Clinical and Neuropsychological Aspects of Closed Head Injury

Dr J Richardson

• Publisher: Psychology Press
• Year: 2013
• Print ISBN: 9780863777516
• eBook ISBN: 9781317774822
• Topic: Psychology
• Subtopic: Cognitive Neuroscience & Neuropsychology
• Index: Psychology

In all industrialised countries, closed head injuries are responsible for vast numbers of hospital admissions and days of work lost. For instance, about 120,000 patients are admitted to hospital in the United Kingdom each year with a diagnosis that reflects closed head injury. Such injuries are a major cause of deaths following accidents, especially those that involve children and young people, and they are also a major cause of handicap and morbidity among the survivors. This clinical condition is intrinsically a neurological one, but its proper evaluation demands an understanding of the associated psychology and psychopathology. At the same time, a major neurological condition with such a high level of incidence ought to be extremely informative about the functioning of the human brain and hence provide a major focus for neuropsychological investigation. In this book, the author seeks to integrate these two different perspectives by reviewing the clinical and neuropsychological aspects of closed head injury in a manner that is equally intelligible to researchers interested in the effects of brain damage upon human behaviour and to practitioners who are responsible for the assessment, management and rehabilitation of head-injured patients. This is the second edition of a book which was first published in 1990, and which has been extensively revised in the light of the subsequent research in the field. The book begins by considering the epidemiology, causes and structural neuropathology of closed head injury. It then considers the impact of closed head injury on memory, cognition, language, communication, personality and social behaviour. Finally it outlines the outcome, the mechanisms of recovery and the prospects for rehabilitation.

CHAPTER ONE

Definitions, epidemiology, and causes

In all industrialised countries, closed head injuries are responsible for vast numbers of hospital admissions and days of work lost. For instance, over 120,000 patients are admitted to hospital in the United Kingdom each year with a diagnosis that reflects closed head injury. Such injuries are a major cause of deaths following accidents, especially those that involve children and young people, and they are also a major cause of disablement and morbidity among the survivors. The population of individuals who have sustained head injuries is a substantial one and one that is not likely to decrease in the foreseeable future. However, the clinical problem of treating these vast numbers of patients is not going to be solved by any dramatic medical breakthrough. Rather, it must be tackled by seeking a better appreciation of the condition that these people present.

This clinical condition is intrinsically a neurological one, but its proper evaluation demands an understanding of the associated psychology and psychopathology. At the same time, a major neurological condition with such a high incidence ought to be extremely informative about the functioning of the human brain and hence provide a major focus for neuropsychological investigation. In this book, I have tried to integrate these two different perspectives by reviewing the clinical and neuropsychological aspects of closed head injury in a manner that is equally intelligible to researchers who are interested in the effects of brain damage upon human behaviour and to practitioners who are responsible for the assessment, the management, and the rehabilitation of head-injured patients.

An initial remark is necessary concerning my terminology. Nowadays, it is generally recommended that clinical descriptors should follow rather than precede the nouns that they qualify to avoid labelling people by their clinical conditions or disabilities: thus, one should talk of “people who have a disability” rather than of “disabled people”, and certainly not of “the disabled” (see American Psychological Association, 1994, pp. 59–60). For the same reason, one should talk of “people who have sustained a head injury” rather than “head-injured people”. Nevertheless, the exclusive use of the former expression in a publication of this sort would soon become cumbersome and repetitive, and so I shall use these expressions interchangeably in this book.

DEFINITIONS

Closed and open head injuries

Strictly speaking, a closed head injury is an injury to the head that does not expose the contents of the skull. Such an injury can be distinguished from an open head injury in which the dura mater (the membrane that lines the interior of the skull) is torn and consequently the contents of the skull are exposed. This distinction is important in connection with the patient’s immediate clinical management because of the risk of infection. However, it is of only limited value for present purposes, because head injuries of both sorts can occur that are otherwise relatively similar in terms of their clinical and neuropsychological consequences.

It is more useful, if rather less precise, to use the term “closed head injury” to denote an injury in which the primary mechanism of damage is one of blunt impact to the head (Levin, Grossman, & Kelly, 1976a). This usually arises either as the result of rapid acceleration of the head due to a physical blow from a relatively blunt object or as the result of rapid deceleration of the head due to contact with a blunt and relatively immovable object or surface (although compression injuries resulting from crushing of the head may occasionally be encountered). A blunt impact may cause an open head injury by inducing a fracture of the vault or the base of the skull. Indeed, some authorities nowadays prefer to talk in terms of “blunt head injury” rather than “closed head injury”.

In this sense, closed head injuries are conventionally distinguished from penetrating head injuries of the sort produced by sharp instruments, such as knives or umbrellas, or by explosively propelled missiles, such as bullets or fragments of shells. The latter account for most cases of head injury sustained in military conflicts (Dresser et al., 1973; Russell, 1951). During peace-time, the incidence of penetrating head injury is much less common, though in some parts of the United States gunshot wounds (self-inflicted or otherwise) are the most common cause of fatal head injury (Frankowski, 1986).

Closed and penetrating head injuries differ not merely in terms of their likely external causes, but also in the patterns of neurological deficit to which they tend to give rise. In particular, penetrating head injuries produced by low-velocity missiles may well give rise to severe focal brain lesions but they often cause little or no disturbance of consciousness (Russell, 1951; Salazar et al., 1986). In contrast, closed head injuries are much more likely to produce disturbances of consciousness and diffuse cerebral damage. In this book I shall be concerned solely with the clinical and neuropsychological aspects of closed head injuries as just defined; that is, a closed head injury is an injury to the head in which the primary mechanism of damage is one of blunt impact.

The International Classification of Diseases (ICD) was originally developed by the World Health Organisation for the classification and comparison of morbidity and mortality data and for the indexing of hospital records. In terms of the ninth revision, ICD-9 (World Health Organisation, 1977, chap. XVII), cases of head injury are classified as follows (cf. Jennett, 1996; Jennett & Teasdale, 1981, pp. 1–2):

800	Fracture of vault of skull
801	Fracture of base of skull
802	Fracture of face bones
803	Other and unqualified skull fractures
804	Multiple fractures involving skull or face with other bones
850	Concussion
851	Cerebral laceration and contusion
852	Subarachnoid, subdural and extradural haemorrhage, following injury
853	Other and unspecified intracranial haemorrhage following injury
854	Intracranial injury of other and unspecified nature.

The practical utility of this classification is rather limited, as Jennett (1996) remarked, because it is based on pathological rather than clinical criteria, because the categories are not mutually exclusive, and because they are not explicitly related to clinical criteria of the severity of the injury.

Some authors have excluded ICD-9 category 802 (”Fracture of face bones”) from consideration (e.g. Caveness, 1979; Jennett & MacMillan, 1981; Sosin, Sniezek, & Waxweiler, 1995; cf. also Brookes et al., 1990), apparently on the assumption that injuries of this sort are unlikely to give rise to serious brain damage. To be sure, the facial skeleton consists of compressible, energy-absorbing bones that cushion and protect the intracranial structures in the event of a frontal impact. Nevertheless, many patients with major facial injuries, especially those involving the forehead, show clear deficits on neurological examination, and in such cases computerised tomography (CT) reveals a variety of intracranial lesions (Lee, Wagner, & Kopaniky, 1987).

The US Department of Health and Human Services developed a clinical modification of ICD-9 (ICD-9-CM) “to serve as a useful tool in the area of classification of morbidity data for indexing of medical records, medical care review, and ambulatory and other medical care programs, as well as for basic health statistics” (Public Health Service, Health Care Financing Administration, 1980, p. xvii). The disease classification of the original three-digit categories relating to a fracture of the skull (i.e. 800, 801, 803, and 804) was expanded along the following lines (chap. 17):

800.0	Closed without mention of intracranial injury
800.1	Closed with cerebral laceration and contusion
800.2	Closed with subarachnoid, subdural, and extradural haemorrhage
800.3	Closed with other and unspecified intracranial haemorrhage
800.4	Closed with intracranial injury of other and unspecified nature
800.5	Open without mention of intracranial injury
800.6	Open with cerebral laceration and contusion
800.7	Open with subarachnoid, subdural, and extradural haemorrhage
800.8	Open with other and unspecified intracranial haemorrhage
800.9	Open with intracranial injury of other and unspecified nature

The preamble to the relevant section of ICD-9-CM explained that in this context “open” subsumed the following descriptions: “compound”, “infected”, “missile”, “puncture”, and “with foreign body”. All other cases of nonpathological skull fracture (including those described as “comminuted”, “depressed”, “elevated”, “fissured”, “linear”, and “simple”) were classified as “closed” fractures. A somewhat different subclassification was applied to the original three-digit categories relating to intracranial injury without a fracture of the skull (i.e. 851, 852, 853, and 854), based on whether there was mention of an open intracranial wound.

The tenth revision, ICD-10, introduced a different coding scheme for “injuries to the head” (World Health Organisation, 1992, chap. XIX). Only certain headings within this scheme are relevant to closed head injuries as they were defined earlier:

S02.0	Fracture of vault of skull
S02.1	Fracture of base of skull
S02.2	Fracture of nasal bones
S02.3	Fracture of orbital floor
S02.4	Fracture of malar and maxillary bones
S...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• Acknowledgements
• Series preface
• Abbreviations
• 1. Definitions, epidemiology, and causes
• 2. Mechanisms of structural pathology
• 3. Retrograde amnesia and post-traumatic amnesia
• 4. Memory function
• 5. Cognition and language
• 6. Subjective complaints and personality disorders
• 7. Outcome, recovery, and rehabilitation
• References
• Author index
• Subject index