Promoting Growth in Behavioral Neurology: A Path Forward.

Behavioral neurology & neuropsychiatry (BNNP) is a field that seeks to understand brain-behavior relationships, including fundamental brain organization principles and the many ways that brain structures and connectivity can be disrupted, leading to abnormalities of behavior, cognition, emotion, perception, and social cognition. In North America, BNNP has existed as an integrated subspecialty through the United Council for Neurologic Subspecialties since 2006. Nonetheless, the number of behavioral neurologists across academic medical centers and community settings is not keeping pace with increasing clinical and research demand. In this commentary, we provide a brief history of BNNP followed by an outline of the current challenges and opportunities for BNNP from the behavioral neurologist's perspective across clinical, research, and educational spheres. We provide a practical guide for promoting BNNP and addressing the shortage of behavioral neurologists to facilitate the continued growth and development of the subspecialty. We also urge a greater commitment to recruit trainees from diverse backgrounds so as to dismantle persistent obstacles that hinder inclusivity in BNNP-efforts that will further enhance the growth and impact of the subspecialty. With rapidly expanding diagnostic and therapeutic approaches across a range of conditions at the intersection of neurology and psychiatry, BNNP is well positioned to attract new trainees and expand its reach across clinical, research, and educational activities.

Altered Allocation of Vertical Attention in Individuals With Autism Spectrum Disorder.

BACKGROUND: Typical adults most frequently orient their attention to other people's eyes, whereas individuals with autism spectrum disorder (ASD) orient their attention to other people's mouths. Typical adults also reveal visuospatial biases on tasks such as vertical and horizontal line bisections. Therefore, the difference in face viewing might be related to a more general group difference in the allocation of vertical attention. OBJECTIVE: To use vertical line bisection and quadrisection tasks to evaluate whether individuals with ASD have a more downward-oriented vertical attentional bias than do typical individuals. METHOD: We recruited 20 individuals with ASD and 20 control participants matched for age (6-23 years), IQ, and sex. We asked the individuals to bisect and quadrisect lines on the top and bottom when the vertical lines were placed at the intersection of their right, left, and center egocentric sagittal planes and their coronal plane. The distances from the true midpoint and quadripoint were measured, and between-group performances were compared. RESULTS: No significant difference was found between the ASD and control groups for vertical line bisections or lower line quadrisections. However, when the ASD group was compared with the control group for higher line quadrisections, the ASD group exhibited a greater upward deviation. CONCLUSION: There is no downward vertical attentional spatial bias associated with ASD that could help to explain these individuals' attentional bias toward the mouth. However, additional studies are required to learn if this atypical upward vertical attentional bias might account for some of the symptoms and signs associated with ASD.

Hemodialyzed Individuals' Left Spatial Attentional Bias Is Normalized Following Successful Kidney Transplantation.

BACKGROUND: Healthy people have a leftward spatial attentional bias, called pseudoneglect. Individuals with end-stage renal disease (ESRD) who are receiving hemodialysis often demonstrate an increase in their leftward spatial attentional bias. Whereas a successful kidney transplant often improves the cognitive functions of individuals who previously received hemodialysis, the effect of a kidney transplant on this abnormal allocation of spatial attention has not been investigated. OBJECTIVE: To investigate the effects of kidney transplant on individuals who were being treated with dialysis and had an increase in their left spatial attentional bias. METHOD: The performance of 20 hemodialyzed individuals with ESRD on the line bisection test was compared to that of 17 demographically matched individuals with ESRD, who had received a kidney transplant, and 23 demographically matched healthy controls (HC). RESULTS: All of the participants exhibited a left spatial bias on the line bisection task. When compared with the HC, the hemodialyzed individuals demonstrated a significantly greater left spatial bias. There was, however, no difference in spatial bias between the HC and the individuals who had received a kidney transplant. CONCLUSION: A successful kidney transplant can improve patients' abnormal leftward allocation of spatial attention. However, future studies are needed to better understand the mechanisms of this spatial attentional bias in hemodialyzed individuals and the normalization of bias following transplantation.

Spatial artistic displays of emotional valence.

Background: While right-left hemispheric valence dichotomies have been demosntrated in various lesion stidues, it not entirely known if these dichotomies are portrayed in art. Methods: We examined 192 paintings to learn if there is an association between paintings that portray happy-positive or sad-negative scenes and the agent looking to the right or left side relative to their head's midsagittal plane. Results: There were 38 paintings with a positive valence and 32 with a negative valence in which the eyes were turned rightward or leftward. Of 38 positive valence paintings, 28 had the agent looking rightward, and 10 looking leftward. Of 32 negative valence paintings, 15 had the agent looking rightward and 17 leftward. Discussion: Hemisphere activation is associated with contralateral deviation of the eyes. Whereas the right hemisphere mediates negative emotions allocates spatial attention to both left and right hemispace, the left hemisphere primarily allocates attention to the right. Since the left hemisphere appears to mediate positive emotions and the right hemisphere negative emotions, results from this study are consistent with hemispheric emotional valence attentional hypotheses. However, the relationship between artist knowledge about gaze and the utilization of gaze direction to portray emotional experiences is not known.

Right up- left down.

BACKGROUND: When performing the clock-drawing test healthy participants often draw the clock face using a counter clockwise movement. The reason for this circular directional bias is not known. These actions may be related to the development of motor or attentional programs that associate leftward with downward movements, and rightward with upward movements. METHODS: To further examine this down-left, up-right programming hypothesis, we examined the direction of circular movements made during cursive writing by dividing the first curved movements into the following pairs, up versus down, and leftward versus rightward. RESULTS AND CONCLUSIONS: With almost all the letters analyzed, when initially moving upward there was a simultaneous rightward movement and when initially moving downward a leftward movement. The results suggest that there appears to be a relationship between downward and leftward movements as well as between upward and right rightward movements. In addition, there is some evidence to suggest that the right-upward movements may be mediated by the left hemisphere and left-downward movements by the right hemisphere. Although our results suggest motor or spatial attentional programs may account for counter clockwise face drawing, activities such as learned writing direction may influence this spatial bias. Therefore, additional research is needed to better understand if these spatial biases are learned or intrinsic and the neuropsychological mechanisms that might account for these asymmetries.

Early-Motor Phenotype Relates to Neuropsychiatric and Cognitive Disorders in Huntington's Disease.

OBJECTIVE: To determine the relationships between the motor phenotype and the presence of specific neuropsychiatric and neuropsychological disorders in patients with early motor-manifest Huntington's disease (HD). METHODS: From the Enroll-HD study, 3,505 individuals with HD who had ≤5 years of motor symptoms were classified based on the predefined parkinsonism/chorea index into chorea-dominant (n = 1125), parkinsonism-dominant (n = 867), and mixed-motor phenotype (n = 1513) groups. An analysis was performed on the results of the short Problem Behaviors Assessment. This test assesses patients for neuropsychiatric disorders such as depression, irritability/aggression, apathy, obsessive-compulsive behaviors, and psychosis as well as cognitive disorders by using neuropsychological tests such as the Stroop Interference test, Trail Making Test Part A and B, letter fluency, Symbol Digit Modality test, and animal fluency test. RESULTS: In these early motor-manifest HD individuals, motor phenotype was associated with neuropsychiatric and cognitive changes. Independent of the age of motor onset, motor duration and severity, CAG repeat expansion, and medication use, the parkinsonism-dominant group had more severe neuropsychiatric disorders (depression, apathy, obsessive-compulsive behaviors, and psychosis) and poorer performance on all cognitive tests than those patients in the mixed-motor phenotype and chorea-dominant groups. The patients in the chorea-dominant group had less apathy and depression than those in the mixed-motor phenotype group. CONCLUSIONS: In the early stage of motor-manifest HD, parkinsonism-dominant patients appear to have more severe neuropsychiatric disturbances and more cognitive impairments than those HD patients with chorea-dominant and mixed-motor phenotypes. Future studies should explore the brain mechanisms of these disorders and the possible treatments. © 2020 International Parkinson and Movement Disorder Society.

Degenerative dementia with proximal radial and lower vertical spatial neglect.

A 75 year-old man had a two-year history of progressive memory loss, trouble with finances and getting lost. On examination, he scored 16/30 in MoCA test, noticeably impaired on the attentional tasks. His screening bloodtests werenormal. Brain imaging revealed hippocampal atrophy and bilaterallarge areas of leukoaraiosis below posterior parietal lobes. On vertical line bisection he revealed a large upward bias and on radial bisection, a distal bias. Degeneration of his posterior parietal cortex may have caused both the leukoaraiosis and vertical-radial neglect. Unawareness of portions of space can be a source of disability and cause injury. Therefore, patients with degenerative dementia, especially those with similar patterns of leukoaraiosis or parietal degeneration should be tested for vertical and radial forms of spatial neglect.

Musical hallucinations with a right frontotemporal stroke.

MUSICAL HALLUCINATIONS: have been reported in association with psychiatric diseases, brain stem strokes, deafness, degenerative diseases, intoxications, pharmacologic agents, and epilepsy. We present a patient who in the absence of these disorders developed musical hallucinations from an infarction of the right hemisphere that primarily injured his right frontal and anterior temporal lobes. This report discusses some of the possible mechanisms for this patient's presentation. Although the mechanism of his musical hallucinations remains unclear, recognition of this uncommon syndrome is important when structuring rehabilitation and management for patients with stroke who have this disorder.

Proactive interference apraxic agraphia: a writing and drawing disorder associated with corticobasal syndrome.

Proactive interference is when a previously performed task impairs performance on a current task. It is often associated with memory tasks and has not been reported to interfere with writing or drawing. We evaluated a left-handed man diagnosed with corticobasal syndrome who had a two-year history of progressive agraphia. On the sentence writing and clock drawing tasks, he initially wrote letters and numbers correctly but revealed an increase of movement errors as the tasks progressed. We propose the term "proactive interference apraxic agraphia" for this novel disorder. Prefrontal dysfunction may cause an impairment in disengaging from previously activated motor programs.

Upper Vertical Spatial Neglect With A Right Temporal Lobe Stroke.

Individuals with a hemispheric infarction often reveal inattention to, or neglect of, contralesional lateral space (ie, hemispatial neglect). Individuals with a bilateral ventral temporal-occipital lesion have been shown to demonstrate upper vertical neglect, and those with a bilateral parietal-occipital lesion have been shown to demonstrate lower vertical neglect. However, to our knowledge, there have been no reports of individuals with vertical neglect from a unilateral hemispheric lesion. We report on a 72-year-old, right-handed male who developed transient left hemiparesis. On examination, he had left facial weakness and he bisected horizontal lines to the left of the midline (ie, ipsilesional neglect). In addition, on a line bisection test involving nine vertical line bisections, he demonstrated downward deviation in the majority of the trials; healthy individuals deviate upward. On brain imaging, our patient revealed a cerebral infarction, primarily affecting the right temporal lobe; the temporal lobes contain the ventral attentional network that allocates attention upward. There is also some evidence that, whereas the right hemisphere mediates attention upward, the left mediates attention downward. Therefore, injury to the right temporal lobe may account for our patient's upward neglect with downward deviation. However, further studies are needed to better understand the pathophysiology of vertical neglect.

Feeling and Looking Down: Impact of Depressive Symptoms on the Allocation of Vertical Attention.

BACKGROUND: Emotions and moods are often expressed using verbal, vertical spatial metaphors (eg, "I'm feeling down"). The reason for using these vertical metaphors is unknown; however, when individuals experience depressive symptoms, they often become self-reflective and ruminative. These mental activities are associated with activation of the default network, including the parietal lobes. The parietal lobes are a critical component of the dorsal visual attentional network, which allocates attention downward. Therefore, activation of the default network may create a downward bias of vertical attention. OBJECTIVE: To investigate whether depressive mood disposition, as measured by the number of depressive symptoms experienced by an individual, influences their allocation of vertical attention. METHODS: We used the Hospital Anxiety and Depression Scale to evaluate depressive symptoms in 48 right-handed individuals with a mean age of 57.31 (±17.14) years. We also asked the participants to mark the center (bisect) of 24 vertical and 24 horizontal lines. RESULTS: Overall, the individuals deviated their bisections of vertical lines upward (M=2.66 mm; SD=3.85). A stepwise linear regression analysis revealed that the number of depressive symptoms an individual experienced was significantly associated with a reduction in the magnitude of this upward vertical bias (P=0.009; R=0.138), such that the number of depressive symptoms was associated with the reduction (lowering) of their upward bias. CONCLUSION: Depressive symptoms may be associated with a relative lowering of the vertical attentional bias, and this lowering may be related to increased activation of portions of the default network.

The Influence of Focused and Sustained Spatial Attention on the Allocation of Spatial Attention.

OBJECTIVE: The objective of this study was to evaluate the impact of directed and sustained attention on the allocation of visuospatial attention. Healthy people often have left lateral and upward vertical spatial attentional biases. However, it is not known whether there will be an increase in bias toward the attended portion of the stimulus when volitional spatial attention is allocated to a portion of a stimulus, whether there are asymmetrical spatial alterations of these biases, and how sustained attention influences these biases. METHODS: We assessed spatial bias in 36 healthy, right-handed participants using a variant of horizontal and vertical line bisections. Participants were asked to focus on one or the other end of vertical or horizontal lines or entire vertical or horizontal lines, and then to bisect the line either immediately or after a 20 second delay. RESULTS: We found a significant main effect of attentional focus and an interaction between attentional focus and prolonged viewing with delayed bisection. Focusing on a certain portion of the line resulting in a significant deviation toward the attended portion and prolonged viewing of the line prior to bisection significantly enhanced the degree of deviation toward the attended portion. CONCLUSIONS: The enhanced bias with directed and sustained attention may be useful modifications of the line bisection test, particularly in clinical populations. Thus, future studies should determine whether prolonged viewing with delayed bisection and spatially focused attention reveals attentional biases in patients with hemispheric lesions who perform normally on the traditional line bisection test. (JINS, 2019, 25, 65-71).

Improved Accuracy on Lateralized Spatial Judgments in Healthy Aging.

OBJECTIVES: Healthy young adults often demonstrate a leftward spatial bias called "pseudoneglect" which often diminishes with aging. One hypothesis for this phenomenon is an age-related deterioration in right hemisphere functions (right hemi-aging). If true, then a greater rightward bias should be evident on all spatial attention tasks regardless of content. Another hypothesis is a decrease in asymmetrical hemispheric activation with age (HAROLD). If true, older participants may show reduced bias in all spatial tasks, regardless of leftward or rightward biasing of specific spatial content. METHODS: Seventy right-handed healthy participants, 33 younger (21-40) and 37 older (60-78), were asked to bisect solid and character-letter lines as well as to perform left and right trisections of solid lines. RESULTS: Both groups deviated toward the left on solid line bisections and left trisections. Both groups deviated toward the right on right trisections and character line bisections. In all tasks, the older participants were more accurate than the younger participants. CONCLUSIONS: The finding that older participants were more accurate than younger participants across all bisection and trisection conditions suggests a decrease in the asymmetrical hemispheric activation of these specialized networks important in the allocation of contralateral spatial attention or spatial action intention.

Vertical and Radial Attentional Neglect in Corticobasal Syndrome.

Corticobasal degeneration (CBD), a tau-related neurodegenerative disease, is characterized by limb rigidity, dystonia, myoclonus, apraxia, and cognitive deficits. We report a patient with probable corticobasal syndrome, a major phenotype of CBD, who revealed both lower vertical and proximal radial attentional neglect on line bisection tests. Brain imaging revealed bilateral parietal atrophy with hypometabolism in the bilateral parietal, dorsolateral prefrontal, and premotor cortices. Bilateral impairment in the dorsal attentional network reduces the allocation of spatial attention to lower and proximal space, causing lower vertical and proximal radial attentional neglect. Screening for various types of spatial neglect may be important in tailoring management and rehabilitation strategies for patients with CBD.

Chronological Effects of Emotional Valence on the Self-selected Retrieval of Autobiographical Memories.

BACKGROUND AND OBJECTIVE: Salience of emotional autobiographical memories may have temporal patterns associated with valence. Recall of negative emotional memories is often important in survival and well-being. Based on the possible survival value of negative memories, we posited that when given an open-ended request to recall either a sad or a happy memory, people are more likely to recall an older sad memory than a happy one. METHODS: We asked 20 healthy participants, aged 18-63 years, to freely recall happy and sad emotional memories and estimate the length of time that had passed since the recalled event had occurred. We analyzed the age of each memory based on valence. RESULTS: Sixteen of 20 participants volunteered a more remote sad than happy memory (P<0.05). Older participants' sad memories were more remote (P<0.05), but the ratio of happy to sad memories was not affected by age. CONCLUSIONS: Self-selected free retrieval of autobiographical happy and sad emotional memories reveals a time bias. Although the reason for this temporal dichotomy is unknown, it may be that engaging systems involved in defense and survival alters the encoding and/or retrieval characteristics of the memory that modify salience.

Age-Related Changes in the Allocation of Vertical Attention.

OBJECTIVES: Healthy individuals often have a leftward and upward attentional spatial bias; however, there is a reduction of this leftward bias with aging. The right hemisphere mediates leftward spatial attention and age-related reduction of right hemispheric activity may account for this reduced leftward bias. The right hemisphere also appears to be responsible for upward bias, and this upward bias might reduce with aging. Alternatively, whereas the dorsal visual stream allocates attention downward, the ventral stream allocates attention upward. Since with aging there is a greater atrophy of the dorsal than ventral stream, older participants may reveal a greater upward bias. The main purpose of this study was to learn if aging influences the vertical allocation of spatial attention. METHODS: Twenty-six young (17 males; mean age 44.62±2.57 years) and 25 healthy elderly (13 males; mean age 72.04±.98 years), right-handed adults performed line bisections using 24 vertical lines (24 cm long and 2 mm thick) aligned with their midsagittal plane. RESULTS: Older adults had a significantly greater upward bias than did younger adults. CONCLUSIONS: Normal upward attentional bias increases with aging, possibly due to an age-related reduction of the dorsal attentional stream that is responsible for the allocation of downward attention. (JINS, 2018, 24, 1121-1124).

Left hemispatial neglect with a splenial lesion.

With injury of the anterior two-thirds of the corpus callosum, each hemisphere's attentional bias to contralateral hemispace becomes manifest with each hand deviating ipsilaterally during line bisection tasks. Patients with infarctions in the right posterior cerebral artery distribution with occipital and splenial damage can also exhibit spatial neglect. The goal of this report is to learn the role of the splenium of the corpus callosum in mediating visuospatial attention. A right-handed woman with Marchiafava-Bignami disease and damage to the splenium of her corpus callosum without evidence of a mesial frontal, parietal, or occipital injury was assessed for spatial neglect with line bisections. When bisecting lines in her left hemispace with her right hand, she deviated to the right, but revealed no major deviations when the line was place in the midline, in right hemispace, or when bisecting lines with her left hand. This patient provides evidence that damage to the splenium can induce a special form of asymmetrical spatial neglect. This asymmetry might be related to the disconnected right hemisphere's ability to allocate attention to both right and left hemispaces with the disconnected left hemisphere's ability to allocate attention to the right but not left hemispace.

A Degenerative Form of Mixed Transcortical Aphasia.

Mixed transcortical aphasia (MTA) is characterized by decreased spontaneous speech, impaired naming, and poor comprehension, but with intact repetition. MTA has been reported to be the sequela of left hemisphere watershed infarction that isolates Wernicke's perisylvian arc. We report a 55-year-old right-handed woman who began having word-finding difficulty and then gradually developed impaired spontaneous speech, comprehension, and naming, but with intact repetition. Magnetic resonance imaging showed atrophy in the left frontal, parietal, and temporal lobes. This patient demonstrates that MTA can occur as a result of neurodegenerative disease. Further research is needed to learn whether progressive MTA is a late stage of primary progressive aphasia, examine the neuropathology associated with this syndrome, and identify treatment strategies.

Correction to: SPG7 and Impaired Emotional Communication.

The original version of this article unfortunately contained an incorrect assignment of affiliations of Linwei Zhang and Tetsuo Ashizawa.

SPG7 and Impaired Emotional Communication.

The goal of this report is to describe the genetic mutations of a patient with cerebellar degeneration who had ataxia and impaired emotional communication that led to damage of family relationships. We extracted genomic DNA from peripheral blood lymphocytes and performed whole exome sequencing (WES) in this patient and his unaffected parents and siblings. Found mutations were confirmed by Sanger sequencing in each individual. We found compound heterozygous mutations in the paraplegin (SPG7) gene. One mutated allele has been previously described as a disease-causing missense mutation for spastic paraplegia type 7 (SPG7) (c.1529C > T, p.Ala510Val). The second mutated allele involved a single nucleotide deletion which results in a frameshift in the coding sequence (c.2271delG, p.Met757fs*65). The second allele is similar to, but unique from, other described, SPG7-linked truncation mutations. The abnormal emotional communication in this patient broadens the phenotypic boundary of SPG7.