1
|
Pilotto F, Del Bondio A, Puccio H. Hereditary Ataxias: From Bench to Clinic, Where Do We Stand? Cells 2024; 13:319. [PMID: 38391932 PMCID: PMC10886822 DOI: 10.3390/cells13040319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Revised: 01/30/2024] [Accepted: 02/01/2024] [Indexed: 02/24/2024] Open
Abstract
Cerebellar ataxias are a wide heterogeneous group of movement disorders. Within this broad umbrella of diseases, there are both genetics and sporadic forms. The clinical presentation of these conditions can exhibit a diverse range of symptoms across different age groups, spanning from pure cerebellar manifestations to sensory ataxia and multisystemic diseases. Over the last few decades, advancements in our understanding of genetics and molecular pathophysiology related to both dominant and recessive ataxias have propelled the field forward, paving the way for innovative therapeutic strategies aimed at preventing and arresting the progression of these diseases. Nevertheless, the rarity of certain forms of ataxia continues to pose challenges, leading to limited insights into the etiology of the disease and the identification of target pathways. Additionally, the lack of suitable models hampers efforts to comprehensively understand the molecular foundations of disease's pathophysiology and test novel therapeutic interventions. In the following review, we describe the epidemiology, symptomatology, and pathological progression of hereditary ataxia, including both the prevalent and less common forms of these diseases. Furthermore, we illustrate the diverse molecular pathways and therapeutic approaches currently undergoing investigation in both pre-clinical studies and clinical trials. Finally, we address the existing and anticipated challenges within this field, encompassing both basic research and clinical endeavors.
Collapse
Affiliation(s)
- Federica Pilotto
- Institut Neuromyogène, Pathophysiology and Genetics of Neuron and Muscle, Inserm U1315, CNRS-Université Claude Bernard Lyon 1 UMR5261, 69008 Lyon, France
| | - Andrea Del Bondio
- Institut Neuromyogène, Pathophysiology and Genetics of Neuron and Muscle, Inserm U1315, CNRS-Université Claude Bernard Lyon 1 UMR5261, 69008 Lyon, France
| | - Hélène Puccio
- Institut Neuromyogène, Pathophysiology and Genetics of Neuron and Muscle, Inserm U1315, CNRS-Université Claude Bernard Lyon 1 UMR5261, 69008 Lyon, France
| |
Collapse
|
2
|
Seritan AL. Advances in the Diagnosis and Management of Psychotic Symptoms in Neurodegenerative Diseases: A Narrative Review. J Geriatr Psychiatry Neurol 2023; 36:435-460. [PMID: 36941085 PMCID: PMC10578041 DOI: 10.1177/08919887231164357] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 03/23/2023]
Abstract
Background: Approximately 15% of older adults may experience psychotic phenomena. Primary psychiatric disorders that manifest with psychosis (delusions, hallucinations, and disorganized thought or behavior) account for less than half. Up to 60% of late-life psychotic symptoms are due to systemic medical or neurological conditions, particularly neurodegenerative diseases. A thorough medical workup including laboratory tests, additional procedures if indicated, and neuroimaging studies is recommended. This narrative review summarizes current evidence regarding the epidemiology and phenomenology of psychotic symptoms encountered as part of the neurodegenerative disease continuum (including prodromal and manifest stages). Results: Prodromes are constellations of symptoms that precede the onset of overt neurodegenerative syndromes. Prodromal psychotic features, particularly delusions, have been associated with an increased likelihood of receiving a neurodegenerative disease diagnosis within several years. Prompt prodrome recognition is crucial for early intervention. The management of psychosis associated with neurodegenerative diseases includes behavioral and somatic strategies, although evidence is scarce and mostly limited to case reports, case series, or expert consensus guidelines, with few randomized controlled trials. Conclusion: The complexity of psychotic manifestations warrants management by interprofessional teams that provide coordinated, integrated care.
Collapse
Affiliation(s)
- Andreea L. Seritan
- University of California, San Francisco Department of Psychiatry and UCSF Weill Institute for Neurosciences, CA, USA
| |
Collapse
|
3
|
Simona K, Veronika M, Zahinoor I, Martin V. Neuropsychiatric symptoms in spinocerebellar ataxias and Friedreich ataxia. Neurosci Biobehav Rev 2023; 150:105205. [PMID: 37137435 DOI: 10.1016/j.neubiorev.2023.105205] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2022] [Revised: 04/14/2023] [Accepted: 04/29/2023] [Indexed: 05/05/2023]
Abstract
Apart from its role in motor coordination, the importance of the cerebellum in cognitive and affective processes has been recognized in the past few decades. Spinocerebellar ataxias (SCA) and Friedreich ataxia (FRDA) are rare neurodegenerative diseases of the cerebellum presenting mainly with a progressive loss of gait and limb coordination, dysarthria, and other motor disturbances, but also a range of cognitive and neuropsychiatric symptoms. This narrative review summarizes the current knowledge on neuropsychiatric impairment in SCA and FRDA. We discuss the prevalence, clinical features and treatment approaches in the most commonly reported domains of depression, anxiety, apathy, agitation and impulse dyscontrol, and psychosis. Since these symptoms have a considerable impact on patients' quality of life, we argue that further research is mandated to improve the detection and treatment options of neuropsychiatric co-morbidities in ataxia patients.
Collapse
Affiliation(s)
- Karamazovova Simona
- Center of Hereditary Ataxias, Department of Neurology, 2nd Faculty of Medicine and Motol University Hospital, Charles University, Prague, Czech Republic
| | - Matuskova Veronika
- Center of Hereditary Ataxias, Department of Neurology, 2nd Faculty of Medicine and Motol University Hospital, Charles University, Prague, Czech Republic.
| | - Ismail Zahinoor
- Departments of Psychiatry, Clinical Neurosciences, and Community Health Sciences, Cumming School of Medicine; Hotchkiss Brain Institute and O'Brien Institute of Public Health, University of Calgary, Calgary, Alberta, Canada
| | - Vyhnalek Martin
- Center of Hereditary Ataxias, Department of Neurology, 2nd Faculty of Medicine and Motol University Hospital, Charles University, Prague, Czech Republic
| |
Collapse
|
4
|
Tichanek F. Psychiatric-Like Impairments in Mouse Models of Spinocerebellar Ataxias. CEREBELLUM (LONDON, ENGLAND) 2023; 22:14-25. [PMID: 35000108 DOI: 10.1007/s12311-022-01367-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/03/2022] [Indexed: 06/14/2023]
Abstract
Many patients with spinocerebellar ataxia (SCA) suffer from diverse neuropsychiatric issues, including memory impairments, apathy, depression, or anxiety. These neuropsychiatric aspects contribute per se to the reduced quality of life and worse prognosis. However, the extent to which SCA-related neuropathology directly contributes to these issues remains largely unclear. Behavioral profiling of various SCA mouse models can bring new insight into this question. This paper aims to synthesize recent findings from behavioral studies of SCA patients and mouse models. The role of SCA neuropathology for shaping psychiatric-like impairments may be exemplified in mouse models of SCA1. These mice evince robust cognitive impairments which are shaped by both the cerebellar as well as out-of-cerebellar pathology. Although emotional-related alternations are also present, they seem to be less robust and more affected by the specific distribution and character of the neuropathology. For example, cerebellar-specific pathology seems to provoke behavioral disinhibition, leading to seemingly decreased anxiety, whereas complex SCA1 neuropathology induces anxiety-like phenotype. In SCA1 mice with complex neuropathology, some of the psychiatric-like impairments are present even before marked cerebellar degeneration and ataxia and correlate with hippocampal atrophy. Similarly, complete or partial deletion of the implicated gene (Atxn1) leads to cognitive dysfunction and anxiety-like behavior, respectively, without apparent ataxia and cerebellar degeneration. Altogether, these findings collectively suggest that the neuropsychiatric issues have a biological basis partially independent of the cerebellum. As some neuropsychiatric issues may stem from weakening the function of the implicated gene, therapeutic reduction of its expression by molecular approaches may not necessarily mitigate the neuropsychiatric issues.
Collapse
Affiliation(s)
- Filip Tichanek
- Department of Pathological Physiology, Faculty of Medicine in Pilsen, Charles University, alej Svobody 1655/76, 323 00, Plzen, Czech Republic.
- Laboratory of Neurodegenerative Disorders, Biomedical Center, Faculty of Medicine in Pilsen, Charles University, alej Svobody 1655/76, 323 00, Plzen, Czech Republic.
| |
Collapse
|
5
|
Okamoto N, Ikenouchi A, Ide S, Hashimoto Y, Yoshimura R. A Young Japanese Patient with Spinocerebellar Ataxia Type 3 Presenting Depressive State with Cenesthopathy and Delusion: a Case Report. THE CEREBELLUM 2021; 21:1135-1138. [PMID: 34705199 PMCID: PMC9596515 DOI: 10.1007/s12311-021-01338-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Accepted: 10/20/2021] [Indexed: 11/30/2022]
Abstract
Depressive state is a common complication of spinocerebellar ataxia type 3 (SCA3). To the best of our knowledge, cases of SCA3 presenting with cenesthopathy have not been described. Here, we present a case of a severe depressive state with cenesthopathy and delusion in a young Japanese man with SCA3. A 43-year-old Japanese man with SCA3 developed a severe depressive state with associated cenesthopathy and delusion. He was treated with escitalopram (10 mg/day) and olanzapine (2.5 mg/day). Computed tomography showed atrophy of the cerebellum, bilateral superior cerebellar peduncle, and tegmentum of the pons. Single-photon emission computed tomography demonstrated reduced blood flow in the cerebellum, vermis, and brainstem. After 8 weeks, his depressive state and delusion improved; however, his cenesthopathy persisted. We encountered a case of a severe depressive state with cenesthopathy and delusion in a young Japanese man with SCA3. This case supports previous studies that the cerebellum could have a role beyond motor functions.
Collapse
Affiliation(s)
- Naomichi Okamoto
- Medical Center for Dementia, University Hospital, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-Ku, Kitakyushu, Fukuoka, 8078555, Japan.,Department of Psychiatry, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Atsuko Ikenouchi
- Medical Center for Dementia, University Hospital, University of Occupational and Environmental Health, 1-1 Iseigaoka, Yahatanishi-Ku, Kitakyushu, Fukuoka, 8078555, Japan. .,Department of Psychiatry, University of Occupational and Environmental Health, Kitakyushu, Japan.
| | - Satoru Ide
- Department of Radiology, University of Occupational and Environmental Health, Kitakyushu, Japan
| | - Yu Hashimoto
- Department of Neurology, Neurological Institute Graduate School of Medicine, Kyushu University, Fukuoka, Japan
| | - Reiji Yoshimura
- Department of Psychiatry, University of Occupational and Environmental Health, Kitakyushu, Japan
| |
Collapse
|
6
|
Pinheiro AP, Schwartze M, Kotz SA. Cerebellar circuitry and auditory verbal hallucinations: An integrative synthesis and perspective. Neurosci Biobehav Rev 2020; 118:485-503. [DOI: 10.1016/j.neubiorev.2020.08.004] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 06/30/2020] [Accepted: 08/07/2020] [Indexed: 02/06/2023]
|
7
|
Mastammanavar VS, Kamble N, Yadav R, M N, Jain S, Kumar K, Pal PK. Non-motor symptoms in patients with autosomal dominant spinocerebellar ataxia. Acta Neurol Scand 2020; 142:368-376. [PMID: 32677041 DOI: 10.1111/ane.13318] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2020] [Revised: 07/08/2020] [Accepted: 07/12/2020] [Indexed: 01/24/2023]
Abstract
OBJECTIVE The non-motor manifestations of motor predominant disorders have been an area of active interest in recent times. The objective of the study was to determine the prevalence of non-motor symptoms in patients with genetically confirmed spinocerebellar ataxia (SCA). MATERIALS AND METHODS Forty-one patients of SCA and 48 age-, gender-, and education-matched controls were included. The severity of ataxia was evaluated using the International Cooperative Ataxia Rating Scale (ICARS) and cognitive impairment using a neuropsychological battery. Non-motor features were assessed using standardized scales (HAM-A, HAM-D, Modified Fatigue Severity Scale, RLS questionnaire, ESS, PSQI, WHOQOL, RBDSQ, and BPI). The data were compared with controls and correlated with the severity of ataxia. RESULTS There were 17 SCA1, 14 SCA2, and 10 SCA3 patients. The mean age of presentation was 35.7 ± 7.9 years for SCA1, 31.1 ± 7.9 years for SCA2, and 30.5 ± 9.5 years for SCA3 patients. The neuropsychological evaluation showed severe impairment of attention, executive functions, visuospatial function, motor speed, response speed, and memory. The severity of ataxia was more for SCA2 patients (ICARS of 39.5 ± 24.4). Ataxia severity was correlated with MMSE, fatigue scale, depression scale, and REM sleep behavior disorder in SCA1 individuals and global cognition, fatigue, anxiety, and depression scales, and RLS in SCA3 patients. All patients reported quality of life as dissatisfied. These patients also had sleep disturbances in the form of RBD, RLS, and EDS. CONCLUSIONS In addition to the motor symptoms, patients with SCA have several non-motor symptoms that impair the quality of life.
Collapse
Affiliation(s)
| | - Nitish Kamble
- Department of Neurology National Institute of Mental Health and Neurosciences Bangalore India
| | - Ravi Yadav
- Department of Neurology National Institute of Mental Health and Neurosciences Bangalore India
| | - Netravathi M
- Department of Neurology National Institute of Mental Health and Neurosciences Bangalore India
| | - Sanjeev Jain
- Department of Psychiatry National Institute of Mental Health and Neurosciences Bangalore India
| | - Keshav Kumar
- Department of Clinical Psychology National Institute of Mental Health and Neurosciences Bangalore India
| | - Pramod Kumar Pal
- Department of Neurology National Institute of Mental Health and Neurosciences Bangalore India
| |
Collapse
|
8
|
Neuropsychiatric Symptoms as a Reliable Phenomenology of Cerebellar Ataxia. THE CEREBELLUM 2020; 20:141-150. [PMID: 33000380 DOI: 10.1007/s12311-020-01195-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 09/23/2020] [Indexed: 10/23/2022]
Abstract
While cerebellar ataxia (CA) is a neurodegenerative disease known for motor impairment, changes in mood have also been reported. A full account of neuropsychiatric symptomology in CA may guide improvements in treatment regimes, measure the presence and severity of sub-clinical neuropsychiatric disturbance symptomology in CA, and compare patient versus informant symptom recognition. Neuropsychiatric phenomena were gathered from CA patients with genetic and unknown etiologies and their informants (e.g., spouse or parent). Information was obtained from in-person interviews and the Center for Epidemiologic Studies Depression Scale. Responses were converted to the Neuropsychiatric Inventory-Questionnaire (NPI-Q) scores by consensus ratings. Patient NPI-Q scores were evaluated for symptom prevalence and severity relative to those obtained from healthy controls. Patient-informant NPI-Q score disagreements were evaluated. In this cohort, 95% of patients presented with at least one neuropsychiatric symptom and 51% of patients with three or more symptoms. The most common symptoms were anxiety, depression, nighttime behaviors (e.g., interrupted sleep), irritability, disinhibition, abnormal appetite, and agitation. The prevalence of these neuropsychiatric symptoms was uniform across patients with genetic versus unknown etiologies. Patient and informant symptom report disagreements reflected that patients noted sleep impairment and depression, while informants noted irritability and agitation. Neuropsychiatric disturbance is highly prevalent in patients with CA and contributes to the phenomenology of CA, regardless of etiology. Clinicians should monitor psychiatric health in their CA patients, considering that supplemental information from informants can help gauge the impact on family members and caregivers.
Collapse
|
9
|
Locke TM, Fujita H, Hunker A, Johanson SS, Darvas M, du Lac S, Zweifel LS, Carlson ES. Purkinje Cell-Specific Knockout of Tyrosine Hydroxylase Impairs Cognitive Behaviors. Front Cell Neurosci 2020; 14:228. [PMID: 32848620 PMCID: PMC7403473 DOI: 10.3389/fncel.2020.00228] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 06/30/2020] [Indexed: 01/22/2023] Open
Abstract
Tyrosine hydroxylase (Th) expression has previously been reported in Purkinje cells (PCs) of rodents and humans, but its role in the regulation of behavior is not understood. Catecholamines are well known for facilitating cognitive behaviors and are expressed in many regions of the brain. Here, we investigated a possible role in cognitive behaviors of PC catecholamines, by mapping and testing functional roles of Th positive PCs in mice. Comprehensive mapping analyses revealed a distinct population of Th expressing PCs primarily in the posterior and lateral regions of the cerebellum (comprising about 18% of all PCs). To identify the role of PC catecholamines, we selectively knocked out Th in PCs using a conditional knockout approach, by crossing a Purkinje cell-selective Cre recombinase line, Pcp2-Cre, with a floxed tyrosine hydroxylase mouse line (Thlox/lox) to produce Pcp2-Cre;Thlox/lox mice. This manipulation resulted in approximately 50% reduction of Th protein expression in the cerebellar cortex and lateral cerebellar nucleus, but no reduction of Th in the locus coeruleus, which is known to innervate the cerebellum in mice. Pcp2-Cre;Thlox/lox mice showed impairments in behavioral flexibility, response inhibition, social recognition memory, and associative fear learning relative to littermate controls, but no deficits in gross motor, sensory, instrumental learning, or sensorimotor gating functions. Catecholamines derived from specific populations of PCs appear to support cognitive functions, and their spatial distribution in the cerebellum suggests that they may underlie patterns of activation seen in human studies on the cerebellar role in cognitive function.
Collapse
Affiliation(s)
- Timothy M. Locke
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, United States
- Department of Pharmacology, University of Washington, Seattle, WA, United States
| | - Hirofumi Fujita
- Department of Otolaryngology—Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States
| | - Avery Hunker
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, United States
| | - Shelby S. Johanson
- Geriatric Research, Education and Clinical Center, Veteran’s Affairs Medical Center, Puget Sound, Seattle, WA, United States
| | - Martin Darvas
- Department of Pathology, University of Washington, Seattle, WA, United States
| | - Sascha du Lac
- Department of Otolaryngology—Head and Neck Surgery, Johns Hopkins University, Baltimore, MD, United States
- Department of Neurology, Johns Hopkins University, Baltimore, MD, United States
- Department of Neuroscience, Johns Hopkins University, Baltimore, MD, United States
| | - Larry S. Zweifel
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, United States
- Department of Pharmacology, University of Washington, Seattle, WA, United States
| | - Erik S. Carlson
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA, United States
- Geriatric Research, Education and Clinical Center, Veteran’s Affairs Medical Center, Puget Sound, Seattle, WA, United States
| |
Collapse
|
10
|
Rossi M, Farcy N, Starkstein SE, Merello M. Nosology and Phenomenology of Psychosis in Movement Disorders. Mov Disord Clin Pract 2020; 7:140-153. [PMID: 32071931 DOI: 10.1002/mdc3.12882] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2019] [Revised: 11/02/2019] [Accepted: 12/01/2019] [Indexed: 12/13/2022] Open
Abstract
Background Psychotic symptoms, such as delusions and hallucinations, are part of the clinical picture of several conditions presenting movement disorders. Phenomenology and epidemiology of psychosis in Parkinson's disease have received wide attention; however, the presence of psychosis in other movement disorders is, comparatively, less well known. Objectives To review psychotic symptoms present in different movement disorders. Methods A comprehensive and structured literature search was performed to identify and analyze data on patients with movement disorders and comorbid psychosis. Results In monogenic parkinsonisms, such as PARK-GBA, PARK-LRRK2, and PARK-SNCA, visual hallucinations related to dopamine replacement therapy are frequent as well as are delusions in PARK-LRRK2 and PARK-SNCA, but not in PARK-GBA. Different types of delusions and hallucinations are found in Huntington's disease and other choreic disorders. In Tourette's syndrome, paranoid delusions as well as visual, olfactory, and auditory hallucinations have been described, which usually develop after an average of 10 years of disease. Delusions in ataxias are more frequent in ATX-TBP, ATX-ATN1, and ATX-ATXN3, whereas it is rare in Friedreich's ataxia. Psychosis is also a prominent and frequent clinical feature in Fahr's disease, Wilson's disease, neurodegeneration with brain iron accumulation, and some lysosomal storage disorders, whereas it is uncommon in atypical parkinsonisms and dystonia. Psychosis usually occurs at late disease stages, but may appear as onset symptoms of the disease, especially in Wilson's disease, Huntington's disease, late-onset Tays-Sachs, and Niemann-Pick. Conclusion Psychosis is a frequent comorbidity in most hyper- and hypokinetic movement disorders. Appropriate recognition is relevant both in the early and late disease stages.
Collapse
Affiliation(s)
- Malco Rossi
- Movement Disorders Section, Neuroscience Department Raul Carrea Institute for Neurological Research (FLENI) Buenos Aires Argentina.,Pontificia Universidad Catolica Argentina (UCA) Buenos Aires Argentina
| | - Nicole Farcy
- Movement Disorders Section, Neuroscience Department Raul Carrea Institute for Neurological Research (FLENI) Buenos Aires Argentina
| | - Sergio E Starkstein
- School of Psychiatry and Clinical Neurosciences University of Western Australia Crawley WA Australia
| | - Marcelo Merello
- Movement Disorders Section, Neuroscience Department Raul Carrea Institute for Neurological Research (FLENI) Buenos Aires Argentina.,Pontificia Universidad Catolica Argentina (UCA) Buenos Aires Argentina.,Argentine National Scientific and Technological Research Council (CONICET) Buenos Aires Argentina
| |
Collapse
|
11
|
Prediction, Psychosis, and the Cerebellum. BIOLOGICAL PSYCHIATRY: COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2019; 4:820-831. [PMID: 31495402 DOI: 10.1016/j.bpsc.2019.06.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 05/30/2019] [Accepted: 06/01/2019] [Indexed: 12/19/2022]
Abstract
An increasingly influential hypothesis posits that many of the diverse symptoms of psychosis can be viewed as reflecting dysfunctional predictive mechanisms. Indeed, to perceive something is to take a sensory input and make a prediction of the external source of that signal; thus, prediction is perhaps the most fundamental neural computation. Given the ubiquity of prediction, a more challenging problem is to specify the unique predictive role or capability of a particular brain structure. This question is relevant when considering recent claims that one aspect of the predictive deficits observed in psychotic disorders might be related to cerebellar dysfunction, a subcortical structure known to play a critical role in predictive sensorimotor control and perhaps higher-level cognitive function. Here, we review evidence bearing on this question. We first focus on clinical, behavioral, and neuroimaging findings suggesting cerebellar involvement in psychosis and, specifically, schizophrenia. We then review a relatively novel line of research exploring whether computational models of cerebellar motor function can also account for cerebellar involvement in higher-order human cognition, and in particular, language function. We end the review by highlighting some key gaps in these literatures, limitations that currently preclude strong conclusions regarding cerebellar involvement in psychosis.
Collapse
|