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Due to the complexity of the diseases and the number of tests involved, examination of the central nervous system (CNS) is relatively difficult in the exam setting. Candidates should realize that an attempt to carry out every aspect of the physical examination of the CNS will take too long and is obviously impractical. Appropriate signs need to be elicited quickly to identify the existence of a lesion, its anatomical localization, and likely pathology. Hence, the examination of this system requires plenty of practise and a polished technique. In the exam, you may be asked to examine, for example, just the motor system, or the upper or the lower limb, rather than an examination of the whole central nervous system. Prepare yourself for a screening examination, which will uncover most signs in a relatively short time. Remember, a detailed assessment of complex disorders is never a part of the MRCPCH Clinical Exam. In this chapter, some areas have been explored extensively, keeping in mind the possibility of a ‘small area’ being examined. As the focus is mainly on examination technique and not theoretical aspects, basic neuroanatomy which has not been dealt with here should be read about elsewhere. Key competence skills required in the neurological examination are given in table 8.1. Neurological assessment begins with the first contact with the child, that is the moment you enter the room. It is necessary to have a predetermined, systematic order of examination so that important signs are not overlooked. However, you should be ready to adapt the examination technique, depending on the child’s age and the level of cooperation (e.g. compliant teenager, difficult toddler). Candidates should realize that a great deal can be learned by inspection before touching the child. Integration of observations with specific findings gathered during the neurological examination will fetch much credit. Candidates are often not expected to reach a diagnosis in a short case. They are expected to define the deficit, decide on the anatomical level, if possible, and then consider the likely causes. Abnormalities commonly seen in the exam include cerebral palsy, hemiplegia, quadriplegia, diplegia, primary myopathy, and hereditary motor sensory neuropathies. It is productive to have a pattern recognition approach to neurological disorders.

The previous chapter provided an overview of the anatomy of the CNS, concentrating on structures that can be seen during dissection of the human brain and spinal cord or the study of anatomical models of these structures. Some indication of the function of different components of the CNS has been given in Chapter 15, but this chapter shows how the various anatomical components of the CNS are functionally linked together through sensory and motor pathways. These pathways enable the nervous system to convey information over considerable distances, to integrate the information, and formulate functional responses that coordinate activities of different parts of the body. It will be necessary to introduce some other structures in addition to those described in Chapter 15 during the description of major pathways; most are not visible to the naked eye and even when seen in microscopical sections, they require considerable practice to distinguish them. However, they are important landmarks or relay stations in the central nervous pathways and you need to know of them for a full understanding of pathways. As emphasized in Chapter 14, our views of the structure and function of many aspects of the nervous system are constantly subject to revision in the light of new clinical and experimental observations and methods of investigation. This applies to nerve pathways just as much as any other aspect of the nervous system. This chapter presents a summary of current views on somatic sensory and motor functions and their application to the practice of dentistry. The special sensory pathways of olfaction, vision, and hearing are described in Chapter 18 in the context of the cranial nerves that form the first part of these pathways. The information conveyed from the periphery by the sensory components of spinal and cranial nerves is destined to reach the cerebral cortex or the cerebellum. You will be conscious of sensory information that reaches the cerebral cortex, but mostly unaware of information that does not travel to the cortex. However, this does not mean that sensory information that does not attain cortical levels is of no value. For example, sensory neurons or their collateral processes form the afferent limbs of many reflex arcs.

The definition of weakness is important, because many patients who self-describe a ‘weak limb’ will actually have a clumsy limb (ataxia), a numb limb (reduced sensation), or a limb that is too painful to move. The time course of the onset of the symptoms in general reflects the time course of the underlying pathology: • Sudden onset (seconds to minutes) usually implies either trauma (e.g. displaced vertebral fractures due to major trauma) or certain vascular insults (e.g. stroke, transient ischaemic attack (TIA)). • Subacute onset (hours to days) suggests a progressive demyelination (e.g. Guillain–Barre syndrome, multiple sclerosis) or a slowly expanding haematoma (e.g. subdural haematoma). • Chronic onset (weeks to months), is consistent with pathologies such as a slow-growing tumour or motor neuron disease (progressive degeneration of motor neurons). As only acute and subacute limb weakness will present acutely to generalists in hospital (chronic onset cases will most likely be referred to neurology from primary care), we have limited the chapter to these cases. Limb movement requires an intact pathway from the cerebral cortex, down the corona radiata, internal capsule, and pons, along the corticospinal tract of the spinal cord, out along a nerve root, and down a peripheral nerve to the neuromuscular junction and muscle itself. If a patient has limb weakness, there must be a lesion somewhere in this pathway. Figure 26.2 gives the differential diagnosis for limb weakness. Mr Walker has presented with rapid onset of left-sided arm weakness. Key clues in the history to elicit include: • Exact time of onset? This is critical in suspected strokes because the window of time in which to confirm the diagnosis and administer thrombolysis (if appropriate) is only 4.5 hours from onset of symptoms (after that, you risk doing more harm than good to the patient). If you suspect a stroke in a patient within that time frame, call the thrombolysis team immediately. In this case, all we can say is that the onset was at some point in the 7 hours between 11 p.m. (when he went to sleep) and 6 a.m. (when he woke up), so we cannot confidently say the onset was within 4.5 hours.

Due to the complexity of the diseases and the number of tests involved, examination of the central nervous system (CNS) is relatively difficult in the exam setting. Candidates should realize that an attempt to carry out every aspect of the physical examination of the CNS will take too long and is obviously impractical. Appropriate signs need to be elicited quickly to identify the existence of a lesion, its anatomical localization, and likely pathology. Hence, the examination of this system requires plenty of practise and a polished technique. In the exam, you may be asked to examine, for example, just the motor system, or the upper or the lower limb, rather than an examination of the whole central nervous system. Prepare yourself for a screening examination, which will uncover most signs in a relatively short time. Remember, a detailed assessment of complex disorders is never a part of the MRCPCH Clinical Exam. In this chapter, some areas have been explored extensively, keeping in mind the possibility of a ‘small area’ being examined. As the focus is mainly on examination technique and not theoretical aspects, basic neuroanatomy which has not been dealt with here should be read about elsewhere. Key competence skills required in the neurological examination are given in table 8.1. Neurological assessment begins with the first contact with the child, that is the moment you enter the room. It is necessary to have a predetermined, systematic order of examination so that important signs are not overlooked. However, you should be ready to adapt the examination technique, depending on the child’s age and the level of cooperation (e.g. compliant teenager, difficult toddler). Candidates should realize that a great deal can be learned by inspection before touching the child. Integration of observations with specific findings gathered during the neurological examination will fetch much credit. Candidates are often not expected to reach a diagnosis in a short case. They are expected to define the deficit, decide on the anatomical level, if possible, and then consider the likely causes. Abnormalities commonly seen in the exam include cerebral palsy, hemiplegia, quadriplegia, diplegia, primary myopathy, and hereditary motor sensory neuropathies. It is productive to have a pattern recognition approach to neurological disorders.