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Area 34: Uncus

From: Neuropsychiatry, Neuropsychology, Clinical Neuroscience
3rd Edition,
by Rhawn Joseph, Ph.D.
(Academic Press, New York, 2000)




THE UNCUS OF THE TEMPORAL LOBES


by Rhawn Joseph, Ph.D.

FUNCTIONAL NEUROANATOMY OF THE UNCUS, AREA 34

TEMPORAL LOBE TOPOGRAPHY

The temporal lobe is the most heterogenous of the four lobes of the human brain, as it consists of six layered neocortex, four to five layered mesocortex, and 3 layered allocortex, with the hippocampus and amygdala forming its limbic core.

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As detailed in chapters, 5, 12, over the course of evolution the dorsally situated hippocampus became displaced and progressively assumed a ventral position, during the course of which it also contributed to the neocortical development of portions of the parietal, occipital and temporal lobe. Similarly, portions of the amygdala became increasingly cortical in structure, and together with the hippocampus, contributed to the evolution of the anterior, medial, superior, and lateral temporal lobes.

The amygdala is buried beneath the surface of area 34, a bulbous cortical tissue referred to as the Uncus.

Because so much of the temporal lobe evolved from these limbic nuclei, unlike the other lobes, it consists of a mixture of allocortex, mesocortex, and neocortex, with allocortex and mesocortex being especially prominent in and around the medial-anterior inferiorally located uncus, beneath which and which abuts the amygdala and hippocampus.

Given the role of the amygdala and hippocampus in memory, emotion, attention, and the processing of complex auditory and visual stimuli, the temporal lobe became similarly organized (Gloor, 1997). Broadly considered, the neocortical surface of the temporal lobes can be subdivided into three main convolutions, the superior, middle, and inferior temporal gyri, which in turn are separated and distinguished by the sylvian fissure and the superior, middle, and inferior temporal sulci. Each of these subdivision performs different (albeit overlapping) functions, i.e. auditory, visual, and auditory-visual-affective perception including memory storage.

The uncus of the inferior temporal lobe harbors the amygdala and hippocampus, performs complex visual integrative activities including visual closure, and contains neurons which respond selectively to faces and complex geometric and visual stimuli (Gross & Graziano 1995; Nakamura et al. 1994; Rolls 1992; Tovee et al. 1994). The inferior and middle temporal lobes, are the recipients of one two diverging (dorsal and ventral) streams of visual input arising from within the occipital lobe and thalamus (Ungerlieder & Mishkin, 1982); i.e. the pulvinar and dorsal medial nucleus of the thalamus. The dorsal stream is more concerned with the detection of motion and movement, orientation, binocular disparity, whereas the ventral stream is concerned with the discrimination of shapes, textures, objects and faces, including individual faces (Baylis et al., 1985; Perrett et al., 1984, 1992). This information flows from the primary visual to visual association areas and is received and processed in the temporal lobes and is then shunted to parietal lobe, and to the amygdala and entorhinal cortex (the gateway to the hippocampus) where it may then be learned and stored in memory.

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TEMPORAL LOBE INJURIES & MEMORY LOSS

Although a variety of neurochemical and neuroanatomical regions are involved in the formulation of memory, it has long been known that damage or the neurosurgical removal of the temporal lobes can produce profound disturbances in the learning and recollection of verbal and visual stimuli (Milner, 1958; Kimura, 1963; Nunn et al., 1999; Ploner et al., 1999; Squire, 1987, 1992). For example, left temporal lobectomy, siezures or lesions involving the inferior temporal areas can moderately disrupt immediate and severely impair delayed memory for verbal passages, and the recall of verbal paried-associates, consonant trigrams, word lists and number sequences (Delaney et al. 1980; Meyer, 1959; Meyer & Yates,1955; Milner, 1958, 1968; Milner & Teuber, 1968; Weingartner, 1968). Similarly, severe anterograde and retrograde memory loss for verbal material has been noted when the anterior and posterior temporal regions (respectively) are electrically stimulated (Ojeman et al., 1968, 1971).

In contrast, right temporal lesions or lobectomy significantly impair recognition memory for tactile and recurring visual stimuli such as faces and meaningless designs, as well as memory for object position and orientation, and visual-pictorial stimuli (Corkin, 1965; Delaney et al., 1980; Evans et al. 1995; Kimura, 1963; Milner, 1968; Nunn et al., 1999; Ploner et al., 1999; Taylor, 1969). Electrical stimulation of the right anterior and posterior temporal region also causes respectively, severe anterograde and retrograde memory loss for designs and geometric stimuli, and impairs memory for faces Fried et al., 1982; Ojeman et al., 1968).

With bilateral removal of the inferior temporal region there results a condition which has been variably referred to as "psychic blindness" and the "Kluver-Bucy syndrome". However, as explained in chapter 13, this is due to destruction of the amygdala. If the mesial regions are removed, severe memory disturbances involving visual and auditory stimuli result such that the patient suffers a permanent anterograde amnesia, including facial processing impairments (Young et al. 1995).

Based on lesion, temporal lobectomy and electrical stimulation studies it thus appears that the anterior temporal region is more involved in initial consolidation storage phase of memory, whereas the posterior region is more involved in memory retrieval and recall. In addition, as based on event-related functional magnetic imaging (Brewer et al., 1998; Wagner et al., 1999), it appears that the temporal lobes directly interact with the frontal lobes in memorization and remembering. Indeed, the greater the activation of the frontal and temporal lobes (and associated tissues), the greater is the likelihood that subjects will remember whereas reduced activity is associated with forgetting. Hence, these areas interact to promote memory and retention. In consequence, if the frontal lobe is injured, and even if the temporal lobes are spared, patients may demonstrate significant memory loss --due to an inability to correctly search for and find the memory (see chapter 19).

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HALLUCINATIONS

The functional integrity of the temporal lobes, the inferior regions in particular, are highly important in regard to the memorization and recollection of various auditory, visual, olfactory, and emotional experiences. When destroyed, disconnected from sources of input, or compromised in some fashion, the ability to store information and to draw visual-verbal mnemonic imagery from memory is severely attenuated.

Conversely, when the temporal lobes and/or the limbic nuclei buried within its depths (i.e. the amygdala and hippocampus) are artificially or abnormally activated it sometimes occurs that visual-auditory imagery as well as a variety of emotional reactions are evoked involuntarily. These may take the form of complex hallucinations, dream-like states, confusional episodes, or may involve the abnormal attribution of emotional significance to otherwise neutral thoughts and external experiences.

HALLUCINATIONS & THE INTERPRETATION OF NEURAL "NOISE".

Hallucinations may occur secondary to tumors or seizures involving the occipital, parietal, frontal, and temporal lobe (Gloor, 1997; Halgren, 1992; Penfield & Perot, 1963), or arise secondary to toxic exposure, high fevers, general infections, exhuastion, starvation, extreme thirst, partial or complete hearing loss including otosclerosis, and with partial or complete blindness such as due to glacoma (Bartlet, 1951; Flournoy 1923; Lindal et al. 1994; Pesme, 1939; Rhein, 1913; Ross et al., 1975; Rozanski & Rosen, 1952; Semrad, 1938; Tarachow, 1941). Interestingly, when secondary to peripheral hearing loss, frequently individuals report hearing certain songs and melodies from their childhood --melodies which they had usually long forgotten. In addition, individuals suffering from cortical blindness, i.e. Anton's syndrome (Redlich & Dorsey, 1945) and deafness (Brown, 1972), as well as those recovering from Wernicke's aphasia, frequently experience hallucinations.

In general, hallucinations secondary to loss of visual or auditory input appears to be secondary to the interpretation of neural noise. That is, with loss of input various brain regions begin to extract or assign meaningful significance to random neural events, or to whatever input may be received. Thus we find that subjects will hallucinate when placed in sensory reduced environments or even when movement is restricted (Lilly, 1956, 1972; Lindsley, 1961; Shurley, 1962; Zuckerman & Cohen, 1964).

Conversely, hallucinations can occur due to increased levels of neural noise as well. For example, if an area of the neocortex is abnormally activated that area in turn may act to interpret its own neural activity, and/or as a function of the activation of "feature detectors." For example, those neurons that subserve facial recognition, and word recognition, and object recognition, may become simultaneously activated--as well as all associated memories--and in consequence, the brain attempts to interpret what it experiences.

However, the degree of interpretative activity depends on the type of processing performed in the region involved. In this regard we find that hallucinations become increasingly complex as the disturbance expands from primary to association areas and as involvement moves from the occipital to anterior temporal regions (Critchley, 1939; Penfield & Perot, 1963; Tarachow, 1941) --which is one of the major interpretive regions of the neocortex (Gibbs, 1951; Gloor 1990, 1992; Halgren 1992; Penfield & Perot, 1963). That is, in the primary regions, neural noise is given a simple interpretation (simple hallucinations), whereas in the association and multi-associational areas, the individual begins to hallucination secondary to "feature detector" activation, such that they may see faces, chairs, trees, hear voices, music, and so on, all of which is experienced as a mosaic of something real.

For example, tumors or electrical stimulation of the occipital lobe produce simple hallucinations such as colors, stars, spots, balls of fire, flashes of light, whereas with superior temporal involvement the patient may experience crude noises, such as buzzing, roaring sounds, bells, and an occasional voice or sounds of music. However, these same neurons become activated when presented with colors, spots, flashes of light, bells, and so on.

However, with anterior and inferior temporal abnormalities, the hallucinations become increasing complex consisting of both auditory and visual features, including faces, people, objects, animals, etc. (Critchley, 1939; Penfield & Perot, 1963; Tarachow, 1941). This is because there is a ventral stream of visual experience which becomes increasingly complex as information is transmitted from the primary to secondary to association, to multi-modal areas in the temporal lobes where neurons fire in response to complex objects, including faces. The anterior-inferior temporal regions, therefore, give rise to the most complex forms of imagery because cells in this area are specialized for the perception and recognition of specific forms. Moreover, structures such as the amygdala and hippocampus become activated and in consequence, memories and emotions may also be evoked, such that the experience may also become personally meaningful and include real individuals and real events that are produced from memory (Gloor, 1997; Penfield & Perfot, 1963).

It has frequently been reported that as compared to other cortical areas, the most complex and most forms of hallucination occur secondary to temporal lobe involvement (Critchley, 1939; Malh et al., 1964; Horowitz et al., 1968; Penfield & Perot, 1963; Tarachow, 1941) and that the hippocampus and amygdala (in conjunction with the temporal lobe) appear to be the responsible agents (Gloor 1990, 1992, 1997; Gloor et al., 1982; Horowitz et al., 1968; Halgren et al., 1978). For example, Bancaud et al. (1994), Halgren et al., (1978), and Horowitz and colleagues (1968) note that hippocampal stimulation was predominatly associated with either fully formed and/or memory-like hallucinations including feelings of familiarity, and secondarily dream-like hallucinations. However, stimulation limited to the neocortex generally failed to produce complex hallucinations unless the amygdala became activated (Gloor et al., 1982). In this regard, it appears that limbic activation, and activation of the amygdala in particular (Gloor, 1997) is necessary in order to bring to a conscious level percepts which are being processed in the temporal lobes.

LSD. This does not mean, however, that neocortical involvement is not necessary for frequently it is the interpretive interaction of the temporal lobe which gives rise to certain types of hallucinations; i.e. bringing them to a conscious level. That is, although the amygdala (perhaps acting on the hippocampus) may be responsible for the hallucination, the hallucinaton requires an interactions between the amygdala, hippocampus, and the neocortex, for it is only when the "hallucination" envelops the neocortex of the temporal lobe that the individual becomes "conscious of them."

For example, it is well known that the ingestion of LSD will trigger the formation of vivid and complex auditory and visual hallucinations. Following LSD administration electrophysiological abnormalities are noted in the amyugdala and hippocampus (Chapman et al., 1963). However, if the temporal lobes are surgically removed there is a significant decrease (with unilateral removal, Serafetinides, 1965) or complete abolishion (with bilateral temporal lobe removal) of LSD induced hallucinatory activity (Baldwin et al., 1955)--even when the amygdala and hippocampus are spared. That is, if the overlying neocortex is destroyed the individual will fail to hallucination--or at least to become conscious of the hallucination. Of course, if the overlying temporal lobe is destroyed the amygdala and hippocampus also become disconnected, and cannot help but be injured.

Nevertheless, studies with LSD and temporal lobe neocortical resection suggest that the neocortex is associated with consciousness and the limbic system with the unconscious, and if the pathways between them are destroyed, hallucinations cease to be experienced consciously.

Interestingly, the hallucinatory effect of LSD appears to be greatest in the right temporal lobe (Serafetinides, 1965). That is, destruction of the right temporal lobe abolishes LSD-induced hallucinations, where with left temporal destruction, the individual continues to hallucination. Likewise, Penfield and Perot (1963) report that the most vivid hallucination tend to be triggered from the right not the left temporal lobe.

DREAMING

Vivid, visual-auditory and sometimes intensely emotional hypnogic dream imagery is clearly associated with REM sleep (Foulkes, 1962; Goodenough, Shapiro, Holden, & Steinschriber,1959; Monroe, Rechtschaffen, Foulkes, & Jensen, 1965). As discussed in detail in Chapter 10, electrophysiological studies or measures of cerebral blood flow have indicated that the right hemisphere becomes highly active during REM, whereas conversely the left brain becomes more active during N-REM (Goldstein et al., 1972; Hodoba, 1986; Meyer et al., 1987).

It has also been reported that abnormal and seizure-like activity in the right temporal and temporal-occipital area acts to increase dreaming and REM sleep for an atypically long time period. Similarly, REM sleep increases activity in this same region much more than in the left hemisphere (Hodoba, 1986) indicating that there is a specific complementary relationship between REM sleep, dreaming, and right temporal-occipital electrophysiological activity.

In this regard, although not conclusive, there seems to be a convergence of evidence which suggests that the right temporal lobe may be more involved than the left in the production of visual-auditory hallucinations and dream-like mental states be they produced secondary to LSD, electrical stimulation, abnormal seizure activity, or occurring naturally during sleep.

As pertaining to right vs. left cerebral involvement in the production and recollection of hallucinations and dreams it is interesting to note that Horowitz et al., (1968), reported that electrically induced hallucinated events were usually forgotten by patients within 10 to 15 minutes after the experience, and when questioned the next day memory was not improved. Similar forgetting patterns are characteristic of memory for normal sleep induced dreams as well (Joseph, 1988a). That is, it becomes progressively more difficult to recall one's dreams as one spends time in or awakens during NonREM (Wolpert & Trosman, 1958) -which is associated with high left temporal lobe and low right lobe activitity.

TEMPORAL LOBE (PARTIAL COMPLEX) SEIZURES & EPILEPSY

Temporal lobe epilepsy is often associated with atrophy and sclerosis of the hippocampus in about 50% of such patients (Mathern, 1999; Mitchell et al., 1999), with yet others demonstrating sclerosis in the amygdala (Wolf & Blumcke 1999) and uncal regions. In fact, according to Gloor (1997, p. 692), "studies on temporal lobe epilepsy provide evidence that the amygdala is involved inmany of the common symptoms and signs that occur in the course of temporal lobe seizures." Gloor (1997, p. 693), also argues that "hippocampal sclerosis is most likely a consequence of prolonged seizures or status epilepticus, particularly when occurring in early childhood and can therefore be regarded as a lesion induced by seizures rather than a causative agent." Gloor (1997) further suggests that the seizure is either produced by the amygdala, which then envelops the hippocampus, and/or that both must give rise to the seizure simultaneously. In support of this position are the findings of Feindel and Rasmussen (1991) who report 65 of 100 neurosurgery epilepsy patients in whom the amygdala and the hippocampus was removed showed a favorable outcome, whereas an equal number showed a favorable outcome if just the amygdala was removed and the hippocampus was spared.

Because the hippocampus and amygdala have the lowest seizure thresholds of all other brain structures, when injured they are thus highly likely to develop seizure activity and thus give rise to temporal lobe epilepsy.

There are a number of factors which can independently give rise to temporal lobe epilepsy (Kotagal & Luders, 1999; Mathern, 1999; Mitchell et al., 1999; Trimble, 1991; Wolf & Blumcke 1999). For example, incisural hernation at the time of brith is a major cause of amygdala injury and hippocampal sclerosis. Head injuries also cause injuries to the temporal region due to contusion from the bony structures in which it is encased. That is, if the head is struck, the inferior and anterior temporal regions may strike against the skull and may even be sheared due to rotational forces. Also middle ear infections are associated with disturbances involving the temporal lobe which result in TLE (Kotagal & Luders, 1999).

In addition, as detailed in chapter 30, severe and repeated early emotional trauma can in fact injure the immature hippocampus and temporal lobe, giving rise to a propensity to develop kindling as well as abnormal neural networks. This would make these individuals are more likely to develop psychotic and severe emotional and dissociative disorders.

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Usually, during the course of a temporal lobe seizure, there are no abrupt and drastic alterations in motor activity such as tonic-clonic spasms (Kotagal & Luders, 1999; Trimble, 1991, 1996). However, some patients may simply cease to respond and stare blankly straight ahead, make licking or smacking movements of the lips, and/or fiddle with their clothing, as if picking up pieces of lint. Although conscious-awareness is lost, these patients are not unconscious. Rather, their mental state is one of absence. In fact, they may appear awake and conscious, although unable to speak or respond to questions, and behaviorally their actions seem semi-purposeful. Nevertheless, sometimes it is extremely obvious that they are experiencing a seizure, whereas in some cases an inexperienced observor may only have the impression that the person is acting somewhat odd.

Nevertheless, unless the patient has several different seizure foci, the same characteristic behavioral manifestations are elicited every time a patient has a seizure. The patient does not simply stare on one occasion and on the next begin rolling his eyes and cry out.

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AURAS & AUTOMATISMS

Some patients also note an aura immediately prior to seizure onset (Kotagal & Luders, 1999; Trimble, 1991, 1996). This may involve feelings of fear or anxiety, alterations in gastric motility, or unpleasant tastes or in particular, odors (e.g. burning rubber or feces), i.e. an olfactory aura (Gloor, 1997). Some patients may lick and repeatedly smack their lips.

Presumably, the experience of olfactory hallucinations is due to abnormal activation of the rhinencephalon (the "nose brain") and thus limbic nuclei such as the amygdala (Gloor, 1997). Possibly the licking and smacking movements are also due to activation of the amygdala and other limbic structures associated with food consumption. Changes in gastrict motility may be secondary to insular activation and/or limbic participation.

Automatisms associated with TLE occur in up to 75-95% of patients which is twice what occurs with lesions outside the temporal lobe (Kotagal & Luders, 1999; Trimble, 1991, 1996). Thse includes staring, searching, groping, lip smaking, spitting, gropoing, staring, salivation. Also laughing, cryng, hssing, gritting or gnasing of teeth, clenching the fist, confused talking, scraming, shouting, standing, wrunning, walking, kissing, and so on.

Common visceral reactions associated with TLE auras include feelings of a racing or flutering heart, incuding pounding or throbbing (Kotagal & Luders, 1999; Trimble, 1991, 1996) also there may be feelings of smothering or chocking. Body sensation include numbness, tenseness, pressure and heaviness. Ther may also be visual sensations such as macro or micro or of things be very hear or far (Gloor, 1997).

Feelings of strangeness or familiarity are also common (Gloor, 1997; Kotagal & Luders, 1999; Trimble, 1991, 1996). deja vue occurs in up to 20% of such patients, usually with right cerebral seizures within the temporal lobe. Some claim to have feelings like a desire to ge alone, or of wanting something but not knowing what.

Olfactory hallucinations are not uncommon and are usually quite disagreeable and include smells like burnign meat, fish, lime, acid fumes, burnign shit. There may also be gustatory sesatniosn which are also usually disagreeable coupled with very bad and bitter or metalic and sour tastes.

Fear is one of the most common feelings, which include feelings of panic, terror, or of soemting horrible about to happen (Daly, 1958; Gibbs, 1958; Penfield & Jasper, 1954; Williams, 1956). Some patients have experienced fear coupled with sexual sensations, including fear associated with a feeling of sexual climax, or feelings of being sexually pentrated following by orgasm then a loss of consciousness. Although one patient stated it was like "a red hot pocker being inserted into her vagina."

Hence, there are a vast range of aura and experiental phenomenon associated with temporal lobe epilepsy, many of which reflect the possible activation of those structures innervated by the amygdala. Not uncommonly these experiential phenomenon begin just before the seizure. In summary, these include fear, coupled with the remembrance of a fearful or traumatic memories, rising epigastric sensations, chest sensations, nausea, heart palpations, feelings of cold or warmth, shivering, pallor or flushing of the face, respiratory changes inlcuding apnea, salavation, belching, farting, sweating, and vaginal secretions in women which may be accompanied by sexual feelings or behaviors (Daly, 1958; Gloor, 1997; Penfield & Jasper, 1954; Remillard et al., 1983). Moreover, many of these same exact feelings and behaviors can be triggered by direct stimulation of the amygdala (Chapman, 1960; Chapman et al., 1954; Gloor, 1997; Halgren, 1992; Kaada, 1951, 1972), including deja vu--the feeling of familiarity/reminiscence.

In addition, patients may act out on these emotions and auras. There have been reported instances of patient's suddenly lashing out and even attempting to attack those close by, while in the midst of a seizure (Saint-Hilaire et al., 1980), and/or attacking, kicking, and destroying furniture and other objects (Ashford et al., 1980). Patient's have also behaved violently with direct stimulation of the amygdala (Mark et al., 1972), as have a variety of animal subjects (see chapter 13).

Others have responded with behaviors indicative of extreme fear, or conversely, extreme pleasure, including laughter and mirth. Moreover, some patients have acted out sexually during a seizure, such as by displaying their penis, or lying on the floor with legs spread and thrusting, even moaning with pleasure and experiencing libidinous feelings in the vagina and thighs, coupled with an orgasm (Currier, Little, Suess and Andy, 1971; Gloor, 1997; Remillard et al., 1983).

SEXUAL SEIZURES

The primate amygdala is sexually differentiated (Nishizuka & Arai, 1981) and in conjunction with the overlying temporal lobe, is capable of detecting sexually significant stimuli, and can determine and detect gender differences such as male and female faces and the emotions they convey (Hasselmo, Rolls, & Baylis, 1989, Heit et al., 1988; Rolls, 1984). Because the amygdala is involved in sexuality and is sexually differentiated, activation of the amygdala can produce penile erection (Kling and Brothers, 1992; MacLean, 1990; Robinson and Mishkin, 1968; Stoffels et al., 1980) sexual feelings (Bancaud et al., 1970; Remillard et al., 1983), sensations of extreme pleasure (Olds and Forbes, 1981), memories of sexual intercourse (Gloor, 1986), as well as ovulation, uterine contractions, lactogenetic responses, and orgasm (Backman and Rossel, 1984; Currier et al., 1971; Freemon and Nevis,1969; Warneke, 1976; Remillard et al., 1983; Shealy and Peel, 1957).

By contrast, injuries to and/or seizure activity within the amygdala/temporal lobe may result in bizarre sexual changes, such as continuous masturbation and indiscriminate, often hypersexual hetero- and homosexual behaviors including attempts at sex with inanimate objects (Kling and Brothers, 1992; Kluver and Bucy, 1939; Pribram and Bagshaw 1953; Terzian and Ore, 1955). Hypersexuality following amygdala injury has been documented among numerous species, including cats and dogs (Blumer 1970; Kling and Brothers, 1992).

Humans with an abnormally activated or severely injured amygdala/temporal lobe may expose and manipulate their genitals (Leutmezer et al., 1999), masturbate in public, and attempt to have sex with family members or individuals of the same sex (Blumer, 1970; Kolarsky, Freund, Macheck, and Polak, 1967; Terzian and Ore, 1955). Moreover, abnormal activity involving the amygdala and overlying temporal lobe has been associated with the the development of hyposexuality (Taylor, 1971; Heirons and Saunders, 1966; Toon, Edem, Nanjee, and Wheeler, 1989), hypersexuality (Blumer, 1970) as well as homosexuality, transvestism, and thus confusion over sexual orientation (Davies and Morgenstern, 1960; Kolarsky et al., 1967). In fact, abnormal- or seizure activity within the amygdala or overlying temporal lobe may induce an individual to engage in "sexual intercourse" even in the absence of a partner. For example, Currier and colleagues (1971, p. 260) described a female temporal lobe seizure patient who was "sitting at the kitchen table with her daughter making out a shopping list" when she suffered a seizure. "She appeared dazed, slumped to the floor on her back, lifted her skirt, spread her knees and elevated her pelvis rhythmically. She made appropriate vocalizations for sexual intercourse such as: It feels so good...further, further."

EMOTION

The most common emotional reactions and sensations which occur secondary to or during the course of a temporal lobe seizure include feelings of fear, anxiety, depression, depersonalization, pleasure, unpleasure, and familiarity (Bear, 1979; Cendes, et al. 1994; Herman & Chhabria, 1980; Gloor, 1997; Gloor et al., 1982; Perez & Trimble, 1980; Trimble 1991; Slater & Beard 1963; Strauss et al., 1982; Weil, 1956; Williams, 1956), fear being the most frequently experienced. Many of these same feelings are also triggered by electrical stimulation of the temporal lobes, amygdala and hippocampus (Gloor, 1972, 1997; Gloor et al., 1982; Heath, 1964; Mullan & Penfield, 1959).

Depression (lasting from hours to weeks) may occur as an immediate sequela to the seizure, many patients also experiencing confusion. A depressive aura may also precede and thus hearld the coming of a seizure by hours or even days (Trimble 1991, 1996; Williams, 1956). This may be due in part to the role of the temporal lobe (and amygdala) is storing emotional and personal memories, including those with are negative, depressing and traumatic (Abrams & Taylor, 1979; Cimino, et al. 1991 Cohen, Penick & Tarter, 1974; Deglin & Nikolaenko, 1975; Shagass et al.,1979; Wexler, 1973) such that when activated, depressive moods and memories may be provoked. For example, Abrams and Taylor (1979) and Shagass et al. (1979) have found that depressed patients demonstrated more right vs left temporal lobe electrophysiological activity and EEG abnormalities. Moreover, others have argued that ECT administered to the right vs left temporal lobe is more likely to alleviate depressive symptoms (Cohen, et al, 1974; Deglin & Nikolaenko, 1975).

Rather than increased emotionality, some patients complain of emotional blocking, and feelings of emptiness: "feelings don't reach me anymore" (Weil, 1956). Presumably this is a consequence of limbic disconnection. That is, the siezure foci (or lesion) acts to deconnect the limbic areas from the temporal (or orbital frontal) lobes. In consequence, percepts and thoughts no longer come to be assigned emotional or motivational significance.

TEMPORAL LOBE EPILEPSY & RELIGIOUS EXPERIENCE

It has been reported by a number of neuroscientists that some patients who experience temporal lobe epilepsy, seizures, or related abnormalties sometimes experience very sexual as well as bizarre, unusual and fearful mental phenomenon including dissociative states, feelings of depersonalization, and hallucinogenic and dream-like recollections involving threatening men, naked women, sexual intercourse, religion, the experience of god, as well as demons and ghosts and pigs walking upright dressed as people (Bear 1979; Daly 1958; Gloor 1986, 1992; Halgren 1992; Horowitz et al. 1968; Penfield & Perot 1963; Slater & Beard 1963; Taylor 1972 1975; Trimble 1991; Weingarten, et al. 1977; Williams 1956). Moreover, some individuals report communing with spirits or receiving profound knowledge from the Hereafter, following temporal lobe activation (Daly 1958; MacLean 1990; Penfield & Perot 1963; Williams 1956).

One young many had repeated conversations with God. One day God informed this young man that he was Jesus Christ, could perform miracles and could fly. Believing that he was in fact The Christ, since god had told him so, he climbed upon a roof and leaped into the air, with disasterous results (Sommer 1880).

Intense activation of the temporal lobe, hippocampus, and amygdala has been repeatedly reported to give rise to a host of sexual, religious and spiritual experiences; and chronic hyperstimulation can induce an individual to become hyper-religious or visualize and experience ghosts, demons, angels, and even God, as well as claim demonic and angelic possession or the sensation of having left their body (Bear 1979; Daly 1958; Gloor 1986, 1992; Horowitz et al. 1968; MacLean 1990; Mesulam 1981; Penfield & Perot 1963; Schenk, & Bear 1981; Slater & Beard 1963; Subirana & Oller-Daurelia, 1953; Trimble 1991; Weingarten, et al. 1977; Williams 1956). Indeed, as detailed in chapter 9, the temporal lobe, amygdala and hippocampus enables humans to have religious, spiritual and mystical experiences (Bear 1979; Daly 1958; d'Aquili & Newberg 1993; Mesulam 1981; Trimble 1991).

In one case, a 37 year-old manager of a car dealership had been struck by a car while walking across a street, and was slammed against the pavement, striking his head. According to this fellow (GM), once he gained "consciousness" he realized he was standing next to his body, which was still lying in the street. He could see that his head was bloody, and he could see that he was unconscious and he could see other people rushing over to where he lay. However, this dissociative hallucination only lasted a few seconds, and then he was back in his body, regaining consciousness. GM states that his experience was a "revalation" and although he had never been religious, that he became very religious, and began reading the Bible, volunteering at a local church, and writing a religious column for a small local newspaper. He also began having repeated episodes where he would float beside his body. As his wife complained that he was repeatedly "blanking out" and as he was also having memory problems, he sought medical help, was referred for neuropsychological testing, which revealed significant disturbances of memory, and evidence of temporal lobe epilepsy. Subsequent EEG demosntrated bilateral spiking and theta activity over the temporal lobes.

OUT OF BODY, HEAVENLY & "OTHERWORLDLY EXPERIENCES"

Penfield and Perot (1963) describe several patients who during a seizure claimed they could see themselves in different situaitons. One woman stated that "it was though I were two persons, one watching, and the other having this happen to me," and that it was she who was doing the watching as if she was completely separated from her body. According to Penfield, "It was as though the patient were attending a play and was both actor and audience.

Other patients claim to have quite pleasent aurs and describe feelings such as elation, security, eternal harmony, immense joy, paradisiacal happiness, euphoria, completeness. Between .5 and 20% of such patients claim such feelings (Williams, 1956; Daly, 1958). One patient of Williams (1956) claimed that his attacks began with a "sudden feeling of extrreme well being involvign all my senses. I see a curtain of beautiful colors before my eyes and experience a pleasant but indescribable taste in my mouth. Objects feeling pleasurably warm. the room assumes vast proportions, and I feel as if in anothe world."

A patient described by Daly claimned his seizure felt like "a sunny day when your friends are all around you." He then felt disociated from his body, as if he were looking down upon himself and wathcing his actions.

Williams (1956) describes a patient who claimed that during an aura she experienced a feeling that she was being lifted up out of her body, coupled with a very pleasant sensation of eleation and the sensation that she was "just about to find out knowlede no one else shares, something to do with the line between life and death."

Subirana and Oller-Daurelia (1953) described two patients who experienced ecastic feelings of either "extrraordinary beatitude" or of paradise as if they had gone to heaven and noted that his fantastic feelings lasted for hours.

Other patients have noted that feelings and things suddenly become "cyrstal clear" or that they have a feeling of clairvoyance, or of having the truth revealed to them, or opf having achieved a sense of greater awareness and of a new awarness such that sounds, smells and visual objects seemd to have a greater meaning and sensibility.






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