Memory is one of the best-studied complex cognitive functions described in the neuropsychological literature. Excellent textbooks and research articles about memory and the brain are, and continue to be, published. Yet, it is difficult to integrate clinical and applied features of memory disorders with basic science data. This may be due to our uncertainty about whether a damaged brain functions like a healthy brain and whether results about cerebral functioning and memory processes for a healthy individual can be applied equally well to someone who has incurred brain damage. Brain circuitry is altered in the presence of brain injury, including the mechanisms of remembering and forgetting. Basic clinical studies of normal memory teach us what is “not” normal but we have learned far less about “how” the brain really functions in the presence of amnesia.
The Amnesias: A Clinical Textbook of Memory Disorders has a strong conceptual and theoretical base and is addressed to clinicians. This book is concerned with cerebral functions and the decay of memory mechanisms and processes: the amnesias. Every good book should begin by defining and clarifying the subject under study, which is deftly accomplished. In Chapter 1, Phenomena and Constructs, Andrew C. Papanicolaou writes clearly and extensively on the confusion that exists in ordinary speech and in technical discourse regarding the term “memory”. He clarifies that when we use the term memory, we are referring to any of at least six distinct possibilities: a function, brain structures, neural codes, experiences, a category label, or a system. These distinctions are expressed with elegance, intelligence, and clarity. Explanation is provided about the common and diverse aspects of aphasia, agnosia, and apraxia, of mnemonic and amnesic phenomena, of the varieties of episodic and semantic memories, and, of implicit memories and their groupings. Autobiographical memories are explained in the context of episodic, semantic, and implicit memories. The author also provides ample discussion about constituent functions of the primary system, immediate or short-term memory, working memory, and retrieval before addressing the secondary memory system and its constituent functions. He ends with an overview of amnesia syndromes. This is a compact and clear chapter that is essential reading for those who must understand the phenomenon of memory in their day-to-day clinical practice.
Chapter 2, by Pramod Dash et al., focuses on the Putative Brain Mechanisms of the Various Memory Functions. The authors discuss the gross anatomical unit that constitutes the mechanisms of basic primary and secondary memory functions, microscopic biochemical events, and the influence of hormones and drugs on memory systems. They explain which brain structures are involved in encoding and retrieval, and consolidation. They also discuss the mechanisms of the secondary memory system, the long-term storage of memory traces, the role of the thalamus in memory function, and the relationships between memory and emotions. An important part of this chapter is the clear explanation of how neurotransmitter systems are involved in memory and what effect drugs, hormones, or stress will have on these systems.
Chapter 3, by Alexandra Economou et al., entitled Age-Related Memory Decline, begins by defining normal or successful aging as the absence of specific diagnostic or medical conditions, and intact physical and cognitive functioning. The authors then discuss the symptoms of memory difficulties in the elderly. The section dedicated to the differential diagnosis between dementia and normal memory problems related to aging includes two descriptive cases that follow age-related brain changes. The chapter ends with responses to four questions regarding age-related memory decline.
Chapter 4, by Economou et al., Amnesia Associated With the Dementias, explains how dementia-related amnesic syndromes vary not only in the neuroanatomical location of the damage but also in the progression and spreading of the degeneration. Six cases illustrate different syndromes: mild Alzheimer disease, strategic thalamic infarct dementia, temporal variant frontotemporal dementia, subcortical ischemic vascular dementia, Parkinson disease dementia, and frontal variant frontotemporal dementia. The chapter concludes with a discussion about epidemiology and predisposing factors, differential diagnosis, pathophysiology, prognosis and treatment, and conclusions and speculations.
Chapter 5, by Papanicolaou et al., Semantic Amnesia, is dedicated to consideration of the loss of, or inaccessibility to, facts and concepts that have been part of one's store of knowledge. Three clinical cases illustrate the syndrome and special emphasis is given to differential diagnosis, pathophysiology, and prognosis and treatment.
Rebecca Billingsley-Marshall et al. authored Chapter 6, Limbic Amnesia. Damage to the limbic system results in anterograde and retrograde deficits in explicit memory, the most consistent symptom being anterograde episodic amnesia. The authors explain how to test and confirm the symptoms associated with medial temporal lobe amnesia, diencephalic amnesia, and basal forebrain amnesia, and they also discuss precipitating factors, differential diagnosis, pathophysiology, and prognosis and treatment.
Chapter 7, Traumatic Amnesia, by Mary Kosmidis et al., is concerned with memory disorders associated with a traumatic brain injury (TBI). Symptoms are presented through study of three cases from the literature. The types of memories affected by TBI and associated neuropsychiatric sequelae are discussed, as are precipitating factors, pathophysiology, and prognosis and treatment.
Simos and Papanicolaou authored Chapter 8, Transient Global Amnesia, in which they describe an apparently benign disorder of memory that has a sudden and disconcerting onset, is resolved almost entirely within a few hours, and rarely lasts more than 24 hours. Three cases from the literature are presented along with a thorough discussion of definition and clinical symptoms. As in other chapters, precipitating factors, differential diagnosis, pathophysiology, and prognosis and treatment are well discussed.
In Chapter 9, Papanicolaou and Kosmidis grapple with a condition that is difficult to diagnose: Transient Epileptic Amnesia. It is characterized by transient episodes of amnesia, which take place while the patient behaves normally. Clinical features and differential diagnosis are discussed.
Chapter 10, Electroconvulsive Therapy-Induced Amnesia, by Papanicolaou and Kosmidis, describes memory impairment that occurs after electroconvulsive therapy (ECT), and which is characterized by a disruption of the process of consolidation of newly learned information during induced seizures.
In Chapter 11, Savvidou et al. discuss Psychogenic Amnesias. Three characteristics are well described: that psychogenic amnesia is exclusively retrograde in nature, is highly selective, and has deficits that are reversible. Four clinical cases are presented and different controversial treatments are described.
Papanicolaou, in the 12th and final chapter, writes Notes for a Theory of Memory with the intention of providing a theoretical framework within the reasonable working hypotheses that are widely accepted today. The book ends with an Appendix of Neuropsychological Tests written by Loring, and an extensive number of references covering current and significant literature on memory and amnesias.
In general, it is important to note that despite being a collective effort, the book is also the work of one author in particular. Papanicolaou participated in every chapter, and ensured that each had a similar structure. This gives the book a special coherence for which the reader is grateful. Overall, this well-written book clearly discusses relevant concepts and research. Clinicians will want to include The Amnesias: A Clinical Textbook of Memory Disorders in their resource library and will value it as a practical handbook that covers amnesia syndromes likely to be encountered in neurological or psychological patients. It is an indispensable resource for university teaching on amnesia and related disorders and it is equally indispensable for any neuropsychologist, neurologist, or neuropsychiatrist. Books such as this one are also particularly important for memory researchers, given its numerous heuristic suggestions. It is a book I highly recommend.
