Pathologic nystagmus: a classification based on electro-oculographic recordings.

The widespread availability of eye movement recording systems has added a new dimension to our ability to accurately describe nystagmus. Electrooculography (EOG) is the simplest and most readily available system. With EOG the effect of loss of fixation (either with eyes closed, or eyes open in darkness) can be accurately assessed and quantitative evaluation of nystagmus speed, frequency and amplitude is easily made. Of equal importance, it provides a permanent record that can be compared with nystagmus recorded in other patients. By comparing clinical observation with paper recordings, both students and experienced clinicians can become more efficient in recognizing different varieties of nystagmus.     

Understanding empathy and related phenomena.

Over a period of time, the author arrived at a few tentative postulates concerning empathy and related processes based on some of his experiences and observations. The central theme of these postulates is, firstly, that interpersonal interaction is an interaction of the personal-space fields. Secondly, empathy, therapeutic benefit, and the professional stress are all related to the same process of interpersonal interaction. This interaction takes place as an enmeshment of personal spaces of the interacting individuals, and involves transfer of a wide range of information in the affective, cognitive, and other areas. This is because the personal spaces have fieldlike qualities analogous to what Kurt Lewin described. Thus, such phenomena as empathy, therapeutic benefit, professional stress are all consequences of the same process. It is possible to substantiate these postulates by diverse evidences in the published literature. The natural consequences of such an interpersonal interaction are empathic understanding, transfer of mood states (like hope, distress or expectancy), affective states (like anxiety, sadness, anger or hostility), ideas, images and even attitudes and values, etc. This phenomenon of transfer can explain such processes as therapeutic benefit in individual and group settings, professional stress, shared delusions, and even experimenter bias. Whether one becomes aware of such transferred information or not depends upon the intent and sensitivity of the participants.     

A Jacksonian and biopsychosocial hypothesis concerning borderline and related phenomena

OBJECTIVE: The aim of this paper is to develop an aetiological model for borderline personality disorder. METHOD: The postulates of Hughlings Jackson are used to provide a preliminary explanatory framework for borderline phenomena. As a necessary background to this discussion, the findings concerning abuse in the early history of borderline personality disorder (BPD) and other conditions, notably somatisation disorder and dissociative states, are briefly reviewed. Other data, including family studies, which might have significance in the aetiology of BPD are also reviewed. RESULTS: The hypothesis is put forward that the symptoms of BPD are due to the failure of 'experience-dependent' maturation of a cascade of neural networks, with prefrontal connections, which become active relatively late in development and which coordinate disparate elements of central nervous system function. These networks subserve higher psychological functions, including attentional focus and affect regulation. They also underpin the reflective function necessary to the emergence of self as the stream of consciousness, which appears at about the age of 4 years. CONCLUSION: Adverse developmental circumstances may produce an interrelated set of symptom clusters, with associated neural network disturbances that are amenable to investigation with psychometric and brain imaging techniques. Since these disturbances are seen as 'experience-dependent', they are considered reversible, at least in part.     

Optokinetic nystagmus as related to neonatal position

The objective of this study was to assess the role of the newborn vestibular system on the infant's preferred position. Neonatal electronystagmography was recorded from 80 full-term healthy neonates in the prone and supine positions. Records were analyzed by the clinical ranking of dysmetria and dysrhythmia and computerized fractal analysis. A significantly (P < .002) decreased organization of the electronystagmography signal was observed in the prone compared with the supine position. These results concur with the previously documented, more optimal physiologic functioning in the supine compared with prone position in infancy. It is possible that the vestibular system, among other factors, plays a role in the more protective supine position in infancy.     

Pathologic hair-pulling: a review of the literature and case reports.

Pathologic hair-pulling (trichotillomania) has been described in the dermatologic and psychiatric literature for the last century, but has become the focus of increased attention in the last few years. Once thought to be either a wholly benign condition or a symptom of obsessive-compulsive disorder, more recently hair-pulling has been noted in the context of numerous types of psychopathology, and has been reported to respond to several different types of intervention, both psychological and somatic. Estimates of its prevalence have varied widely. Because of the disparate conclusions of the literature on this condition, a more careful assessment of diagnostic validity is recommended.     

Epileptic nystagmus.

Epileptic nystagmus is a rare, ictal phenomenon characterized by rapid, repetitive eye movements caused by epileptic activity. We report on a patient with cryptogenic focal epilepsy who presented a long-lasting (>30mn) episode of left head and eyes deviation and left-beating nystagmus not crossing the midline. Interictal EEG showed right temporal abnormalities.[Published with video sequences].     

Latent nystagmus and acquired pendular nystagmus masquerading as spasmus nutans.

SUMMARY: We used ocular motility recordings to identify the characteristics of a rare combination of conjugate, horizontal jerk, and pendular nystagmus in a 9-year-old boy. The clinical diagnoses were amblyopia, left esotropia, congenital nystagmus, and an apparently uniocular pendular nystagmus that mimicked spasmus nutans. Ocular motility recordings revealed an unusual latent/manifest latent nystagmus, pendular nystagmus with characteristics of an acquired nystagmus, and uniocular saccades. The ocular motor data identified clinically unrecognized types of nystagmus and suggested that the pendular nystagmus was acquired in infancy rather than as a result of failure to develop good vision or binocularity. The presence of uniocular saccades adds to the mounting evidence that individual control for each eye exists in humans.     

Primary position upbeat nystagmus. A clinicopathologic study

Eye movements were studied with electro-oculography in a patient with primary position, large amplitude, upbeat nystagmus. The upbeat nystagmus increased in amplitude on upward gaze, decreased on downward gaze, and was not altered by loss of fixation. The patient could not produce smooth pursuit movements upward or to the left, but had normal saccadic and vestibular induced eye movements in all directions. At necropsy, a low grade glioma was found involving primarily the medulla and caudal pons. The inferior olives and prepositus hypoglossal nuclei were diffusely infiltrated with tumor. These results suggest (1) primary position upbeat nystagmus is due to a defect in the upward smooth pursuit system, (2) the lower brain stem at the level of the inferior olives and nucleus prepositus hypoglossi is important in the mediation of vertical pursuit, and (3) primary position upbeat nystagmus can result from damage to several nuclei and interconnecting pathways in the caudal brain stem and midline cerebellum involved in control of vertical smooth pursuit.     

Neurotoxicity related to lithium and neuroleptic combinations? A retrospective review.

The question of toxic interactions resulting from combinations of lithium and neuroleptic drugs is largely based on anecdotal reports. We replicated the methods of Miller and Menninger (1987) who reported that 27% of manic patients on treatment with lithium and neuroleptics developed toxicity. We found no cases of neurotoxicity as defined in the earlier report. Pharmacologic mechanisms and differences in the clinical findings of the two studies are discussed.     

Are schizophrenia and affective disorder related? A selective literature review.

OBJECTIVE: Although most modern investigators accept the Kraepelinian view that schizophrenia and affective disorder are biologically distinct, others have suggested the psychoses are on a continuum of liability. This article is a selective review of evidence for the continuum model. METHOD: The author focuses on family, twin, and adoption data that do not support the Kraepelinian view of psychosis. Evidence characterized to a lesser extent includes the frequency of intermediate forms of illness (i.e., schizoaffective disorder), the inability to separate psychoses by classical symptoms into well-defined clusters, and the inability of laboratory measures to clearly define psychotic subgroups. RESULTS: The data demonstrate that schizophrenia and affective disorder do co-occur in some families. Whether this co-occurrence reflects true overlap is unclear, and significant pathophysiological heterogeneity may underlie clinical continuity. In some recent studies the inclusion of nonmelancholic depressions in the affective illness category may have masked overlap. CONCLUSIONS: The author suggests that the Kraepelinian view of psychoses may need modification. Future research should focus on factors that may reveal overlap between schizophrenia and affective disorder: severity of schizophrenia and affective disorder in probands, severity of depression in relatives, the effect of the unipolar-bipolar disorder relationship on the co-occurrence of affective disorder and schizophrenia, and the relationship of nongenetic factors that might alter the clinical expression of a shared genotype. Also, investigators should not presume a dichotomy or continuum but should examine pure and mixed pedigrees and look for state- and trait-related endophenotypes, the convergence of which would provide the basis for focused molecular genetic study.     

Periodic alternating nystagmus and rebound nystagmus in spinocerebellar ataxia type 6.

We report on a family with ataxia type 6 (SCA6) showing peculiar oculomotor symptoms. The proband presented with periodic alternating nystagmus (PAN), and her 2 brothers had rebound nystagmus and gaze-evoked nystagmus. They carried the identical mutation (the number of expanded CAG repeat, 24) in the CACNA1A gene. The intrafamilial variability of oculomotor symptoms may be ascribed to factors other than CAG repeat expansion size in SCA6.     

Periodic alternating nystagmus.

Three patients with periodic alternating nystagmus (PAN) are described in detail. Digital computer methods were used to quantify their disordered eye movement in an attempt to understand the pathophysiology. One of the patients was unusual in showing rebound nystagmus with fixation and PAN without fixation. Each patient had hyperactive vestibular responses and the phase and gain of the PAN cycles were altered in a predictable fashion by vestibular stimuli. It is postulated that PAN represents cyclical firing between reciprocally connected groups of inhibitory neurons within the vestibular and oculomotor nuclei. The cyclical firing is initiated by a critical imbalance of tonic input to either group of normally functioning neurons.     

Phantom limbs and related phenomena in recent traumatic amputations

Seventy-three soldiers who had traumatic amputations were examined from 1 to 6 months after limb loss. All experienced phantom limb sensations and 67 percent experienced phantom limb pains, usually transient. Stump pain occurred in 43 percent and was associated with phantom pain in 54 percent of these. Of the 23 percent of the entire group who had evident stump pathology, 33 percent had phantom pains only, 20 percent had stump pains only, 40 percent had both, and 7 percent were pain-free. All stump ends exhibited an area of hyperpathia with hypoesthesia. Phantom pain probably results from peripheral or spinal cord mechanisms, or both, rather then from more rostral mechanisms.