Objective: We describe a rare case of paroxysmal nonkinesigenic dyskinesia (PKND) in a patient with GLUT1 deficiency syndrome (GLUT1-DS).

Background: Various movement disorders are a common feature of GLUT1-DS, with nonepileptic paroxysmal events occurring in 28% of patients [1]. Among these, paroxysmal kinesigenic dyskinesia (PKD), while still rare, is recognized within the literature. In contrast, PNKD is notably less common in GLUT1-DS. Because of this, PNKD remains less explored in this syndrome and its treatment differs from PKD, changing how we approach these patients.

Method: Case report

Results: A 24-year-old male with GLUT1-DS and intractable seizures status post-VNS placement presented with abnormal movements. He developed episodic head and neck movements following VNS replacement, with an unremarkable workup for post-operative device malfunction or breakthrough seizures. On examination, he displayed involuntary movements, including bilateral eyebrow chorea, intermittent abrupt extensor posturing of the head and right upper extremity, and brief jerking of both hands and arms towards midline. Movements typically occurred at rest and were triggered by fatigue and emotional stress. His presentation was most consistent with PNKD. Though the ketogenic diet is the gold standard for managing GLUT1-DS, the patient struggled with maintaining compliance [1]. A combination of botulinum toxin injections, carbidopa/levodopa, carbamazepine, and clonazepam resulted in moderate improvement of his symptoms.

Conclusion: GLUT1-DS is a rare genetic disorder causing impaired glucose transport to the brain, leading to epilepsy, developmental delay, and movement disorders like dystonia, ataxia, and dyskinesias [1,2]. PKD is a rare, but well-described movement disorder in GLUT1-DS, marked by brief, involuntary movements triggered by sudden motion, often treatable with anti-seizure medications [3]. In contrast, PNKD is a less recognized manifestation of GLUT1-DS. PNKD episodes occur without movement triggers and are instead provoked by factors like stress, fatigue, or fasting. Unlike PKD, PNKD tends to be less responsive to traditional anti-seizure medications. Management may involve alternative therapies, including benzodiazepines or neurotoxin injections [3]. Recognizing PNKD potential presentation in GLUT1-DS is crucial for accurate diagnosis and appropriate management.

References: 1. Pons R, Collins A, Rotstein M, Engelstad K, De Vivo DC. The spectrum of movement disorders in Glut-1 deficiency. Mov Disord. 2010 Feb 15;25(3):275-81.
2. Coleman J, Dean M. Longstanding Paroxysmal Dyskinesia in GLUT1 Deficiency Syndrome. Mov Disord Clin Pract. 2020 Sep 29;7(Suppl 3):S96-S98.
3. Unterberger I, Trinka E. Diagnosis and treatment of paroxysmal dyskinesias revisited. Ther Adv Neurol Disord. 2008 Sep;1(2):4-11.

« Back to 2025 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/paroxysmal-nonkinesigenic-dyskinesia-in-glut1-deficiency-syndrome-a-rare-manifestation/