Myotonic Dystrophy Type 1 With Cerebellar Ataxia and Cerebellar Atrophy
Bibliographic record
Abstract
Dear Editor, Myotonic dystrophy (DM) is a dominantly inherited muscular dystrophy involving multiple systems. 1 We report a case with cerebellar ataxia and cerebellar atrophy that was finally diagnosed as DM type 1 (DM1).A 50-year-old female presented with a 4-year history of progressive gait imbalance and slurred speech.She had been diagnosed with diabetes about 20 years previously, and had cataracts for 8 years.She developed grip myotonia at the age of 20 years.Her younger brother had diabetes for about 10 years and had been walking unsteadily for almost 2 years.Our patient presented with bilateral temporal muscle atrophy, frontal alopecia, and severe gait ataxia requiring support.A neurological examination revealed dysarthria and weakness of bilateral eyelids and neck flexion.Nystagmus was absent.Bilateral hyperalgesia and reduced vibratory sensation were found distal to the ankle joints.Light-touch and position senses were intact.The strengths of bilateral wrist flexion, bilateral grip and finger extension/flexion, bilateral plantar dorsiflexion, and all proximal limbs were grades 4+, 4, 4, and 5, respectively.Her tendon reflexes and muscle tone were decreased.A negative Romberg sign and clumsy rapidly alternating hand movements were observed.Bilateral finger-to-nose and heel-to-shin tests were abnormal.No pyramidal sign was observed.Magnetic resonance imaging (MRI) demonstrated high-intensity T2-weighted lesions in the white matter of the temporal pole and the periventricular region (Fig. 1A).MRI also showed prominent cerebellar atrophy, which had deteriorated from 2018 to 2022 (Fig. 1B-D).Consistent with the MRI findings, in 2018 the patient starting developing unsteadiness and slurred speech, but she could still walk with assistance and engage in communication.However, by 2022 she had lost the ability to walk and communicate.The Mini-Mental State Examination (19 points) and Montreal Cognitive Assessment (12 points) revealed impaired cognition.A nerve conduction velocity study revealed polyneuropathy mainly involving the sensory and motor axons.Electromyography indicated myogenic damage and myotonia potentials in multiple muscles.Electronystagmography revealed damage to the cerebellum and its related fibers.Genetic sequencing revealed the abnormal expansion of a CTG triplet repeat in the noncoding region of the DMPK gene (135 copies).However, we could not obtain genetic data for her younger brother.Based on genetic findings, the patient was diagnosed with DM1.Manifestations supporting a diagnosis of multiple-system atrophy (MSA) or other neurodegenerative diseases were not found.Whole-exome sequencing did not reveal other pathogenic mutations.Repeat expansions associated with spinocerebellar ataxia were examined in genes including ATXN1, ATXN2, ATXN3, CACNA1A, ATXN7, ATXN8, PPP2R2B, TBP, ATN1, FXN, ATXN10, and NOP56, but no abnormality was found.Neuroimaging abnormalities of DM1 are mainly found in the frontal and anterior temporal lobes, including cortical atrophy and subcortical white-matter hyperintensities. 2,
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.001 | 0.005 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.002 | 0.001 |
| Bibliometrics | 0.002 | 0.001 |
| Science and technology studies | 0.001 | 0.001 |
| Scholarly communication | 0.002 | 0.003 |
| Open science | 0.002 | 0.001 |
| Research integrity | 0.005 | 0.005 |
| Insufficient payload (model declined to judge) | 0.003 | 0.003 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".