PRINCIPLES OF NEUROLOGY - PART 5 pot

25 The Limbic Lobes and the Neurology of Emotion In medical parlance, much license is taken with the terms emotional problem and stress, which are applied indiscriminately to states of anxiety and depression, strong reactions to distressing life events, so-called psychosomatic diseases, and many other symptoms for which a ready explanation is not available. To some physicians, the terms are synony- mous with functional disorders, the implication being that function of the brain can change without a physical basis. Our objections to this idea are set forth in the introduction to the section on psychiatric diseases. By emotion, we mean a condition of the organism involving certain bodily changes (mainly visceral ones, under the control of the autonomic nervous system) in association with a mental state of excitement or perturbation and usually leading to an impulse to action or to a certain type of behavior. Happiness, love, hate, fear, and anger are exam- ples of primary emotions; gloom, anxiety, and amiability are thought to represent lesser degrees of emotion. If emotion is intense, there may ensue a disturbance of intellectual functions—i.e., a measure of disor- ganization of ideas and actions—and a tendency toward a more auto- matic behavior of ungraded and stereotyped type. Affect refers to the outward manifestations of the emotional state. The cerebral mechanisms that control emotion are located in the limbic system. The latter comprises the medial parts of the temporal, frontal, and parietal lobes and their central connections with the amygdaloid nuclei, septal region, preoptic area, hypothalamus, anterior thalamus, habenula, and central midbrain tegmentum (Fig. 25-1). The peripheral effector apparatus is the autonomic nervous system and the visceral and other structures under its control. NEUROLOGY OF EMOTIONAL DISTURBANCES The most studied and best-known derangements of emotion are listed below. Emotional states that are associated with hallucinations and delusions are considered in Chaps. 55 and 56. I. Disturbances of emotionality A. Due to perceptual abnormalities (illusions and hallucinations) B. Due to cognitive derangements (delusions) 216 4777 Victor Ch 25 p216-221 6/11/01 2:07 PM Page 216 Copyright 1998 The McGraw-Hill Companies, Inc. Click Here for Terms of Use. II. Disinhibition of emotional expression A. Emotional lability B. Pathologic laughing and crying III. Heightened irritability, rage reactions, and aggressivity IV. Apathy and placidity A. Klüver-Bucy syndrome B. Other syndromes: abulia, akinetic mutism, psychomotor asthenia V. Altered sexuality VI. Endogenous fear, anxiety, depression, and euphoria EMOTIONAL LABILITY The emotions of the infant and child are easily provoked and little inhibited. Their control is achieved gradually, through maturation of the brain and through learning and conditioning. To be “grown up” implies an ability to inhibit one’s emotions; not that there is less feeling with CHAPTER 25 / THE LIMBIC LOBES AND NEUROLOGY OF EMOTION 217 FIG. 25-1 Sagittal schematic of the limbic system. The major limbic structures and their relationship to the thalamus, hypothalamus, and midbrain tegmentum are shown. (From Angevine and Cotman, with permission.) 4777 Victor Ch 25 p216-221 6/11/01 2:07 PM Page 217 maturation, but rather the outward expression of it is suppressed. The acceptable display of emotion in adults varies between the sexes and in different cultures. Any patient whose cerebrum has been damaged by disease is prone to exaggerated emotional lability. Tears come too easily; loud and prolonged laughter is evoked by mildly amusing events or remarks. A sentimental movie, meeting an old friend, or hearing the national anthem results in an embarrassing display of weeping. The response is more or less appropriate to the stimulus, and the affect is congru- ent with the visceral and motor components of emotional expression. The precise anatomic substrate is not known. To a lesser degree, aging alone loosens emotional control, but the condition is most prominent with diffuse degenerative and multifocal vascular lesions of the brain, which have so far not lent themselves to exact clinicoanatomic corre- lation. PATHOLOGIC (FORCED, SPASMODIC) LAUGHING AND CRYING In this state, as a consequence of cerebral disease, the patient is readily provoked to outbursts of uncontrollable laughter and, far more fre- quently, crying, sometimes continuing to the point of exhaustion. In general, the reaction is consonant with the stimulus situation and the feeling or affect is appropriate, although the provocative stimulus can be remarkably slight—for example, the mere mention of the patient’s family or the sight of his doctor. In some patients, no relationship between stimulus, affect, and response can be discerned. Characteristic of both pathologic laughter and crying is the invariability of the response and its excessive nature (the expression of mild degrees of pleasure or sadness is not possible). All the facial, bulbar, and respira- tory muscles, which provide the substrate of emotional expression and are innervated by the motor nuclei of the lower brainstem, appear to be liberated from cerebral control. The condition is often a part of pseudobulbar palsy due to multiple vascular, demyelinative (multiple sclerosis), or motor system disease (amyotrophic lateral sclerosis) in which corticobulbar tracts are interrupted bilaterally. However, forced laughing and crying may be observed without discernible weakness of faciobulbar muscles, and vice versa. These clinical observations sug- gest that the pontomedullary mechanisms involved in pseudobulbar palsy and in forced laughing and crying are under the control of two distinct supranuclear mechanisms, which may be affected separately or together. The administration of antidepressants may lessen both spasmodic laughing and crying and the emotionally labile states. 218 PART II / CARDINAL MANIFESTATIONS OF NEUROLOGIC DISEASE 4777 Victor Ch 25 p216-221 6/11/01 2:07 PM Page 218 ANGER, AGGRESSIVITY, RAGE, AND VIOLENCE The control of these reactions is also achieved during the processes of maturation and “civilization.” Raw emotion is sublimated into socially acceptable behavior patterns. Tantrums, aggressivity, and rage are turned into competitiveness in sports, scholastic activities, and boldness in business ventures. The rate at which this developmental sequence proceeds varies from one person to another (Chap. 28). In some, espe- cially males, the process is not complete until 25 to 30 years of age or even later; until that time, the abnormal behavior is called sociopathic or a manifestation of borderline psychiatric disorder (Chap. 56). Persons with behavioral reactions of this type, can, with little provocation, change from a calm demeanor to a state of wild rage, with blindly furious impulses to violence and destruction. They appear out of contact with reality and are impervious to all argument and pleading. What is so obviously abnormal is the provocation of such behavior by some trifling event and a degree of reaction that is out of all proportion to the stimulus. Rage reactions of this magnitude may also be encountered in the following medical settings: (1) as part of a psychomotor seizure; (2) as a transient phenomenon in acute metabolic derangements; (3) as a manifestation of certain brain tumors or the aftermath of stroke or head injury particularly of the temporal lobes; or (4) as a manifestation of mania or psychosis. As many as 70 percent of the 410,000 patients suf- fering brain injury each year in the United States are left in an irritable, aggressive state. Alcoholism may be an aggravating factor. The loca- tion of the lesions in the few cases in which they have been identified is shown in Fig. 25-2. In treatment, behavior modification techniques reduce violent outbursts in as many as 75 percent of cases. When violent behavior is secondary to psychotic ideation, antipsychotic drugs are the favored treatment. Some authors have had success with propranolol and drugs of similar action. PLACIDITY AND APATHY A quantitative reduction in all psychomotor activity is the most common behavioral alteration in patients with cerebral disease. There are fewer thoughts, fewer words, and fewer movements per unit of time (“psychomotor asthenia”). That this is not a pure motor deficit is dis- closed in conversation with the patient, who shows a lack of ongoing psychic activity, a slowness in thinking, and a diminished perceptivity, inquisitiveness, and interest in his surroundings. Depending on how one views this state, there is a heightened threshold to stimulation, reduced CHAPTER 25 / THE LIMBIC LOBES AND NEUROLOGY OF EMOTION 219 4777 Victor Ch 25 p216-221 6/11/01 2:07 PM Page 219 attentiveness, an inability to focus the mind and maintain an alert atti- tude, apathy, or a lack of drive or impulse (abulia). By collating the data of several neurologists, Poeck charted the lesions associated with a state of placidity and apathy (Fig. 25-2). ALTERED SEXUALITY The normal pattern of sexual behavior may be altered with diseases of the limbic system. Lesions of the orbital parts of the frontal lobes may remove moral-ethical restraints, with indiscriminate hypersexuality. With superior prefrontal lesions, apathy and lack of impulse reduce sexual drive as well as other functions. We have observed an occasional case of marked hypersexuality in male and female patients with en- cephalitis and temporal lobe tumor, but the exact anatomy of the lesions could not be ascertained. Stimulation of the ventral septal area has evoked sensations of pleasure and lust, and sexual arousal has been reported with psychomotor seizures arising from medial temporal foci. 220 PART II / CARDINAL MANIFESTATIONS OF NEUROLOGIC DISEASE FIG. 25-2 A. Localization of lesions that, in humans, can lead to aggressive behavior and placidity. B. Localization of lesions that, in humans, can lead to placidity, release of oral behavior, and hypersexuality. (From Poeck, with permission.) 4777 Victor Ch 25 p216-221 6/11/01 2:07 PM Page 220 Diminished libido and hyposexuality are common manifestations of depressive illness and, conversely, mania is an important cause of hypersexuality. Most temporal lobe epileptics prove to be hyposexual. ANXIETY, FEAR, AND DEPRESSION These emotional states may occur episodically or persistently with lesions of the medial temporal lobe in the region of the amygdaloid body and its connections with the thalamus and hypothalamus. Williams observed such emotional disturbances as part of a seizure in 80 of 2000 epileptics. Fear and anxiety were three times more frequent than depression. Attacks of anger and rage have been induced by stimulation of the amygdala through depth electrodes, and destruction of the central part of this structure has allegedly abolished fear reactions. Some of the abnormal emotional effects of seizure activity can be abolished by the administration of carbamazepine or other antiepileptic drugs (see Chap. 16). For a more detailed discussion of this topic, see Adams, Victor, and Ropper: Principles of Neurology, 6th ed, pp 508–521. ADDITIONAL READING Angevine JB Jr, Cotman CW: Principles of Neuroanatomy. New York, Oxford University, 1981, pp 253–283. Geschwind N: The clinical setting of aggression in temporal lobe epilepsy, in Field WS, Sweet WH (eds): The Neurobiology of Violence. St. Louis, Warren H. Green, 1975. Panksepp J: Mood changes, in Vinken PJ, Bruyn GW, Klawans HL (eds): Handbook of Clinical Neurology, vol 45. Amsterdam, North-Holland, 1985, pp 271–285. Poeck K: Pathophysiology of emotional disorders associated with brain dam- age, in Vinken PJ, Bruyn GW (eds): Handbook of Clinical Neurology, vol 3: Disorders of Higher Nervous Activity. Amsterdam, North-Holland, 1969, pp 343–367. Poeck K: Pathological laughter and crying, in Vinken PJ, Bruyn GW, Klawans HV (eds): Handbook of Clinical Neurology, vol 45. Amsterdam, North-Hol- land, 1985, pp 219–225. Williams D: The structure of emotions reflected in epileptic experiences. Brain 79:29, 1956. CHAPTER 25 / THE LIMBIC LOBES AND NEUROLOGY OF EMOTION 221 4777 Victor Ch 25 p216-221 6/11/01 2:07 PM Page 221 26 Disorders of the Autonomic Nervous System and Respiration The visceral and homeostatic functions of the human organism, which are essential to life and survival of the species, are involuntary and under the control of the autonomic nervous system, acting in unison with the endocrine glands. The autonomic nervous system consists of two parts: a craniosacral (parasympathetic) and a thoracolumbar (sympathetic). The cerebral control of these two systems resides in the hypothalamus. These features are illustrated in Figs. 26-1 and 26-2. The outflow of sympathetic fibers from the spinal cord and their distribution are illustrated in Fig. 26-3. The anatomic details are described in Principles. The diseases that affect the autonomic nervous system are sum- marized in this chapter, and the hypothalamic-pituitary syndromes in Chap. 27. TESTS FOR ABNORMALITIES OF AUTONOMIC FUNCTION These tests are outlined in Table 26-1. The use of the simpler ones (listed in the table as noninvasive bedside tests and tests of pupillary innervation), coupled with clinical inquiry and examination, permits the diagnosis of the following disorders. Pandysautonomia (Dysautonomic Polyneuropathy) This is a relatively rare type of acute or subacute polyneuropathy char- acterized by the almost exclusive affection of sympathetic and parasympathetic postganglionic fibers. The disease occurs sporadically in adults and children and is thought to represent an autoimmune or postinfectious disorder, similar to the Guillain-Barré syndrome. In a few cases it has been linked in some way to the Epstein-Barr virus, or to HIV, and rarely to an underlying neoplasm (paraneoplastic dysauto- nomia). Clinically, over a period of a week or a few weeks, the patient develops anhidrosis, orthostatic hypotension, an invariant pulse rate, paraly- sis of pupillary reflexes, impaired bladder and bowel function, gastric anacidity and hypomotility, and loss of lacrimation, salivation, and pilomotor and vasomotor reflexes in the skin. Somatic sensory and motor functions and tendon reflexes are generally preserved, but some 222 4777 Victor Ch 26 p222-234 6/11/01 2:07 PM Page 222 Copyright 1998 The McGraw-Hill Companies, Inc. Click Here for Terms of Use. CHAPTER 26 / DISORDERS OF THE AUTONOMIC NERVOUS SYSTEM 223 FIG. 26-1 The parasympathetic (craniosacral) division of the autonomic nervous system. Preganglionic fibers extend from nuclei of the brainstem and sacral segments of the spinal cord to peripheral ganglia. Short postganglionic fibers extend from ganglion cells to the effector organs. The lateral-posterior hypothalamus is part of the supranuclear mechanism for the regulation of parasympathetic activities. The frontal and limbic parts of the supranuclear regulatory apparatus are not indi- cated in the diagram (see text). (From CL Noback, R Demarest, The Human Nervous System, 3rd ed, New York, McGraw-Hill, 1981, with permission.) 4777 Victor Ch 26 p222-234 6/11/01 2:07 PM Page 223 224 PART II / CARDINAL MANIFESTATIONS OF NEUROLOGIC DISEASE FIG. 26-2 The sympathetic (thoracolumbar) division of the autonomic nervous system. Preganglionic fibers extend from the intermediolateral nuclei of the spinal cord to the paraspinal autonomic ganglia (sympathetic chain), and postganglionic fibers extend from the ganglion cells to the effector organs, according to the scheme in Fig. 26-3. (From CL Noback, R Demarest, The Human Nervous System, 3rd ed, New York, McGraw-Hill, 1981, with permission.) 4777 Victor Ch 26 p222-234 6/11/01 2:07 PM Page 224 patients complain of acral paresthesias or pain. The entire syndrome may be a part of an otherwise typical case of Guillain-Barré polyneuropathy or have some shared features, such as areflexia or distal sensory loss. The CSF protein is normal or elevated. Recovery is the rule. Idiopathic, or Primary, Orthostatic Hypotension In this chronic condition there is a failure of reflex constriction of resis- tance and capacitance vessels in the lower extremities upon standing; as a result, there is excessive pooling of blood in large veins of the legs and pelvis, venous return and cardiac output are diminished, and blood pressure falls precipitously, often with syncope (see Chap. 18). Correc- tive vasomotor reflexes are incompetent, and plasma catecholamine and renin fail to rise adequately. Two types of primary orthostatic hypotension have been identified: 1. The first type (originally described by Bradbury and Eggleston) is believed to involve mainly the postganglionic sympathetic fibers, with sparing of the parasympathetic, somatosensory, and motor fibers. Orthostatic hypotension develops gradually, most often in middle-aged women. Cases are sporadic and the cause unknown. CHAPTER 26 / DISORDERS OF THE AUTONOMIC NERVOUS SYSTEM 225 FIG. 26-3 Sympathetic outflow from the spinal cord and the course and distribution of sympathetic fibers. The preganglionic fibers are in heavy lines; postganglionic fibers are in thin lines. (From Pick, with permission.) 4777 Victor Ch 26 p222-234 6/11/01 2:07 PM Page 225 [...]... relationships of these small aggregates of cells, which lie between the thalamus and optic chiasm, are illustrated in Fig 2 7-1 The medial group—i.e., the cells 2 35 Copyright 1998 The McGraw-Hill Companies, Inc Click Here for Terms of Use 4777 Victor Ch 27 p23 5- 2 42 236 6/11/01 2:08 PM Page 236 PART II / CARDINAL MANIFESTATIONS OF NEUROLOGIC DISEASE FIG 2 7-1 Diagram of the hypothalamic-pituitary axis... late-life depression, and its potential to reset sleep rhythms For a more detailed discussion of this topic, see Adams, Victor, and Ropper: Principles of Neurology, 6th ed, pp 55 4 57 0 ADDITIONAL READING Asa SL, Kovacs K: Histological classification of pituitary disease Clin Endocrinol Metab 12 :56 7, 1983 Breningstall GN: Gelastic seizures, precocious puberty and hypothalamic hamartoma Neurology 35: 1180,... the medial part of the hypothalamus (tuberal nuclei) fail to stimulate the production of GH and FSH in the adenohypophysis A profound apathy may be added The usual causes are craniopharyngioma (suprasellar cyst), pituitary adenoma, cholesteatoma, and other rare tumors Disturbances of Regulation of Temperature, Appetite, and Sleep Lesions of the posterior part of the hypothalamus result in hypothermia... 4 parts other than head; distinguishes short and long lines 5 years Skips; names 4 colors, counts 10 pennies; dresses and undresses; asks questions about meaning of words Copies square and triangle; distinguishes heavier of 2 weights; more detailed drawing of a human figure 4777 Victor Ch 28 p24 3-2 58 6/11/01 2:08 PM Page 251 CHAPTER 28 / DEVELOPMENT OF THE NERVOUS SYSTEM 251 TABLE 2 8-4 Timetable of. .. Fetus Age, Size (crown-rump Nervous system days length), mm development 18 1 .5 Neural groove and tube 21 3.0 Optic vesicles 26 3.0 Closure of anterior neuropore 27 3.3 Closure of posterior neuropore; ventral horn cells appear 31 4.3 Anterior and posterior roots 35 5.0 Five cerebral vesicles 42 13.0 Primordium of cerebellum 56 25. 0 Differentiation of cerebral cortex and meninges 150 2 25. 0 Primary cerebral... Concepts, 5th ed Amsterdam, Elsevier, 1997 Bannister R, Mathias CJ (eds): Autonomic Failure: A Textbook of Clinical Disorders of the Autonomic Nervous System, 3rd ed New York, Oxford University, 1992 Blaivas JG: The neurophysiology of micturition: A clinical study of 55 0 patients J Urol 127: 958 , 1982 Bradbury S, Eggleston C: Postural hypotension: A report of three cases Am Heart J 1:73, 19 25 Cohen J,... Hypotension In clinical practice, the most common type of orthostatic hypotension is that induced by drugs (beta blockers, diuretics, central ␣-agonists, L-dopa, etc.) Blood loss and extreme dehydration are other common causes In several types of polyneuropathy—diabetic, Guillain-Barré, amyloid, porphyric, toxic, alcoholic-nutritional—the autonomic fibers may be damaged, and some of the symptoms of. .. polymyositis, or Lambert-Eaton syndrome may begin in this way There are also instances of isolated unilateral or bilateral phrenic nerve paresis following surgery or an infectious illness One type may be neuritic, akin to brachial neuritis (Parsonage-Turner syndrome) For a more detailed discussion of this topic, see Adams, Victor, and Ropper: Principles of Neurology, 6th ed, pp 52 2 55 3 ADDITIONAL READING... 35: 1180, 19 85 Martin JB, Reichlin S: Clinical Neuroendocrinology, 2nd ed Philadelphia, Davis, 1987 Reichlin S: Neuroendocrinology, in Wilson JD, Foster DW (eds): Williams Textbook of Endocrinology, 8th ed Philadelphia, Saunders, 1992, pp 1 35 219 4777 Victor Ch 28 p24 3-2 58 PART III 6/11/01 2:08 PM Page 243 GROWTH AND DEVELOPMENT OF THE NERVOUS SYSTEM AND THE NEUROLOGY OF AGING Copyright 1998 The McGraw-Hill... for this derangement It occurs most often as a transient feature of subarachnoid hemorrhage or after head injury The distinction of a salt-wasting syndrome from SIADH 4777 Victor Ch 27 p23 5- 2 42 6/11/01 2:08 PM Page 239 CHAPTER 27 / HYPOTHALAMIC AND NEUROENDOCRINE DISORDERS 239 is important, because treatment consists of the administration of an increased amount of intravenous fluid and sodium and not . Handbook of Clinical Neurology, vol 45. Amsterdam, North-Hol- land, 19 85, pp 219–2 25. Williams D: The structure of emotions reflected in epileptic experiences. Brain 79:29, 1 956 . CHAPTER 25 / THE. Victor, and Ropper: Principles of Neurology, 6th ed, pp 50 8 52 1. ADDITIONAL READING Angevine JB Jr, Cotman CW: Principles of Neuroanatomy. New York, Oxford University, 1981, pp 253 –283. Geschwind. Klawans HL (eds): Handbook of Clinical Neurology, vol 45. Amsterdam, North-Holland, 19 85, pp 271–2 85. Poeck K: Pathophysiology of emotional disorders associated with brain dam- age, in Vinken PJ, Bruyn

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