1
|
Vacchiano V, Bonan L, Liguori R, Rizzo G. Primary Lateral Sclerosis: An Overview. J Clin Med 2024; 13:578. [PMID: 38276084 PMCID: PMC10816328 DOI: 10.3390/jcm13020578] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/15/2024] [Accepted: 01/17/2024] [Indexed: 01/27/2024] Open
Abstract
Primary lateral sclerosis (PLS) is a rare neurodegenerative disorder which causes the selective deterioration of the upper motor neurons (UMNs), sparing the lower motor neuron (LMN) system. The clinical course is defined by a progressive motor disability due to muscle spasticity which typically involves lower extremities and bulbar muscles. Although classically considered a sporadic disease, some familiar cases and possible causative genes have been reported. Despite it having been recognized as a rare but distinct entity, whether it actually represents an extreme end of the motor neuron diseases continuum is still an open issue. The main knowledge gap is the lack of specific biomarkers to improve the clinical diagnostic accuracy. Indeed, the diagnostic imprecision, together with some uncertainty about overlap with UMN-predominant ALS and Hereditary Spastic Paraplegia (HSP), has become an obstacle to the development of specific therapeutic trials. In this study, we provided a comprehensive analysis of the existing literature, including neuropathological, clinical, neuroimaging, and neurophysiological features of the disease, and highlighting the controversies still unsolved in the differential diagnoses and the current diagnostic criteria. We also discussed the current knowledge gaps still present in both diagnostic and therapeutic fields when approaching this rare condition.
Collapse
Affiliation(s)
- Veria Vacchiano
- IRCCS, Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, 40139 Bologna, Italy; (V.V.); (R.L.)
| | - Luigi Bonan
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126 Bologna, Italy;
| | - Rocco Liguori
- IRCCS, Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, 40139 Bologna, Italy; (V.V.); (R.L.)
- Department of Biomedical and Neuromotor Sciences (DIBINEM), University of Bologna, 40126 Bologna, Italy;
| | - Giovanni Rizzo
- IRCCS, Istituto delle Scienze Neurologiche di Bologna, UOC Clinica Neurologica, 40139 Bologna, Italy; (V.V.); (R.L.)
| |
Collapse
|
2
|
Bede P, Pradat PF, Lope J, Vourc'h P, Blasco H, Corcia P. Primary Lateral Sclerosis: Clinical, radiological and molecular features. Rev Neurol (Paris) 2021; 178:196-205. [PMID: 34243936 DOI: 10.1016/j.neurol.2021.04.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2021] [Revised: 04/23/2021] [Accepted: 04/29/2021] [Indexed: 10/20/2022]
Abstract
Primary Lateral Sclerosis (PLS) is an uncommon motor neuron disorder. Despite the well-recognisable constellation of clinical manifestations, the initial diagnosis can be challenging and therapeutic options are currently limited. There have been no recent clinical trials of disease-modifying therapies dedicated to this patient cohort and awareness of recent research developments is limited. The recent consensus diagnostic criteria introduced the category 'probable' PLS which is likely to curtail the diagnostic journey of patients. Extra-motor clinical manifestations are increasingly recognised, challenging the view of PLS as a 'pure' upper motor neuron condition. The post mortem literature of PLS has been expanded by seminal TDP-43 reports and recent PLS studies increasingly avail of meticulous genetic profiling. Research in PLS has gained unprecedented momentum in recent years generating novel academic insights, which may have important clinical ramifications.
Collapse
Affiliation(s)
- P Bede
- Pitié-Salpêtrière University Hospital, Sorbonne University, Paris, France; Computational Neuroimaging Group, Trinity College Dublin, Ireland.
| | - P-F Pradat
- Pitié-Salpêtrière University Hospital, Sorbonne University, Paris, France
| | - J Lope
- Computational Neuroimaging Group, Trinity College Dublin, Ireland
| | - P Vourc'h
- Department of Biochemistry and Molecular Biology, CHRU Bretonneau, Tours, France; UMR 1253 iBrain, Université de Tours, Inserm, France
| | - H Blasco
- Department of Biochemistry and Molecular Biology, CHRU Bretonneau, Tours, France; UMR 1253 iBrain, Université de Tours, Inserm, France
| | - P Corcia
- UMR 1253 iBrain, Université de Tours, Inserm, France; ALS and MND centre (FILSLAN), University of Tours, "iBrain", inserm, France
| |
Collapse
|
3
|
Extra-motor cerebral changes and manifestations in primary lateral sclerosis. Brain Imaging Behav 2021; 15:2283-2296. [PMID: 33409820 DOI: 10.1007/s11682-020-00421-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/12/2020] [Indexed: 12/22/2022]
Abstract
Primary lateral sclerosis (PLS) is classically considered a 'pure' upper motor neuron disorder. Motor cortex atrophy and pyramidal tract degeneration are thought to be pathognomonic of PLS, but extra-motor cerebral changes are poorly characterized. In a prospective neuroimaging study, forty PLS patients were systematically evaluated with a standardised imaging, genetic and clinical protocol. Patients were screened for ALS and HSP associated mutations, as well as C9orf72 hexanucleotide repeats. Clinical assessment included composite reflex scores, spasticity scales, functional rating scales, and screening for cognitive and behavioural deficits. The neuroimaging protocol evaluated cortical atrophy patterns, subcortical grey matter changes and white matter alterations in whole-brain and region-of-interest analyses. PLS patients tested negative for known ALS- and HSP-associated mutations and C9orf72 repeat expansions. Voxel-wise analyses revealed anterior cingulate, dorsolateral prefrontal, insular, opercular, orbitofrontal and bilateral mesial temporal grey matter changes and white matter alterations in the fornix, brainstem, temporal lobes, and cerebellum. Significant thalamus, caudate, hippocampus, putamen and accumbens nucleus volume reductions were also identified. Extra-motor clinical manifestations were dominated by verbal fluency deficits, language deficits, apathy and pseudobulbar affect. Our clinical and radiological evaluation confirms considerable extra-motor changes in a population-based cohort of PLS patients. Our data suggest that PLS should no longer be considered a neurodegenerative disorder selectively affecting the pyramidal system. PLS is associated with widespread extra-motor changes and manifestations which should be carefully considered in the multidisciplinary management of this low-incidence condition.
Collapse
|
4
|
Pioro EP, Turner MR, Bede P. Neuroimaging in primary lateral sclerosis. Amyotroph Lateral Scler Frontotemporal Degener 2020; 21:18-27. [PMID: 33602015 DOI: 10.1080/21678421.2020.1837176] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 10/08/2020] [Accepted: 10/09/2020] [Indexed: 12/15/2022]
Abstract
Increased interest in the underlying pathogenesis of primary lateral sclerosis (PLS) and its relationship to amyotrophic lateral sclerosis (ALS) has corresponded to a growing number of CNS imaging studies, especially in the past decade. Both its rarity and uncertainty of definite diagnosis prior to 4 years from symptom onset have resulted in PLS being less studied than ALS. In this review, we highlight most relevant papers applying magnetic resonance imaging (MRI), magnetic resonance spectroscopy (MRS), and positron emission tomography (PET) to analyzing CNS changes in PLS, often in relation to ALS. In patients with PLS, mostly brain, but also spinal cord has been evaluated since significant neurodegeneration is essentially restricted to upper motor neuron (UMN) structures and related pathways. Abnormalities of cortex and subcortical white matter tracts have been identified by structural and functional MRI and MRS studies, while metabolic and cell-specific changes in PLS brain have been revealed using various PET radiotracers. Future neuroimaging studies will continue to explore the interface between the PLS-ALS continuum, identify more changes unique to PLS, apply novel MRI and MRS sequences showing greater structural and neurochemical detail, as well as expand the repertoire of PET radiotracers that reveal various cellular pathologies. Neuroimaging has the potential to play an important role in the evaluation of novel therapies for patients with PLS.
Collapse
Affiliation(s)
- Erik P Pioro
- Section of ALS & Related Disorders, Neurological Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Martin R Turner
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, UK
| | - Peter Bede
- Computational Neuroimaging Group, Trinity College Dublin, Dublin, Ireland
| |
Collapse
|
5
|
Finegan E, Li Hi Shing S, Siah WF, Chipika RH, Chang KM, McKenna MC, Doherty MA, Hengeveld JC, Vajda A, Donaghy C, Hutchinson S, McLaughlin RL, Hardiman O, Bede P. Evolving diagnostic criteria in primary lateral sclerosis: The clinical and radiological basis of "probable PLS". J Neurol Sci 2020; 417:117052. [PMID: 32731060 DOI: 10.1016/j.jns.2020.117052] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 07/15/2020] [Accepted: 07/17/2020] [Indexed: 12/24/2022]
Abstract
INTRODUCTION Primary lateral sclerosis is a rare neurodegenerative disorder of the upper motor neurons. Diagnostic criteria have changed considerably over the years, and the recent consensus criteria introduced 'probable PLS' for patients with a symptom duration of 2-4 years. The objective of this study is the systematic evaluation of clinical and neuroimaging characteristics in early PLS by studying a group of 'probable PLS patients' in comparison to a cohort of established PLS patients. METHODS In a prospective neuroimaging study, thirty-nine patients were stratified by the new consensus criteria into 'probable' (symptom duration 2-4 years) or 'definite' PLS (symptom duration >4 years). Patients were evaluated with a standardised battery of clinical instruments (ALSFRS-r, Penn upper motor neuron score, the modified Ashworth spasticity scale), whole genome sequencing, and underwent structural and diffusion MRI. The imaging profile of the two PLS cohorts were contrasted to a dataset of 100 healthy controls. All 'probable PLS' patients subsequently fulfilled criteria for 'definite' PLS on longitudinal follow-up and none transitioned to develop ALS. RESULTS PLS patients tested negative for known ALS- or HSP-associated mutations on whole genome sequencing. Despite their shorter symptom duration, 'probable PLS' patients already exhibited considerable functional disability, upper motor neuron disease burden and the majority of them required walking aids for safe ambulation. Their ALSFRS-r, UMN and modified Ashworth score means were 83%, 98% and 85% of the 'definite' group respectively. Motor cortex thickness was significantly reduced in both PLS groups in comparison to controls, but cortical changes were less widespread in 'probable' PLS on morphometric analyses. Corticospinal tract and corpus callosum metrics were relatively well preserved in the 'probable' group in contrast to the widespread white matter degeneration observed in the 'definite' group. CONCLUSIONS Our clinical and radiological analyses support the recent introduction of the 'probable' PLS category, as this cohort already exhibits considerable disability and cerebral changes consistent with established PLS. Before the publication of the new consensus criteria, these patients would have not been diagnosed with PLS on the basis of their symptom duration despite their significant functional impairment and motor cortex atrophy. The introduction of this new category will facilitate earlier recruitment into clinical trials, and shorten the protracted diagnostic uncertainty the majority of PLS patients face.
Collapse
Affiliation(s)
- Eoin Finegan
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, Ireland
| | - Stacey Li Hi Shing
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, Ireland
| | - We Fong Siah
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, Ireland
| | - Rangariroyashe H Chipika
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, Ireland
| | - Kai Ming Chang
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, Ireland; Electronics and Computer Science, University of Southampton, Southampton, United Kingdom
| | - Mary Clare McKenna
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, Ireland
| | - Mark A Doherty
- Complex Trait Genomics Laboratory, Smurfit Institute of Genetics, Trinity College Dublin, Ireland
| | - Jennifer C Hengeveld
- Complex Trait Genomics Laboratory, Smurfit Institute of Genetics, Trinity College Dublin, Ireland
| | - Alice Vajda
- Complex Trait Genomics Laboratory, Smurfit Institute of Genetics, Trinity College Dublin, Ireland
| | - Colette Donaghy
- Department of Neurology, Belfast, Western Health & Social Care Trust, UK
| | | | - Russell L McLaughlin
- Complex Trait Genomics Laboratory, Smurfit Institute of Genetics, Trinity College Dublin, Ireland
| | - Orla Hardiman
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, Ireland
| | - Peter Bede
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, Ireland.
| |
Collapse
|
6
|
Chipika RH, Christidi F, Finegan E, Li Hi Shing S, McKenna MC, Chang KM, Karavasilis E, Doherty MA, Hengeveld JC, Vajda A, Pender N, Hutchinson S, Donaghy C, McLaughlin RL, Hardiman O, Bede P. Amygdala pathology in amyotrophic lateral sclerosis and primary lateral sclerosis. J Neurol Sci 2020; 417:117039. [PMID: 32713609 DOI: 10.1016/j.jns.2020.117039] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 06/19/2020] [Accepted: 07/13/2020] [Indexed: 12/26/2022]
Abstract
Temporal lobe studies in motor neuron disease overwhelmingly focus on white matter alterations and cortical grey matter atrophy. Reports on amygdala involvement are conflicting and the amygdala is typically evaluated as single structure despite consisting of several functionally and cytologically distinct nuclei. A prospective, single-centre, neuroimaging study was undertaken to comprehensively characterise amygdala pathology in 100 genetically-stratified ALS patients, 33 patients with PLS and 117 healthy controls. The amygdala was segmented into groups of nuclei using a Bayesian parcellation algorithm based on a probabilistic atlas and shape deformations were additionally assessed by vertex analyses. The accessory basal nucleus (p = .021) and the cortical nucleus (p = .022) showed significant volume reductions in C9orf72 negative ALS patients compared to controls. The lateral nucleus (p = .043) and the cortico-amygdaloid transition (p = .024) were preferentially affected in C9orf72 hexanucleotide carriers. A trend of total volume reduction was identified in C9orf72 positive ALS patients (p = .055) which was also captured in inferior-medial shape deformations on vertex analyses. Our findings highlight that the amygdala is affected in ALS and our study demonstrates the selective involvement of specific nuclei as opposed to global atrophy. The genotype-specific patterns of amygdala involvement identified by this study are consistent with the growing literature of extra-motor clinical features. Mesial temporal lobe pathology in ALS is not limited to hippocampal pathology but, as a key hub of the limbic system, the amygdala is also affected in ALS.
Collapse
Affiliation(s)
- Rangariroyashe H Chipika
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Foteini Christidi
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland; Department of Neurology, Aeginition Hospital, University of Athens, Greece
| | - Eoin Finegan
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Stacey Li Hi Shing
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Mary Clare McKenna
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Kai Ming Chang
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland; Electronics and Computer Science, University of Southampton, Southampton SO17 1BJ, United Kingdom
| | - Efstratios Karavasilis
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland; 2nd Department of Radiology, Attikon University Hospital, University of Athens, Athens, Greece
| | - Mark A Doherty
- Complex Trait Genomics Laboratory, Smurfit Institute of Genetics, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Jennifer C Hengeveld
- Complex Trait Genomics Laboratory, Smurfit Institute of Genetics, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Alice Vajda
- Complex Trait Genomics Laboratory, Smurfit Institute of Genetics, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Niall Pender
- Department of psychology, Beaumont Hospital Dublin, Ireland
| | - Siobhan Hutchinson
- Department of Neurology, St James's Hospital, James's St, Ushers, Dublin 8 D08 NHY1, Ireland
| | - Colette Donaghy
- Department of Neurology, Belfast, Western Health & Social Care Trust, UK
| | - Russell L McLaughlin
- Complex Trait Genomics Laboratory, Smurfit Institute of Genetics, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Orla Hardiman
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland
| | - Peter Bede
- Computational Neuroimaging Group, Biomedical Sciences Institute, Trinity College Dublin, 152-160 Pearse Street, Dublin 2, Ireland.
| |
Collapse
|
7
|
Finegan E, Chipika RH, Shing SLH, Hardiman O, Bede P. Primary lateral sclerosis: a distinct entity or part of the ALS spectrum? Amyotroph Lateral Scler Frontotemporal Degener 2019; 20:133-145. [PMID: 30654671 DOI: 10.1080/21678421.2018.1550518] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Primary lateral sclerosis (PLS) has been traditionally viewed as a distinct upper motor neuron condition (UMN) but is increasingly regarded as a sub-phenotype within the amyotrophic lateral sclerosis (ALS) spectrum. Despite established diagnostic criteria, formal diagnosis can be challenging and the protracted diagnostic journey and uncertainty about longer-term prognosis cause considerable distress to patients and caregivers. PLS patients are invariably excluded from ALS clinical trials, while PLS pharmacological trials are lacking. There remains an unmet need for diagnostic biomarkers for upper motor neuron predominant conditions and prognostic indicators regarding prognosis, survival, and risk of conversion to ALS. Validated biomarkers will not only have implications for individualized patient care but also serve as outcome measures in pharmaceutical trials. Given the paucity of post-mortem studies in PLS, novel pathological insights are generally inferred from state-of-the-art imaging studies. Computational neuroimaging has already contributed significantly to the characterization of PLS-associated pathology in vivo and has underscored the role of neuro-inflammation, the presence of extra-motor changes, and confirmed pathological patterns similar to ALS. This systematic review assesses the current state of PLS research across clinical, neuroimaging and neuropathological domains from a combined clinical and academic perspective. We discuss patterns of pathological overlap with other ALS phenotypes, examine if the biological processes of PLS warrant therapeutic strategies distinct from ALS, and evaluate the evidence that classes PLS as a distinct clinico-pathological entity.
Collapse
Affiliation(s)
- Eoin Finegan
- a Computational Neuroimaging Group, Academic Unit of Neurology , Biomedical Sciences Institute, Trinity College , Dublin , Ireland
| | - Rangariroyashe H Chipika
- a Computational Neuroimaging Group, Academic Unit of Neurology , Biomedical Sciences Institute, Trinity College , Dublin , Ireland
| | - Stacey Li Hi Shing
- a Computational Neuroimaging Group, Academic Unit of Neurology , Biomedical Sciences Institute, Trinity College , Dublin , Ireland
| | - Orla Hardiman
- a Computational Neuroimaging Group, Academic Unit of Neurology , Biomedical Sciences Institute, Trinity College , Dublin , Ireland
| | - Peter Bede
- a Computational Neuroimaging Group, Academic Unit of Neurology , Biomedical Sciences Institute, Trinity College , Dublin , Ireland
| |
Collapse
|