Segmental Myoclonus and Epilepsy in a Child with GAD 65 Antibodies
Bibliographic record
Abstract
Keywords: GAD 65 antibodies, Child, Myoclonus, Epilepsy Glutamic acid decarboxylase (GAD) is a rate-limiting enzyme for the synthesis of γ-aminobutyric acid (GABA), an inhibitory neurotransmitter.It is widely distributed in the central nervous system but is also present in other organs, especially the pancreas.Elevated GAD 65 antibodies have diverse clinical associations, including stiff person syndrome (SPS), cerebellar ataxia, limbic encephalitis, epilepsy, ocular motor disorders, type 1 diabetes mellitus, 1,2 and rarely myoclonus.3-6 GAD 65 antibody-associated neurological syndromes, mostly SPS or epilepsy, are rarely reported in pediatrics.2,7 Many patients improve after immune therapy and some, whose presentation includes seizures, become seizure free. 1 Elevated GAD 65 antibodies may be associated with tumors.However, such an association is rare in children. 1 A 7.5-year-old-girl, previously healthy and intellectually normal, presented with a few days history of self-limited right-sided throbbing headache and a new-onset focal tonicclonic seizure with bilateral spread lasting 5 min.She concurrently developed right sided then bilateral continuous, high frequency, semi-rhythmic facial muscle twitching, consistent with myoclonus, most prominent on the right face and upper lip (Video).The myoclonus was present during wakefulness and sleep.Six weeks later, the myoclonus spread to her right thumb and tongue.She did not develop myoclonus anywhere else.She did not feel the myoclonus.The myoclonus responded partially to treatment with clonazepam.Levetiracetam was started following a second, 2.5 min focal unaware seizure, 10 d after the first seizure.There were no signs of encephalopathy, cognitive decline, or regression.She could eat, drink, and speak normally.Pregnancy, delivery, development, and past medical history were unremarkable.Parents are non-consanguineous.There was no family history of seizures, autoimmune, or movement disorders.The patient's full neurological exam was normal apart from the myoclonus.Blood tests were normal including CBC, extended electrolytes, glucose, liver and thyroid function, uric acid, copper, ceruloplasmin, ESR, CRP, C3, C4, immunoglobulins, rheumatoid factor, ANCAs, anti-TPO, and phospholipid (cardiolipin and β2-glycoprotein) antibodies.ANA screen was positive (low titers at 1:40 for speckled and 1:80 for nucleolar antinuclear antibodies detected by immunofluorescence), but dsDNA and extractable nuclear antigens were negative.Urinary vanillylmandelic acid and homovanillic acid were negative.CSF investigations revealed normal glucose and lactate, with a slightly elevated protein (0.29 g/l, normal range: 0.12-0.24)and cell count (8 cells, 97% lymphocytes).Oligoclonal bands were present in the CSF with no corresponding bands in the serum.GAD 65 antibodies were 'highly positive' in CSF and serum as tested by a cell-based immunoassay (CBA: Euroimmun AG, Luebeck, Germany), performed by MitogenDx, Calgary, Canada.Serum level of anti-GAD 65 as tested by an enzyme-linked
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
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 | 0.000 | 0.002 |
| Meta-epidemiology (narrow) | 0.002 | 0.001 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.003 | 0.002 |
| Science and technology studies | 0.002 | 0.001 |
| Scholarly communication | 0.001 | 0.002 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.003 | 0.003 |
| Insufficient payload (model declined to judge) | 0.003 | 0.001 |
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".