. Sensory information can be divided into protopathic and epicritic sensibility. These two modalities are processed in different parts of the nervous system. There is a somatotopy for both sensory and motor functions in the central nervous system. As different systems follow different paths, it is possible to make a topical diagnosis by combining the patient’s signs and symptoms. History-taking and clinical examination are therefore crucial when taking decisions to carry out further investigation. By finding particular symptoms, it is possible to make a diagnosis of ‘non-organic disorder’.

J. B. M. Kuks, J. W. Snoek

5. Motor control

Abstract

Motor control is regulated by sensory information and internal planning. There is teamwork between sensory cortical areas, basal nuclei and the cerebellum. In the case of basal ganglia dysfunction, motion is restricted, and in the case of cerebellar problems it is too extensive. This can be seen by observing body movements: especially gait and ocular movement and speech may be dysarthric. In the case of unilateral disturbances, the contralateral basal ganglia or the ipsilateral cerebellum may be involved. It is fairly easy to identify the pyramidal tract, the basal ganglia, the cerebellum or deep sensation as the cause of a movement disorder. Non-organic problems frequently present as a disorder of movement.

J. B. M. Kuks, J. W. Snoek

6. Brainstem and cranial nerves

Abstract

The brainstem is the portal between the brain and the spinal cord, through which signals pass in both directions. The brainstem also acts as the ‘spinal cord’ for the cranial senses and muscles. Various biogenic amines are produced in the brainstem, which regulate mood, vigilance, attention and initiative (see above). Ten of the twelve cranial nerves lead to or from the brainstem. Unlike the spinal cord nuclei, they are usually controlled by both cortex hemispheres. The brainstem performs various vital and autonomic motor system functions. Failure of the brainstem gives rise to a life-threatening condition. An EMV score provides an indication of brainstem function. Discrete failure can be associated with a wide variety of syndromes, in the context of which the problem can be localized on the basis of the combined clinical symptoms.

J. B. M. Kuks, J. W. Snoek

7. Autonomic nervous system, hypothalamus and pituitary gland

Abstract

The autonomic nervous system originates in the hypothalamus. It has two parts: a sympathetic system, with neurons in the lateral horns of the spinal cord and the prevertebral nuclei, and a parasympathetic system, with nuclei in the medulla oblongata and the conus of the spinal cord. The final neurons of the parasympathetic system are located close to the organs they serve, in contrast to other peripheral neurons, which are located in or close to the spinal cord. In each organ of the body, there is interaction between the two parts of the autonomic nervous system. This chapter considers in turn the hypothalamus, the pituitary gland, cardiovascular regulation, pupillomotor control, and control of the bladder and bowels.

J. B. M. Kuks, J. W. Snoek

8. The higher cerebral functions

Abstract

The brain is made up of a phylogenetically primitive part (the limbic system) and a more modern part. The more primitive part is the seat of aggression, emotion and episodic learning. The processes controlled from the modern part include perception, interpretation and association, and planning. Aphasia, agnosia and apraxia are the main disorder groups relevant in this context. The dominant hemisphere (usually the left) has an analytical function, while the non-dominant hemisphere has a more emotional and strategic function. Cortical function disorders cannot always be localized. Both the cortex itself and its internal and external connections can play a role. Disorders of the latter are known as disconnection syndromes. Memory cannot be attributed to any one region. Declarative memory (facts and associations) is associated mainly with the parieto-temporo-occipital regions, while emotional and episodic memory is housed in the more primitive regions, working memory in the basal nuclei. A lot can be learnt about the function of the cerebrum from simple bedside testing.

J. B. M. Kuks, J. W. Snoek

9. The visual system

Abstract

The visual system runs from the eye to the occipital cortex and from there back to the cortical regions, which handle the functional (parietal) and emotional (temporal) processing of visual information. The system is strongly lateralized: external events on the right are processed in the left cerebrum and vice versa. A disorder can normally be localized within the visual system by testing the visual fields. After being registered in the occipital cortex, visual signals are analysed and synthetized to form an identifiable concept. The main disorders of the central visual functions are visual hallucinations and delusion, palinopsia, neglect, loss of spatial awareness, inability to name things or read, and inability to recognize functional objects or faces.

J. B. M. Kuks, J. W. Snoek

10. Cerebral meninges and the cerebrospinal fluid system

Abstract

The cerebrospinal fluid (CSF) system lies at the centre of the brain and extends throughout the nervous system, between the two innermost cerebral meninges. CSF is produced in the ventricles and drains from the top of the convexity in the dural venous sinuses. The function of the CSF is not entirely clear. However, it is known to perform a mechanical function. Analysis of the CSF for sugar, proteins, immunoglobulins, cells and other substances provides a basis for accurate diagnosis, since various conditions are associated with distinct CSF- characteristics. Disorders of the CSF- system can lead to hydrocephalus, intracranial hypertension and intracranial hypotension (all of which can be treated with reasonable efficacy).

J. B. M. Kuks, J. W. Snoek

11. The cerebrovascular system

Abstract

The cerebrum is served both by the carotid arteries and the vertebral artery (which unite to form the basilar artery). These three blood vessels are connected by the circle of Willis, so that if one fails the others can take over to a degree. Failure of the basilar artery is inevitably catastrophic, however, since the brainstem is deprived of oxygenated blood. Regulation of the cerebral vascular system is autonomous of the rest of the body, so that a fall in blood pressure does not immediately affect the cerebrum. If cerebral perfusion is impaired, infarction can occur. That gives rise to various syndromes, depending on which region is affected. Blood vessel abnormalities in the form of aneurysms, arteriovenous malformations, dissection and a number of less common problems lead to neurological conditions and potentially to serious disability. Diagnosis is based on contrast medium tracking, MRI and/or sonography.

M. Uyttenboogaart, J. B. M. Kuks, J. W. Snoek

12. Diseases of the muscle and neuromuscular junction

Abstract

Diseases of the muscles and the neuromuscular junction have a common symptom, namely loss of strength. Atrophy and cramps are also found. Many muscular diseases have a genetic cause and are almost untreatable, but this is why it is very important to recognize acquired diseases, as a good deal can usually be done about them therapeutically. When classifying muscular diseases a distinction needs to be made between proximal and distal myopathies, and between diseases with and without myotonia. Myasthenia is a special case: unlike most other muscular diseases it often causes diplopia, and the severity of the symptoms fluctuates. Myasthenias are usually autoimmune diseases and as such respond well to treatment, but incorrect treatment can cause life-threatening situations. In cases of muscular disease care needs to be taken with anaesthesia and good genetic advice must be given.

J. B. M. Kuks, J. W. Snoek

13. Disorders of the motor neurons, nerve roots and peripheral nerves

Abstract

Neurological diseases are far more commonly acquired than muscular diseases. They can be classified based on anatomy, loss of function and pathophysiology. Acquired dysfunction can be caused by metabolic disorders, vascular disorders, compression and inflammation. Anterior horn cell (motor neuron) disorders are purely motor syndromes. Amyotrophic lateral sclerosis (ALS) is the most notorious cause. Inflammatory neuropathies also manifest themselves mainly as motor disorders; they have an acute (Guillain-Barré syndrome) or chronic course (chronic inflammatory demyelinating polyneuropathy, CIDP) and respond well to treatment. Various local nerve problems can be diagnosed as mononeuropathy or plexopathy. Polyneuropathy is a common systemic disease; a few types are treatable, so targeted diagnosis is warranted.

P. A. van Doorn, J. B. M. Kuks, J. W. Snoek

14. Neurological pain syndromes

Abstract

Pain can be classified into nociceptive (tissue damage) and neuropathic (nerve damage, neurogenic). Radicular syndrome is defined as pain radiating from the neck into the shoulder and/or arm (cervical radicular syndrome, CRS) or from the back into the buttock and/or leg (lumbar radicular syndrome, LRS), accompanied by one or more symptoms or signs that are congruent with damage to a specific cervical or lumbosacral root respectively. Radicular syndrome is usually but not consistently the result of irritation or compression of a nerve root due to a prolapsed or ruptured (herniated) disc or bony compression (= compression caused by bone formation inside or just outside the vertebral canal). Radiating pain can also occur without nerve constriction being present; this is called pseudoradicular syndrome. Cervical and lumbar radicular syndromes share many similarities, but there are also clear differences in both symptomatology and treatment. There is a differential diagnosis in both CRS and LRS. In the case of very severe, especially nocturnal, pain in the shoulder, one should also consider the possibility of neuralgic amyotrophy, and in the case of severe nocturnal pain in the lumbosacral region that of neuroborreliosis. A history of malignancy, of course, points to the possibility of metastatic root compression. If cervical radicular syndrome is suspected, the physical examination is aimed at distinguishing between radicular and pseudoradicular syndrome. The indication for surgery in the case of radicular syndrome caused by a herniated disc is based primarily on clinical and not on MRI findings. Both CRS and LRS are clinical diagnoses, based mainly on the history, with physical examination having only limited value. Watchful waiting pays off, but not for everyone. Cauda equina syndrome (CES) is an indication for emergency surgery.

R. J. M. Groen, J. B. M. Kuks, J. W. Snoek

15. Diseases of the spinal cord

Abstract

The causes of myelopathy are many and various. The damage to the spinal cord may be complete (as in the case of a complete spinal cord injury) but it is more often incomplete (as in the case of an incomplete traumatic spinal cord injury and most types of myelopathy due to non-traumatic causes). There are some classic spinal cord syndromes, but in practice they do not generally display classic symptomatology. In practice, information from the history-taking combined with examination of the main tract systems enables the height of the damage to be localized and a differential diagnosis to be formulated.

R. J. M. Groen, J. B. M. Kuks, J. W. Snoek

16. Disorders of the cranial nerves

Abstract

Diseases of the cranial nerves result in sensory function loss and/or the loss of facial motor control. Hearing and sight may be lost, for example, double vision or vertigo may occur, swallowing and speech may become difficult, and the face may become paralysed or hypersensitive. Cranial nerve problems can usually be traced and resolved. That is the case, for example, with viral infections, compression due to intracranial hypertension, drug poisoning, autoimmune disorders and meningitis.

J. B. M. Kuks, J. W. Snoek

17. Cerebral infarction and cerebral haemorrhage

Abstract

Cerebral infarctions and cerebral haemorrhages are cerebrovascular disorders (strokes). Strokes are a major cause of mortality and disability. Imaging is required to make the correct diagnosis. Cerebral infarctions are caused primarily by atherosclerosis, but there are cardiac and other – albeit rare – causes. A TIA is in fact an impending cerebral infarction and needs to be diagnosed quickly. The possibility of thrombolysis during the acute phase means that a cerebral infarction is a medical emergency. Hypertension, amyloid angiopathy and vascular malformations can cause intracranial bleeding. Subarachnoid haemorrhages are usually caused by a ruptured aneurysm. Rare cerebrovascular disorders are cerebral venous sinus thrombosis and cerebral vasculitis. The treatment of stroke patients requires a multidisciplinary approach. If residual symptoms are present after a cerebral infarction or cerebral haemorrhage the success of rehabilitation is affected by cognition and mood.

P. J. Nederkoorn, M. Uyttenboogaart, J. B. M. Kuks, J. W. Snoek

18. Epilepsy and other paroxysmal disorders

Abstract

There are many types of seizure, and by no means every seizure is caused by epilepsy. Seizures need to be classified as precisely as possible, as the classification affects the likelihood of a symptomatic or hereditary cause and the treatment and prognosis. Treatment for epilepsy needs to be tailored to the patient. In addition to drug treatment – and sometimes surgery – it is important to consider lifestyle and life stage (contraception, pregnancy, etc.).

O. F. Brouwer, C. A. van Donselaar, J. B. M. Kuks, J. W. Snoek

19. Altered consciousness

Abstract

Full consciousness is characterized by wakefulness, focused attention and normal cognitive function. A coma patient by definition has closed eyes, does not respond to commands and does not talk. If a patient is comatose, the cause needs to be found as soon as possible. Coma can be caused by damage to brain tissue (structural coma) or metabolic dysregulation. It can be due to a brain herniation syndrome. Herniation syndromes obey certain laws. Altered consciousness due to a metabolic disorder does not usually have a sudden onset. The prognosis for postanoxic coma depends on how long the patient has been unconscious. If there is no obvious cause of the coma, the possibility of non-convulsive status epilepticus should always be considered. Decrease in the level of consciousness without loss of consciousness is often indicative of a diffuse cortical disorder. Delirium patients have impaired attention to and perception of their surroundings. Frontal injuries can produce a state of ‘lack of will’ (abulia). Patients in a vegetative state have no contact with their surroundings. Cerebral death is a diagnosis that can only be made if strict conditions are met.

J. B. M. Kuks, J. W. Snoek

20. Head and brain injuries

Abstract

Every year Accident and Emergency departments see large numbers of patients with head injuries, some including brain injuries. These brain injuries are usually mild, and the vast majority of these patients do not develop any complications. It is important to provide good-quality standardized care in the acute phase, as a very small proportion of these patients develop potentially severe intracranial complications that can be fatal if not diagnosed and treated in time. Brain injuries can be classified into two types, diffuse and focal. A head injury may be accompanied by damage to the neurocranium and base of the skull, which in turn can lead to cranial nerve damage and leakage of CSF. If a patient survives a severe brain injury, the severity of the residual disability will be determined far more by mental and cognitive than physical sequelae.

B. Jacobs, J. B. M. Kuks, J. W. Snoek

21. Headache and facial pain

Abstract

Headache is a very common complaint in both primary and secondary care. Careful history-taking is the most important tool for diagnosing it. Some types respond well to treatment, others are virtually intractable to standard treatments. Tension-type headache and migraine are the most common types. There can sometimes be a potentially serious underlying cause (symptomatic headache). Clinicians need to be on the lookout for red-flag symptoms.

M. D. Ferrari, J. Haan, J. B. M. Kuks, J. W. Snoek

22. Neurological tumours and neurological complications of malignant conditions

Abstract

Brain tumours can cause general (non-focal) and focal symptoms. The most common brain tumours are low-grade and high-grade tumours that arise from glial tissue (gliomas); there are also tumours that arise from the dura mater (meningiomas). Neuromas (schwannomas) arise from myelin-forming cells. Cerebral metastases develop in 20 % of cancer patients. Leptomeningeal metastases are located in and around the meninges and cause headache and nerve root dysfunction. Intramedullary tumours and metastases are rare. Damage to the myelum in cancer is caused mainly by vertebral metastases that spread into the epidural space. Paraneoplastic syndromes can affect the entire nervous system.

J. J. Heimans, J. B. M. Kuks, J. W. Snoek

23. Infections of the central nervous system and meninges

Abstract

Meningitis is usually caused by a virus, in which case the prognosis is good and the treatment usually symptomatic. Bacterial meningitis is far less common, but its progression is far more severe. Encephalitis or meningoencephalitis also involves inflammation of the brain parenchyma. The key symptoms of all these infections are headache and fever. Both of these are non-specific symptoms and need not both be present, and by no means every patient with these symptoms will have an intracranial infection. Diagnosing infections of the central nervous system and meninges can therefore be difficult, especially in very young and very old patients, who generally display far less classic symptoms.

M. C. Brouwer, J. B. M. Kuks, J. W. Snoek

24. Multiple sclerosis and related disorders

Abstract

Multiple sclerosis is a disease of the central nervous system that is the most common cause of disability among young adults in the Western world. It is characterized by a wide variety of neurological symptoms, a combination of new transient symptoms and gradually progressive loss of function over a lengthy period. There are several types of progression. The criterion for diagnosing it is abnormalities that are dissociated in time and place. MRI is the most important diagnostic test. There is no causal treatment for MS as yet, although there are immunomodulatory and immunosuppressive treatments. There are also symptomatic treatments. MS needs to be distinguished from other demyelinating disorders.

B. W. van Oosten, J. B. M. Kuks, J. W. Snoek

25. Spinocerebellar disorders

Abstract

Spinocerebellar disorders are often neurodegenerative diseases. They constitute a large group of rare disorders characterized by various manifestations of ataxia, in some cases with selective dysfunction of other systems (e.g. the corticospinal tract). Damage to the corticospinal tract is the key symptom of other neurodegenerative disorders, namely hereditary spastic paraplegia and primary lateral sclerosis. The ability to diagnose these various disorders has improved enormously thanks to the rapid developments in DNA testing. The treatment is currently still purely symptomatic.

H. P. H. Kremer, J. B. M. Kuks, J. W. Snoek

26. Diseases of the basal ganglia

Abstract

Extrapyramidal disorders are caused by abnormalities in the mesencephalon and basal ganglia. Parkinsonism exists in two forms, typical (Parkinson’s disease) and atypical. Parkinson’s disease, the most common chronic disease of the CNS after the 50th year of life, always causes more than just motor symptoms. The diagnosis is based on clinical criteria; structural and functional imaging may be needed to distinguish the various forms of atypical parkinsonism from Parkinson’s disease itself. There are good treatments available for Parkinson’s disease, and a multidisciplinary approach is required. Atypical parkinsonian disorders include vascular parkinsonism, drug-induced parkinsonism, multiple system atrophy, progressive supranuclear palsy and corticobasal degeneration. Extrapyramidal symptoms other than parkinsonism are tremor, chorea, ballism, myoclonus, tics and dystonia.

P. Cras, T. van Laar, J. B. M. Kuks, J. W. Snoek

27. Dementia

Abstract

Dementia is an acquired disorder involving the deterioration of various cognitive functions with intact consciousness. The early symptoms and signs are non-specific, and patterns only become recognizable at later stages. The most common cause of dementia is Alzheimer’s disease; it can also be caused by vascular brain damage. Frontotemporal dementia is characterized mainly by changes in behaviour. Dementia with Lewy bodies is a combination of dementia and parkinsonism. Creutzfeldt-Jakob disease is a rapidly progressive fatal condition. Dementia can develop in the late stages of AIDS and syphilis.

P. Cras, P. Scheltens, J. B. M. Kuks, J. W. Snoek

28. Neurological abnormalities in children

Abstract

Although many neurological disorders can affect children as well as adults, many are specific to childhood, such as congenital abnormalities of the nervous system and perinatal brain damage. The severity and nature of congenital disorders depend on the cause of the damage and when it occurred. Impaired proliferation and migration of neurons can cause learning disabilities, motor problems and epilepsy. Congenital disorders due to chromosomal aberrations often cause learning disabilities. Intrauterine infections can cause severe abnormalities. Hereditary metabolic diseases can cause developmental disorders but may not manifest themselves until later in life. Neurocutaneous diseases are disorders involving the ectodermal structures of the nervous system and skin. Childhood ataxia can be a manifestation of very different disorders.

O. F. Brouwer, M. A. A. P. Willemsen, J. B. M. Kuks, J. W. Snoek

29. Neurological complications of non-neurological disorders and as adverse effects of therapy

Abstract

Neurological disorders resulting from deregulation of the body’s internal environment, problems with more peripheral organs and the adverse effects of therapy are commonplace. Mitigation is often possible if the diagnosis is not overlooked.

J. B. M. Kuks, J. W. Snoek

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