Behaviour, physiology and experience of pathological laughing and crying in amyotrophic lateral sclerosis

Two's company: Biobehavioral research with dyads

The development of paradigms for studying dyadic interaction in the laboratory and methods and analytics for dealing with dyadic data is described. These are illustrated with research findings from the author and others with particular focus on dyadic measures of linkage or synchrony in physiology, expressive behavior, and subjective affective experience.

Radiological correlates of pseudobulbar affect: Corticobulbar and cerebellar components in primary lateral sclerosis

INTRODUCTION

Pseudobulbar affect (PBA) is a distressing symptom of a multitude of neurological conditions affecting patients with a rage of neuroinflammatory, neurovascular and neurodegenerative conditions. It manifests in disproportionate emotional responses to minimal or no contextual stimulus. It has considerable quality of life implications and treatment can be challenging.

METHODS

A prospective multimodal neuroimaging study was conducted to explore the neuroanatomical underpinnings of PBA in patients with primary lateral sclerosis (PLS). All participants underwent whole genome sequencing and screening for C9orf72 hexanucleotide repeat expansions, a comprehensive neurological assessment, neuropsychological screening (ECAS, HADS, FrSBe) and PBA was evaluated by the emotional lability questionnaire. Structural, diffusivity and functional MRI data were systematically evaluated in whole-brain (WB) data-driven and region of interest (ROI) hypothesis-driven analyses. In ROI analyses, functional and structural corticobulbar connectivity and cerebello-medullary connectivity alterations were evaluated separately.

RESULTS

Our data-driven whole-brain analyses revealed associations between PBA and white matter degeneration in descending corticobulbar as well as in commissural tracts. In our hypothesis-driven analyses, PBA was associated with increased right corticobulbar tract RD (p = 0.006) and decreased FA (p = 0.026). The left-hemispheric corticobulbar tract, as well as functional connectivity, showed similar tendencies. While uncorrected p-maps revealed both voxelwise and ROI trends for associations between PBA and cerebellar measures, these did not reach significance to unequivocally support the "cerebellar hypothesis".

CONCLUSIONS

Our data confirm associations between cortex-brainstem disconnection and the clinical severity of PBA. While our findings may be disease-specific, they are consistent with the classical cortico-medullary model of pseudobulbar affect.

Definitions, phenomenology, diagnosis, and management of the disorders of laughter and crying in amyotrophic lateral sclerosis (ALS): Consensus from ALS and Motor Neuron Disease Scientific Department of the Brazilian Academy of Neurology

The spectrum of neuropsychiatric phenomena observed in amyotrophic lateral sclerosis (ALS) is wide and not fully understood. Disorders of laughter and crying stand among the most common manifestations. The aim of this study is to report the results of an educational consensus organized by the Brazilian Academy of Neurology to evaluate the definitions, phenomenology, diagnosis, and management of the disorders of laughter and crying in ALS patients. Twelve members of the Brazilian Academy of Neurology - considered to be experts in the field - were recruited to answer 12 questions about the subject. After exchanging revisions, a first draft was prepared. A face-to-face meeting was held in Fortaleza, Brazil on 9.23.22 to discuss it. The revised version was subsequently emailed to all members of the ALS Scientific Department from the Brazilian Academy of Neurology and the final revised version submitted for publication. The prevalence of pseudobulbar affect/pathological laughter and crying (PBA/PLC) in ALS patients from 15 combined studies and 3906 patients was 27.4% (N = 1070), ranging from 11.4% to 71%. Bulbar onset is a risk factor but there are limited studies evaluating the differences in prevalence among the different motor neuron diseases subtypes, including patients with and without frontotemporal dementia. Antidepressants and a combination of dextromethorphan and quinidine (not available in Brazil) are possible therapeutic options. This group of panelists acknowledge the multiple gaps in the current literature and reinforces the need for further studies.

Mild behavioral impairment as a potential marker of predementia risk states in motor neuron diseases

BACKGROUND AND PURPOSE

Mild behavioral impairment (MBI) has been increasingly regarded as the neurobehavioral axis of predementia risk states, but a specific investigation of its detection as a potential marker of prodromal dementia in motor neuron diseases (MNDs) is still lacking. The aims of our study were therefore to explore MBI in MNDs both at onset and over the disease course, and to evaluate its relationship with baseline and longitudinal cognitive features.

METHODS

Sixty MND patients with cognitive/behavioral, mood, and motor examinations were recruited and followed longitudinally for up to 15 months. Associations between baseline MBI symptoms and clinical features were tested using the Spearman correlation coefficient. Based on longitudinal data, relative deltas of variation for each cognitive measure were generated, and linear regression models were then used to evaluate the role of baseline MBI symptoms in predicting longitudinal rates of cognitive decline.

RESULTS

At disease onset, the most impaired MBI domain was affective/emotional dysregulation, followed by impulse dyscontrol, apathy, and social inappropriateness. Greater MBI symptoms correlated with more severe baseline motor, cognitive/behavioral, and mood disturbances (p values from <0.001 to 0.05). Longitudinally, the greatest decline was observed in the affective/emotional dysregulation domain, followed by impulse dyscontrol, apathy, and social inappropriateness. Greater MBI symptoms at onset were significant predictors of more severe longitudinal cognitive decline in both amyotrophic lateral sclerosis (ALS)-specific and ALS-nonspecific functions (p values from <0.001 to 0.03).

CONCLUSIONS

MBI represents a valuable clinical marker of incident cognitive decline in MNDs, and its evaluation has good potential for detecting dementia in its preclinical/prodromal phase.

Incongruences Between Facial Expression and Self-Reported Emotional Reactivity in Frontotemporal Dementia and Related Disorders

OBJECTIVE

Emotional reactivity normally involves a synchronized coordination of subjective experience and facial expression. These aspects of emotional reactivity can be uncoupled by neurological illness and produce adverse consequences for patient and caregiver quality of life because of misunderstandings regarding the patient's presumed internal state. Frontotemporal dementia (FTD) is often associated with altered social and emotional functioning. FTD is a heterogeneous disease, and socioemotional changes in patients could result from altered internal experience, altered facial expressive ability, altered language skills, or other factors. The authors investigated how individuals with FTD subtypes differ from a healthy control group regarding the extent to which their facial expressivity aligns with their self-reported emotional experience.

METHODS

Using a compound measure of emotional reactivity to assess reactions to three emotionally provocative videos, the authors explored potential explanations for differences in alignment of facial expressivity with emotional experience, including parkinsonism, physiological reactivity, and nontarget verbal responses.

RESULTS

Participants with the three main subtypes of FTD all tended to express less emotion on their faces than they did through self-report.

CONCLUSIONS

Exploratory analyses suggest that reasons for this incongruence likely differ not only between but also within diagnostic subgroups.

Prevalence and Factors Related to Pathological Laughter and Crying in Patients With Amyotrophic Lateral Sclerosis

Objective: This study aimed to explore the prevalence and clinical correlates of pathological laughter and crying (PLC) in patients with amyotrophic lateral sclerosis (ALS).

Methods: A total of 1,031 ALS patients were enrolled between August 2012 and August 2019. The PLC was recorded by a face-to-face interview. Other characteristics of patients, including depression, anxiety, cognition, and behavior function, were also evaluated. The potential associated factors of PLC were explored using forward binary regression analysis. Survival was analyzed in groups using propensity score matching (PSM) and Cox proportional hazards models.

Results: The prevalence of PLC was 11.4% in all patients at baseline. Bulbar-onset and female patients had higher prevalence of PLC. The multivariate regression analysis indicated that PLC in ALS was associated with bulbar onset (p < 0.001), late disease stage (p < 0.001), and higher score in the Hamilton Depression Rating Scale (HDRS) (p = 0.012). The higher score of HDRS was significantly and independently associated with PLC occurrence in bulbar-onset patients (p = 0.032). The late disease stage was related to PLC occurrence in spinal-onset patients (p < 0.001). After comparison with matched pairs by using PSM, PLC at baseline had no impact on survival.

Conclusion: PLC was not uncommon in ALS, especially in bulbar-onset and female patients. We highlighted that the emotional state other than cognitive function had possible relationship with PLC in ALS.

Autonomic factors do not underlie the elevated self-disgust levels in Parkinson's disease

INTRODUCTION

Parkinson's disease (PD) is manifested along with non-motor symptoms such as impairments in basic emotion regulation, recognition and expression. Yet, self-conscious emotion (SCEs) such as self-disgust, guilt and shame are under-investigated. Our previous research indicated that Parkinson patients have elevated levels of self-reported and induced self-disgust. However, the cause of that elevation-whether lower level biophysiological factors, or higher level cognitive factors, is unknown.

METHODS

To explore the former, we analysed Skin Conductance Response (SCR, measuring sympathetic activity) amplitude and high frequency Heart Rate Variability (HRV, measuring parasympathetic activity) across two emotion induction paradigms, one involving narrations of personal experiences of self-disgust, shame and guilt, and one targeting self-disgust selectively via images of the self. Both paradigms had a neutral condition.

RESULTS

Photo paradigm elicited significant changes in physiological responses in patients relative to controls-higher percentages of HRV in the high frequency range but lower SCR amplitudes, with patients to present lower responses compared to controls. In the narration paradigm, only guilt condition elicited significant SCR differences between groups.

CONCLUSIONS

Consequently, lower level biophysiological factors are unlikely to cause elevated self-disgust levels in Parkinson's disease, which by implication suggests that higher level cognitive factors may be responsible.

Brainstem Correlates of Pathological Laughter and Crying Frequency in ALS

Pseudobulbar affect is a disorder of emotional expression commonly observed in amyotrophic lateral sclerosis (ALS), presenting as episodes of involuntary laughter, or crying. The objective of the current study was to determine the association between frequency of pathological laughter and crying (PLC) episodes with clinical features, cognitive impairment, and brainstem pathology. Thirty-five sporadic ALS patients underwent neuropsychological assessment, with a subset also undergoing brain imaging. The Center for Neurological Study Lability Scale (CNS-LS) was used to screen for presence and severity of pseudobulbar affect (CNS-LS ≥ 13) and frequency of PLC episodes. Presence of pseudobulbar affect was significantly higher in bulbar onset ALS (p = 0.02). Frequency of PLC episodes was differentially associated with cognitive performance and brainstem integrity. Notably pathological laughter frequency, but not crying, showed a significant positive association with executive dysfunction on the Trail Making Test B-A (R² = 0.14, p = 0.04). Similarly, only pathological laughter frequency demonstrated a significant negative correlation with gray matter volume of the brainstem (R² = 0.46, p < 0.01), and mean fractional anisotropy of the superior cerebellar peduncles (left: R² = 0.44, p < 0.01; right: R² = 0.44, p < 0.01). Hierarchical regression indicated brainstem imaging in combination with site of symptom onset explained 73% of the variance in pathological laughter frequency in ALS. The current findings suggest emotional lability is underpinned by degeneration across distinct neural circuits, with brainstem integrity critical in the emergence of pathological laughter.

Cognitive and Behavioral Manifestations in ALS: Beyond Motor System Involvement

Amyotrophic lateral sclerosis (ALS) has long been considered to be a purely motor disorder. However, it has become apparent that many ALS patients develop cognitive and behavioral manifestations similar to frontotemporal dementia and the term amyotrophic lateral sclerosis-frontotemporal spectrum disorder (ALS-FTSD) is now used in these circumstances. This review is intended to be an overview of the cognitive and behavioral manifestations commonly encountered in ALS patients with the goal of improving case-oriented management in clinical practice. We introduce the principal ALS-FTSD subtypes and comment on their principal clinical manifestations, neuroimaging findings, neuropathological and genetic background, and summarize available therapeutic options. Diagnostic criteria for ALS-FTSD create distinct categories based on the type of neuropsychological manifestations, i.e., changes in behavior, impaired social cognition, executive dysfunction, and language or memory impairment. Cognitive impairment is found in up to 65%, while frank dementia affects about 15% of ALS patients. ALS motor and cognitive manifestations can worsen in parallel, becoming more pronounced when bulbar functions (affecting speech, swallowing, and salivation) are involved. Dementia can precede or develop after the appearance of motor symptoms. ALS-FTSD patients have a worse prognosis and shorter survival rates than patients with ALS or frontotemporal dementia alone. Important negative prognostic factors are behavioral and personality changes. From the clinician's perspective, there are five major distinguishable ALS-FTSD subtypes: ALS with cognitive impairment, ALS with behavioral impairment, ALS with combined cognitive and behavioral impairment, fully developed frontotemporal dementia in combination with ALS, and comorbid ALS and Alzheimer's disease. Although the most consistent ALS and ALS-FTSD pathology is a disturbance in transactive response DNA binding protein 43 kDa (TDP-43) metabolism, alterations in microtubule-associated tau protein metabolism have also been observed in ALS-FTSD. Early detection and careful monitoring of cognitive deficits in ALS are crucial for patient and caregiver support and enable personalized management of individual patient needs.

Smaller Volume in Left-Lateralized Brain Structures Correlates with Greater Experience of Negative Non-target Emotions in Neurodegenerative Diseases

Subjective emotional experience that is congruent with a given situation (i.e., target emotions) is critical for human survival (e.g., feeling disgusted in response to contaminated food motivates withdrawal behaviors). Neurodegenerative diseases including frontotemporal dementia and Alzheimer's disease affect brain regions critical for cognitive and emotional functioning, resulting in increased experience of emotions incongruent with the situation (i.e., non-target emotions, such as feeling happy when seeing someone grieving). We examined neuroanatomical correlates of subjective experience of non-target emotions in 147 patients with neurodegenerative diseases and 26 healthy individuals. Participants watched three films intended to elicit particular target emotions and rated their experience of negative and positive target and non-target emotions after watching each film. We found that smaller volume in left hemisphere regions (e.g., caudate, putamen, and dorsal anterior insula) was associated with greater experience of negative non-target emotions. Follow-up analyses confirmed that these effects were left-lateralized. No correlates emerged for positive non-target emotions. These findings suggest that volume loss in left-hemisphere regions produces a more diffuse, incongruent experience of non-target emotions. These findings provide a potential neuroanatomical basis for understanding how subjective emotional experience is constructed in the brain and how this can be disrupted in neurodegenerative disease.

The spectrum of involuntary vocalizations in humans: A video atlas

In clinical practice, involuntary vocalizing behaviors are typically associated with Tourette syndrome and other tic disorders. However, they may also be encountered throughout the entire tenor of neuropsychiatry, movement disorders, and neurodevelopmental syndromes. Importantly, involuntary vocalizing behaviors may often constitute a predominant clinical sign, and, therefore, their early recognition and appropriate classification are necessary to guide diagnosis and treatment. Clinical literature and video-documented cases on the topic are surprisingly scarce. Here, we pooled data from 5 expert centers of movement disorders, with instructive video material to cover the entire range of involuntary vocalizations in humans. Medical literature was also reviewed to document the range of possible etiologies associated with the different types of vocalizing behaviors and to explore treatment options. We propose a phenomenological classification of involuntary vocalizations within different categorical domains, including (1) tics and tic-like vocalizations, (2) vocalizations as part of stereotypies, (3) vocalizations as part of dystonia or chorea, (4) continuous vocalizing behaviors such as groaning or grunting, (5) pathological laughter and crying, (6) vocalizations resembling physiological reflexes, and (7) other vocalizations, for example, those associated with exaggerated startle responses, as part of epilepsy and sleep-related phenomena. We provide comprehensive lists of their associated etiologies, including neurodevelopmental, neurodegenerative, neuroimmunological, and structural causes and clinical clues. We then expand on the pathophysiology of the different vocalizing behaviors and comment on available treatment options. Finally, we present an algorithmic approach that covers the wide range of involuntary vocalizations in humans, with the ultimate goal of improving diagnostic accuracy and guiding appropriate treatment. © 2019 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Pathological Crying and Laughing in Motor Neuron Disease: Pathobiology, Screening, Intervention

Pathological crying and laughing (PCL) has significant quality-of-life implications in amyotrophic lateral sclerosis (ALS); it can provoke restrictive life-style modifications and lead to social isolation. Despite its high prevalence and quality of life implications, it remains surprisingly understudied. Divergent pathophysiological models have been proposed, centered on corticobulbar tract degeneration, prefrontal cortex pathology, sensory deafferentation, and impaired cerebellar gate-control mechanisms. Quantitative MRI techniques and symptom-specific clinical instruments offer unprecedented opportunities to elucidate the anatomical underpinnings of PCL pathogenesis. Emerging neuroimaging studies of ALS support the role of cortico–pontine–cerebellar network dysfunction in context-inappropriate emotional responses. The characterization of PCL-associated pathophysiological processes is indispensable for the development of effective pharmacological therapies.

Pseudobulbar Affect in Parkinsonian Disorders: A Review

Pseudobulbar affect (PBA) is a neurological symptom of inappropriate and uncontrollable laughter or crying that occurs secondary to a variety of neurological conditions, including parkinsonian disorders. PBA is a socially and emotionally debilitating symptom that has been estimated to affect 3.6% to 42.5% of the population with Parkinson's disease. While indexing measures and treatment options for PBA have been extensively studied in neurological conditions such as amyotrophic lateral sclerosis and multiple sclerosis, there has been considerably less attention given in the literature to PBA in parkinsonian disorders. The purpose of this review is to discuss the pathophysiology of PBA, its prevalence and impact on quality of life in parkinsonian disorders, and the treatment options currently available. Areas requiring further study, including the development of standardized, cross-culturally validated methods of symptom assessment, and evidence-based studies exploring the efficacy of current treatment options in parkinsonian disorders, are also highlighted.

Frontotemporal dementia

Recent research reveals an overlap between frontotemporal dementia (FTD) and a variety of primary psychiatric disorders, challenging the artificial divisions between psychiatry and neurology. This chapter offers an overview of the clinical syndromes associated with FTD while describing links between these syndromes and neuroimaging. This is followed by a review of the neuropathology and genetic changes in the brain. We will illustrate the syndromic overlap that exists between FTD and several primary psychiatric disorders including bipolar affective disorder and schizophrenia. Emphasis will be placed on the behavioral variant of FTD (bvFTD), which is the common clinical syndrome seen with degeneration of the frontal lobes and is the most likely to be encountered in psychiatric settings.

Clinical and Radiological Markers of Extra-Motor Deficits in Amyotrophic Lateral Sclerosis

Amyotrophic lateral sclerosis (ALS) is now universally recognized as a complex multisystem disorder with considerable extra-motor involvement. The neuropsychological manifestations of frontotemporal, parietal, and basal ganglia involvement in ALS have important implications for compliance with assistive devices, survival, participation in clinical trials, caregiver burden, and the management of individual care needs. Recent advances in neuroimaging have been instrumental in characterizing the biological substrate of heterogeneous cognitive and behavioral deficits in ALS. In this review we discuss the clinical and radiological aspects of cognitive and behavioral impairment in ALS focusing on the recognition, assessment, and monitoring of these symptoms.

Laughter, crying and sadness in ALS

BACKGROUND

Pseudobulbar affect (PBA) is prevalent in amyotrophic lateral sclerosis (ALS), but there is limited information on its associations and course.

OBJECTIVES

Explore prevalence, associations, course and manifestations of PBA in outpatient cohort of patients with ALS and examine its relationship to depression.

METHODS

Self-reported measures of PBA and depression (Center for Neurologic Study-Lability Scale (CNS-LS) and Patient Health Questionnaire (PHQ-9), respectively) were obtained from consecutive patients with ALS using tablet devices in waiting rooms (Knowledge Program).

RESULTS

PBA (CNS-LS ≥13) was seen in 209/735 patients (28.4%). PBA was associated with bulbar onset and dysfunction, upper motor neuron dysfunction, cognitive impairment, depression and lower quality of life. A multivariable model that included lower bulbar and gross motor subscores, female gender, younger age and shorter duration of disease predicted PBA with 74% accuracy. CNS-LS scores increased only slowly with time. Women with PBA reported more crying than men. Crying (but not laughter) correlated with depression, and crying was associated with poorer quality of life. Exploratory factor analysis of pooled questions of CNS-LS and PHQ-9 identified three underlying factors (laughter, crying and depression) loaded on appropriate questions of the respective instruments.

CONCLUSION

This study identifies associations of PBA and additionally finds PBA (especially crying-predominant PBA) more prevalent in women with ALS. Although the two self-report instruments (CNS-LS and PHQ-9) discriminate well between PBA and depression, there is significant overlap between depression and crying in PBA. Studies of PBA should stratify for gender, examine crying and laughter as separate outcomes and adjust for depression.

Altered resting-state functional activity in isolated pontine infarction patients with pathological laughing and crying

We used resting-state functional magnetic resonance imaging to investigate the global spontaneous neural activity involved in pathological laughing and crying after stroke. Twelve pathological laughing and crying patients with isolated pontine infarction were included, along with 12 age- and gender-matched acute isolated pontine infarction patients without pathological laughing and crying, and 12 age- and gender-matched healthy controls. We examined both the amplitude of low-frequency fluctuation and the regional homogeneity in order to comprehensively evaluate the intrinsic activity in patients with post-stroke pathological laughing and crying. In the post-stroke pathological laughing and crying group, changes in these measures were observed mainly in components of the default mode network (medial prefrontal cortex/anterior cingulate cortex, middle temporal gyrus, inferior temporal gyrus, superior frontal gyrus, middle frontal gyrus and inferior parietal lobule), sensorimotor network (supplementary motor area, precentral gyrus and paracentral lobule), affective network (medial prefrontal cortex/anterior cingulate cortex, parahippocampal gyrus, middle temporal gyrus and inferior temporal gyrus) and cerebellar lobes (cerebellum posterior lobe). We therefore speculate that when disinhibition of the volitional system is lost, increased activation of the emotional system causes pathological laughing and crying.

Behavioral Treatment of Pseudobulbar Affect: A Case Report

PURPOSE

To determine if it is possible to successfully treat pseudobulbar affect (PBA) using a behavioral approach.

DESIGN AND METHODS

Two experiments were conducted, each a double reversal design with the same single subject in both. The first experiment tested the hypothesis that the rate of PBA could be controlled by manipulation of its consequences. The second experiment tested the hypothesis that use of a self-control procedure would control the rate of PBA.

FINDINGS

Rate of PBA could not be controlled by consequence manipulation, but rate of PBA could be controlled through use of a self-control procedure.

PRACTICE IMPLICATIONS

Pending confirmatory research, behavioral interventions utilizing self-control procedures should be considered in patients with PBA.

Pathological laughter as prodromal manifestation of transient ischemic attacks--case report and brief review

BACKGROUND

Based on a case report, the authors reviewed the data about involuntary emotional expression disorder (IEED). IEED includes the syndromes of pathological laughing and crying (PLC) and emotional lability (EL). PLC is a rare disorder of emotional expression characterized by relatively uncontrollable episodes of laughter and crying or both that do not have an apparent motivating stimulus.

CASE PRESENTATION

Authors report the case of a 59-year-old man who presented with recurrent episodes of PLC of approximately 2 min duration, consisting of accelerated breathing, emission of guttural, snoring sounds, frowning of the eyebrows, followed by laughter accompanied by motor restlessness of all four limbs. PLC episodes preceded left carotid transient ischemic attacks (TIA's) manifested by reversible aphasia and right hemiparesis. Electroencephalography performed during PLC episodes revealed no spike-wave activity. Brain magnetic resonance imaging showed lacunar infarcts in the left lenticulo-capsulo-thalamic area and multiple round lesions in the cortical-subcortical and in the deep white matter of frontal-parietal-occipital lobes bilaterally, with T2 hyperintensity, T1 isointensity and no diffusion changes. The episodes were interpreted as transient ischemic attacks although gelastic seizures could not be excluded. The etiological investigations revealed unstable plaques on the left carotid artery bulb and the aortic arch and a degenerative mitral valve stenosis. The patient was treated first with antiplatelet therapy and antiepileptic drugs but PLC stopped only after anticoagulation was started. During follow-up the patient continued to have left carotid and vertebrobasilar TIA's being on oral anticoagulation. The patient became asymptomatic only after mitral valve replacement was performed.

CONCLUSIONS

This case illustrates the difficulty distinguishing between gelastic epilepsy and TIA's in cases of PLC episodes and discuss the neuroanatomic bases and pathophysiology of this rare condition.

Impaired corticopontocerebellar tracts underlie pseudobulbar affect in motor neuron disorders

OBJECTIVE

The objectives of the study were (1) to determine the prevalence and characteristics of pseudobulbar affect (PBA) in patients with primary lateral sclerosis (PLS) and amyotrophic lateral sclerosis (ALS) in an outpatient clinic population, and (2) to test the hypothesis that damage of inputs to the cerebellum, leading to cerebellar dysmodulation, is associated with PBA.

METHODS

Chart review of all patients with PLS and ALS seen between 2000 and 2013. The examining neurologist documented the presence or absence of PBA in 87 patients. Forty-seven patients also had diffusion tensor imaging (DTI) studies. Tract-based spatial statistics were used to compare DTI of patients with and without PBA to identify altered white matter tracts associated with PBA.

RESULTS

Thirty-one of 50 patients with PLS and 12 of 37 patients with ALS had PBA. Psychiatric/emotional assessment found congruence between mood and affect during episodes, but excessive magnitude of the response. DTI studies of 25 PLS and 22 ALS patient brains showed reduced fractional anisotropy of the corticospinal and callosal white matter tracts in all patients. Patients with PBA additionally had increased mean diffusivity of white matter tracts underlying the frontotemporal cortex, the transverse pontine fibers, and the middle cerebellar peduncle.

CONCLUSIONS

PBA is common in PLS. Imaging findings showing disruption of corticopontocerebellar pathways support the hypothesis that PBA can be viewed as a "dysmetria" of emotional expression resulting from cerebellar dysmodulation.

Review of Dextromethorphan 20 mg/Quinidine 10 mg (NUEDEXTA(®)) for Pseudobulbar Affect

Pseudobulbar affect (PBA) is a dysfunction of emotional expression characterized by involuntary outbursts of crying or laughing disproportionate or unrelated to mood, occurring in patients with various underlying neurologic disorders. This review describes the clinical data supporting dextromethorphan (DM) hydrobromide combined with quinidine sulfate (Q) as treatment of PBA and briefly surveys the ongoing debates concerning the terminology for dysfunction of emotional expression, as well as the ongoing searches for its brain substrates. Until recently, pharmacologic intervention consisted chiefly of off-label antidepressants. In October 2010, however, DM/Q at 20/10 mg twice daily received approval from the United States Food and Drug Administration for PBA in any setting, and in June 2013, dosages of 20/10 and 30/10 mg twice daily (labeled as 15/9 and 23/9 mg, respectively, DM/Q base) received approval from the European Medicines Agency. DM is an uncompetitive N-methyl-d-aspartate (NMDA) glutamate receptor antagonist, a sigma-1 receptor agonist, and a serotonin and norepinephrine reuptake inhibitor. To block DM hepatic metabolism, thereby increasing DM bioavailability, Quinidine, a cytochrome P450 2D6 inhibitor, is coadministered at a dosage well below those for treating cardiac arrhythmia. Three large-scale DM/Q trials have utilized PBA-episode counts and the Center for Neurologic Study-Lability Scale (CNS-LS), a validated PBA rating scale, to measure efficacy. In a 4-week study of patients with PBA in amyotrophic lateral sclerosis (ALS), DM/Q 30/30 mg was superior to its component drugs. A 12-week, double-blind, placebo-controlled study of DM/Q 30/30 mg showed similar efficacy in patients with PBA in multiple sclerosis (MS). A subsequent 12-week study of patients with PBA and ALS or MS showed superiority to placebo for the 20/10 and 30/10 mg doses. Efficacy was maintained during a 12-week, open-label extension (30/10 mg dose), with further improvement of mean CNS-LS scores. Across these studies, DM/Q was generally safe and well tolerated, with no evidence of clinically relevant cardiac or respiratory effects. DM/Q is being studied (currently unapproved) for conditions including agitation in autism and in dementia.

Depression and disease progression in amyotrophic lateral sclerosis: A comprehensive meta-regression analysis

Depression in people with amyotrophic lateral sclerosis, a fatal and progressive neurodegenerative disorder, is a serious issue with important clinical consequences. However, physical impairment may confound the diagnosis when using generic questionnaires. We conducted a comprehensive review of literature. Mean scores from depression questionnaires were meta-regressed on study-level mean time since onset of symptoms. Data from 103 studies (3190 subjects) indicate that the Beck Depression Inventory and, to a lesser degree, the Hospital Anxiety and Depression Scale are influenced by the time since symptom onset, strongly related to physical impairment. Our results suggest that widely used depression scales overestimate depression due to confounding with physical symptoms.

Subtle retinal pathology in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is characterized by neuro-ophthalmological abnormalities beyond disturbed oculomotor control such as decreased visual acuity and disturbed visual evoked potentials. Here we report retinal alterations in a cohort of 24 patients with clinically definite (n = 20) or probable (n = 4) ALS as compared to matched controls. High-resolution spectral domain optical coherence tomography with retinal segmentation revealed a subtle reduction in the macular thickness and the retinal nerve fiber layer (RNFL) as well as a marked thinning of the inner nuclear layer (INL). Our data indicate an unprecedented retinal damage pattern and suggest neurodegeneration beyond the motor system in this disease.

Emotional and behavioral dyscontrol after traumatic brain injury

Emotional and behavioral dyscontrol are relatively common neuropsychiatric sequelae of traumatic brain injury and present substantial challenges to recovery and community participation. Among the most problematic and functionally disruptive of these types of behaviors are pathologic laughing and crying, affective lability, irritability, disinhibition, and aggression. Managing these problems effectively requires an understanding of their phenomenology, epidemiology, and clinical evaluation. This article reviews these issues and provides clinicians with brief and practical suggestions for the management of emotional and behavioral dyscontrol.

Emotional and behavioral symptoms in neurodegenerative disease: a model for studying the neural bases of psychopathology

Disruptions in emotional, cognitive, and social behavior are common in neurodegenerative disease and in many forms of psychopathology. Because neurodegenerative diseases have patterns of brain atrophy that are much clearer than those of psychiatric disorders, they may provide a window into the neural bases of common emotional and behavioral symptoms. We discuss five common symptoms that occur in both neurodegenerative disease and psychopathology (i.e., anxiety, dysphoric mood, apathy, disinhibition, and euphoric mood) and their associated neural circuitry. We focus on two neurodegenerative diseases (i.e., Alzheimer's disease and frontotemporal dementia) that are common and well characterized in terms of emotion, cognition, and social behavior and in patterns of associated atrophy. Neurodegenerative diseases provide a powerful model system for studying the neural correlates of psychopathological symptoms; this is supported by evidence indicating convergence with psychiatric syndromes (e.g., symptoms of disinhibition associated with dysfunction in orbitofrontal cortex in both frontotemporal dementia and bipolar disorder). We conclude that neurodegenerative diseases can play an important role in future approaches to the assessment, prevention, and treatment of mental illness.

Dysfunctions within limbic-motor networks in amyotrophic lateral sclerosis

Previous studies have shown that affective symptoms are part of the clinical picture in amyotrophic lateral sclerosis (ALS), the most common motor neuron disorder in elderly people. Diffuse neurodegeneration of limbic regions (e.g., prefrontal cortex [PFC], amygdala) was demonstrated in ALS post-mortem, although the mechanisms of emotional dysregulation in ALS in vivo remain unclear. Using functional imaging, we assessed the brain responses to emotional faces in 11 cognitively unimpaired ALS patients and 12 healthy controls (HCs). We tested whether regional activities and connectivity patterns in the limbic system differed between ALS patients and HCs and whether the variability in clinical measures modulated the neuroimaging data. Relative to HCs, ALS patients displayed greater activation in a series of PFC areas and altered left amygdala-PFC connectivity. Anxiety modulated the right amygdala-PFC connectivity in HCs but not in ALS patients. Reduced right premotor cortex activity and altered left amygdala-supplementary motor area connectivity were associated with longer disease duration and greater disease severity, respectively. Our findings demonstrate dysfunctions of the limbic system in ALS patients at early stages of the disease, and extend our knowledge about the interplay between emotional brain areas and the regions traditionally implicated in motor control.

The epidemiology and pathophysiology of pseudobulbar affect and its association with neurodegeneration

Pseudobulbar affect is a disorder resulting from neurologic damage manifesting as sudden, stereotyped affective outbursts that are not reflective of internal emotion. A literature review was completed to examine the current understanding of the epidemiology, characterization, diagnosis, pathophysiology, and treatment of pseudobulbar affect. This review revealed that it is common in neurodegenerative disorders but is poorly recognized, placing significant impacts on patients and their families. The disorder appears to result from a disruption of the cortico-limbic-subcortical-thalamic-pontocerebellar network involved in emotional expression and regulation with resulting disruptions of neurotransmitter systems. Effective treatment is available with agents such as selective serotonin reuptake inhibitors and dextromethorphan combined with quinidine, but further well-designed comparative studies are needed. Advances in technology such as neuroimaging may enhance knowledge about the pathophysiology of this disorder, and help guide future interventions.

Pseudobulbar dysarthria in the initial stage of motor neuron disease with dementia: a clinicopathological report of two autopsied cases

We retrospectively analyzed the clinical features of two cases of neurodegenerative disease, whose initial symptoms were motor speech disorder and dementia, brought to autopsy. We compared the distributions of pathological findings with the clinical features. The main symptom of speech disorder was dysarthria, involving low pitch, slow rate, hypernasality and hoarseness. Other than these findings, effortful speech, sound prolongation and initial difficulty were observed. Moreover, repetition of multisyllables was severely impaired compared to monosyllables. Repetition and comprehension of words and sentences were not impaired. Neither atrophy nor fasciculation of the tongue was observed. Both cases showed rapid progression to mutism within a few years. Neuropathologically, frontal lobe degeneration including the precentral gyrus was observed. The bilateral pyramidal tracts also showed severe degeneration. However, the nucleus of the hypoglossal nerve showed only mild degeneration. These findings suggest upper motor neuron dominant motor neuron disease with dementia. We believe the results indicate a subgroup of motor neuron disease with dementia whose initial symptoms involve pseudobulbar palsy and dementia, and which shows rapid progression to mutism.

Amyotrophic lateral sclerosis

PURPOSE OF REVIEW

The field of amyotrophic lateral sclerosis (ALS) has seen a number of remarkable advances during recent years that will be summarized in this review.

RECENT FINDINGS

In particular, the progress in the molecular neuropathology with the discovery of pathogenic mutations in TAR DNA binding protein (TARDBP), fused in sarcoma (FUS), ubiquilin2 (UBQLN2) and most recently C9ORF72 (abbreviation for the open reading frame 72 on chromosome 9) has further substantiated the - clinically temporarily forgotten - relation of classic ALS to frontotemporal degeneration (FTD). Also, major progress has been made by the discovery of genes relevant for the disease, and pathogenetic concepts have been suggested which imply that not one, but multiple genetic and cell biological hits are involved in the causation of the disease. Progress in interventional therapies has remained poor; important recent examples are the failure of the interventional lithium and pioglitazone trials. However, a study of a third interventional compound - dexpramipexol - raises substantial hopes that the class of chemicals originally represented by riluzole - benzothiazoles - may provide additional therapeutic progress for ALS patients.

SUMMARY

Tremendous progress has been made in the field of ALS based on recent neuropathological and genetic discoveries. Moreover, the role of metabolism and nutrition in the pathogenesis of the disease is debated and may potentially serve as a future therapeutic target. For the facilitation and cost reduction of clinical trials, the development and international standardization of disease-specific 'wet' and 'dry' biomarkers is essential.