Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disorder affecting both the upper and lower motor neurons. Although ALS typically leads to death within 3 to 5 years after initial symptom onset, approximately 10% of patients with ALS live more than 10 years after symptom onset. We set out to determine similarities and differences in clinical presentation and neuropathology in persons with ALS with long vs. those with standard duration. Participants were United States military Veterans with a pathologically confirmed diagnosis of ALS (n = 179), dichotomized into standard duration (<10 years) and long-duration (≥10 years). The ALS Functional Rating Scale-Revised (ALSFRS-R) was administered at study entry and semi-annually thereafter until death. Microglial density was determined in a subset of participants. Long-duration ALS occurred in 76 participants (42%) with a mean disease duration of 16.3 years (min/max = 10.1/42.2). Participants with long-duration ALS were younger at disease onset (P = 0.002), had a slower initial ALS symptom progression on the ALSFRS-R (P < 0.001) and took longer to diagnose (P < 0.002) than standard duration ALS. Pathologically, long-duration ALS was associated with less frequent TDP-43 pathology (P < 0.001). Upper motor neuron degeneration was similar; however, long-duration ALS participants had less severe lower motor neuron degeneration at death (P < 0.001). In addition, the density of microglia was decreased in the corticospinal tract (P = 0.017) and spinal cord anterior horn (P = 0.009) in long-duration ALS. Notably, many neuropathological markers of ALS were similar between the standard and long-duration groups and there was no difference in the frequency of known ALS genetic mutations. These findings suggest that the lower motor neuron system is relatively spared in long-duration ALS and that pathological progression is likely slowed by as yet unknown genetic and environmental modifiers.
Chronic traumatic encephalopathy (CTE) is a progressive neurodegenerative disorder linked to repetitive head impacts and has been associated with amyotrophic lateral sclerosis (ALS), a fatal, degenerative neuromuscular disorder. The Department of Veterans Affairs Biorepository Brain Bank (VABBB) is a tissue repository that collects antemortem disease progression data and postmortem central nervous system tissue from veterans with ALS. We set out to determine the frequency of co-morbid ALS and CTE in the VABBB cohort and to characterize the clinical, genetic, and pathological distinctions between participants with ALS only and those with both ALS and CTE (ALS+CTE). Of 155 participants, 9 (5.8%) had neuropathologically confirmed ALS+CTE. Participants with ALS+CTE were more likely to have a history of traumatic brain injury (p < 0.001), served during the first Persian Gulf War (p < 0.05), and to have more severe tau pathology within the frontal cortex and spinal cord (p < 0.05). The most common exposures to head impacts included contact sports (n = 5) and military service (n = 2). Clinically, participants with ALS+CTE were more likely to have bulbar onset ALS (p = 0.006), behavioral changes (p = 0.002), and/or mood changes (p < 0.001). Overall, compared with ALS in isolation, comorbid ALS+CTE is associated with a history of TBI and has a distinct clinical and pathological presentation.
Chronic traumatic encephalopathy (CTE) is a neurodegenerative disease associated with repetitive mild traumatic brain injury. It is defined pathologically by the abnormal accumulation of tau in a unique pattern that is distinct from other tauopathies, including Alzheimer's disease (AD). Although trauma has been suggested to increase amyloid β peptide (Aβ) levels, the extent of Aβ deposition in CTE has not been thoroughly characterized. We studied a heterogeneous cohort of deceased athletes and military veterans with neuropathologically diagnosed CTE (n = 114, mean age at death = 60) to test the hypothesis that Aβ deposition is altered in CTE and associated with more severe pathology and worse clinical outcomes. We found that Aβ deposition, either as diffuse or neuritic plaques, was present in 52 % of CTE subjects. Moreover, Aβ deposition in CTE occurred at an accelerated rate and with altered dynamics in CTE compared to a normal aging population (OR = 3.8, p < 0.001). We also found a clear pathological and clinical dichotomy between those CTE cases with Aβ plaques and those without. Aβ deposition was significantly associated with the presence of the APOE ε4 allele (p = 0.035), older age at symptom onset (p < 0.001), and older age at death (p < 0.001). In addition, when controlling for age, neuritic plaques were significantly associated with increased CTE tauopathy stage (β = 2.43, p = 0.018), co-morbid Lewy body disease (OR = 5.01, p = 0.009), and dementia (OR = 4.45, p = 0.012). A subset of subjects met the diagnostic criteria for both CTE and AD, and in these subjects both Aβ plaques and total levels of Aβ1–40 were increased at the depths of the cortical sulcus compared to the gyral crests. Overall, these findings suggest that Aβ deposition is altered and accelerated in a cohort of CTE subjects compared to normal aging and that Aβ is associated with both pathological and clinical progression of CTE independent of age.
INTRODUCTION: Validity of the 2014 traumatic encephalopathy syndrome (TES) criteria, proposed to diagnose chronic traumatic encephalopathy (CTE) in life, has not been assessed. METHODS: A total of 336 consecutive brain donors exposed to repetitive head impacts from contact sports, military service, and/or physical violence were included. Blinded to clinical information, neuropathologists applied National Institute on Neurological Disorders and Stroke/National Institute of Biomedical Imaging and Bioengineering CTE criteria. Blinded to neuropathological information, clinicians interviewed informants and reviewed medical records. An expert panel adjudicated TES diagnoses. RESULTS: A total of 309 donors were diagnosed with TES; 244 donors had CTE pathology. TES criteria demonstrated sensitivity and specificity of 0.97 and 0.21, respectively. Cognitive (odds ratio [OR] = 3.6; 95% confidence interval [CI]: 1.2–5.1), but not mood/behavior or motor symptoms, were significantly associated with CTE pathology. Having Alzheimer's disease (AD) pathology was significantly associated with reduced TES accuracy (OR = 0.27; 95% CI: 0.12–0.59). DISCUSSION: TES criteria provided good evidence to rule out, but limited evidence to rule in, CTE pathology. Requiring cognitive symptoms in revised criteria and using AD biomarkers may improve CTE pathology prediction.
Blast exposure is associated with traumatic brain injury (TBI), neuropsychiatric symptoms, and long-term cognitive disability. We examined a case series of postmortem brains from U.S. military veterans exposed to blast and/or concussive injury. We found evidence of chronic traumatic encephalopathy (CTE), a tau protein–linked neurodegenerative disease, that was similar to the CTE neuropathology observed in young amateur American football players and a professional wrestler with histories of concussive injuries. We developed a blast neurotrauma mouse model that recapitulated CTE-linked neuropathology in wild-type C57BL/6 mice 2 weeks after exposure to a single blast. Blast-exposed mice demonstrated phosphorylated tauopathy, myelinated axonopathy, microvasculopathy, chronic neuroinflammation, and neurodegeneration in the absence of macroscopic tissue damage or hemorrhage. Blast exposure induced persistent hippocampal-dependent learning and memory deficits that persisted for at least 1 month and correlated with impaired axonal conduction and defective activity-dependent long-term potentiation of synaptic transmission. Intracerebral pressure recordings demonstrated that shock waves traversed the mouse brain with minimal change and without thoracic contributions. Kinematic analysis revealed blast-induced head oscillation at accelerations sufficient to cause brain injury. Head immobilization during blast exposure prevented blast-induced learning and memory deficits. The contribution of blast wind to injurious head acceleration may be a primary injury mechanism leading to blast-related TBI and CTE. These results identify common pathogenic determinants leading to CTE in blast-exposed military veterans and head-injured athletes and additionally provide mechanistic evidence linking blast exposure to persistent impairments in neurophysiological function, learning, and memory.
In: Johnson , J O , Chia , R , Miller , D E , Li , R , Kumaran , R , Abramzon , Y , Alahmady , N , Renton , A E , Topp , S D , Gibbs , J R , Cookson , M R , Sabir , M S , Dalgard , C L , Troakes , C , Jones , A R , Shatunov , A , Iacoangeli , A , Al Khleifat , A , Ticozzi , N , Silani , V , Gellera , C , Blair , I P , Dobson-Stone , C , Kwok , J B , Bonkowski , E S , Palvadeau , R , Tienari , P J , Morrison , K E , Shaw , P J , Al-Chalabi , A , Brown , R H , Calvo , A , Mora , G , Al-Saif , H , Gotkine , M , Leigh , F , Chang , I J , Perlman , S J , Glass , I , Scott , A I , Shaw , C E , Basak , A N , Landers , J E , Chiò , A , Crawford , T O , Smith , B N , Traynor , B J , Smith , B N , Ticozzi , N , Fallini , C , Gkazi , A S , Topp , S D , Scotter , E L , Kenna , K P , Keagle , P , Tiloca , C , Vance , C , Troakes , C , Colombrita , C , King , A , Pensato , V , Castellotti , B , Baas , F , Ten Asbroek , A L M A , McKenna-Yasek , D , McLaughlin , R L , Polak , M , Asress , S , Esteban-Pérez , J , Stevic , Z , D'Alfonso , S , Mazzini , L , Comi , G P , Del Bo , R , Ceroni , M , Gagliardi , S , Querin , G , Bertolin , C , Van Rheenen , W , Rademakers , R , Van Blitterswijk , M , Lauria , G , Duga , S , Corti , S , Cereda , C , Corrado , L , Sorarù , G , Williams , K L , Nicholson , G A , Blair , I P , Leblond-Manry , C , Rouleau , G A , Hardiman , O , Morrison , K E , Veldink , J H , Van Den Berg , L H , Al-Chalabi , A , Pall , H , Shaw , P J , Turner , M R , Talbot , K , Taroni , F , García-Redondo , A , Wu , Z , Glass , J D , Gellera , C , Ratti , A , Brown , R H , Silani , V , Shaw , C E , Landers , J E , Dalgard , C L , Adeleye , A , Soltis , A R , Alba , C , Viollet , C , Bacikova , D , Hupalo , D N , Sukumar , G , Pollard , H B , Wilkerson , M D , Martinez , E M G , Abramzon , Y , Ahmed , S , Arepalli , S , Baloh , R H , Bowser , R , Brady , C B , Brice , A , Broach , J , Campbell , R H , Camu , W , Chia , R , Cooper-Knock , J , Ding , J , Drepper , C , Drory , V E , Dunckley , T L , Eicher , J D , England , B K , Faghri , F , Feldman , E , Floeter , M K , Fratta , P , Geiger , J T , Gerhard , G , Gibbs , J R , Gibson , S B , Glass , J D , Hardy , J , Harms , M B , Heiman-Patterson , T D , Hernandez , D G , Jansson , L , Kirby , J , Kowall , N W , Laaksovirta , H , Landeck , N , Landi , F , Le Ber , I , Lumbroso , S , Macgowan , D J L , Maragakis , N J , Mora , G , Mouzat , K , Murphy , N A , Myllykangas , L , Nalls , M A , Orrell , R W , Ostrow , L W , Pamphlett , R , Pickering-Brown , S , Pioro , E P , Pletnikova , O , Pliner , H A , Pulst , S M , Ravits , J M , Renton , A E , Rivera , A , Robberecht , W , Rogaeva , E , Rollinson , S , Rothstein , J D , Scholz , S W , Sendtner , M , Shaw , P J , Sidle , K C , Simmons , Z , Singleton , A B , Smith , N , Stone , D J , Tienari , P J , Troncoso , J C , Valori , M , Van Damme , P , Van Deerlin , V M , Van Den Bosch , L , Zinman , L , Landers , J E , Chiò , A , Traynor , B J , Angelocola , S M , Ausiello , F P , Barberis , M , Bartolomei , I , Battistini , S , Bersano , E , Bisogni , G , Borghero , G , Brunetti , M , Cabona , C , Calvo , A , Canale , F , Canosa , A , Cantisani , T A , Capasso , M , Caponnetto , C , Cardinali , P , Carrera , P , Casale , F , Chiò , A , Colletti , T , Conforti , F L , Conte , A , Conti , E , Corbo , M , Cuccu , S , Dalla Bella , E , D'Errico , E , Demarco , G , Dubbioso , R , Ferrarese , C , Ferraro , P M , Filippi , M , Fini , N , Floris , G , Fuda , G , Gallone , S , Gianferrari , G , Giannini , F , Grassano , M , Greco , L , Iazzolino , B , Introna , A , La Bella , V , Lattante , S , Lauria , G , Liguori , R , Logroscino , G , Logullo , F O , Lunetta , C , Mandich , P , Mandrioli , J , Manera , U , Manganelli , F , Marangi , G , Marinou , K , Marrosu , M G , Martinelli , I , Messina , S , Moglia , C , Mora , G , Mosca , L , Murru , M R , Origone , P , Passaniti , C , Petrelli , C , Petrucci , A , Pozzi , S , Pugliatti , M , Quattrini , A , Ricci , C , Riolo , G , Riva , N , Russo , M , Sabatelli , M , Salamone , P , Salivetto , M , Salvi , F , Santarelli , M , Sbaiz , L , Sideri , R , Simone , I , Simonini , C , Spataro , R , Tanel , R , Tedeschi , G , Ticca , A , Torriello , A , Tranquilli , S , Tremolizzo , L , Trojsi , F , Vasta , R , Vacchiano , V , Vita , G , Volanti , P , Zollino , M & Zucchi , E 2021 , ' Association of Variants in the SPTLC1 Gene with Juvenile Amyotrophic Lateral Sclerosis ' , JAMA neurology . https://doi.org/10.1001/jamaneurol.2021.2598
Importance: Juvenile amyotrophic lateral sclerosis (ALS) is a rare form of ALS characterized by age of symptom onset less than 25 years and a variable presentation. Objective: To identify the genetic variants associated with juvenile ALS. Design, Setting, and Participants: In this multicenter family-based genetic study, trio whole-exome sequencing was performed to identify the disease-associated gene in a case series of unrelated patients diagnosed with juvenile ALS and severe growth retardation. The patients and their family members were enrolled at academic hospitals and a government research facility between March 1, 2016, and March 13, 2020, and were observed until October 1, 2020. Whole-exome sequencing was also performed in a series of patients with juvenile ALS. A total of 66 patients with juvenile ALS and 6258 adult patients with ALS participated in the study. Patients were selected for the study based on their diagnosis, and all eligible participants were enrolled in the study. None of the participants had a family history of neurological disorders, suggesting de novo variants as the underlying genetic mechanism. Main Outcomes and Measures: De novo variants present only in the index case and not in unaffected family members. Results: Trio whole-exome sequencing was performed in 3 patients diagnosed with juvenile ALS and their parents. An additional 63 patients with juvenile ALS and 6258 adult patients with ALS were subsequently screened for variants in the SPTLC1 gene. De novo variants in SPTLC1 (p.Ala20Ser in 2 patients and p.Ser331Tyr in 1 patient) were identified in 3 unrelated patients diagnosed with juvenile ALS and failure to thrive. A fourth variant (p.Leu39del) was identified in a patient with juvenile ALS where parental DNA was unavailable. Variants in this gene have been previously shown to be associated with autosomal-dominant hereditary sensory autonomic neuropathy, type 1A, by disrupting an essential enzyme complex in the sphingolipid synthesis pathway. Conclusions and Relevance: These data broaden the phenotype associated with SPTLC1 and suggest that patients presenting with juvenile ALS should be screened for variants in this gene.